M14 Forum

M1A's r BEST · February 10th, 2012, 02:51 AM

There are a lot of factors involved in a slam fire besides the primer type.

For the first few years I reloaded for my M1A I used Federal bench rest primers with no issues. Way back up in the hills of WV I didn't have access to the internet to tell me it was bad to use those primers (there was no internet in the late 70's/early 80's). After the store I got my primers at stopped carrying Federal primers I used standard CCI large rifle primers with no issues.

A few months back, when I first reloaded for my .300 black out in my recently built AR15 I used Remington small pistol primers to light up the first 50 rounds I loaded since I was using H110 powder at only 17 grains behind a 150 grain bullet. I felt it was very similar in amount of powder and bullet weight to some magnum pistol loads so I used a pistol primer - no issues with the first 50 (fired in an AR15 by the way).

Ever been involved in an industrial accident investigation? I have. Several. You spend many hours over several days meeting, talking, researching, observing and end up (quite often) developing new tools, new methods, revising existing tool/methods/procedures or even raw materials - when you never really find out the true root cause. It could have been this, or this, and that, or something else, or maybe this contributed, etc., etc., etc. In the end you have several "maybes" with all kinds of ways to prevent these possibilities that had nothing to do with the root cause.

I will never personally "test" the theories by making bad reloads on purpose to see whether or not high primers, dirty primer pockets, dirty chambers, gummed up firing pin channels in the bolt, etc. result in a slam fire. I just know that so far, with my reloads and my rifles I've not had an issue in M1A's, M1 Garands or AR15's.

Some day I'm going to start my "list" of things that I've done/seen that, according to the internet, will result in instant destruction of you gun/car, etc.

If for no other reason that you need to be sure your rifle will operate correctly when you really need it - keep it clean. If for no other reason than accuracy and consistency, make your reloads "right", again, so that they do what you need them to do when you need them to do it.

Silverton4 · February 10th, 2012, 04:34 AM

Thanks everybody for the responses. Y'all covered everything I was wondering about and several things that never occurred to me. The info about slow burn propellant overloading the gas system is one that I couldn't have thought of since I had no solid understanding of the design. The info about the need for the bolt to slam home from at least halfway addressed the thought I had about single loading a round or soft loading one from the mag by gliding the bolt down by hand.

Now I know that a slam fire isn't the only danger to my rifle from non-spec ammo.

Great forum. Y'all have helped me a lot with the input.

Francis · February 10th, 2012, 05:14 AM

4000+ rounds through my M1A, never a slam fire. Mostly commercial and hand loaded ammo with commercial components.

I never chamber load, always load the magazine even when single loading.

I saw a slam fire on range once in an M16 when chamber loaded.

Cheers

smkummer · February 10th, 2012, 05:27 AM

I thought the M14 gas system was much improved over the M1 to have a pressure relief type of system to address different burning rates of propelants? If not, then I am learing something new here. I still only load BL-C(2) for my 147 BTFMJ and 172 grain match bullets as that was one of the original powders.

Dreampiper · February 10th, 2012, 06:56 AM

Burn rate issues have been discussed a lot here. Do a search and see what you think. From what I have read and the opinions of respected members here, yes the m14 system is more tolerant, but the speed of the impulse is as important to consider as the volume of gas allowed into the piston before the excess bleeds off. That is my simplification based on the info I have seen, if it's incorrect I'm sure someone will adjust me.

Seventh Fleet · February 10th, 2012, 07:27 AM

Take that box of 180 grain bullets back where you bought them and swap them for some Winchester white box 147 grain bullets for your M-1A. Conventional wisdom says that you are to stay away from 180 and heavier bullets in M-14's since at they may at the very least end up bending your op rod.

7th

Silverton4 · February 11th, 2012, 03:10 AM

Quote:

Originally Posted by Seventh Fleet

Take that box of 180 grain bullets back where you bought them and swap them for some Winchester white box 147 grain bullets for your M-1A. Conventional wisdom says that you are to stay away from 180 and heavier bullets in M-14's since at they may at the very least end up bending your op rod.

7th

I got'em at Wal-Mart and they have a no-return policy on ammo. I'll have to trade them with a local hunter or give'em away but I won't run them through my rifle. I'll get the white box Winchester, though, if my Portugese NATO rounds are too slow getting here. Thanks

Peter M. Eick · February 12th, 2012, 05:49 AM

The problem with shooting something like 180 grn winchesters is that this particular lot might be fine but the next may be too hot. Remember they don't use canister powders, they just take the lot they get, run some sophisticated pressure tests to determine how much powder to use and then load them up.

The pressure at the port may vary enough to bend your rod if they go a little hot, or the powder lot peaks a bit latter than the last lot.

slamfire1 · February 12th, 2012, 06:24 PM

That is a vexing question.

Commercial ammunition is not something you control. Commercial manufacturers are free to use whatever components they want, switch them when they can make more profit, and don’t have to tell you anything.

