.308 Limited Pen. Test Report

[ChiefBDT]

This report concerns the comprehensive testing and evaluation of the .308 Win. Match (Limited Penetration) ammunition for potential sniper / counter sniper operations.

The following are the results of this study.

AMMUNITION: Limited Penetration
CALIBER: .308 [7.62X51]
PROJECTILE: 168 grain H.P.
MANUFACTURER: Black Hills Ammunition
P.O. Box 3090, Rapid City, S.D. 57709

TEST WEAPON No. 1: Remington 700 PSS (.308)
OPTICS: Leopold 10X
STOCK: McMillian / Glass bedded with Harris Bi-Pod

TEST WEAPON No. 2: Springfield M1A Match (.308)
OPTICS: Leopold 10X
STOCK: E-2

TEST WEAPON No. 3: Remington 700 PSS (.308)
OPTICS: Springfield Armory 4-14 x 56 (3rd. Gen.)
STOCK: Original Mfg. Composite with Harris Bi-Pod.


November 08th. 2002 at 1400. The ammunition was first tested at a Metropolitan Police Range in the Midwest under the following conditions.







WEATHER: Partly Cloudy / 46 degrees (f).
WIND: 0-2 M.P.H. (N/W)
RELATIVE HUMIDITY: 52 percent.
EVELATION: 1604 ft. (G.P.S.)

The ammunition was Cronographed through test weapons 1 and 3. with an average muzzle velocity of 2537 F.P.S. at 15 feet from the weapons muzzle. This ammunition Muzzle Velocity proved very consistent with a deviation of +/- 6 F.P.S.

Test Weapon No. 2 showed a slight decrease in average Muzzle Velocity at 2522 F.P.S. and again proved consistent with a deviation of +/- 11 F.P.S. Again this test was conducted with the Chronograph 15 feet from the weapons muzzle.

The first penetration test was conducted at 25 yards with Test Weapon No. 2. This test was conducted on a ballistic water tank unit. The ballistic testing unit has 10 mil. Baffles every 4 inches, to a maximum penetration length of 24 inches.

Penetration averaged 9.5 inches and produced a very violent impact display. The testing unit encapsulated the entire projectile, however, it fragmented into numerous pieces. The largest fragment recovered was 59 grains. Of all the rounds tested, none were recovered intact.

The second penetration test was conducted at 100 yards with Test Weapons 1 and 3 using the same ballistic testing unit.

Penetration averaged 8.5 inches and again proved to have a very violent impact display compared to other match ammunition we have tested. Again, of all the rounds tested, none were recovered intact.

The final penetration test was conducted with Test Weapon No. 2 on a 3.5 x 3.5 inch block of hardwood covered with 10mil. plastic, at 25 yards.

The entrance hole measured .32 in. and there was no exit hole. However, the plastic coating on the back of the test media was fractured. The projectile remained encapsulated in this media and was found to be mostly intact. Expansion was .48 in. of the largest fragment recovered.

The first accuracy tests were conducted with Test Weapon No. 1 at a distance of 100 yds.

NOTE: Test Weapon No. 1 is zeroed for Federal Gold Medal Match [168 grain BTHP], at 100 yards.

The cold shot impacted 1.23 inches (High / Right) at approximately 2 o’clock, from point of aim.

The second and third rounds impacted 1 inch right at approximately 3 o’clock from point of aim.

Another three shot group, hot barrel, provided a .75 group, 1 inch right at 3 o’clock from point of aim.

Test Weapon No. 1 was cleaned and allowed to cool for 20 minutes.

At this point we fired a 3 round group with the Federal Match with Test Weapon No. 1. After the cold shot, which is consistently .75 to 1.25 inches high at 12 o’clock, we managed a .5 inch group at approximately .75 in. .5 inches low (6 o’clock) from point of aim.

