Firing pin question, Is small OK?

original: forum.m1911.org
Retrieved: November 07, 2011
Last Post: October 27, 2011

nanoman
26th October 2011

Firing pin question, Is small OK?

I bought a cobbled up/mis-matched 45 cal 1911. Upon disassembly I discovered how bad I got ripped off. Many parts were worn out.

A few questions. The slide is a Springfield Armory and has a small firing pin. Is this useable for 45 acp? Is it safe? The pin that was in there was a larger one that someone ground down with a bench grinder, hence I need a replacement.


wjkuleck
26th October 2011

As mentioned it another current thread, S, Inc. slides are made to accept a firing pin of proprietary diameter: bigger than 9mm/.38, smaller than .45. This is the case for their .45 ACP pistols. The firing pin diameter, so long as it is proper for the slide, is of no consequence in .45 pistols. In fact, Caspian Arms slides are made to accept the smaller .9mm/.38 firing pin dimension, whether for .45 ACP or 9mm/.38 or .40.

Simply replace the firing pin with an S, Inc.-dimension firing pin, available from many vendors of 1911 firing pins.


Hawkmoon
26th October 2011

More to the point, the Springfield firing pin IS smaller than a standard 1911 (.45 Auto) firing pin, so yours may be correct even though it's not as large as you expected it to be. The standard firing pin should measure .093" diameter at the tip. A 9mm/.38 Super measures .068", and Springfield's firing pins measure .075".


wjkuleck
26th October 2011

Quote:
More to the point, the Springfield firing pin IS smaller than a standard 1911 (.45 Auto) firing pin, so yours may be correct even though it's not as large as you expected it to be. The standard firing pin should measure .093" diameter at the tip. A 9mm/.38 Super measures .068", and Springfield's firing pins measure .075".

Hawkmoon, I took the OP's meaning to be that someone turned down a .45 ACP firing pin to fit the S, Inc.'s intermediate dimension, "bigger than 9mm/.38, smaller than .45 ACP."


niemi24s
26th October 2011

So now we have 1911 firing pins with tip OD's of 0.068", 0.075" and [all the way up to] 0.093". Uh-oh! Who'll be the first manufacturer to reap the economic benefit of filling the gap and come out with a slide needing a 0.084" firing pin?


nanoman
27th October 2011

Thanks for the info. It is much appreciated.


Hawkmoon
27th October 2011

Quote:
Hawkmoon, I took the OP's meaning to be that someone turned down a .45 ACP firing pin to fit the S, Inc.'s intermediate dimension, "bigger than 9mm/.38, smaller than .45 ACP."

He did say it appeared to have been ground smaller, but he didn't state how much smaller. Even if it was ground down from a .45 firing pin, if it's the correct diameter it may not be necessary to replace it.


niemi24s
27th October 2011

I would, however, closely examine its tip to insure its shape is a good hemisphere with the curve tangent to the sides. If not tangent, it means the tip curve was not blended into the sides and there's an abrupt transition where these surface meet which might make it easier for a primer cup to fail in hot ammunition. Maybe.


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