questions on back bore shotgun barrels
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Dave McCracken
Moderator In Memoriam
Back boring is cited as a way to cut kick, improve patterns for better long range performance , cure cancer, etc. It differs from overboring in that it's a retrofit. Overbores start out as larger than standard.
Metal is removed by reaming, drilling and polishing. It can be done on any shotgun barrel, though most backboring occurs in target shotguns.
Anything that removes barrel metal should be considered very carefully in advance.
Cold weather usage may see a obturation problem with some loads and wads in a larger than usual barrel.
It's a nice to have, not an essential. If it's kick reduction you're after, lighter loads are a better way. If it's better patterns, tweaking the ammo is better.
HTH...
Metal is removed by reaming, drilling and polishing. It can be done on any shotgun barrel, though most backboring occurs in target shotguns.
Anything that removes barrel metal should be considered very carefully in advance.
Cold weather usage may see a obturation problem with some loads and wads in a larger than usual barrel.
It's a nice to have, not an essential. If it's kick reduction you're after, lighter loads are a better way. If it's better patterns, tweaking the ammo is better.
HTH...
Clemson
Member
To add to what Dave says, back-boring works well for premium shells and for reloaded ammunition that uses one-piece wads. If you shoot a lot of promotional ammunition, e.g. Wally World "Dove & Quail" shells from Federal, Winchester, Remington, or any of several others, you may get card wads with a shot wrapper. The card wads won't seal the bore well with a back-bored barrel, and you may well get blown patterns. The plastic wads, on the other hand, have a plastic skirt over the powder that expands to seal the bore. This can also be a problem for lengthened forcing cones. If you plan to shoot good ammunition, either factory or reloads, then back-boring may make sense for you. If you are one of those people who spends $1800 on a shotgun and then feeds it $3.00/box ammo, you may be disappointed.
The only undisputed effect of overboring an existing bbl is that it reduces the weight of the bbls and changes the balance. You will also have to have it "rechoked" or put mutichokes in. Expensive stuff when done properly. Don't even think about having it done by anyone that doesn't do it full time with a great reputation.
So, for example, if you had an older Beretta 682 with 32" bbls or a Remington 3200 with 30-32" bbls and you wanted them "lighter" upfront, you could have them overbored to achieve that.
Don't bother with a single bbl auto or pump. You can buy bbls for that.
I had to have it done once, don't ask
, and it did lighten up the bbls noticably.
Side note: some factory O/U's that come with overbored bbls are actually heavier than standard, since they are larger and maintain the same "width" as a standard, i.e. Browning 425 for example.
So, for example, if you had an older Beretta 682 with 32" bbls or a Remington 3200 with 30-32" bbls and you wanted them "lighter" upfront, you could have them overbored to achieve that.
Don't bother with a single bbl auto or pump. You can buy bbls for that.
I had to have it done once, don't ask
, and it did lighten up the bbls noticably.Side note: some factory O/U's that come with overbored bbls are actually heavier than standard, since they are larger and maintain the same "width" as a standard, i.e. Browning 425 for example.
C.R.Sam
Moderator Emeritus
Hmmm..
Overbored plus brass hulls.
Why didn't I think of playin with that before bein nearly out of brass.
Sam
Overbored plus brass hulls.
Why didn't I think of playin with that before bein nearly out of brass.
Sam
At the risk of stepping on someones toes, I am often amazed at how willing people are to comment on subjects that they know nothing about.
Backboring it the process of reaming a shotgun barrel to produce a choke where there is none or to increase the restriction of an existing choke. The amount of metal removed is minute. Example: A cyl. bore barrel with a .725" bore is reamed to produce a .020" choke. That means that the wall thickness is reduced by .010". The thickness at the muzzle of a typical 18" 870 barrel is .080' + or - .010. The barrel is much thicker in the area where the pressure is highest. Backboring has no practical effect on the strength of the barrel.
Weight reduction? I have handled thousands of barrels before and after backboring. I can not detect a reduction in weight and it would probably be difficult to see the difference on anything but a very good scale.