NOTE: This test was conducted 3 times with the same results. The Limited Penetration Ammunition consistently printed a .75 group, approximately 1.5 inches high and to the right at 2 o’clock..

Test Weapon No. 2 (M1A) consistently printed a 1.0 to 1.75 inch group at 100 yards.

ACCURACY TEST NO. 2

After the cleaning and cooling of Test Weapon No. 1 accuracy was tested at 200 yards. This test was conducted for grouping, point of aim / point of impact differential.

With the Limited Penetration Ammunition we averaged groups of 2.25 to 3.5 inches. The mean average impact point was 6.25 inches low at approximately 4 o’clock from point of aim.

ACCURACY TEST NO. 3.

DATE: November 15, 2002 at 1530
LOCATION: Las Vegas, Nevada
WEATHER: Sunny / 72 degrees (f)
WIND: 0 mph
RELATIVE HUMIDITY: 28 percent.
EVELATION: 2404 ft. (G.P.S.)

The first accuracy test was conducted with Test Weapon No. 3 at 200 yards.

NOTE: Test Weapon No. 3 is zeroed for Federal Gold Medal Match [168 grain BTHP], at 100 yards.

The cold shot printed 6.5 inches low and to the right at approximately 4 o’clock.

A subsequent 3 round group was fired with an amazing measurement of 1.0 inches, 6.0 inches low and to the right, at 5 o’clock..

This test was repeated one additional time with the same results.

ACCURACY TEST NO. 4.

This test was conducted at 100 yards after the cleaning and cooling of Test Weapon No. 3.

The cold shot printed 2.25 inches high and to the right at 2 o’clock.

Two 3 round groups averaged .75 inches, 2.0 inches right at 3 o’clock from point of aim.

All personnel that participated in the testing of this ammunition were extremely impressed with the results.

The muzzle velocity seemed very consistent through our chronograph with a very low deviation differential.

The Limited Penetration capabilities were more than we expected. The only mystery to us would be the extreme fragmentation of the rounds when they impacted water. Our opinion is that this would not be a “Bad Thing”. However, we would like to do further testing on other media and through obstacles, such as glass, to see if this would effect the rounds capabilities.

The accuracy was very impressive with the only adjustments one would have to make would be to correct for point of aim / point of impact.

Thumbs Up!!! from all of us on this round. It performs remarkably and should be seriously considered for any tactical team, Law Enforcement or Military.

Brad Trelstad


Director of Tactical Training
TMTA, Inc.

[ChiefBDT]

After posting I noticed that none of the "Bullet Points" copied into the post. This report has not been submitted. Any comments or additions are appreciated.

Thanks in advance,

ChiefBDT

[Invisible J]

Call me a dumbass, but does a "ballistic water tank unit" serve the same purpose as ballistic gelatin in that it displays wound cavity characteristics?

[EchoFiveMike]

No, it just gives you pen depth and you can recover bullets and judge their final performance, but no cavity. There is a conversion factor for gel to water, but I don't recall that off the top of my head. S/F...Ken M

[(1VB)compforce]

my memory may be a bit shaky, but I believe the conversion for 10% gel is

w/6*2.5=p

where

w =number of inches of penetration in water (assumes a 1/16" baffle every 6 inches)

p=inches of penetration in gel

It's been a while since I did the conversion though, so don't take this as gospel. I'll look it up tomorrow, time to go run now.

Jay

P.S. btw, that reduces to w *.416667 = p

I always used the other because it was easier to calculate off the top of my head.

[Invisible J]

Ah, okay, thanks guys.

Chief, all in all looks like a good write up. As you mentioned, some test shots with different types of glass would be good, to include spawl patterns and deflection of the round. Unless these gents know something I dont (educate me if you do), and as I'm sure you know yourself, there's no foolproof way to predict those factors, but it's good to at least make sure there's no unusual tendencies of the round when shot through glass.

Also, now that I am a bit better informed about the ballistic water tank, some gel shots would probably be a good idea in order to display wound characteristics.

