Why Deep Chamfer on Barrel Chamber?

[RGRobinett]

I use a rounded tip micrometer as the solder tends to curl.

Nice, Gene. I'm just a do-it-yourslf guy, but to check bolt-nose clearance, have always used lead-core 'squirts' from my bullet core-forming dies. I make clearance between 0.007 & 0.010" - I see nothing to gain with tighter here. Glad to see I'm not alone . . . RG

 

[gunsandgunsmithing]

The Stiller Drop Ports were extremely critical in the nose to barrel clearance On the BR and PPC chambers. They have a Remington Style bolt nose and extractor, and with the case chambered, the forward end of the extractor groove was actually Inside the bolt nose a tad.

it all worked, you just had to hold the dimensions within .005 or so.

Yes, I think that's a down side to a remington style extractor, that it takes a pretty deep bolt face to use it. Of course, the remington, the bolt nose goes well into the counterbore...three rings of steel design is very good. Well engineered, but it still leaves more unsupported case than most actions because of that style of extractor.

 

[Walt Krafft]

That print is how I do them for Tubb 2000 rifles.

 

[gunsandgunsmithing]

That print is how I do them for Tubb 2000 rifles.

Honestly, I'm not familiar with the t2000 tenon and design. But following the mfgs print is never a bad idea. I think altering it much is making someone spread eagle for a lawsuit if something bad happened.

 

[dnellans]

I'm with you. I'm guessing he's done something like the pic I'm about to post. Stiller did this on some of their actions. But the bolt nose had a small flat on the end instead of going to a full cone nose and it used a snap in remington style of extractor so that the full nose diameter wasn't compromised anywhere.

I'm not picturing how it can reduce unsupported case unless done pretty much just like Stiller did his, with the flat nose on the end of the bolt. He also used a very shallow cone angle, fwiw.

Sorry for pic quality but the original is even worse. Lol!

Interesting - I’ve never come across a hybrid coned nose like that. I love that it says “Very important info” and actually warns that increasing the nose clearance will result in unsupported case above the web!

 

[Dusty Stevens]

Interesting - I’ve never come across a hybrid coned nose like that. I love that it says “Very important info” and actually warns that increasing the nose clearance will result in unsupported case above the web!

Its very important because if you didnt follow that print not only did it lose support, it didnt work

 

[ChrisNZ]

Bubba's enthusiasm clearly knows no bounds looking at those examples..