Barrel Bending Tips

[cowboysteve]

Howdy Gents! I've dusted off the NW trade Gun I built almost 20 years ago, and found it's shooting typically low. Trying to consistently guessimate how much barrel to show ain't going to cut it for good accuracy. So, it looks like I might have to bend it. Using the search function I can't seem to find any tips. One guy suggested putting the barrel on two blocks of wood at each end, and using a large "C" clamp on a block in the middle to bend it down towards the table. Seems reasonable. Any pointers from the smoothbore crowd?

 

[Eterry]

A gunsmith friend swears he saw this in a shop years ago; a smith was working on a single shot that was hitting too low, he folded a towel on his bench, took the barrel out of the stock, reared back and swatted the towel as hard as he could with the muzzle, then put it back together. He had to do it twice before the barrel came around to grouping right.
Just a thought :stir:
Eterry

 

[cowboysteve]

Yup! That's what a old friend said too! I guess I was looking for some method more "gentle" than whacking a bench or thumping it across a log. Shoot! I'd probably accidentlly shift my grip and end up shooting sideways around trees.

 

[coloradoclyde]

I knew a guy who said he use to bend barrels in the crotch of a tree...

 

[matt denison]

The C clamp idea works.

I use known dimension blocks on th ends like 3/4" then use drill bits for guages to know how much I have gained on the barrel. I set the end blocks up on a piece of heavy wall square tubing under my bench press. I bend the barrel down until it touches, say, a 1/2 inch drill bit in the middle then I know that I have bent it 1/4" even though it will of course spring back quite a bit of that. Once I gain about 1/8 inch I reassemble the gun and take it out to shoot and see where it is hitting. If 1/8" moved POI 4 inches then I can estimate how much farther to bend it. Not real scientific but sort of....I think it is better than bending it wedged in the bumper of a dump truck or banging it on the bench.

 

[19 16 6]

Now I don't know here, I might be going completely crazy, but I will say it anyhow.
It's not the barrel that needs bending. It's the stock that is the problem.

Is this a gun mount / stock fit problem ?

Sorry but the bending remedy does not sound like good gun smithing as much as Bubbarising to buggery.
O.

 

[Grandpa Ron]

Bending the barrel is quite common and had been for a long time. Some of the finest rifle barrels are hand aligned on a bending frame. The object there is to make them straight.

The blocks and C clamps seem like the better option, as opposed to just smacking it into position.

As mentioned, proper stock fit is an alternate approach. It would be my first choice but I have steam bent a couple of stocks and it too is not for the faint of heart.

 

[cowboysteve]

Thanks for the confirmation that the "C" clamp idea is a good one.
And, the stock on a Trade Gun is not the problem. In order to use the flat of the barrel to sight along, the barrel will have to be bent to adjust the point of impact. Pretty common requirement, and not a Bubba fix.

 

[smoothshooter]

I used the " C " clamp method years ago on 4 or 5 modern shotgun barrels and it worked just fine. It usually took several attempts, but all ended well. Start out conservatively until you get a feel for the process. The barrel will always spring back some when you release the pressure from the clamp, but that doesn't mean your adjustment had no effect. What you are actually doing is " flexing " it. You will get better results if you screw the clamp down, and go do something else for a few minutes, after which you return and release the pressure. The barrel seems to stay adjusted better if you leave the pressure on a while so that it takes a " memory " better, so to speak of the new adjustment.
A crooked barrel problem will not be completely solved by bending the stock, as this method will only put the point of impact coincidental to point of aim AT ONE DISTANCE ONLY. If the barrel is shooting to the left for example, it will continue drifting to the left further and further as the range increases except for the one distance that the stock bending zeroed for. At distances shorter than that which zero was achieved, the barrel will pattern to the RIGHT.
To simplify, just do your bends, a little at a time, and shoot a test pattern from a good rest after each adjustment, and you will do fine!

 

[Flint62Smoothie]

I've done 2 so far ... a 42" barrel by the C-clamp method with calipers for measurements and a 54" barrel by pulling it from the stock and sticking it under the heavy benchrest-type range bench I was shooting from, using 'seat of the pants' as my measurements and both worked out fine!

In regards to sight picture, I still need to visualize a pencil lying across the breech, where the base of the sight sits upon the top of the pencil. But it works!

In fact I taped a pencil stub across the breech and would shoulder it and cheek it a few times a day for weeks ... to help build 'muscle memory'. I advise that ALL smoothbores shooters try that trick to become better shots with their smoothies!

 

[cowboysteve]

So, are you saying you left approximately a 1/4" (your pencil) of visual barrel. With my Trade Gun that's also what I need to "show" to hit dead on at 50 yards. I want to bend the barrel so my turtle front sight is sitting right on the visual flat of the barrel. Does this sound right? It would eliminate the need to remember to raise my sight picture to show the 1/4" visual gap between the turtle and the barrel flat.

 

[stantdm]

I think the C clamp method makes sense. Whacking it on a towel could have some bizarre results, especially if I was the one doing the whacking.

 

[Britsmoothy]

Good points.
Mine could do with a tweak!

B.

 

[Dane]

I've bent both smooth and rifled barrels using the block and c clamp methods. Use a straight edge in the middle, find a drill bit that will just slide in to the gap in the center. Bend and release till the next size bit will slide in. Then you know that you're mking progress.
However, on a smoothie, I've never bent one for elevation.
Your eye is the rear sight, so where you put your rear sight will determine elevation.
Mounting the gun consistently will bring it to point of impact.

 

[54ball]

We have a saying in the the Fire Service, Try before you Pry. You would be surprised in how many doors that are pried open or cut into were unlocked. Nobody thought to turn the knob.

I have found that a heavier charge in a smoothbore raises impact. You may indeed have to bend it but I would do so only as a last resort.

 

[cowboysteve]

Good points. I realize that position on the stock is critical, however in this case I believe it's just plain physics. When I sight along the barrel flat so the turtle front sight is "resting" on the barrel flat, it's hitting 8" low at 50 yards. I have to raise the turtle sight a 1/4" off the flat to hit spot on. Floating the front sight in air off of the barrel flat seems like it will be prone to consistency error.

 

[19 16 6]

Try before you Pry.
I have found that a heavier charge in a smoothbore raises impact.

Two good points here.
If deliberate aiming like a target rifle, a gun that is built & designed to be shot instinctively, then problems arise.
As a young bloke I always shot rifle. When I first picked up a shotgun The stupid thing would not shoot where I wanted it to so I put it down.
Thinking shotguns were useless I did not go back near them for years until a friend taught me how to use them. If anything, he bent my mind to fit the gun.
Hey, but bend away; No skin off my back.
I just pray that I never buy a used gun off you fellows. :grin:
O.

 

[19 16 6]

Bending the barrel is quite common and had been for a long time. Some of the finest rifle barrels are hand aligned on a bending frame. The object there is to make them straight.

Yes, I know this is common practice to bend to straight. This is completely the flip side to bending crooked.
Not that I want to pick an argument but bending crooked just seems so wrong to me.
Like I have a bad flinch & shoot 4 o'clock. Bend the barrel up & to the left is not the solution.
O.

 

[matt denison]

"If deliberate aiming like a target rifle, a gun that is built & designed to be shot instinctively, then problems arise."

What gun would that be?

:stir:

 

[matt denison]

I just pray that I never buy a used gun off you fellows

If you did it would probably be hitting right where you pointed it. :grin: