6BR/22BR Lapua: Max Unsupported Case?

[Rubicon Prec.]

I have't worked with these cartridges before because they just aren't that common in my game. This is probably a very obvious thing for you all.

I thought I read somewhere years ago that the 6BR and 22BR Lapua case heads were shorter than most others and could be dangerous with too large chamfer at the chamber end. This is going to be a repeater so I'd like to make sure it feeds decently from a mag so I'd like to get the largest chamfer that is safe. Would .160"-.170" of unsupported case be safe with this cartridge? I don't have brass on hand to measure the case head thickness.

 

[NezRongero]

You can see from this how thick/thin the web is relative to the typical neck wall for comparison.

 

[jackie schmidt]

I have't worked with these cartridges before because they just aren't that common in my game. This is probably a very obvious thing for you all.

I thought I read somewhere years ago that the 6BR and 22BR Lapua case heads were shorter than most others and could be dangerous with too large chamfer at the chamber end. This is going to be a repeater so I'd like to make sure it feeds decently from a mag so I'd like to get the largest chamfer that is safe. Would .160"-.170" of unsupported case be safe with this cartridge? I don't have brass on hand to measure the case head thickness.

To add to what Nez posted, here is the actual thickness of the web of a Lapua 6BR case.

http://benchrest.com/attachment.php?attachmentid=21395&stc=1&d=1535138461

With 6PPC and 6BR cases, I just break about a .010 bevel, especially with a Stiller drop port. Of course, these are solid bottom Benchrest Rifles where the case doesn't depend on the chamfer.

 

[Rubicon Prec.]

Excellent info. Thanks.

 

[Rubicon Prec.]

Reamer came in so I finally got around to cutting this. To be safe, in went with a .020”/60* chamfer, for a maximum of .155” of unsupooeted case. If they can safely be built on an action with a Remington style recessed bolt nose, this is more than safe. I’ve been doing a .040”/60* for others common cases such as a couple 284 Shehanes picture day behind.