FAQ for KINETIC PULSE
Return to KINETIC PULSE and ballistics analysis by james n. hall
QUESTION: What reloading data do you use for the 6.5X55mm?
ANSWER: 140gr bullet with a duplex load of two
powders: 5010 and H380
Also I have used duplex of H414 and H870 with the 140gr.
Anyone who wants to use this reload data should be warned that these
data worked for me and they need to be worked up cautiously with the
common sense of a good reloader. ANY ONE USING THIS DATA IS ON THEIR OWN!
140gr bullet 22 grs H380 and 28 grs 5010 (you
need a funnel to insert 5010).
therefore mix the two powders before inserting in to the case.
I use a large 45-70 case and pour from this to the 6.5X55mm case.
Primer is standard large rifle.
This load is used for practice and gives more than factory velocities.
140gr match bullet with duplex load of (24.5 grs
H414 and 24.5 grs H870).
Primer is standard large rifle.
This load is very accurate for me. 1" group at 300 yards.
All pressures will leave the primer 'round' and yet better than factory velocities.
QUESTION: Why are hollow point bullets more accurate?
ANSWER: Perhaps any bullet made precisely will
be accurate, although
many match target bullets that I have used were also hollow point.
I have used 7.62 nato with full metal jackets that are not hollow
point yet were match. The manufacture of match bullets are facilitated
by design of a hollow point. Another reason is the soft lead exposed to
deformation will make a bullet less accurate due to the impact with
air is not a symmetrical air foil. (Many a time I have seen the soft
point bullet deformed in feeding from the magazine.) Perhaps the
weight distribution is more central to the center of ballistic profile.
One other theory is that the air is pressurized in the hollow point
and can cause the air foil to be air against air with no irregularity.
Full metal jacket bullets have lead bases and they can be deformed
by the extreme pressure of burning powder where the hollow point is
solid based from a cup inserted with lead and shape to the hollow
point in a last operation.
QUESTION: Why do hollow point bullets assist mushrooming?
ANSWER: As the bullet moves the material away
the material is forced in to the hollow point and then will cause
a hydraulic pressure to expand the hollow point widening the hollow point
cavity exposing more surface to the medium. This will continue til the
tear drop shape is approached or the mushroom of the projectile.
I have put a thick grease in the hollow point cavity and the mushrooming is
speeded up slightly.
QUESTION: Have you tried Barnes X bullets?
TEST AND EMAIL RESPONSE:
Well I have made some test with the Barnes X bullets. According to
Barnes the design is intended to shoot through and the "petals" of
copper alloy is to open up and lacerate down the bullet path
causing blood path exit wound. This is not how I have seen high
power bullet perform. There is a shock factor that is caused by
the impact. Cutting through is like an arrow effect. Anyway upon
loading my 6.5X55mm with my pet load of 22 grains of h380 and 26 grains
of H870 and the Barns bullets that Barnes so graciously gave to me to test,
I went to the range to see what the pressures would be like. I suspected
that the pressures would run much higher due to the solid construction.
The Hornady 140 grains gave me an inch group from the Win Classic feather
weight and the load look safe to test the Barnes. But I fired 5 round
through a custom Turkish small ring 98 and a brand new swedish 6.5X55 barrel.
(swedish barrels fit into the turkish small ring 98 with no modification)
I did not want to test the Barnes 140 grain X bullet on my pretty Winchester
so After five rounds with the small ring 98 I Fired the first Barnes through
it. It was obviously louder and more pressure due to the greater recoil.
This told me that you have to load the Barnes with greater discretion. I will
when I get a load that I can feel comfortable shooting. And has less pressure.
My impact tests will come later when the load is developed. Also I figure
to use a 8X57mm 98 as it is better adapted to shooting hard bullets. If you
use small caliber's such as the 270 and 7mm be carefull to start under to
compensate for the obvious pressure increases. My first impression is to use
Barnes X bullets on a gun you don't treasure. Well This all for now.
I probably will post this on my web site. James N. Hall
QUESTION: How does the 6.5X55mm compare with other
calibres for actual
ANSWER: My experience is with a modern rifle chambered
for 6.5X55mm swedish
it appears to do anything the 270 winchester will do. Impact tests in clay
however indicates the 6.5X55 will penetrate deeper and then 'explode' more
than the 270 win. One deer I have taken a 400 yards shows that the 6.5X55mm
140 gr nosler will pass through the deer and bury 6 inches in to the bank of
dirt behind. Excessive meat damage was noted. This load was a duplex load
muzzle velocity was 2850 ft/s. My experience would be to stay with factory
pressures for deer to save meat. Larger game such as Elk is possible, and
the superb accuracy makes for sure kill placement on Elk. My neighbor who
hunts three states says the 6.5X55mm swedish is superior to the 270 winchester
in his actual hunting experiences.
