29 February 2008, 08:52
kududeSetting the Head Space on 10/22: Incredible!
I had done most of the big things to increase accuracy of my 10/22's short of buying a VQ barrel and Kidd trigger. I was getting groups with one rifle that were consistently about .25", but suffered the occasional aberration. After reading a lot over at Rim Fire Central, I felt that my firing pin needed to be pinned.
The theory, for those of you who may be new to rim fire super guns, flyers are caused by ignition variances, and the floating pin in the 10/22 lets the pin drift up and you get un-uniform primer strikes which equal flyers.
I sent the bolt off to CPC, a sponsor over there at RFC, with a check for $58 for the work and shipping and in two weeks got back a totally tuned bolt. It is a thing of beauty, with the side you see jeweled. The firing pin is pinned in place and can only go right where theory says it must. The pin is also "narrowed" so it hits with more energy.
Results: At 25yds, I fired four, five groups today in the manner of the 1/4inch club over at RFC. They fire four rounds, measure the diameter of each with a micrometer, add them and average them. They then do the same with the five shot groups and subtract the average "hole" size from the side to side measurement of the groups, and then average the size of the four groups. My groups were .036, .214, .098, and .122 inch; and the average was .118". Ammo used was SK Standard. Needless to say, I was very pleased.
I am sending the bolt to my other 10/22 off tomorrow for the "bolt job." I can recommend this to anyone seeking to wring the most out of their .22lr. With ammo going up and Wolf and SK selling at ridiculous prices, this may let me use one of the less expensive brands for practice and reserve the good stuff for competitions. Kudude
29 February 2008, 16:21
DMBRandy at CPC does excellent work, and is a man of his word. I support him any way I can. He has done bolts for me too, and accuracy is improved.
Don
01 March 2008, 06:22
LeadlobberThanks for the report I have wondered about this 'bolt job' for some time.
01 March 2008, 08:47
kududequote:
Originally posted by kudude:
I had done most of the big things to increase accuracy of my 10/22's short of buying a VQ barrel and Kidd trigger. I was getting groups with one rifle that were consistently about .25", but suffered the occasional aberration. After reading a lot over at Rim Fire Central, I felt that my firing pin needed to be pinned.
The theory, for those of you who may be new to rim fire super guns, flyers are caused by ignition variances, and the floating pin in the 10/22 lets the pin drift up and you get un-uniform primer strikes which equal flyers.
I sent the bolt off to CPC, a sponsor over there at RFC, with a check for $58 for the work and shipping and in two weeks got back a totally tuned bolt. It is a thing of beauty, with the side you see jeweled. The firing pin is pinned in place and can only go right where theory says it must. The pin is also "narrowed" so it hits with more energy.
Results: At 25yds, I fired four, five groups today in the manner of the 1/4inch club over at RFC. They fire four rounds, measure the diameter of each with a micrometer, add them and average them. They then do the same with the five shot groups and subtract the average "hole" size from the side to side measurement of the groups, and then average the size of the four groups. My groups were .036, .214, .098, and .122 inch; and the average was .118". Ammo used was SK Standard. Needless to say, I was very pleased.
I am sending the bolt to my other 10/22 off tomorrow for the "bolt job." I can recommend this to anyone seeking to wring the most out of their .22lr. With ammo going up and Wolf and SK selling at ridiculous prices, this may let me use one of the less expensive brands for practice and reserve the good stuff for competitions. Kudude
PS: Someone pointed out the slightly oversized .22lr holes and I noted their lateral elongation. This was caused by shooting at an angle from the bench next to the 25yd pitch in order to see the 50 and 100 yd pitches. k-d