I doubt that backboring alone will have much, if any effect on recoil, however, it is usually done in conjuction with lengthing the forcing cone which does have an effect on felt recoil.
The entire penal system in Alaska, the Anchorage P.D., Alaska State Troopers, Fairbanks Airport Police and many other Alaska LE agencies use Vang Comp modified shotguns. It gets pretty nippy up there, so there goes the concern over cold weather problems.
Believe what you want. It's still a free country.
Backboring it the process of reaming a shotgun barrel to produce a choke where there is none or to increase the restriction of an existing choke. The amount of metal removed is minute. Example: A cyl. bore barrel with a .725" bore is reamed to produce a .020" choke. That means that the wall thickness is reduced by .010". The thickness at the muzzle of a typical 18" 870 barrel is .080' + or - .010. The barrel is much thicker in the area where the pressure is highest. Backboring has no practical effect on the strength of the barrel.
Weight reduction? I have handled thousands of barrels before and after backboring. I can not detect a reduction in weight and it would probably be difficult to see the difference on anything but a very good scale.
I doubt that backboring alone will have much, if any effect on recoil, however, it is usually done in conjuction with lengthing the forcing cone which does have an effect on felt recoil.
The entire penal system in Alaska, the Anchorage P.D., Alaska State Troopers, Fairbanks Airport Police and many other Alaska LE agencies use Vang Comp modified shotguns. It gets pretty nippy up there, so there goes the concern over cold weather problems.
Believe what you want. It's still a free country.
Gearhead Jim
Member
Briley did a backbore job and lengthened the forcing cones on my Browning BSS 12, 28" bbls. Also installed choke tubes, which do not change the weight. The boring/cones reduced weight by about 4 oz, all of course on the front of the gun. It seems to balance and handle better (for me) than before, patterns great with AA #8 loads. Haven't tested the cheap shells yet.
DML,
Rather "strong" opening statement for this forum.
As Gearhead Jim detailed on his bbl job, a 4 oz change(reduction) in weight, although a small percentage of the total weight of the shotgun, does indeed significantly alter the balance of the gun and make the gun "lighter" up front. Whether that is good, bad or indifferent is up to the shooter.
I have had the same experience with two identical trap bbls, one back bored, the other standard. The balance and feel difference is substantial.
Perhaps, with HD type shotguns, weight reductions in these type of shotguns is not noticable- I don't know.
But, with weighted and balanced O/U's and side by sides, ounces increased or decreased and where they are added or removed are noted and talked about by clay target shooters, because it does matter!!
Forcing cones might have an effect on felt recoil for certain people, but only if you tell them in advance they have been lengthened and they reduce recoil.
Rather "strong" opening statement for this forum.
As Gearhead Jim detailed on his bbl job, a 4 oz change(reduction) in weight, although a small percentage of the total weight of the shotgun, does indeed significantly alter the balance of the gun and make the gun "lighter" up front. Whether that is good, bad or indifferent is up to the shooter.
I have had the same experience with two identical trap bbls, one back bored, the other standard. The balance and feel difference is substantial.
Perhaps, with HD type shotguns, weight reductions in these type of shotguns is not noticable- I don't know.
But, with weighted and balanced O/U's and side by sides, ounces increased or decreased and where they are added or removed are noted and talked about by clay target shooters, because it does matter!!
Forcing cones might have an effect on felt recoil for certain people, but only if you tell them in advance they have been lengthened and they reduce recoil.
After working in the gun business for many years, I get a bit tired of people who are ignorant of the subject but are more then willing to display that ignorance. Perhaps it would be better for all if I stayed off of this forum. It would help keep my blood pressure down.
An HD shotgun typically has one barrel about 18" long. The weight lose from backboring would be about 1 ounce or less.
Believe what you want.
An HD shotgun typically has one barrel about 18" long. The weight lose from backboring would be about 1 ounce or less.
Believe what you want.
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