The kp comparison below demonstrate that with numbers.
6.5.55mm Swedish Norma Factory
Velocity/fps kp/400 Kinetic Energy/fp grs Muzzle 100 200 300 400 kp Muzzle 100 200 300 400 6.5x55 139 2790 2630 2470 2320 2163 1927 2403 2135 1883 1661 1444 270 Win. 130 3140 2885 2640 2405 2160 1678 2846 2403 2012 1670 1347 150 2800 2615 2345 2260 2080 1996 2611 2278 1975 1701 1441 30-06 Spr. 150 2970 2860 2400 2140 1923 1577 2938 2392 1918 1525 1232 180 2700 2490 2295 2110 1913 2236 2914 2478 2105 1779 1463
QUESTION: Just how does the 5.56 Nato and 7.62x39mm compare?
ANSWER: Below are the numbers of both. Check it out for your self.
DISTANCE KINETIC PULSE WEIGHT VELOCITY ENERGY MOMENTUM Muzzle 1071 kp 55 gr 3300 ft/s 1329 ft-lb 0.806 slug ft/s 100 yd 671 kp 55 gr 2824 ft/s 974 ft-lb 0.690 slug ft/s 200 yd 406 kp 55 gr 2389 ft/s 697 ft-lb 0.584 slug ft/s 300 yd 241 kp 55 gr 2004 ft/s 490 ft-lb 0.489 slug ft/s 400 yd 137 kp 55 gr 1666 ft/s 339 ft-lb 0.407 slug ft/s 500 yd 77 kp 55 gr 1374 ft/s 231 ft-lb 0.336 slug ft/s 600 yd 46 kp 55 gr 1157 ft/s 163 ft-lb 0.283 slug ft/s 7.62x39mm or AK 47 Standard round .310 diameter bullet DISTANCE KINETIC PULSE WEIGHT VELOCITY ENERGY MOMENTUM Muzzle 2061 kp 123 gr 2400 ft/s 1573 ft-lb 1.311 slug ft/s 100 yd 1424 kp 123 gr 2122 ft/s 1229 ft-lb 1.159 slug ft/s 200 yd 971 kp 123 gr 1867 ft/s 951 ft-lb 1.020 slug ft/s 300 yd 655 kp 123 gr 1638 ft/s 732 ft-lb 0.895 slug ft/s 400 yd 433 kp 123 gr 1427 ft/s 556 ft-lb 0.779 slug ft/s 500 yd 289 kp 123 gr 1249 ft/s 426 ft-lb 0.682 slug ft/s 600 yd 206 kp 123 gr 1114 ft/s 338 ft-lb 0.608 slug ft/s
The only thing I can say about the 5.56 Nato is rebore all the rifles to 6 mm and use a 70 gr bullet with the same case and the ballistics will greatly improve with only 15 gr weight per bullet increase!
6 mm Nato with a 70 gr .244 diameter bullet and a 223 remington/5.56 Nato case.
