Kirst 45 Colt Konverter Chamber Mouth Dia.

[philthephlier]

I just installed this cylinder on an 1858 Pietta Remington. The chamber mouths measure .446 in all five chambers. Did they miss the final reamer or is that correct? A.452 bullet will be .446 when it hits the forcing cone. Am I missing something?

 

[ClemBert]

According to the specs I have on the Pietta 1858 the measurement from land to land is .440 and the measurement for the groves is .450. This firearm has 6 lands and subsequently 6 grooves. Those groves are cut .005 deep (from the land to the bottom of the groove). According to your measurements the bullet is going to be forced down to .446 then it will be cut .003 on all sides by the lands. Meaning that the bullet will ride on the lands but will have a .002 clearance from touching the bottom of the grooves. Sounds to me like you are in business.

 

[philthephlier]

Bad Measuring on my part, Sorry.

I drove a freshly cast .453 bullet through one of the chambers and it exited at .452. Then I slugged the bore and my Pietta has 7 lands and grooves, lands about 1/2 the width of the grooves and thus very difficult to get an accurate read of the bore and groove diameters. But I think I'm home free, range tests to follow.