Chambering Issue
- Thread starter ldpace
- Start date
Thanks for all the help. Finally worked it out. The brass was oversized by only 0.0005 just forward of the base/head. This was difficult for me to accurately measure. This area is supposed to be 0.471 on a 30 BR, I noticed that the .308 is supposed to be .470 at the same place, so I ran the cases through an Lee 308 FL sizing die with the decapping rod removed and it resized them enough to chamber without issue. My Redding Competition S FL neck bushing dies were not getting the FULL length resized. The previous chamber must have been slightly oversized in this area which created the problem. I have fire formed them and they rechamber fine even before resizing.
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CMaier
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F. Guffey
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F. Guffey
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You hit a wall; I like the part about ‘the double check’. I am unorthodox when it comes to measuring chambers. , I measure short chambers and I measure long chambers. I would not start on a chamber until I determined how far the reamer had to be advanced to complete (the chamber). Then there are head space gages. When making head space gages I never understood the infatuation with one head space gage. I like the idea of knowing how far I have to go, then there is that part about going too far, I want to know ‘by how far’.
Then there is the completed chamber with the bolt installed; the bolt makes the chamber a dark place and most difficult to see anything; that should not be a problem. All of my dies and presses have threads; threads allow me to adjust the die to, off or below the top of the shell holder. Most reloaders are fire formers; they chamber a round then pull the trigger and then become fire formers. I form first then fire.
Forming before firing is difficult if for no other reason there is a shortage of brass for reloaders that know what they are doing. I have long chamber; my long chambers are long from the shoulder to the bolt face. One chamber is .016” longer than a minimum length/full length sized case. To put it another way the chamber is .011” longer than a go-gage length chamber or .002” longer than a field reject length gage when the cage is measured from the shoulder to the head of the cage.
When forming cases for the long chamber I use 280 Remington cases. I adjust the die off the shell holder .014” then form the case and finish by full length sizing with the .014” gap between the shell holder and bottom of the die. The .014” give me the magic .002” clearance. Bump? More like wrecked it; I shortened the 280 case from the shoulder to the head of the case .037” and no the shoulder did not move.
My cases do not have head space because SAAMI does not designate head space for the case, the symbol for head space is absent on the case drawing. This does not lock me up or drive me to the curb. I use the length of the case from the shoulder to the case head to off set head space in the chamber from the shoulder of the chamber to the bolt face.
Chamber cast; that is another topic that has never been finished when discussed on a reloading forum.
F. Guffey