Picked up my new browning A bolt M 1000, 300 WM,scoped it and headed out to the farm. Found out when I got there only 1 out of 10 cartridges would fit in the chamber, had some fun and came home. I went straight to my bench and started measureing things. Found out the chamber is .513 like it is supposed to be, (just in front of the belt) because any case that measured .5136 wouldn't fit. Anyone know which of the companys makes their brass the right size because Rem &Win sure doesn't . Some cases were up to .516. I think I'll send the gun back for a little chamber polishing but I don't want to 'loosen' it up to much. Thanks for any help/ideas.
FAT brass
- Thread starter bradanita
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royinidaho
Well-Known Member
That is a very infrequent problem......
I wouldn't take it anywhere except to where it was purchased.
On a new rifle u shouldn't be exposed to any further costs......
Also, check reamer size for the Win Mag. I think the .513 would be for the cartridge and a little larger for the chamber. I'm no expert on this but check it out.
Did some searching......
Reamer size may not be able to be determined as every one is ground slightly different. Factory reamers may (or may not?) get reground as they dull. If so the chambers would get smaller as the reamer ages......
The belted case head spaces on the belt (at least for new brass) and should have no problem chambering a new factory case.
Is the case binding at the head, just ahead of the belt, as indicated by difficult extraction and scratch marks or hitting the shoulder too soon?
I wouldn't take it anywhere except to where it was purchased.
On a new rifle u shouldn't be exposed to any further costs......
Also, check reamer size for the Win Mag. I think the .513 would be for the cartridge and a little larger for the chamber. I'm no expert on this but check it out.
Did some searching......
Reamer size may not be able to be determined as every one is ground slightly different. Factory reamers may (or may not?) get reground as they dull. If so the chambers would get smaller as the reamer ages......
The belted case head spaces on the belt (at least for new brass) and should have no problem chambering a new factory case.
Is the case binding at the head, just ahead of the belt, as indicated by difficult extraction and scratch marks or hitting the shoulder too soon?
Moman
Well-Known Member
Bradanita, I'll give you the measurements from my Rem 700. I use Norma 300 WM brass and just ahead of the belt, new brass measures .509: The fired brass from my chamber measures .514: Resized brass from my Forster FL die measures .513: Some were just a hair under, but I can only measure to the thousandth, some were probably .5127 with the eyeometer.
Is this factory ammo or reloads? If reloads, can you put the brass through your die to bump this area back a little?
Is this factory ammo or reloads? If reloads, can you put the brass through your die to bump this area back a little?
MSU Marksman
Well-Known Member
I think the biggest quesiton is, are you Full Length sizing the brass first? Are you sure that your FL die is set up for FL sizing and not just neck sizing?
Hey guys thanks. After a little more investigateing I found a couple of burr's in the chamber, a small one 3/4" from the shoulder, and one big one at the belt, I forced a oversized case into the chamber (.514) and it came out hard and looked like a miniature snow plow had scraped the brass about 1/8" into a little pile. Seeing as how this is a brand new gun it went back to Browning. My brass is a mix of FL sized and new
royinidaho
Well-Known Member
ah ha! the sweet taste of success...