[EchoFiveMike]

I did some testing of M118LR and M118 SB vs glass a while back(almost a year), and it was kinda interesting. The old 173gn FMJ was mucho better vs glass than the SMK used in the M118LR, the SMK was deformed enough that I have serious doubts about it's ability to penetrate a skull if you miss the C-O cavity and hit the forehead. Deflection was not a huge problem. I was testing over a 10' separation between the glass panel and the target and deflection was less than 1" from point of aim. Spalling was a non-issue. With 3/16" inch safety glass, the glass spall did not have enough energy to imbed in a standard cardboard IDPA target. I intend to go back and do some other testing with other bullets, different glass, severe angles etc, but the local ranges are really harsh about me blowing glass all over their facilities. This is a four shot group through the safety glass with 173gn FMJ M118SB(brown box) at 100 yds. This is about as good as some lots of that crap will shoot anyways. M40A1 #221379, about 25-30 degrees F last winter. S/F...Ken M

[EchoFiveMike]

As you notice on the previous picture, you do get some perforation of the target with the jacket fragments. This was one of the largest ones we found, it was sticking in the back of the target. The paw belongs to Sniper 14. S/F...Ken M

[Invisible J]

E5M, good gouge, thanks. For our experimentation with glass shots, we built a 3 sided "room", the frame being 2x4's with white sheets stretched over them to form the walls. Where the fourth wall would have been went the test glass, then a styrofoam mannequin head or paper target would go into the center of the "room".

The sheets were pretty good as far as marking spawl that could be physically harmful and resisting what would not, then we could just mark the punctures with a marker and use the same sheets for a few more shoots.

[EchoFiveMike]

Cool, that's a good idea re: the sheets. I'm trying to snake some mannequins for shooting too. Quite honestly, I'm of the opinion that most of the fragments generated by glass shooting are not going to be a big deal to the hostage. They're going to bleed a little, like they got cut shaving, and you really want to try and shoot when they are not looking at the window cause of the eyes, but they'll live. Police might have some liability issues, but that's life. For the USMC, half these twits we pull out shouldn't have been there in the first place. Like these three do gooders that got wasted yesterday. Damn, it's nice to see that kind of good hearted charity in the world, but the ME? Please, go to Appalachia or something if you want to help the needy. S/F...Ken M

PS: It's "spall"

[ChiefBDT]

Guys thanks for the comments. I too would like to see more testing on Bal. Gel. however, after looking all over the internet I can't seem to find the formula. Water tank is great for its intended purpose, but your right it would be nice to see the cav. Regarding the glass test, your reading my mind. Working on it now. Glass, as you know, is a real pain in the ass, but worth it. If you would like I can do the whole photo thing, once I figure out how to get them on here.

Stay safe,

ChiefBDT

[Invisible J]

Chief, found this in my wanderings across the internet, maybe it'll help:

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Subject: Ballistic Gelatin Recipe
By: Ed Harris @1:109/120.3006 via 1:2410/271 FIDOnet

The target material is prepared from gelatin, USP. The government
laboratories purchase this as Pharmagel A, Type 250 from the Kind & Knox Co., Park 80 West, Plaza 2, Saddle Brook, NJ 07662. The last time I bought any was in 1984, and at that time the price was $2.40/lb., or about $600 for a 55 gal. drum, shipped F.O.B. from Sioux City, IA.

The powder is mixed 10 percent by weight in warm, but not boiling water until dissolved, and then poured into moulds and chilled in a large refrigerator. The standard block size is 15x15x30cm for handgun bullets and 20x20x50cm for rifle bullets, but improvised moulds such as from cal. .50 M2A1 ammunition cans work well.

