Turkey gun bore diameter differences

[Tom007]

Wanted to get some thoughts on why gun makers use different diameters in the bores of their 12 gauge guns. I did some research on the popular 12 gauges and found the following:

Remington 870: .727
Mossberg 835: .775
Winchester 1300: .729
Benelli SBE: .725
Browning BPS:.726

As you can see, the Mossberg seems to have the largest factory bore diameter. Could this be a reason why the Mossbergs are known to shoot awesome patterns? If so, why wouldn't other manufacturers follow suit here? I welcome your thoughts.  Thanks....

[AppalachianHollers]

Winchester no longer makes the 1300; their current pump-action has a .740 bore (have to use Invector+ chokes).

Patterns great.


Sent from my iPhone using Tapatalk

[Tom007]

Thanks my friend...

[AppalachianHollers]

I wonder if the newest generation of BPS' also have a .740 bore, indicating that the Browning-Winchester brand has been persuaded by Mossberg's success with the radical overboring.
Only that they want hunter to be able to still shoot rifled slugs with some accuracy, an impossibility from what I understand with the  Mossberg 835.


Sent from my iPhone using Tapatalk

[Tom007]

Yes, makes sense. My 1300's, the older NWTF laminated ones hold a great pattern probably due to the larger bore? Maybe less shot deformation?

[bbcoach]

2 or 3 thousandths doesn't make a lot of difference.  To answer your question about the Mossy's, yes IMO the over bored barrel makes ALL the difference when it comes to the way they pattern. 

[Tom007]

Agreed, I am shocked the other companies do not over-bore their guns......thanks, be safe...

[Spurs Up]

Technically the ole Mossy 835 and 935 are overbored to 10 gauge diameter, not backbored. As another poster noted, you shouldn't shoot slugs through them. You can, I'm sure...

Theoretically over boring, and backboring too, should reduce pressures and recoil (835 owners can laugh now).  If you buy into that, with everything else being equal, physics suggest a loss of velocity. I've heard some waterfowlers who are into handloading add that you may not get a good seal between the wad petals and the larger diameter barrel as the load travels down the overbored barrel. With steel or HTL shot, that might lead to scoring of the barrel and maybe contribute to loss of velocity. Other than that

[Tom007]

Great info, sorry, you are correct, I meant over-bored. Thanks for catching that. Be safe......

[ShootingABN!]

would Mossberg have a patent on the overbore for 12 gauge? I remember when Mossberg and Federal partnered for the 3.5".... Man that's be a minute ago.

[Tom007]

Good question?

[SumToy]

727 to 732 seem to be the place we find that works well.   Now the smaller bore stuff works good just more recoil.   The bore has alot to do with the wad you run.   In our target stuff we play in .709 up to .732.   Now the problem when you get to big bores they can walk around some because of the wad being smaller.   Also in the summer the big bores will work real good but in the colder temps they will fall off.

To give you something to think on.  I shoot a Browning BPS Trap sometime.   675 to 680 with junk federal 23/4 lead 9s it blow a hole at 60 feet BUT let the temps drop in the 50s you better off to trow the shell at the target.    In summer the browning is hard to beat then in winter you better off in the Remington or Moss 500 Winchester stuff . 


I know it affects the turkey loads just dont know how much. 

[the Ward]

727 to 732 seem to be the place we find that works well.   Now the smaller bore stuff works good just more recoil.   The bore has alot to do with the wad you run.   In our target stuff we play in .709 up to .732.   Now the problem when you get to big bores they can walk around some because of the wad being smaller.   Also in the summer the big bores will work real good but in the colder temps they will fall off.

To give you something to think on.  I shoot a Browning BPS Trap sometime.   675 to 680 with junk federal 23/4 lead 9s it blow a hole at 60 feet BUT let the temps drop in the 50s you better off to trow the shell at the target.    In summer the browning is hard to beat then in winter you better off in the Remington or Moss 500 Winchester stuff . 
   

I know it affects the turkey loads just dont know how much. 

Spot on William! Same thing i have found at the shoots. Hot/warm weather i run the browning, when it starts getting cold, the spaghetti gun comes out to play!

[the Ward]

I wonder if the newest generation of BPS' also have a .740 bore, indicating that the Browning-Winchester brand has been persuaded by Mossberg's success with the radical overboring.
Only that they want hunter to be able to still shoot rifled slugs with some accuracy, an impossibility from what I understand with the  Mossberg 835.


Sent from my iPhone using Tapatalk

Yes, all Browning 12 gauges using the Invector Plus choke system are .740 bore size. I believe the Invector Plus came out sometime in the early/mid 90s if i am remembering correctly.

[Tom007]

Great info, thanks so much....