Gunsmithing Flat Bolt Nose or Recessed? Pro's? Con's?

[mildot326]

Hey troops, I'm looking for info on either and some "end user" experience? & I'm not looking to decide which is better etc. Thanks

 

[Supersubes]

I’m confused by your question. Never heard of bolt faces called flat or recessed. Do you mean the breech end of the barrel, as in savage shaped breech vs a Remington style?

 

[mildot326]

So with respect to the option for a Defiance bolt, they have a few , I supposed the "recessed" would be the "Remington" style.

 

[Supersubes]

I see it now. I think the only difference would be how the two control gas in the case of a rupture or blown primer(edge to the recessed). Even then, the installer controls the tolerances which determines the effectiveness of the gas control. I’ve never played with a flat defiance bolt/receiver, so not sure if they take other gas control measures. In the case of a savage or bighorn, they use a bolt lug shaped block which remains in the raceway when the bolt is in battery, to cork things up.

 

[spife7980]

Some claim the flat gives more meat to the bolt making it stronger, some say the recessed lets you put more of it in the barrel which in turn makes the system stronger (Remington’s three rings). Personally I don’t think it makes much difference at all in a modern action that’s well designed. Maybe the flat might be more friendly in feeding as the lug is flush with the end and maybe the recessed could be more particular on feeding by having that extra lip that could catch something that’s too low? In either case the actual design and implementation is above my pay grade but hopefully one of the good action designers or smiths could chime in!

I thought defiance used to have a section explaining it all in depth but it looks like it’s just the pictures now.