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Bat M Bolt nose cone depth.. same on all bolts?

I run this dimension tighter than many. The way I see it is there is no downside to it as long as the two don't come into contact with a sized and loaded round. But when shtf, it's a metering system that has a lot of control over what can come flying at your eyeballs and other parts I'm still fond of. I've never seen a .010 clearance function spilled powder better than .003-.005 yet. The kernels are bigger than either, by quite a bit. Yes, I've dumped the lugss full, just like most of us will do, sooner or later. I see no value in terms of reliability or any other purpose to running this dimension "loose." It's a safety dimension and IMO, should be treated as such...even with a well supported case head. Just my two cents but again...what down side is there?
 
I aim for 5 thou. I got an old barrel from a buddy that I cut down and will be a fire form barrel. I did everything but the cone. I can chuck it up later when I get the bolt and deal with the cone
 
I aim for 5 thou. I got an old barrel from a buddy that I cut down and will be a fire form barrel. I did everything but the cone. I can chuck it up later when I get the bolt and deal with the cone
Remember my solder crush trick? Did you ever get the pma barrel mic to measure the cones?
 
Remember my solder crush trick? Did you ever get the pma barrel mic to measure the cones?
I'll make a few tools like my ez chekrs to measure cone depth with soon. Just haven't decided if I want to do it the cheap way or a little more expensive route. Ultimately, one is as good as the other from what I can tell after doing a couple of different styles.. and the ez chekr will work well, as is, with a 5/8 flat indicator tip and some care in using it. If I do another model for this specific purpose, it'll be to make it pretty much foolproof and if people want it or not.
 
I mis-stated my original question. I was looking for the cone depth/size. Mag bolt needs a deeper/larger cone.

I don't follow. They both have the same spec and print. That said, I happen to have a BAT M with both standard and magnum bolts. I also happen to have a barrel stub cut for an M. Is there something I can measure that can help?
 
Turns out so I AM missing something. Bruce says cones start at the corner of each bolt face, so each bolt face diameter has a difference cone position. Makes sense when I think about it.......
 
Bruce has a cad drawing laying this out i bet he will share with you
I've got these for Kelbly, but not Bat. Great to have.

AMWts8CQDoNlnwtJhJmMXcKymf6NOgoX9dRrqyBg1jpKYBUzHAEn3NESycIWfSaB61LiNm1lAN2yCH3MFPF6NRcc6nzO0izZk5UbDiKJBI5kymjqyzblIgT40uzsLdp4wH8ZPnKQNEwFsEaxfUmiOWkg3vykNA=w1194-h708-no


AMWts8BGi9F3uGY-nc9sw6z8g5wbu-_RYRm0IN3YEeECEAwgDyfhg6VfDYW2wXxNG0h8h3aEJjP-EVVn4BXP4mnnb-kf1QBSSMKaKVMxP3kHXpDfo6nO0LE85C2LK3Y2muCNAxCobVo9OpqZfe_trh_eRl8vsw=w1055-h791-no
 
I recently purchased a mag bolt for M action for a .284 to 300 wsm switch barrel.

Mag bolt will not close with my 284 barrel. The mag bolt cone was contacting the barrel. While the standard bolt cone has .007 clearance between bolt and barrel.

So in my experience, the mag barrel does need a deeper relief (shorter dimension between shoulder and 25° cut).
 

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