DISTANCE KINETIC PULSE WEIGHT VELOCITY ENERGY MOMENTUM Muzzle 1435 kp 70 gr 3100 ft/s 1494 ft-lb 0.964 slug ft/s 100 yd 1014 kp 70 gr 2759 ft/s 1183 ft-lb 0.858 slug ft/s 200 yd 702 kp 70 gr 2441 ft/s 926 ft-lb 0.759 slug ft/s 300 yd 480 kp 70 gr 2150 ft/s 718 ft-lb 0.668 slug ft/s 400 yd 323 kp 70 gr 1883 ft/s 551 ft-lb 0.585 slug ft/s 500 yd 177 kp 70 gr 1544 ft/s 371 ft-lb 0.480 slug ft/s 600 yd 140 kp 70 gr 1425 ft/s 315 ft-lb 0.443 slug ft/s
This appears to give a 34% increase in kinetic pulse and a down range velocity increase of 268 ft/s at 600 yards. Also the bullet will hit 11 inches higher at 600 yards suggesting flatter trajectory. And will add approximately 3.5 oz per 100 rounds of carrying weight. Perhaps that weight increase is worth the improved performance. Also the 300 aac blackout will duplicate or exceed the 7.62x39mm or AK 47 Standard round and will require only a barrel change out and everything else will work. I am going to post this on the http://www.kineticpulse.us/math/kp.html web page also. (after thought:) I have read in Parker O. Ackley's (Utah gunsmith) fine reloading book the discussion of hydrostatic shock in tissue. I also have personal experience with this effect in certain mediums. I believe that there is a pressure wave created when the bullet hits tissue at speeds greater than 2800+ ft/s. This may be due the speed of sound in tissue. This means that the tissue on impact can not bounce off the bullet and accumulates as a wave in front of the bullet travel path. This has the effect of making the medium more dense and increases the transfer of momentum or depletion of momentum from the bullet. Simply this means the bullet will penetrate less than if it were traveling slower (that is less than 2800 ft/s). Thus more energy per unit of bullet penetration is expended. The 5.56 NATO drops below 2800 ft/s around 100 yards. What this all means is there will be an explosive impact at distances under 100 yards. This is perhaps greater at 25 yards than 75 yards due to the rapid loss of energy during bullet travel in air. If you hit water with a hammer on a cement side walk you can observe that the water travels at much higher velocity than the velocity of the hammer in the first place. Thus an expanding bullet can create a hydrostatic shock by mushrooming and forcing the medium or tissue to have move around the bullet even though it is traveling less than 2800 ft/s. This is similar to the water at the face of the hammer is accelerated when hit on a hard surface. The tissue become like a hard surface. Anyone who has 'belly flopped' can attest to the slap of the water effect. So the 5.56 NATO will slap energy into the wound cavity at speed greater than 2800 ft/s or at distances under 100 yards. Therefore at ranges beyond 100 yards the hydrostatic shock may not be seen unless a bone is hit or the bullet is tumbling. Note: Larger diameter bullets will cause greater pressure waves but then they slow down in air to below 2800 ft/s faster also. Update from plinking trip as of Oct 27,2001: Date of test October 27, 2001 3:00pm Bright Sunny day. Rifle Ruger Mini 14 .223 cal or 5.56 Nato chambering. Both bullets were fired forty feet from test material. The test was with two sets of three plastic bottles of water and a backstop of two plywood sheets of 1/2" and 3/4" thickness 2 feet apart. The 1/2" plywood was in front of the 3/4" plywood sheet. Two bottles were of 1 quart each. Four bottles were of 1 gallon each. The quart bottles were in front of the two gallon bottles in front of the plywood back stops for each trial. The bottles were 1/2" apart. The bottles were 6" in front of the 1/2" plywood and the 3/4" plywood was 24" behind further. Hot load was 55gr full metal jackets on top of 23 grains of 2230 for a velocity of 3200 ft/s. Soft load was 55gr full metal jackets on top of 18 grains of 2230 for a velocity of 2650 ft/s. RESULTS: Hot load: First quart bottle penetrated both sides clean no bottle rupture. Second gallon bottle penetrated both sides with explosive rupture and energy display. Third gallon bottle penetrated both sides with mild explosive rupture. Forth plywood 1/2" hit but not penetrated. Fifth plywood 3/4" not touched. Total remaining bullet weight is 49 grains. Could not find missing 6 grains of lead. Bullet intact with flattened shape only loss of lead from shape distortion with no loss of jacket. Soft load: First quart bottle penetrated both sides clean no bottle rupture. Second gallon bottle penetrated both sides with explosive rupture and energy display but not as great. Third gallon bottle penetrated both sides with mild explosive rupture. Forth plywood 1/2" hit and completely penetrated. Fifth plywood 3/4" hit and penetrated 1/2" as bullet stuck in board. Total remaining bullet weight is 53 grains counting small lead extrusion. Total remaining bullet weight is 46 grains not counting small lead extrusion. Found lead extrusion from misshapen bullet. Bullet intact with flattened shape only loss of lead from shape distortion with no loss of jacket. Pictures of the actual bullets The conclusion is that the higher velocity bullet met up with greater resistance and stopped with less penetration but with greater 90 degree energy display. Also the slower bullet penetrated more material with less 90 degree energy display. Perhaps P. O. Ackly was right about the 2800+ ft/s hydro static shock effect. If I were hunting big dangerous game I think that I would use a HEAVY SLOW MOVING BULLET.
QUESTION: Why do you use duplex loads of two different powders for reloading?
