Info on Proof research blanks?

[DJ Fergus]

Can someone tell me what purpose the raised radius around the bore of the breech end and turned down muzzle end of the proof research serve on the non carbon fiber/all steel barrel blanks If any purpose at all. Is it possible these surfaces would be considered trued to the bore?

 

[Bob Wright]

Send a picture. I can only offer a guess that these may be a part of the manufacturing process to aid in their rifling or lapping process, letting the end user crown the muzzle and chamber ream which eliminates it. Just a wild, wild guess....

 

[Rhovee]

It's common for some barrel companies to send blanks that are 2" longer than finished.

 

[lancetkenyon]

These? Nothing. They get cut and turned off.

 

[DJ Fergus]

Ok, is there any purpose for the muzzle being turned down?

 

[lancetkenyon]

None. Even says it must be cut off.

 

[L.Sherm]

They want you to cut that off to get any possibility of a belled mouth at the end of the muzzle. Even companys that dont do that want you to cut an 1" off when you crown

 

[DJ Fergus]

Ok, I knew that the muzzle end gets at least an inch off of it regardless of what brand & that after the chamber is cut the raised radius will be gone. Just curious about why proofs are the only blanks I've saw like this. I suppose the raised radius may possibly be some sort of aid during the lapping and/or manufacturing process.

 

[adam32]

Laziness?

 

[sable tireur]

Can someone tell me what purpose the raised radius around the bore of the breech end and turned down muzzle end of the proof research serve on the non carbon fiber/all steel barrel blanks If any purpose at all.

Those two features are from turning the OD of the barrel and from winding the carbon fiber onto the contoured blank. The feature at the breech end is from holding the barrel on a center and they face off the breech. The spud on the muzzle end is used for spinning the barrel while adding the carbon fiber.

 

[KyCarl]

Extra is tooling material. How could you hold and machine it if every thing was
finished to exact size?

 

[adam32]

Extra is tooling material. How could you hold and machine it if every thing was
finished to exact size?

You can't...but you can at least smooth everything up like everyone else does...and for less $$ per barrel. Like I said...LAZINESS.

 

[L.Sherm]

Live center and dog drive one the chuck side. Everything is turned off the center of the bore they are not drilled perfectly center from one end to the other when drilled.

 

[lancetkenyon]

OP said "on the non-carbon fiber/all steel barrels".
I assume Proof makes all the blanks the same, then turns down the CF barrels to a lighter profile. Before wrapping them.