You will also need Thymol or cinnamon oil as a clarifier, which is
added in the proportion of 1 drop per liter. You will also need heavy duty electric stirrers or an industrial mixer, moulds, a release agent, such as Pam cooking spray for releasing the castings, LD plastic film or Saran wrap for wrapping the blocks, a freezer for storage if you will not use the blocks within a week, and foam coolers to transport them to the range, if you do not have a walk-in cooler near your lab.

To do this right, establish the tare weight of a 5 gallon stainless
steel container in which you will heat the water and mix the gelatin. Ideally this should have a spigot on the bottom to aid decanting the dissolved gelatin into the moulds. Add 12 liters of water to the container and bring the temperature to 65 degs. C and adjust the weight by adding or deleting water to obtain 12,000 grams. Place two electric stirrers into the hot water, one near the top and the other near the bottom of the container. Add three grams of Thymol or 12 drops of cinnamon oil and stir until dissolved in the hot water. Add 1500 grams of Pharmagel A to the hot water, breaking up any lumps with a stainless steel rod or paddle, to supplement the stirrers, as necessary.

After the gelatin is dissolved, in 10-15 minutes, turn off the
stirrers and remove them from the solution. Allow the bubbles and foam to rise to the surface for 20 minutes. If the container used does not have a spigot at the bottom, it is necessary to skim the foam off the surface before transferring the solution to the moulds. Allow the warm gelatin to stand at room temperature for at least one hour after transferring, so additional foam which rises to the top may be removed.

Place the gelatin in a refrigerator overnight at 0-5 degs. C. The
gelatin may then be removed from the moulds by placing the container in hot water. After 15-20 seconds use a spatula to loosen the gelatin from the sides of the container. After two minutes remove the mould from the hot water and invert it over a piece of plastic film spread on a flat surface.

Once the gelatin is removed from the mould it should be allowed to remain at room temperature for one hour, then tightly sealed in
plastic film and the wrapped block inserted into a plastic bag, which is again sealed to prevent evaporation, which drastically changes the consistency of the gelatin. Once tightly wrapped, the blocks can be stored up to six months in a freezer, or up to one week in a refrigerator. Unused blocks should be frozen immediately to retard mold growth. Before firing the blocks must be allowed to thaw and stabilized overnight at a temperature of 5-10 degs. C, because proper consistency is a function of the tempoerature.

Evaluation of the blocks is best accomplished by flash X-ray
photography which permits measurement of transient cavity volume as a function of projectile striking velocity, time, distance penetrated and projectile exit velocity energy deposit). If high speed photographic equipment is not available, it is useful to use a small caliber calibration test shot, such as a steel .177 air rifle shot from a Daisy pump-up air rifle known to give consistent performance, which can be placed as a consistency calibration check in a corner of the block out of the way. The permanent cavity can then be made to stand out well for still photography by injecting a colored water solution of ten drops food dye to a liter of water, using as veterinary syringe or laboratory wash bottle to reach all corners of the permanent cavity. To provide proper scale for the photograph, a piece of graph paper can be photocopied onto overhead transparency film, and used as a template to be positioned over the shot. The block should then be placed on a light table or photographed using diffused,
backlit strobe flash. Detailed ammunition test methodology is
available in various open-source medical and technical references.

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E5M, hukd on fonix werked fer mee :D Thanks man, "spall" it is, hehe.

[ChiefBDT]

Thanks guys for the info. here and PMs. Will keep you updated on future testing.

ChiefBDT

[Sharky]

Glass: Simple, point of aim-point of impact. That goes for most types of glass. You start trying to G-2 a glass shot by figuring out deflection angles and you are asking for trouble. Unless the angle is severe, deflection is minimal. If the angle is that severe, you shouldn't be taking the shot from there anyway. With a good head-on shot, even commercial cockpit glass, deflection is minimal. I would be more interested in the "skip" characteristics of the round, such as bouncing one off the pavement at a Tango hiding behind a car. Just my opinion.


PS: Longrange1947 probably has some good dope on stuff like this as I'm sure SOTIC has done nearly every test you can think of.