Custom Barrel Question

[308cal]

Can a contoured blank, normally used for a bolt gun, be re contoured and finished for an AR-15 barrel?

Reason I ask, is I have a .270 blank, just slightly larger than a #4, and was wondering if I could have an AR barrel built out of it, for a .277 Wolverine?

 

[Kansaswoodguy]

Might try this question on a gun smithing thread. I don't have any idea I just shoot em

 

[budlight]

I'm a somewhat competent machinist with a vert mill and 6 foot lathe. Just take a look at an AR-15 barrel. there are some very difficult machining processes. you have a gas port, the index pin to the upper receiver, and how in the heck can you duplicate the bolt locking lugs without some specialized cnc machine?


Oh I forgot buying a 277-45 reamer and go no go guage

So IMO just buy a barrel

 

[wwbrown]

I'm a somewhat competent machinist with a vert mill and 6 foot lathe. Just take a look at an AR-15 barrel. there are some very difficult machining processes. you have a gas port, the index pin to the upper receiver, and how in the heck can you duplicate the bolt locking lugs without some specialized cnc machine?


Oh I forgot buying a 277-45 reamer and go no go guage

So IMO just buy a barrel

Let me try and help out, you will need to buy a barrel extension, reamer and headspace gauge(s), profile and thread the barrel, then chamber, probably not a first lathe project but doable.

 

[308cal]

Oh, I wasn't referring to myself doing the metal work, I was just wondering if it could be done.

I've had 2 other individuals on another forum tell me it would be no issue at all to complete. However they both build barrels and guns for a living.

 

[screech]

Do able yes. Time consuming for sure on a manual lathe. Honestly it wouldn't be even that hard to do but what would take 5 minutes of CNc time to contour and cut threads and feed ramp would take hours on a manual lathe. Or at least it would for me. Maybe a big gear head lathe could do it faster but the problem will be trying to contour a barrel without a moveable/programmable steady rest the barrel is going to want to chatter real bad if you're taking heavy cuts. Who ever made your barrel may be willing to recontour it possibly. Not sure though.

 

[wwbrown]

Whenever I have done AR barrels I have always used barrel extensions that have the feed ramp already cut, did not ow you could but them any other way. Screech where did you buy your barrel extensions without the feed ramp and was there a sound reason to buy them that way.

Yes, contouring them is a pain eased a bit by the fact that the contours are usually straight. Yes a CNC could do them in minutes but sometimes we do things in a hobby setting that do not make sense from a time standpoint, sometimes the ability to say I did that myself is enough reward in itself.

I keep some Green Mountain uncontoured blanks on the shelf so I can experiment with different configurations AR's, the GM blanks are less than $100 and have pretty good accuracy. The reason some of us have a lathe is to be able to tinker and do one-offs and not as a business and the GM blanks align quite nicely with this type of hobby.