ANSWER: Back a few decades ago, the spectrum of powders were limited to surplus military powders and some commercial powders. The burning rates were specific for certain military use. The sportsman reloader found that there were times that the best performances were not possible with the variety of powders available. Mixing powders became common with those seeking optimum velocities. How this was done is now becoming a lost art. However with all the different powders today there is really no need to duplex or triplex any loads for any cartridge reload. The only cartridge that I duplex for is the 6.5x55mm with 140 gr bullet due to the lack of high pressure loads for this chamber because all the manufactures underload this cartridge and there is not a specific powder designed for it except the Norma powders from Sweden. They are more expensive than the other manufacturers. For Hunting purposes this cost is minimal and it is advised to use Norma powders for this cartridge. However for target shooting where many rounds or consumed in punching holes in paper it is costly to me at least. Therefore I have resorted to duplexing with powders that are less costly. Besides I have gotten some great groups at 300 yards that have made duplexing a habit hard to break. (1" groupings with 140 gr sierra matchking bullet and 22 gr H380 plus 28 gr 5010.) Why mess with a good thing. Pressures with this load have been equal to factory loads and yet the duplex load shoots higher. With this accuracy one can almost figure velocity from the change of impact. If my calculations are correct and a chronograph has been used to backup the calculations once when the opportunity availed itself, the velocity is 2850 ft/s for this cartridge and this load. The other time I have used a duplex is with a 7x57mm with 175 gr bullet. I didn't care about accuracy as this was a plinking trip and I just shot rocks. The rocks did not care at all that I was using duplex loads. This was with a M98 with a 29" barrel and the velocity seemed high as rocks puff up dust to a large degree when hit. My advice is to not use any duplex loads unless you know how to do it as it can be dangerous if not done right. If it is done with knowledge it is quite safe and great performance is possible. The theory is that pressure curves can be flattened to increase velocity with less pressure. Less pressure means less barrel working and vibration--thus greater accuracy. A nice duplex load for the 270 Winchester is 33 grains of H870 25 grains of H380 behind a 140 grain bullet. Starting load is 31 grains H870 and 25 grains H380 and then work up carefully to 33 grains of the H870. Due the 30-06 being very efficient case it does not lend itself to duplexing as I have not been able to get a good load for the 30-06 Springfield. The 270 Win is over bore therefore a good candidate for duplexing. QUESTION: What is the difference between the 30-06 Springfield and the 308 Winchester? ANSWER: 100 yards greater range. After thought: The 30-06 can be downloaded to equal the 308 Winchester but the 308 Winchester can not be uploaded to equal the 30-06 Springfield. The 30-06 Springfield can get the heavy bullet going better due to the greater case capacity. For hunting game the 30-06 is the best due to the greater versatility. For military purposes the 308 is preferred due to the shorter stroke which cycles the gas operated actions quicker. Due to the 30-06 Springfield ability to move the heavier bullet at greater velocity the long range shot will be better in the Old O6. QUESTION: What is a frangible bullet? ANSWER: All bullets are frangible to some degree but some are designed to breakup by hitting any target. When this occurs all energy is dispense at once. This is like getting hit with all the bullet energy in one place. Big Game bullets are intended to penetrate; therefore they are least frangible to prevent shallow wounds. QUESTION: Mr. Hall: I read your article and found it to be quite interesting. It will take some time to digest all of your discussion so I anticipate several passes along with some pencil and paper work to completely understand the impact of your research. There is one small error, however, regarding the constant used in the formulae. In the third paragraph you state that the divisor constant to be used in the kinetic energy formula (and others) is 255179.5, however in all subsequent formulae the value of 225179.5 is used, a difference of 30,000. As the latter figure is consistently used throughout your article may I assume that the first figure is in error and the latter is correct? I have been intrigued by the "foot pounds" values provided by bullet manufacturers and reviews in gun magazines. Having some science background I attempted to reproduce the figures with little success. I did so as I also reload and want to introduce some rational behind the bullet/power combination used other than initial muzzle velocity. Your formula for ke differs from what I remembered by the addition of the ".5" factor for the bullet weight and the introduction of the division by the previously mentioned constant. While I understand the need to convert from grains to pounds I don't understand the factors involved in the formula. Could you explain the reason for the ".5" factor and the deriviation of the