Am building a .45-70 Highwall from barstock for BPCR. About ready to make/fit a firing pin. Wondering about diameters of the firing pins in currently produced Highwalls . The old ones were about .125 dia. ..I imagine that new guns ALL come with smaller dia firing pins for smokeless powder.??

Not an expert by any means, but the high wall I recently got with a broken pin had the smaller diameter hole in the block.  A .07 RCBS decapping pin fit perfectly.

Jack

Have had some trouble with the .065" pins retracting on some actions. Special shaping makes them sharper than I like, although works. Probably not a problem with a Winchester. Been using .080-.085" pins lately that seem to work. Don't know of any new actions with the real fat pins.
Chuck

Chuckster wrote on Jul 30^th, 2013 at 10:47pm:

  Chuck, I usually make my centerfire pins .071 dia. Yeah I've had the smaller pins drag a bit on the primer when extracting in falling block actions. Larger pins with well rounded point would help with that.

There was a good reason for making the firing pin tips smaller and tighter fitting... they don't allow primer flow back or other bad things to happen as easily.  The key is to have that smaller pin fit with just enough clearance to move smoothly without the downside of having drag.  I'm sure you knew this, but you brought up the concept.  I may be wrong, but I am not aware of any modern builder using the larger firing pin on new builds, but there was a cottage industry to bush the larger ones down smaller... there must be a reason for that.  Just sayin'

Froggie

I for one would be interested as why that you might like to use the old 1/8" firing pin style. Once pressures get much above 25K, they are not very good to work with. They give lots of extra pressure to push the firing pin back into the hole, especially with pistol primers.

Frank

ALPHAWOLF45 wrote on Jul 31^st, 2013 at 1:03pm:


Alphawolf45;

     I gave you the answer to your question to the best of my knowledge and tried to explain why.  I'm sorry if you didn't get the answer you obviously wanted or if my tone offended you.  It was well intentioned.  Please remember that many of us also answer many questions in a somewhat generic manner so that other readers of the thread may benefit from the answers as well.   

     Maybe if you told us why you are so set on justifying the use of a large pin firing pin, it will make sense, but as I thought was being made clear, the larger firing pins in high walls and other guns of the day seemed to generate more problems than any benefit they might have brought.

Green Frog

I have not seen the larger firing pin on any of the modern rifles except a few of the Italian ones, and then not as big as 1/8". Most problems I see with firing pin size is when someone wants to convert an old rifle to 22 hornet.