You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
overbore barrel
- Thread starter publius
- Start date
BigD_in_FL
Moderator
IIRC, Beretta does, at least on some models
You do not have a 10 gauge barrel on your Mossberg unless you have had some extensive gunsmithing done. Overbore or backbore usually refers to barrels that have an inside diameter larger than the standard for that gauge. There have been, and are, factory examples produced by several manufacturers. Many gunsmiths offer the service. The merits are usually a source of debate. I got slightly increased velocities with some loads, and a marginal increase in pattern efficiency with several barrels I had backbored.
If you get too big, most plastic wads I have seen start running in to sealing issues. If you have too little or the wrong powder, you can lose a little velocity.
If you get too big, most plastic wads I have seen start running in to sealing issues. If you have too little or the wrong powder, you can lose a little velocity.
Dreaming100Straight
New member
I do not know how current this is but per Mossberg
and see this:
Still, I am not sure that is a true 10 gauge bore as I believe a 10 gauge is a .779" bore diameter. but what is .004"?
* * * 935™ and 835® 12-gauge barrels are overbored to 10-gauge dimensions
and see this:
12-GAUGE MUZZLE COMPARISON: (.775) Overbored 12-gauge 835 Ulti-Mag barrel (left) -vs- our standard (.731) 12-gauge barrel (both barrels are shown with flush-fitting choke tubes installed).
Still, I am not sure that is a true 10 gauge bore as I believe a 10 gauge is a .779" bore diameter. but what is .004"?
Yes, the bore diameter is nominally a 10 gauge, but it is an overbored 12 gauge barrel, not a 10 gauge barrel, was my point. Back when I was experimenting I found I couldn't get good wad sealing over about .742". "Wasted" 2 barrels in the process. I was not dealing with 3-1/2". I have not heard any bad reports on the Mossbergs, so I wonder if the manufacturers have modified the wads, or if some wads do better than others.
The early 3-1/2" 12 gauge BPSs were built on the 10 gauge receiver, and a guy who had a 12 borrowed my 10 and said the barrels would swap. I don't know if the gun would have functioned or not. I do know that was a heavy 12 gauge if it did.
The early 3-1/2" 12 gauge BPSs were built on the 10 gauge receiver, and a guy who had a 12 borrowed my 10 and said the barrels would swap. I don't know if the gun would have functioned or not. I do know that was a heavy 12 gauge if it did.