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Discussion Starter · #1 ·
From the past month, I've fired about 700rds of my reloads on my 9mm 1911. Yesterday I put some more rounds downrange and I had experience 3 misfires. So, I decided to clean it today, to my surprise, I found some sliver of brass inside the FP tunnel. Its obvious its from the primer and its causing the misfire.
What's causing this to happen? Is it the primer or is it the FP? or is it both? What's the cure? Please help! :( :(

P.S.
My load's consist of; Winchester small rifle primer and 4.7gr of Titegroup under a 124gr FMJ.
 

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Check some reloading manuals. Sounds like your loads are too hot, causing the back flow of material into the fireing pin hole.
 

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What gun?
A late model Springfield with ILS locking mainspring housing?
If so, it has a titanium firing pin and a very strong firing pin spring; so as to pass the California drop test.
My Ultra Compact 9mm would completely erase the firing pin indent on factory loads; I expect extrusion back into the hole would have been a problem in the long run. I put in a Brown #826 Springfield size firing pin and Wolff firing pin spring and now get normal indents. I also replaced the locking mainspring cap and short, stiff mainspring with standard parts for the pre-ILS guns. I (or my FLG) used a real GI mainspring cap, shortened for the U.C., and a Wolff UC mainspring. (It can still be locked, if a lawyer ever gets involved.)

If it is some other gun, I dunno; but I'd check the load and if it is not excessive, I'd probably replace the firing pin and spring anyhow.
 

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Discussion Starter · #4 ·
Thanks! But no, its not Ti firing pin. I do have a light FP spring in it, I'll change that, reduce the load and see what happens. If there are anymore suggestions, pls. keep it coming!
 

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In addition to what's been suggested already:

A weak firing pin spring would lead to primer smear rather than primer flow back.

How's the relationship between FP-OD and FP-channel ID? Too much play would cause flow back.

A sharp edge of the channel hole in the breech face can shear metal off primer even with light flow back.

Winchester SR seems too hot fort his combination, although I don't think the possible higher pressure you might get would be too much for this primer to lead to flow back without one or a combination of the above mentioned points.

I'd change the primer first for evaluation.

Quickloader
 

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The firing pin on a 1911 type is an inertia pin, meaning that it is shorter than the firing pin tunnel and can only protrude out the front if stuck a blow at the rear. Then it jumps out and hits the primer, and is retracted by its spring. This is the opposite of, say, a Mauser rifle, where the pin is driven forward by its spring and remains forward until the bolt is operated.

On the 1911, the pressure inside the primer tends to try to force the firing pin back. If pressure is hign or the firing pin does not have enough momentum, pressure can force the pin back and force part of the primer back into the firing pin hole. An instant later, the barrel will drop and any material protruding into the hole will be sheared off.

The solution is not a stronger firing pin spring, in fact the opposite. Aside from a reduction of load or a different primer, you might need a heavier firing pin or a lighter (standard) firing pin spring. Part of the response depends on what (if anything) has been done to the pistol by you or another owner.

There is also the firing pin momentum to consider, and the mainspring (hammer spring) could well be a factor if the hammer is not imparting a heavy enough blow to the firing pin.

Jim
 
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