unusual constant (225179.5)? If there is a reference source for this information perhaps you could just refer me to that instead. Either would be appreciated. Thanks, William Heney Mr. Hall: By all means, please use any or all of my email as you see fit. Thank you for your rapid reply and excellent explanation. Bill Heney wheney @ startpower . net ANSWER: GREAT QUESTION!!! William Heney: Thank you so much for the correction of the typo for the "unusual constant". Yes it should be 225218 grains in a slug or some number very close to that. It come from the use of the unit of weight that is called a slug. At sea level it is enough mass to weigh 32.17350736 lbs on a scale but in physics mass can be at any altitude even in space. It is derived by knowing that there are 7000 grains in 1/32.17350736 of a slug or 1 pound of mass. Since most ballistics units in mass is 1 grain a conversion is need to reduce grains to slugs of mass. Thus a 180 grain bullet is 180/225218 slugs. Most Articles will use Pound-secs Pound-F/S which is 32.17 times the slug ft/s used in this article. Since the energy is using slugs in the formula it will be more consistence to use it in the measure of the momentum. I prefer the slug ft/s rather than the pound - sec which I consider an error. I will now correct my article. If you will allow me I will use your question to explain the corrections. Please let me know by return email. Thanks James. QUESTION: > Do you think the 17 cal Hornady is a good round for varmint hunting? Does > it have the knock down power you would like to see at 200 yards for hunting > coyotes? Could you suggest a better round for varmint hunting? I will be > using the gun mostly for hunting coyotes and bobcats and on occasion some > coons and fox. ANSWER: I worry that the light bullet would only surface wound when there is greater weight than 30 lbs. Smaller weight varmints will be fine especially if the pelt is to be saved. The range should be kept under 125 yards as the kp drops off suddenly. 200 yard hunting varmints seems doubtful and I would expect to see sad failures at that range. This should be a quiet round compared to a .223 but if you handload, the .223 downloaded should do much better than the .17 also the availability of the full metal jacket can be an advantage for the heavier pelt varmints. Raccoons in Utah are big and dogs would have a fight on their terms. I would suspect the .17 would not take down these big raccoons. But I have only shot the .17 remington and at 4000+ ft/s it would be a killer but alas the barrel gets fouled from metal running off at that velocity. But if you have the money and the means to experiment it would be worth hearing back from you if the Hornady 17 is a success. thanks James of Kinetic Pulse. QUESTION: In the changing battle field of the future what round would you recommend for the M14? ANSWER: If one is to stay with the same recoil properties and weight of bullet I would reduce the bore diameter to .284 or 7mm and use the 7mm-08 Remington with a 140 grain bullet. This gives twice the kp at 500 yards than the .308 calibre 147 grain bullet. Otherwise increase the weight of the .308 bullet to 165 grains to get the range increase. The battle fields of the future will be over long distances. Such would be an improvement for the M14 for distance. CARTRIDGE Weight muzzle 100yard 200yard 300yard 400yard 500yard 308_Winchester 180gr 5694 kp 3723 kp 2366 kp 1464 kp 895 kp 564 kp 308_Winchester 150gr 5361 kp 3679 kp 2474 kp 1620 kp 1038 kp 658 kp 308_Winchester 168gr 5250 kp 4227 kp 3382 kp 2680 kp 2112 kp 1649 kp 7mm-08_Remington 120gr 3799 kp 2847 kp 2113 kp 1546 kp 1112 kp 791 kp 7mm-08_Remington 140gr 4480 kp 3588 kp 2851 kp 2249 kp 1758 kp 1362 kp Note: The ballistics is for commercial manufacture but the general idea is the same for the military full metal jacket round. 'kp' is short for Kinetic Pulse. Link to explain kp figures above QUESTION: I found your thesis very interesting. I do have a question about shooting down hill or up hill. If I am shooting about 250 yards uphill or down hill where should the point of aim be? If I am shooting on a flat level trajectory I can aim at the spot I intend to hit and usually do. But I am a little skeptical about aiming at the exact spot when shooting up or down. Could you please enlighten me? Thanks, Peter PS. I am also a primitive bow hunter and know that my point of aim is different in these circumstances. So I keep thinking I must apply then to the rifle also??????? ANSWER: When the bullet travels horizontal to the pull of gravity the change in velocity is strictly due to the air impact and resistance. However when shooting down hill the bullet is somewhat accelerated by the force of gravity. The same with shooting up hill the bullet is slowed down a bit. Usually the change in the bullet impact is minimal with the modern high velocity bullets in short ranges. However with slow bullets the effect is more noticeable. The 250 yards is along the terrain and not on the base of the triangle. The time in flight is the same except the effect on the velocity due to the angle of the bullet or arrow flight. I am sure that arrow flight is more pronounced in gravity influence due to the time in flight. Some compensation is needed for bullets but much more for the arrow.
