Gunsmithing Barrel blank length reduction question

[cconn30]

I currently have numerous barrels on order. I have always ordered the barrels slightly over my desired finished length. As we all know, wait times are rather long.

This brings me to my question. If my desired finished length was 24in, and I found a 32in barrel blank in the appropriate twist and contour ready for immediate sale. Would cutting this 32in barrel back to 24in have a serious effect on barrel performance? I understand it would effect velocity and possibly accuracy. Also a waste of good gun steel.

My example: 1-8 twist 32in MTU contour blank cut down to 24in finished. Thanks in advance.

 

[RADcustom]

Re: Barrel blank length reduction question

Shouldn't hurt a thing.

 

[cconn30]

Re: Barrel blank length reduction question

Thanks for the response. That's what I figured, just needed a second opinion.

 

[Garyc]

Re: Barrel blank length reduction question

Performance, no it won't hurt that. However, you run the risk of having excessive runout between the bore and outside of the barrel. Barrel makers can't drill a perfectly straight hole, the bore always wanders somewhat. Barrel makers contour the barrel at the length specified so when the gunsmith chops off and inch or two the bore is still pretty close to zero runout. Chopping eight inches off of the barrel you might get lucky and have the bore in the center of the barrel, or it could be significantly off.

 

[cconn30]

Re: Barrel blank length reduction question

Thanks Gary. If I am understanding this correctly, it's the last few inches of the bore that have to be "completely straight", and cutting the barrel down an extreme amount could put me past that "completely straight" area and get into the wandering zone. Is this a common occurence for premium barrel makers like Kreiger and Bartlein?

I just saw this thread all ready started. Bore Curvature I guess that will answer most of my questions.

 

[justinbaker]

sorry to bump an older thread, but i was also wondering this same thing

im trying to source a medium palma contour barrel for the LRI group by and i have found a bartlein 31 inch blank

if i want to finish at 26, is this going to be too much to chop off? if so i may just go with a Rem varmint contour thats already at 26 inches

 

[lw8]

It will be fine. Just tell the smith to check it.

 

[walley2960]

Kreiger says good to go. The bore may be off as much as ten thou in relation to the outside diameter. If your smith indicates off the bore when doing the crown its not an issue.

 

[MikeeBooshay]

You are better off whacking a couple inches off each end. When the barrel is lapped, it is not easy to maintain the same internal diameter on the ends, when the lap is stopped and started.

To check this, use a set of reamer pilot bushings in tenths for the caliber in question. Find the bushing that fits snug, then remove 2 inches of barrel. Remeasure with bushings again, you'll see a small variation most of the time.

Don't have a set of reamer pilots? Then don't worry about whether the barrel blank is affected by how much you cut off. Having a straight reamer in the barrel is much more important.........

 

[x ring accuracy]

Buy it! You will have a great barrel!