I would say it would be a questionable practice
with 2 inches sticking out.

Should the tubes expand ahead of the barrels they
would be difficult to remove.

In addition, the tubes are much more likely to be
damaged or bent as they are not protected by the carrier barrels.

I do not believe pressure is an issue but Murphy lives

Mike

ADDED: is the front end centering diameter inside the barrel
or out of the barrel?

Last edited by skeettx; 08/16/13 01:57 PM.
USAF RET 1971-95 [Linked Image from jpgbox.com]