Discussion regarding rifles chambered in 22 TCM
User avatar
By Richard/SIA
#15055 I have an early number TCM rifle (Under #200) that is very easy to cock and barely marks the primer.
It will never set off a round as the firing pin spring is far too weak.
Anyone know a spring that works, hopefully something from Brownells?

I have to fix this one and I've had a few others that were "Iffy" enough that you had to use soft primer ammo.
I will post my results.
User avatar
By 1911SHOOTER
#15056
Richard/SIA wrote:I have an early number TCM rifle (Under #200) that is very easy to cock and barely marks the primer.
It will never set off a round as the firing pin spring is far too weak.
Anyone know a spring that works, hopefully something from Brownells?

I have to fix this one and I've had a few others that were "Iffy" enough that you had to use soft primer ammo.
I will post my results.



Richard,
Try emailing Shawn Fairbairn at shawn@rockislandarmory.com. He is the head gunsmith there
at RIA. I am sure he can help you.
Blackie
User avatar
By Richard/SIA
#15057 I think I may have resolved it.
Dismantled the bolt and found that the firing pin was getting tight near the bottom of it's travel.
Diamond file and lapping compound, it moves freely now.
Will test fire again in the morning in the hope that it does FIRE now.

I noted that some one had worked on it before as evidence by remnants of machinist blue.
Guess they needed to take just a bit more off the high spot.
Seems most factories fire very few rounds in test firing.
User avatar
By Richard/SIA
#15062 The sticky firing pin did not help but was not the complete answer.
Pulled the bolt completely apart again.
Noted that both ends of the firing pin spring were a bit ragged, not dressed.
Also found that one end appeared to have been unwound a bit and was oversize for OD so probably also binding.
I had no spring stock to replace this one with so I dressed the ends and made a new one of the #15027 "Firing pin spring follower" that was about .250" longer above the spring.
That added enough spring pressure that the gun now shoots just fine.

So all it took to resolve this one was time, fine files, dremel tool, a lathe and three trips to the range.