Why do some rifles shoot reloads more accurately than others?
The theory is that bullet deformation or reformation can cause the
bullet to either be more accurate fitting to the groves and lands
of the riflings or is changed in symmetry before exit of the muzzle.
Another theory is that the powder burns at even or uneven power curves
that transmit energy to the bullet consistently from shot to shot.
A third theory is that the ignition of the primer can start this process
the same each and every shot.
A forth theory is the way the cartridge is chambered. Fire-formed cases
present the bullet down the axis of the bore the same each time and is
aligned dead center. Also as in the 6.5X55 Swedish with the long bullets,
the bullet is aligned more accurately due to the long throat and subdues
the tendency to "cock" or misalign the bullet due to case to chamber fit.
A fifth theory is that headspace can cause variance in bullet jump to the
riflings beginning lands or rattle up the throat before it starts to spin.
A sixth theory involves the chamber dimensions and shape of the cartridge
as this will the powder to burn differently than in another shape (such as
short magnums tend to shoot more accurately). Or shorter cases are generally
more accurate that longer cases. Yes, the 308 Winchester can be more
accurate than the 30-06 due to the smaller case.
A seventh theory is the weight of the barrel and the gun in general as the
effect of vibrations coming from the propelling the bullet down the bore is
attenuated due to the greater mass of the barrel.
An eighth theory is that the bedding or fitting of the action and barrel is
closer and tight. An example of this is the glass bedding of rifles to
the stock and action and free floating of the barrel at an optimum point
or in the case of the Ruger rifles there is the actual pressurizing of the
barrel by tensioning it with a point to put an upward pressure on the
barrel. I believe this method is a cost reduced method as glass bedding
is more expensive to implement. Yet out of the box accuracy is their
goal. I like Rugers but I would end up doing a glass bed job to finish the
accurizing of the Rifle. Also I would change the trigger to a better
let off type trigger.
A ninth theory is the hold or the position of the rifle resting on the
sand bag. The rifle must be place the same each and every time on the
sand bag or held the same each and every time.
A tenth theory is bullet and barrel precision. If the bullets are matched
to each other til they are essentially the same. They should shoot the
the same each time. If you have match bullets then you need "match"
everything else. Match barrels, match cases, match primers, etc.
glass bedding these rifles to perfect the stock to action/barrel fit.
Precision makes for accuracy.
An eleventh theory is sighting acuity. Thus the optical sight vs the
iron sights is the development. Generally speaking a 20 power scope
will allow for greater sighting acuity than for a 4 power scope. But
then the 4 power scope is easer to put on a moving target. Also during a
rain storm or a snow storm the optics can be made into a problem. and
the iron sight becomes the best to stand up to the harsh conditions.
A twelveth theory is trigger lock time. If the rifle is stationary and
target is stationary the is is a mute point. But with a moving target
lock time is very important. A rifle with a good trigger is a joy to
shoot and is a great contribution to accuracy.
A thirteenth theory is bullet spin. Riflings were first used to increase
both accuracy and distance the bullet can travel. Some of the 5.56 nato
rifles are going to the quick twist in order to use the longer bullets as
these bullet have greater sectional density and wind bucking qualities.
A fourteenth theory is bullet shape. The boat tail hollow point high
bullet flies through the air better than the spire point or even the
round nose over greater distances.
A fifteenth theory is the muzzle shape. As the bullet exits the muzzle
the shape of the muzzle crown can influence the bullet stability or
direction. The good target rifle will have a barrel crown to match the
kind of bullet shot. The recessed crown is to prevent mechanical damage
to the exit point of the bullet. Flash suppressors will not be accurate
as some crownings unless perfectly designed. On this point there is
the recoil suppressors which can cause great vibrations at the time of
bullet exit. I would not really expect to see such a device on a
target rifle and be successful but who know?.
A sixteenth theory is the shooter. Shooting is an art form and the good
shooter can with the "Zen" of shooting really do marvelous shots despite
all the above theories.
A seventeenth theory is there are more theories than I can list here.
What does diameter of the bullet have to bullet performance?
The narrow bullet will pass through the air or material easier with less
resistance. But when the bullet hits the target the action of passing off
more energy per unit of time is diminished with larger bullet diameter.
