So, I recently got a new .25 cal barrel and a chamber reamer to shoot the new, long, 131 gr Blackjacks. I Bought the Krieger barrel and chamber reamer from Blackjack. Had the barrel chambered and put on my switch barrel receiver by my smith. Everything has gone well and the rifle shoots quite well for me. I'm on my 3rd reloading of my brass and I have begun to have some concerns.
I had a few case separations (4-6) and immediately thought I goofed up on my headspace. I have also noted some problems with chambering a FL sized case in the chamber. Some absolutely do not want to let the bolt close on the loaded round.
I have re-checked the shoulder bump twice and am right on target with an average .002 shoulder bump. Some are .001, some are just over .002, but historically I have seen this and attributed it to the differences in hardness in individual pieces of brass. I'm averaging .002 for the vast majority of cases.
I do anneal the necks of my brass.
I got to measuring my cases today and found that the web is rather small after firing. The cartridge is a 25-284. I'm using 6.5 Lapua brass necked down to 25 cal. and I am skim turning the necks for uniformity and to avoid a donut forming, Specs for both the Winchester and Norma 284 call for a case head diameter of .500. My Fired case heads measure .495-.496. Most run .495.
When I run my brass through the Type S FL neck die, the die only reduces the brass down to .495, and this only if I run the brass through three (3) strokes of the press in and out of the die. Obviously, the brass is still tight after I resize it.
I am certainly not a gunsmith, so I thought I would ask the braintrust here for your opinions.
I think I have decided that my chamber is quite tight. I bought a reamer to have this chamber done, so it has only been used one time on one barrel. Don't know if this makes any difference.
My thinking is that if I could somehow polish the chamber walls, I might get rid of some of the tightness and maybe loaded rounds would chamber easier - or at least with a lot less effort. Sometimes I have to beat the bolt down with my fist to get a round to chamber. Obviously, this isn't right.
I am also wondering if a very tight chamber base would explain the case separations I have experienced.
Is it possible that the chamber is gripping the brass too firmly and only allowing the forward portion of the brass to move when pressurized? I don't know. Just my conjecture, right or wrong. None of the cases have completely separated, but the imminent case head separation ring became visible outside the case and I verified its presence with a sharp probe inside the case body.
So what do you guys think? Am I on the right track, and if so, where/how do I proceed from here. Remember - I'm familiar with rifles, but I'm not a gunsmith!
Thanks in advance for all your good answers.
George
I had a few case separations (4-6) and immediately thought I goofed up on my headspace. I have also noted some problems with chambering a FL sized case in the chamber. Some absolutely do not want to let the bolt close on the loaded round.
I have re-checked the shoulder bump twice and am right on target with an average .002 shoulder bump. Some are .001, some are just over .002, but historically I have seen this and attributed it to the differences in hardness in individual pieces of brass. I'm averaging .002 for the vast majority of cases.
I do anneal the necks of my brass.
I got to measuring my cases today and found that the web is rather small after firing. The cartridge is a 25-284. I'm using 6.5 Lapua brass necked down to 25 cal. and I am skim turning the necks for uniformity and to avoid a donut forming, Specs for both the Winchester and Norma 284 call for a case head diameter of .500. My Fired case heads measure .495-.496. Most run .495.
When I run my brass through the Type S FL neck die, the die only reduces the brass down to .495, and this only if I run the brass through three (3) strokes of the press in and out of the die. Obviously, the brass is still tight after I resize it.
I am certainly not a gunsmith, so I thought I would ask the braintrust here for your opinions.
I think I have decided that my chamber is quite tight. I bought a reamer to have this chamber done, so it has only been used one time on one barrel. Don't know if this makes any difference.
My thinking is that if I could somehow polish the chamber walls, I might get rid of some of the tightness and maybe loaded rounds would chamber easier - or at least with a lot less effort. Sometimes I have to beat the bolt down with my fist to get a round to chamber. Obviously, this isn't right.
I am also wondering if a very tight chamber base would explain the case separations I have experienced.
Is it possible that the chamber is gripping the brass too firmly and only allowing the forward portion of the brass to move when pressurized? I don't know. Just my conjecture, right or wrong. None of the cases have completely separated, but the imminent case head separation ring became visible outside the case and I verified its presence with a sharp probe inside the case body.
So what do you guys think? Am I on the right track, and if so, where/how do I proceed from here. Remember - I'm familiar with rifles, but I'm not a gunsmith!
Thanks in advance for all your good answers.
George
