Back bored shotguns

[Falconflyer]

Increasing the bore diameter is one of the most effective ways of reducing recoil while not reducing payload or velocity. It's right up there with lengthening the forcing cones and choke tubes, that's why a lot of manufacturers have done all three.

 

[warzaw]

Recoil is about physics' payload weight and weight of powder charge are the only things that change or reduce physical recoil all other mods only change felt recoil by spreading it out over a time frame. Never got to love over bore shotguns and I have owned a few.

 

[Falconflyer]

Over bore barrels, lengthened forcing cones and lengthened choke tubes reduce the pressure by spreading it over a longer period of time in the same way that a gas operated shotgun lengthens the recoil impulse for less perceived recoil so yes, the recoil is the same but spread out over a longer time period.

 

[Ashcroft]

Having had and extensively used many shotguns, some overbored, some not, I can’t honestly say that I can attribute differences in felt recoil due to this factor alone. A good test would be to shoot a gun that has two different barrels, one backbored, one standard bore, if several people agree that they can feel the difference in a blind test, then there is something. I’m sure if such a test result was fact various shotgun manufacturers would be jumping at using this information in their advertising and standard bore barrels would cease to be manufactured. We normally use different guns to judge something like this which introduces too many variables. Personally, fit makes a difference in recoil to me, bore size doesn’t.

 

[SHELL SHUCKER]

Over bore barrels, lengthened forcing cones and lengthened choke tubes reduce the pressure by spreading it over a longer period of time in the same way that a gas operated shotgun lengthens the recoil impulse for less perceived recoil so yes, the recoil is the same but spread out over a longer time period.

That's my findings in a 12 ga as well. My Mossy 835 trap gun threw the most consistent patterns for me than any shotgun I've owned. That said, I did lengthen the forcing cone on mine & flex-honed the bore along with adding a Carlson's extended .727 choke tube. Cheapo Federal field & range 2 3/4" shells w/ 1 1/8 oz
loads got me plenty of goodies at the prize shoots.

 

[Brutus]

You have not patterned a 10ga then. I own both and the 10ga hands down over a back bored 12ga any day of the week

I have a 10 gauge Parkhurst that sadly demised Nik Mackinson put back on face, rebrowned the outer and internal honed the barrels.
Patterns lead #4 like nothing else in this world.

 

[Brutus]

I agree with the bps 10ga ruling with bigger shot. I also agree that Mossberg got the 935 right as they do pattern well with bigger heavier loads even slightly better than my a400. The Beretta does better with smaller shot and lighter loads

A side note on black cloud in 10ga. Maybe I have defective loads but it is the tightest shooting shell I've ever fired. The shot cup just doesn't pull away. At 25 yards it's like a slug. Great for long shots and water swatting. The new flex wad makes the black cloud perform like it's intended. Spread out to help those who basically missed. I prefer a dense pattern as my misses are in front or behind rarely over or under so sending pellets out in those directions seems like a waste to me

I haven't found an exact coupling of guns where one is over bored and one isn't to compare recoil feel but if constricting the choke can increase recoil feel I'd like to believe a bigger bore would reduce recoil

Four years ago I experimented with Prairie Storm shotshells. I too found them to pattern very tight.

But I had a solution. Run them in mod/IC barrels of over & under. Superb longer range sharptail medicine when one breaks out if boreal forest onto farmers field.

I understand Prairie Storm is a half and half matrix of Black Cloud and nickel plated(?) shot.

 

[stubblejumper]

Four years ago I experimented with Prairie Storm shotshells. I too found them to pattern very tight.

But I had a solution. Run them in mod/IC barrels of over & under. Superb longer range sharptail medicine when one breaks out if boreal forest onto farmers field.

I understand Prairie Storm is a half and half matrix of Black Cloud and nickel plated(?) shot.

I have never seen upland birds shredded as bad as those shot inside of 25 yards or so with Prairie Storm.

 

[Falconflyer]

Having had and extensively used many shotguns, some overbored, some not, I can’t honestly say that I can attribute differences in felt recoil due to this factor alone. A good test would be to shoot a gun that has two different barrels, one backbored, one standard bore, if several people agree that they can feel the difference in a blind test, then there is something. I’m sure if such a test result was fact various shotgun manufacturers would be jumping at using this information in their advertising and standard bore barrels would cease to be manufactured. We normally use different guns to judge something like this which introduces too many variables. Personally, fit makes a difference in recoil to me, bore size doesn’t.

The reality is that the reduction in felt recoil with overbored barrels is very slight and probably not perceptible to most people. It's mainly just a minor side effect from the quest for better patterns and in that regard I think back boring needs to be paired with longer forcing cones and longer chokes tubes for the full effect.

 

[1963beretta]

The Mossberg 935/835 don't have forcing cones and the factory flush mount chokes are about about three inches long. My Kicks High Flyer choke adds about another inch and a half. Really nice combo.

As for recoil….it is what it is. More recoil is felt with the 935 then with my Browning Silver using the same loads. I agree with the previous comment that less recoil is felt on a proper fitting gun…more so then a gun with an over bored barrel that isnt well fitted

 

[Westward1]

Having had and extensively used many shotguns, some overbored, some not, I can’t honestly say that I can attribute differences in felt recoil due to this factor alone. A good test would be to shoot a gun that has two different barrels, one backbored, one standard bore, if several people agree that they can feel the difference in a blind test, then there is something. I’m sure if such a test result was fact various shotgun manufacturers would be jumping at using this information in their advertising and standard bore barrels would cease to be manufactured. We normally use different guns to judge something like this which introduces too many variables. Personally, fit makes a difference in recoil to me, bore size doesn’t.

My experience as well.

 

[Falconflyer]

The Mossberg 935/835 don't have forcing cones and the factory flush mount chokes are about about three inches long. My Kicks High Flyer choke adds about another inch and a half. Really nice combo.

As for recoil….it is what it is. More recoil is felt with the 935 then with my Browning Silver using the same loads. I agree with the previous comment that less recoil is felt on a proper fitting gun…more so then a gun with an over bored barrel that isnt well fitted

I completely agree with that. A well fitted gun is your best bet for reduced felt recoil, after that it’s reduced payloads and velocity followed by lesser modifications such as back bored barrels and pixie dust. Having said that, there is merit regardless of how small, to over bore, lengthened forcing cone and lengthened choke tubes but these are small things and there’s only so much that can be done.

 

[Brutus]

I have never seen upland birds shredded as bad as those shot inside of 25 yards or so with Prairie Storm.

I only used them in open grain fields edges.
Hammered twitchy sharptails 30+ yards, 20 gauge O/U with the more open chokes.

 

[Hunter7]

Understand but know 100% the 835 doesn't match the 10ga tried and owned that MULE

I have a BPS 10 gauge and nothing else I ever had would drop Canada geese like the big ten. If you can’t shoot worth crap it won’t help you much but if you hit them lookout. Especially back in the days of leadshot. The Federal premium 2 1/4 oz lead BB loads were devastating.