If a bullet mushrooms correctly then the diameter is irrevalent as the
diameter of the bullet is made larger as it passes or hits the target.
A heavy dangerous game will need a greater penetration therefore the
diameter is also not important. If a bullet passes through the game and
then only a percentage of the energy, kp, momentum is exchanged, then there
again the diameter is part of the performance equation as larger bullets
of equal weight with penetrate less if there is no mushrooming.
It is preferred to have the best bullets for the hunter, but the target
shooter is only considering the accuracy over a distance. Not too many
target shooters are willing to endure the recoil of a magnum caliber of
Also the experienced hunter tends to move to a classic calibre that gives
a sure results. Diameter is only a matter of personal preference in that
QUESTION: What of the CZ 52 7.62X25mm Tokarev should I convert it to
a 9X19mm or another 9mm?
ANSWER: NO. I have reloaded and do reload for the Ceska Zbrojovka 1952 model
pistol or for short the CZ 52 in 7.62X25mm caliber. I find the conversion a
bother for no other good reason. It would be better to get a 9mm in a pistol
originally chambered for the ubiquitous 9mm. Personally I favor the 1911
45 acp but became fascinated with the CZ 52 due to the rugged and heavy duty
machining for this pistol. I had to find out why the mysterious surplus
gun was abandoned by the creators. It is now coming to America with all
the charm of a new immigrant. So I decided to see what all the history is
about on this strangely attractive work of Cech workmanship.
First observation is that upon firing it with various surplus ammo is an
adventure in high intensity 30 caliber magnum type of booming blast. Its
bark is certainly greater that its bite or -- is it? Thus began the following
I wanted to compare the ballistics with what I am familiar namely the 45 acp.
So I rigged up a traditional penetration test of pine boards. I sawed up an
eight foot board of 3/4" thickness and mounted on a 2X4 with duct tape and
went to the shooting area. First I fired the factory Sellier & Bellot 85 grain
(which I like for a factory round or the Winchester metric 7.62X25mm
and it does not launch the ejected cases into the eye of any unlucky
bystanders at great velocity. I have noted that the ejection of the cases in
a well loaded cartridge from an automatic pistol can gauge the mechanical
functioning of the pistol.) All Sellier & Bellot 85 grain case eject and land
about 20 feet behind and can be found in the same area more or less which aids
in case recovery as theses cases are boxer primed and I have reloaded them with
Anyway back to the first of the penetration tests. The factory ammo 85 grain
test shot ruined the test as it penetrated all 8 boards and the 2X4 behind it
and hit the dirt embankment with obvious retained velocity. Big surprise.
This round does penetrate wood. But the test medium did not move. Next I
fired the venerable 45 ACP COLT. It hit the test setup and knocked it flat.
As I had only stacked rocks around the base to prop it up. Again I had fail
the test setup. I propped up again and fired the 147 gr 30 cal load at the
board setup and it knocked the test setup at an angle but did not get flattened
like the 45 230 did. This bullet did not knock the board setup down but did
tip it back somewhat. I fired 2 of each of these at the target test boards
for reference. I wanted to take the boards apart and see the results as the
45 did not penetrate and the 147 gr 30 cal did not go through either.
First board test is a test Failure as to depth of penetration because of
1. The S&B smoke through and did not stop at all except in dirt . 2. The long 147 grain 30 caliber tumble in the wood and did not give a clean penetration as the bullet tumbled.
First board test is a test Success as to finding out the 147 gr 30 cal tumbles
in wood. Tumbling is good in pistol bullets after impact. This bullet flew
true in target test and only tumbled at the impact of any medium.
The 85 Sellot & Bellot gr penetrates all the wood 8" hits dirt behind. The 45 230 gr penetrates 8 pine boards or 6" of wood and dents the 2X4 also has a big .45" diameter hole. The 30 caliber 147 gr penetrates 6 boards or 4.5 inches and shreds the wood to the 7th board as the bullet tumbled.
The Second test was to fire the bullets into wet sand. I know the bullets
would not go far in sand. That is wet sand. Wet sand was chosen to check the
crater upon impact as wet sand tends to stay in the form as the bullet passes
the medium. (Dry sand just falls back.) Anyway the bullet poc will stay long
enough to measure it before the wet sand falls back.
