10,000 Rounds of 5.56 PolyFrang Frangible Ammo Cause ZERO Barrel Wear

Hrachya H
by Hrachya H
10,000 Rounds of 5.56 PolyFrang Frangible Ammo Cause ZERO Barrel Wear (1)

Well, that’s what PolyFrang claims in a report published on their website. The test rifles and barrels were made by Armalite. The test was requested by a company called Exelon Nuclear Security and it was conducted during a three month period to determine the amount of barrel wear that could possibly be caused by the use of PolyFrang frangible ammo.

10,000 Rounds of 5.56 PolyFrang Frangible Ammo Cause ZERO Barrel Wear (2)

Below you can find the testing protocols quoted from the mentioned report.

Testing Protocols:

Testing was performed on a new 1 in 7 twist Armalite chrome lined, barreled upper and PolyFrang 5.56mm production ammunition.

The test was continued until 10,000 rounds was fired.

The rifle was shot at a sustained rate of fire with no more than 30 rounds per minute being fired. It was cleaned* and lubed after each 1000 rounds.

Gas Port and chamber temperature was measured after every five 30 round magazines being fired (150 rounds total).

Throat erosion measurements was taken after every 1000 rounds.

The bore was slugged at the start (0 rounds) of the test and at the end (10,000) of the test for measurement comparison.

The bore was visually inspected using a bore scope after every 1000 rounds to determine wear or damage to the throat, rifling or gas port.

Accuracy testing, consisting of bench rest 5 shot groups was performed at the start of the test and after every 1000 rounds.

*Cleaning Defined: Bolt Carrier was removed, bore brush pushed down the barrel, Bolt and Carrier were wiped clean, lubed and replaced.

And here are the results and recommendations quoted from the same source.

Test Results
1. Rifle was shot to 10,000 rounds
2. No throat erosion was detected.
3. No rifling wear was detected.
4. No gas port distortion was detected.
5. No deterioration in accuracy was detected.
6. Barrel chamber and gas port never exceeded 400 degrees during shooting.
7. No ammunition related cycling issues were observed during the test.
8. After 10,000 rounds the barrel slugging revealed no dimensional change to the bore.

1. Since no perceivable wear to the barrel was detected during testing and the ammunition functioned properly in the rifle, I see no issue with recommending it’s use in Armalite rifles.
2. Continue testing rifle and ammunition to reach 20,000 rounds.

These are some really impressive results. Now, obviously, it is expected that frangible Metal Impregnated Polymer (MIP) ammo would be easier on the barrel compared to the standard ball ammunition. However, I would never think that it will cause no measurable wear at all. It basically means you can extensively practice with this ammunition without worrying about reducing the barrel life and decreasing the potential accuracy of your weapon.

What do you think about this report? Do you have an experience of extensively using PolyFrang frangible ammunition? Share your thoughts in the comments section.

Images from www.polyfrang.com

Hrachya H
Hrachya H

Managing Editor Being a lifelong firearms enthusiast, Hrachya always enjoys studying the history and design of guns and ammunition. Should you need to contact him, feel free to shoot him a message at Hrachya@TheFirearmBlog.com

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  • Old Gringo Old Gringo on Apr 09, 2019

    Winchester brand frangible 50 grain, 5.56 ammo is $458 per thousand on line today, whereas regular military ball is about $315. It has been around for years and while I have not shot people with it, I like it fine for shooting in places with cattle or where a ricochet might happen. I keep it in my AR used for home defense. I worked in 4 different law enforcement agencies in the last 50 years, and if it had been available would have been my carry ammo. There is no down side for most law enforcement or personal use. It would not work for military use because they need every inch of penetration possible to shoot through various barriers. Think about it, all defense and 99% of law enforcement use will be at say 50 yards or less. Impact velocity will be about 3,000 fps. It is going to penetrate deeply into flesh and bones, if it blows up, great, hydrostatic shock stops people. My 2 cents.

  • Johnhancok Johnhancok on Apr 10, 2019

    They dont always stand next to reactor. They have facilities all over and multiple buildings on any given sight that may contain "sensitive" materials and components. They also follow those unmarked semi trucks loaded with components all over the country. I think it's more a safer training thing and it's easy on steel targets. I've taken many DOE courses and it's nothing to fire 2000 rounds in a five day course. Shooting steel in a shoot house can get hairy, even for the trainers up on the catwalk. Frangible is also way better for the walls when students miss. You can also be more versatile with targets. You can use stand alone dummies and shoot in directions you cant get away with with other ammo. A lot of shoot houses get predictable because targets end up on the back wall in every room. Nice to make the problem more problematic for the students.