Firing pin hole size

[444Dan]

I have an older H&R frame made in 76' and have read several posts regarding the concern over the firing pin hole size.  Has anybody actually measured the hole size on the older frames vs the NEF SB1 & SB2 frames ?  I really want to add a 357 barrel or perhaps a 30-30 barrel to my older frame.

[trotterlg]

It doesn't seem they were too consistant with the fireing pin sizes.  I have a SB1 frame with a .075 pin and I have had SB1's with larger pins, guess it is just something you have to look at to see what is in your frame.  Larry

[cwlongshot]

With the higher pressure rounds, primer flow into the larger firing pin hole becomes a concern. Generally its better to choose a frame with a small firing pin for any centerfire round.

I just picked up a late 80" shotgun rec for my new 25/35. This is a 38,000 cup rated cartridge, same as the factory offered 30-30. The gun was 75$... I would just look for the same.  BUT, be conscious, you need to fit these and assume all liability in doing so. I feel safe because I know the caliber and I will be loading for it. Even if a factory round made it into the chamber, it would be safe. I wouldn't do this with a higher pressure cartridge and then rely on "loading it down". That is a recipe for disaster should the gun become beyond your control.

CW

[aromakr]

I realize that its not just the firing pin size, but also the alloy of the frame metal, however its not too difficult to bush the receiver and install a smaller firing pin.
Bob

[trotterlg]

Bushing the receiver woud be a real trick, they are not very thick in that area and the fireing pin goes in at an angle so it would be much more difficult than with a bolt gun.  Larry

[444Dan]

Assuming I have one with one of the larger firing pin holes would it safely handle any 357 or 30-30 load you would find in the loading manuals?

[mechanic]

Assuming I have one with one of the larger firing pin holes would it safely handle any 357 or 30-30 load you would find in the loading manuals?

Thats a subjective question.  It depends on a lot of things.  When I first started shooting my 357 on a shotgun receiver, I had perforated primers.  I went to small rifle primers.  When I load "hot" with heavy bullets, it perforated just a couple more.  I decided just to fit the barrel to my 243 SB2 frame and not have to worry about it.  I have shot a lot, (150 or so), with only a couple perforations with the SB1, but I decided it was not worth a risk.

Just me, you make your own decision.

[carbineman]

Assuming I have one with one of the larger firing pin holes would it safely handle any 357 or 30-30 load you would find in the loading manuals?

The Hodgdon #26 manual lists the propellants from several companies along with the pressure for these rounds. This is the book that we use to stay within what we consider the right pressures for the 30-30 Toppers we load for. The lighter weight bullets like the 130 grain Hornady or the 130 grain Barnes X have shown no pressure signs with load data published in that manual. We mainly use ball type propellants and Remington 9 1/2M primers.
As Always Start Low and Work Up as your particular barrel and chamber along with your components could be different than anyone elses.

[aromakr]

Another alternative would be going to a real hard cup primer. CCI makes a NATO spec primer CCI #34 that has a real hard cup. I had a problem with a Martini Cadet chambered for a 218 Mashburn bee. the primer cup would flow into the firing pin hole in some the hotter loads, so the block would not fall. The small NATO primer CCI #41 solved the problem.
Bob