If you have someone out there using the Federal Government to persecute you, then commercial ammunition can be a headache, as this poor man found out:

http://www.falfiles.com/forums/showt...hreadid=183318

Quote:

The rifle in question never doubled on me and I shot it in numerous matches.

The atf got it to double by putting the selector on FA and trying many different types of ammo until they found one with a super soft primer that would double when the hammer followed the bolt home

At the actual test firing that we conducted there were 12 tests with 4 types of ammo and only the Winchester hunting 308 doubled and it did it only twice.

The problem was a worn out firing pin spring.

I never tried to shoot the fal with the selector on FA for the obvious reason of knowing that it could only fire out of battery that to do so would be risking a dangerous outcome.
I also would never shoot expensive hunting ammo $15 a box of 20.

The HTS set (DSA) was not doubling

I work with a Class 2 manf. and I have no reason to shoot a illegal MG we have all the legal ones we could ever need.

The ATF agent that confiscated my FAL's did not do the test he took the rifles to the tech branch in DC where they were "tested"

After many months and $ my lawyer, expert witness and I got to do our test with the ATF and we video taped it and that is when the truth was shown.

A local gun dealer here in NC By the name of Dan D. who for some reason did not like me actually turned the ATF my way by telling them a bunch of lies.

After the many man hours spent on my behalf I think the atf just tried to salvage a conviction of an innocent person to justify all the time spent in their investigation of me.

It is a long story but this sheds light on the jist of it.

I just this week was given back my property except for the one rifle that malfunctoned.

Thanks to diligent work by my Lawyer

I don’t fire commercial ammunition in my M1a’s for several reasons. The first of which, as the savants have mentioned, the first consideration is pressure curve. I don’t want a slow burning powder and magnum level velocities.

The second reason is that I don't have control over what primers are used.

The Army always used the FA34 primer. I found this on page 4-69 of the "Report of the M16 Review Panel Appendix 4 Appendix 4 Ammunition Development Program"

You can find this at http://www.dtic.mil/dtic/index.html.

The Army was having all sorts of issues, slamfires, primer sensitivity, etc, with the early M16’s. The quote from the primer sensitivity section was

Quote:

“Contrary to the requirements for 7.62 mm ammunition, which specifies that the FA34 primer is mandatory, no attempt has been made to standardize on type of primer for 5.56 mm ammunition”.

This report was before the military required the use of a #41 primer, a less sensitive primer, in 5.56 ammunition.

The #34 primer is a less sensitive primer than commercial primers. This is what you want to use in M1a's and Garands. The least sensitive primer you can find. However, some commercial primer makers, noticeably Federal primers, are very proud to tell you they make the most sensitive primer on the market.

You might get a real sensitive Federal primer in your commercial ammunition.

One of the good things about commercial ammunition is that factory fresh ammunition is always of minimum dimensions.

This guy had a tight case, without a doubt the bolt stopped trying to crunch fit his case to the chamber, he had a sensitive primer, and his gun fired out of battery.

http://www.snipercountry.com/HotTips/Slamfire.htm

Quote:

M14/M305: I looked at my personal "slam fire" and here is what happend. I have a NM TRW bolt in a Norinco M305, I shot realoads that were made for and previously shot out of my G-3, the local hunting clubs range I shoot at does not allow magazines, or slings,(go figure) to be used.

My conclusion: headspace is really on the tight side after lapping the bolt in, the realoads even though full sized still had the H&K flutes on them and may not have seated all the way in the chamber, I used thin CCI Bench rest primers in tight PMC brass pockets that were seated real flat, and I had to load the round into the chamber and then close the bolt onto it which causes a higher bolt speed forward that if it would feed a round out of the mag. BAM, Slammfire ! Clearly not the Guns fault, but operator failure. The only damage that I found so far is a small deformation in the OP rod cam were the bolts giudewheel runs. I´ll take her to the range again and fire some factory FMJ out of a Magazine to see if the little deburring I did solved the problem.

The straight wall, no neck .308 case is in a special glass case I reserved for little reminders. This case also includes a 1" truck wheel nut and bolt that I stripped. It was stamped L for left hand thread, but in the heat of battle, what do I know.
"Ende"
Torsten <lasercon@dialup.globe.de>
Germany - Thursday, February 11, 1999 at 08:50:34 (ZULU

If this guy had been using factory ammunition it is likely the slamfire would have been in battery as there would not have been resistance to chambering the round.

Dredsen · February 12th, 2012, 08:00 PM

The main think to keep in mind on slam fire is that you should just be aware that it can happen so that you can keep the gun pointed downrange.

Silverton4 · February 13th, 2012, 12:34 PM

Quote:

Originally Posted by Dredsen

The main think to keep in mind on slam fire is that you should just be aware that it can happen so that you can keep the gun pointed downrange.

Indeed. Always.