The 85 Sellot & Bellot gr penetrates 8.5 inches of wet sand and the diameter of the channel of bullet path is about 2.5 inches for the 8.5 inches the bullet traveled most of the bullet was intact with minimal weight loss . Bullet was shiny on one side indicating it traveled some distance sideways. The 45 230 gr was not tested in sand as the interest was in the penetration properties of the 7.62X25mm Tokarev by now. A 100 gr 30 bullet was tested that was made from a 32 cal XTP Horady by resizing to .309 caliber with a die from Herters bought 20 years ago. The 30 caliber 100 grain resized 32 cal penetrated 8.0 inches of sand and the diameter of the channel of the bullet is about 2 inches. Oh yes the hollow point bullet did mushroom as advertised, it did not tumble. There was significant weight loss due to the mushrooming against the sand. The 30 caliber 147 grain cal penetrated 8.5 inches of sand and the diameter of the channel of the bullet is about 1.3 inches. Not any real weight loss as rifle bullets are tough . Bullet was shiny on one side indicating it traveled the full distance on it's side.
The CZ 52 will not replace the 1911 as the best of the best but it has a
charm of its own. With proper loads it functions flawlessly. The pistol has
two triggers (some call this a decocker). I use the decocker to let down the
hammer the same way you let down the 1911 45 Colt hammer. Then this problem
goes away. The second problem is the magazine release button. There is
not one! But you can get the clip out with a latch near the lanyard.
Thirdly, the trigger is difficult to learn as it is very hard and does not
let off cleanly. I figure it is worth learning to uses this trigger as it
would improve any shooting skills with other pistol with better triggers.
Forth, dry firing the pistol will break the standard firing pin.
Despite the reputation of the 85 grain bullet I liked the 147 grain bullet
as it is subsonic and feels nice to shoot. It will penetrate the same if you
load it to work the slide (as all auto need to be loaded with this in mind) as
in this case certain loads will cycle the action best. My loads for best
operation are as below:
100 grain hollow point bullet 5.0 grains of TITEGROUP with crimp.
load uses small rifle primers.
147 grain 7.62 NATO bullet 3.6 grains of TITEGROUP with crimp. <-- my favorite
Yes your right this bullet is loaded backwards. I have had excellent results
and this round is sweet to shoot.
load uses small rifle primers.
BALLISTICS COMPARISON and LOAD DATA for the CZ 52 7.62X25mm Tokarev DO NOT EXCEED MAXIMUM AS IT COULD BE DANGEROUS AND YOU COULD DAMAGE THE PISTOL _________________________________________________________________ All maximum loads should be used with great caution! The starting loads are recommended and working up to maximum is strongly ADVISED Every CZ 52 varies in bore diameter; what will work in one pistol barrel may cause greater pressures in another CZ 52 7.62X25mm. All safety precautions must be observed with best reloading practices strictly maintained. All bullets tested had a cannelure or crimping groove for best results. All cartridges use small rifle primers. 85 gr load Hodgdon TITEGROUP starting=5.4 grains Maximum=6.2 grains Mass = 85 Velocity = 1500 Kinetic Pulse = 240.367 kp Kinetic Energy = 424.589 ft-lb Momentum = 0.566 slug f/s Energy/Momentum = 750.000 E/M 100 gr load Hodgdon TITEGROUP starting=4.5 grains Maximum=5.3 grains Mass = 100 Velocity = 1275 Kinetic Pulse = 204.312 kp Kinetic Energy = 360.900 ft-lb Momentum = 0.566 slug f/s Energy/Momentum = 637.500 E/M 110 gr load Hodgdon TITEGROUP starting=4.0 grains Maximum=4.8 grains Mass = 110 Velocity = 1159 Kinetic Pulse = 185.695 kp Kinetic Energy = 328.040 ft-lb Momentum = 0.566 slug f/s Energy/Momentum = 579.500 E/M 125 gr load Hodgdon TITEGROUP starting=3.5 grains Maximum=4.2 grains Mass = 125 Velocity = 1020 Kinetic Pulse = 163.450 kp Kinetic Energy = 288.720 ft-lb Momentum = 0.566 slug f/s Energy/Momentum = 510.000 E/M 147 gr load for Hodgdon TITEGROUP starting=3.1 grains Maximum=3.6 grains Mass = 147 Velocity = 867 Kinetic Pulse = 138.821 kp Kinetic Energy = 245.314 ft-lb Momentum = 0.566 slug f/s Energy/Momentum = 433.500 E/M _________________________________________________________________Return to KINETIC PULSE and ballistics analysis by james n. hall
posting created FAQ February 26, 2001
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