Investarm hammer removal

[leadhoarder]

I was wanting to remove the hammer from the lock on my GPR. With my TC you just remove the screw and the hammer comes off pretty easy.

I removed the screw on the investarm lock and i cannot get it to come off the shaft on the lock. I tried to tap it with a plastic mallet but did not want to over do it and gave up. Is there something I am missing here?

 

[Notchy Bob]

I was wanting to remove the hammer from the lock on my GPR. With my TC you just remove the screw and the hammer comes off pretty easy.

I removed the screw on the investarm lock and i cannot get it to come off the shaft on the lock. I tried to tap it with a plastic mallet but did not want to over do it and gave up. Is there something I am missing here?

I've never tried to disassemble a GPR lock, but I understand they are pretty similar to the Thompson Center locks. I've taken those apart and reassembled them a number of times. It is not difficult.

Generally speaking, if the hammer doesn't just lift off, and it seldom does, you need to take off all of the lock's innards first. Bore a blind hole about an inch deep and slightly larger than the diameter of the tumbler in a block of wood. Remove the hammer screw and lay the lock on the wooden block, face up, with the tumbler in the hole in the wood. Use a drift punch that will fit in the hammer screw hole in the tumbler shank without damaging the threads. Use a wood, rawhide, or plastic mallet and tap the punch to drive the tumbler out of the hammer so the tumbler drops into the hole in the block.

You can also use a larger diameter brass punch that will fit in the square hole in the hammer and use that to drive the tumbler out.

I would not recommend "wiggling" or prying the hammer off the tumbler shank. The hammer should be a snug fit, and prying or wiggling can loosen it up.

If your budget allows, L&R Lock Company makes and sells a "hammer puller" gadget that works like a mechanic's gear puller. This supposedly allows removal of a snug-fitting hammer without needing to disassemble the lock. L&R also makes a companion hammer press to reinstall the hammer back on the lock. I don't own these tools and have never seen either one in use, but they look like they ought to work.

Best regards,

Notchy Bob

 

[wiscoaster]

When I removed the hammer from my Traditions Kentucky pistol percussion lock I was surprised at what a heavy hammer and strong blow was required. So be sure you use a brass punch.

 

[Dusty_Traveler]

L&R Lock Company makes and sells a "hammer puller" gadget that works like a mechanic's gear puller. This supposedly allows removal of a snug-fitting hammer without needing to disassemble the lock. L&R also makes a companion hammer press to reinstall the hammer back on the lock.

I use both of these tools, and they are well worth their price if you do regular lock projects/maintenance. The hammer press does require you to remove the bridle when reinstalling the hammer. I'm glad I bought them.

 

[leadhoarder]

Sounds like my TC was well worn and loose when I bought it.

I really do not need to disassemble it right now but because my TC comes off so easily I have gotten into a habit of taking it off and washing it under running water. This also lets me clean the base of the hammer and the lockplate where you cannot get to it with it installed.

 

[TDM]

Sounds like my TC was well worn and loose when I bought it.

I really do not need to disassemble it right now but because my TC comes off so easily I have gotten into a habit of taking it off and washing it under running water. This also lets me clean the base of the hammer and the lockplate where you cannot get to it with it installed.

I fully understand any hesitation with completely disassembling a lock for the first time. I remember feeling like a dog watching television. But it’s a worthwhile learning process and you’ll profit from it. Your not going to tear anything up if you take your time. Lots of resources here on the forum and just ask about anything you can’t find.

 

[leadhoarder]

Yeah I will probably take it apart at some point. I only have around 150 shots on the rifle now and have never messed with the lock other than making sure that it was still clean and lubed. I have a good mechanical aptitude so I am sure I will not have any major issues once I am in there. I have fully disassembled and reassembled modern and more complex firearms.

I for sure are no craftsman though and I know that I should never attempt the kit builds that many on here attempt.

 

[Notchy Bob]

I use both of these tools, and they are well worth their price if you do regular lock projects/maintenance. The hammer press does require you to remove the bridle when reinstalling the hammer. I'm glad I bought them.

That's good to know... Thank you. I was not aware of any sort of review or prior comments on these. I was a little put off by the price, but good tools aren't cheap.

I fully understand any hesitation with completely disassembling a lock for the first time. I remember feeling like a dog watching television. But it’s a worthwhile learning process and you’ll profit from it. Your not going to tear anything up if you take your time. Lots of resources here on the forum and just ask about anything you can’t find.

I agree with everything brother @TDM said . My dad showed me how to disassemble traditional flat spring locks long ago, but I was stymied by my first confrontation with a T/C coil spring lock. The fellows here on this forum explained just how to do it.

Notchy Bob