View Full Version : slam fires

February 2, 2000, 08:02 PM
is it possible to put a small spring over the firing pin of an M1A to totally prevent these without degrading performance?

George Stringer
February 2, 2000, 09:55 PM
Mongrel, just about anything is possible. I've been doing the same thing with the MAS 49/56. I would turn a new firing pin to a smaller body diameter to make room for the spring leaving a shoulder for it to push against. You wouldn't need a very strong spring. Just one stout enough to retract the pin. George

James K
February 2, 2000, 11:17 PM
Hi Mongrel,

As George says, anything can be done. But if you are getting slam fires in an M1A, there may be something more wrong than just not having a firing pin spring.


February 3, 2000, 11:27 AM
Very neat idea! I occasionally like to light my AR up with full auto fire by bouncing the trigger... you know, hold rifle loosely at hip and pull rifle forward into your stationary trigger finger.

Some people have debated that this is dangerously slam firing, but I disagree because there is no way for the pin to protrude through the bolt until it is locked in battery... but just to be sure and safe, I wonder if I could put a spring (maybe from a ball point pen) over the firing pin?

What do you think?


Art Eatman
February 3, 2000, 10:25 PM
Mongrel66: About 15 years back, I bought a Springfield Armory M1A. Went to the bench. Loaded, aimed, and "Boom-boom!" Oops!

I phoned SA, and had a new trigger group as close to instantaneous as USPS could get it to me. Free.

No more oops. And don't believe BATF won't make a court case out of a slam-firing gun!


February 4, 2000, 12:54 PM
i haven't had a slam fire yet....haven't had my m1a to the range yet...but i feel funny thinking a weapon will go off when i chamber a round...the ar10 series had slam fire problems and i think they stuck a spring on the firing pin, thats why i asked.i'd hate to lose half my face in a slam fire..not that i'm particularly good looking, i've just gotten kinda used to the one i have.

February 4, 2000, 03:48 PM
As mentioned, if you are experiencing slam fires, it could be due to other factors. Are you reloading?? If so, are your primers well seated or are they above the surface of the case head?? This will result in slam fires quickly. As I am sure you are aware, slam fires can lead to injury to you or others plus it is quite possible to destroy the rifle which is $$$$$ plus probably a new pair of shorts and trousers!!
(Been there, done that)

Highly suggest you seek out a 'smith w/ experience regarding Service Type weapons and have him check a whole list of things.

February 5, 2000, 10:39 PM
I Had a LEO customer with the same problem several years ago with a Chinese Polytech clone. The disconnector notch was not deep enough, and cut at the wrong angle, so the disconnector would not engage, if I recall correctly. It was an easy fix. May I suggest having a good 'smith check out your trigger group before fitting the rifle with a firing pin return spring? Good Luck- Dakotan

Mouse Gun
February 6, 2000, 12:04 AM
Iv'e had two Poly M14s one I had rebuilt by Fulton Armory(great rifle) and have never had a problem w/slamfires. I did have a doubling problem from a used rifle but that was from a bad trigger job which was an easy fix. I've also loaded about 90% of the ammo for these, the key is case prep(proper sizing, primer pocket uniforming and primer seating, etc.). I uniform all primer pockets on all my rifle brass, you only need to do this once. Like a previous poster mentioned before, a high primer will cause this in a hurry. I'm by no means an expert but I've yet to see a slamfire from factory loaded ball or match ammo with an M1A or M14 type rifle, this is usually traced back to the reloading bench. If you shoot factory ammo I doubt you'll have a problem but if anyone out there has seen this with factory ammo feel free to ring in. This is only based on my experiences and of some friends(small sampling).

Mouse Gun