Cincinnati Slim
Member
Howdy All,
I got my little Franklin Arsenal digital caliper from Midway and some soft lead balls and did some measuring. I have two Remmies and two Colt clones, all from Pietta. I "slugged" the bores and measured the resulting deformed balls. All four guns were very close in measurement; bore groove diameter was 0.448. I then measured the chambers of the cylinders. Again all were very close in size so I guess it is true about Pietta's machine tools being precise new computer controlled stuff. Chamber bores measured 0.444-0.445...too small for optimum accuracy. I keep reading that chambers should be bore groove size or up to 0.002 LARGER for best results. These were 0.004 TOO SMALL !
So I ordered a size 2/A adjustable hand reamer from www.HermansCentral.com
Size range is from 7/16 (0.4375) to 15/32 (0.46875) so my "ideal" size of 0.448-0.450 was covered. The reamer was about twenty bucks. I took a grinder and shortened the threaded end of the reamer about a 1/4 inch so it could go far enough into the chambers. I used plenty of tap cutting oil and reamed out the cylinder's chambers to just over 0.448
My "slugged" balls now fit neatly into the chambers. I'll be heading to the range in the next few days to see if my groups are any better now !
Happy Trails
Slim
I got my little Franklin Arsenal digital caliper from Midway and some soft lead balls and did some measuring. I have two Remmies and two Colt clones, all from Pietta. I "slugged" the bores and measured the resulting deformed balls. All four guns were very close in measurement; bore groove diameter was 0.448. I then measured the chambers of the cylinders. Again all were very close in size so I guess it is true about Pietta's machine tools being precise new computer controlled stuff. Chamber bores measured 0.444-0.445...too small for optimum accuracy. I keep reading that chambers should be bore groove size or up to 0.002 LARGER for best results. These were 0.004 TOO SMALL !
So I ordered a size 2/A adjustable hand reamer from www.HermansCentral.com
Size range is from 7/16 (0.4375) to 15/32 (0.46875) so my "ideal" size of 0.448-0.450 was covered. The reamer was about twenty bucks. I took a grinder and shortened the threaded end of the reamer about a 1/4 inch so it could go far enough into the chambers. I used plenty of tap cutting oil and reamed out the cylinder's chambers to just over 0.448
My "slugged" balls now fit neatly into the chambers. I'll be heading to the range in the next few days to see if my groups are any better now !
Happy Trails
Slim