Shotgun barrel bending jig... change POI

[rbertalotto]

Do you have a shotgun that simply does not shoot to POA?

I did and I needed to do something about it!

"Shotgun Barrel Bending to Change Point Of Impact"

A full report is now posted on my web site:

http://www.rvbprecision.com

or directly here:

http://rvbprecision.com/shooting/shotgun-barrel-bending-change-point-impact.html

https://images44.fotki.com/v1405/photos/2/36012/16085188/IMG_20181203_163534505-vi.jpg

Hope you enjoy it!

[RED333]

That is a nice rig, good job.
Thanks for posting!

[Drm50]

I made similar outfit years ago. Mine is powered by 1/2" rachet. I used it a lot in 70s & 80s, still have
it but haven't had call to use it for years. I think there was an article in gun rags back then about bent shotgun barrels. Guys all of a sudden were discovering their barrel was bent. I only saw a few
bent barrels that resulted from outside forces. One ran over with car, one that was in roll over car
wreck which also busted stock bolt out of action and one a guy fell over a bank with. The later was the only one that was able to be straightened. Most of the ones brought in to be straightened had to
be a little off from factory. There would have to be signs of impact or force on gun to have a bent barrel. It takes a little feel and trail and error to straighten barrel. Mine is cloned off one Brownell was selling.

[ulav8r]

When I was at CST, one of the instructors told how he straightened/bent barrels to correct point of aim. He just applied them to a tire on the nearest vehicle, with a bit of force. The further off the point of aim was, the harder he applied the barrel to the tire.

[jaguarxk120]

You change the point of impact on a shotgun by changing the stock fit.
Trying to bend a barrel and you will go looking for a new barrel!

[GBertolet]

I used a 12 ton hydraulic press, with wooden blocks, cut to the contour of the barrel, to bend an old Stevens single barrel. The barrel had been shortened to 26" at one point in time, and the bore was .742, too big for a screw in choke tube. I was given a Polychoke that was cut off another barrel, and adapted it. With the higher sight bead, it shot low. I learned when Polychoke does an installation, they bend the barrels to correct POI, so that's what I did. It worked out well.

[Nobade]

Yours is more precise than mine. When I needed to regulate my muzzleloader shotgun, I just hit it on a telephone pole and shot it until it hit where it was pointed. No damage to the barrel, no scratches in the finish. You can't tell by looking at it but it is deadly with ball or shot now. When I started it was off by two feet at 50 yards. I couldn't even hit the patterning board with a shot charge!

[dogrunner]

Yours is more precise than mine. When I needed to regulate my muzzleloader shotgun, I just hit it on a telephone pole and shot it until it hit where it was pointed. No damage to the barrel, no scratches in the finish. You can't tell by looking at it but it is deadly with ball or shot now. When I started it was off by two feet at 50 yards. I couldn't even hit the patterning board with a shot charge!

Didn't do my A/5 plain bbl with a phone pole....just sat the thing between two wooden blocks and CAREFULLY brought it to point of aim with a leather mallet.............still, I really appreciate the precision a bending setup such as OP has.........point tho, is that mine worked to perfection and I'd surely do it again!!

[Nobade]

Yeah, I wouldn't do it like that to a customer's gun. But when it's mine I can do what I want.

[WheelgunConvert]

Fitting a shotgun to the individual is the proper way to address point correction. Length is easy, height and offset (there’s a better term, cannot recall) are artisan driven...not many of those around any more.

[megasupermagnum]

Some shotgun barrels are so out of wack, bending the barrel is the best way. The original Benelli SBE was notorious for it. My grandpa had one that when you looked stright down the rib, it would hit 2 feet or more low at 30 yards. It eventually got sold to my uncle who still has it as a slug gun. You could use the Benelli stock shims to make the other barrel shoot POA, but the view down the rib was very odd.

[lightload]

Many years ago Remington taught its law enforcement armorers to change poi on 870's by whacking the mag tube against a sack of shot. The mag cap was screwed on and hit against the shot bag. Another technique was popping the mag cap with a babbit bar.

[DIRT Farmer]

More than one has been adjusted in the field with a forked tree. My 870 was

[W.R.Buchanan]

After coming home with a 3/25 score at the skeet range with my freshly rebuilt Ithaca M37 I inquired with them and they told me the barrel was probably bent. I said Waaahat?

Apparently when you put the barrel on the gun you tighten the mag nut to take up the slack on the barrel. Then the gun gets hot and since you tightened the nut up way more than you should have there is no place for the barrel to go but up. ^ This is a common problem with these guns and the proper way is to tighten the nut then back it off one click, however nobody ever tells you this until it is too late.

My gun was shooting 3 feet high at 20 yards! now it's dead on. Incidentally this is a Ithaca M37 made in 1940 and is the smoothest pump gun I have ever handled. I installed new wood with an English style butt stock and then sent it to Ithaca for Reblueing and a complete go thru. Apparently they didn't pattern the gun while they had it and I had to send it back for them to bend the barrel down.

Randy

[LIMPINGJ]

Beautiful M37 you have there Randy. What gauge?

[W.R.Buchanan]

12 ga.

Randy

[rking22]

I've seen several Cutts installed a bit askew, did you pattern it without the choke tube? By the way, beautiful rebuild, 37s are sweet. Also could just be the much elevated bead on the Cutts body, could definitely put poi low.

[Petander]

I have a 20 gauge Benelli Raffaello that needed correction. Got it used for a good price...

The pattern was only 6" to the left @ 40 yds but once I figured it out I couldn't shoot that gun anymore. Until got the barrel straightened out.

You can't fix a bent barrel with any stock adjustments. And you can't fix your brain knowing your barrel is bent.

[Drm50]

I have herd of forked tree trick. How do you straighten a barrel by whacking it on a telephone pole? That's a new
one on me. I shoot gun rested at 20yds and adjust from results. Never have got one done without several trips
back in jig. It takes a feel because you have to go past where you think you need to be because of spring back.
I'm not sure of the steel in new shotgun barrels and how they react. I have cut down a lot of low end shotguns from 60-80s and found that bores are off center. This means that there is thin places and thick in barrel walls. I
don't know how that would work out in a jig. You couldn't depend on even pressure doing what you want in this situation.

[Petander]

I don't know about whacking... but yes,you need a "feel" for bending.

Shooting like a rifle, beads aligned from a rest can reveal strange things. It took me some reading and talking to gunsmiths before I got the courage to bend a Benelli barrel. And 6" is within many factory specs,go figure...

I've seen a Krieghoff combination gun with barrels crossed real crazy,like a foot horizontal POI difference @ 30 yds... cant fix that.

[egg250]

Tweaking the barrel is a legitimate method to change shotgun POI. I wouldn't be eager to do it on a high end Beretta or such but, on an inexpensive pivot barrel or other type shotgun, it's doable and affordable.

Excessive adjustments on a ribbed barrel or over/under barrel can cause the rib or barrels to separate.

[Petander]

Yeah,I figured I have to learn how do it to be able to use an otherwise very good gun.

I never sell questionable guns to re-circulation -like in this case I think someone did. The gun still looks like new.