M1 firing pin too long?

[Appalacious]

Hey guys,
I got a question from a friend of mine- apparently sent to him from someone who just got an M1.
I'll post it here.  FYI- the chronology is in reverse order, as is usual with emails.

I was asked to forward this to you from the friend that was asking about his M1.

Let me know what you find out about yours.

x

Forward this to your friend.  Apparently, the problem is that the firing pin is longer than normal, and strikes the primer before the bolt is fully closed. 

From: x

Sent: Wednesday, March 11, 2009 12:01 PM
To: x
Subject: Re: FW: M1

The only thing I really know is what the gunsmith told me and showed me. 

He showed me a M1 that had the receiver (base of the bolt where it attaches to the barrel) split open. 

He told me that he's seen several in his work as a firearms forensics expert who's often called around here to testify on firearms related evidence.  I did see some testimonials from attorneys thanking him for whatever he did for them.  No details on that.

Thanks for your help.
______________________________

x

x wrote:

It had to go to a couple others, but here's an answer and more is coming.

-----Original Message-----
From: x
To: x
Subject: M1

Here is an answer to your question from a friend on base that likes old military weapons.

x
Here is his answer:

I've never heard of the firing pin issue, but you do only want to shoot
M2 ball in an M1 because the gas system is tuned for it.  If you shoot the heavier bullets through it, the system may cycle to hard and crack the op rod.  As long as you shoot ammo that's close to the M2 spec you'll be ok.  Most 30.06 is probably close to that spec anyway, you just have to be careful with the heavier stuff.

I'll check the primers on my m2 ball tonight and see if the primers are recessed.  I certainly have never heard that, though.

I wrote the very last part.  Feel free to comment on that, too, if you want.  But I'm mostly interested in the firing pin issue.  I've certainly never heard of that.

Thanks,
j

[cannonman61]

A,

I've worked on a ton of M1's over the years. I have yet to run across one that had a firing pin to long.

I have had M1's that had slam fires due to the bold being so absolutely cruddy that the pin was stuck in the forward position and caused a premature firing. I have also seen cases like you are describing from seriously short headspace caused by foriegn armourers that lacked the proper skill sets/tools or what ever to successfully rebuild an M1. ( I have seen this both on Greek and Korean returns)

Further, the M1 has a disconnector that should prevent the hammer from even going forward to strike the firing pin until the bolt is fully closed and evn if the timing is off the nature of the manifestation of problems seems odd.

To quote your email " the receiver( base of the bolt where it attaches to the barrel) split open" The barrel is screwed into the receiver with timed amce threading. If the work was done right and the chamber cut correctly a premature firing is much more likely to injure the shooter with flying bits of hot, sharp brass than split the receiver at this point as it would also have to split the barrel at the same point. something the email makes no mention of.

As for ammo, The M2 stuff has a crimped primer as does most military stuff and if the gent was firing brass with slightly oversized primer pockets, he may well have found out why the military crimps theirs. Primers could work back out under recoil and if they were sensive, as some are more than others, this too could lead to premature ignition.

Hope this helps.

CM

[Old Dog]

find a copy of Hatcher's Book of the Garand and read it, great book.

According to that book, by the end of the war, with millions of Springfield Armory and Winchester M1's having fired millions of rounds of ammo, not a single one had ever "blown up".  So they attempted to blow one up.  They ran up past the 70,000 psi proof loads used to test each rifle prior to shipment, they continued to increase the powder charge, the got to the point where they were afraid to test the pressures in their special pressure test rifles, the blew up an Arisaka bolt action (know for its strong action) and finally got to what they estimated was 120,000 psi and had a case wall blow out.  They stopped there.  The damage to the rifle was a broken stock, the front of the trigger housing (like the floor plate of a bolt action rifle) was blown off the trigger housing, the bolt swelled up some where gas had vented back into it when the case wall failed.

They replaced the trigger housing and bolt and kept on shooting the standard 50,000 psi GI ball loads in it with no further issues seen.

Yes, I've seen pictures of a pretty badly destroyed M1 Garand before, too.  But it's real uncommon and somebody has to do something really stupid as run of the mill dumb just won't tear one up that bad.

Never heard of a "too long" firing pin either.

If it's not damaged or worn the firing pin can't move forward to strike the primer until the bolt is locked into firing position.  Take your M1 out of the stock.  Turn the receiver over and look at the piece of metal (called a receiver bridge) that runs from one side of the receiver to the other under the back of the bolt.  See the notch in it?  The dog leg sticking down off the back of the firing pin has to line up with that notch in order to move forward and strike the primer.  If the dogleg of the firing pin is badly worn or the receiver bridge has been "messed" with then bad things could happen.  However, it was designed to keep the firing pin from every hitting the firing pin unless the bolt had turned so the lugs were locked into the receiver.

Enjoy that M1.  Don't be afraid of it.  My "shooter" M1 was made in 1944 and rebarreled with a 1953 barrel.  They say it takes around 9 to 10 thousand rounds to wear out a barrel.  My son's M1 was made in 1943 and wears a July 1947 barrel.  My brother's M1 was made in 1942 and wears a 1959 barrel (who know if it's been rebarreled only once or if that barrel is the second rebuiled on that receiver.)

None of the above is an invitation to abuse your M1 with high pressure reloads, just some info to explain the receivers are in no way easy to damage or wear out.

[SamD]

There is a spec for firing pin protrusion, min. and max. and a gage for it in the armorers kit.
Sam

[Appalacious]

Thanks guys, lots of good info.
J

[douglas34474]

From TM9-1275, Ordnance Maintenance U.S. Riflesa, Cal 30 M1, firing pin protrusion , max. 0.059", min 0.044".

HTH

Doug