Shotgun shooting off POA.

[redhawk0]

I have a 1975 Mossberg 500 A/T 12 gauge. I purchased a 28" Ribbed screw-in choke barrel about 1985 for it.

I took it out this past weekend to pattern it for the upcoming Turkey hunt in NH and found it patterns about 16" at 30 yards...BUT it shoots low and right by about 8". I don't want to do anything with it until after the Turkey hunt...I'll just compensate til then.

But...what is the recommended method to get POA and POI closer. Can the barrel be "bent" slightly to compensate for this?
What would be the recommended method to do this?

Could an extended choke (new this season) cause a shift? I've never noticed it before and I will check it out with another choke just as a verification...but everything points to the barrel being bent...well...I'd like to know what I can do about it.

redhawk

[GBertolet]

A common practice is to bend the barrel. I have bent them in a hydraulic press, while some put the barrel in the crook of a tree and bend. There are many methods to get what you want. Shotgun barrels are relatively thin, and bend easily.

[NSB]

Before you bend the barrel, try a different choke. I have sent chokes back and gotten them replaced because the choke itself was causing the problem. This isn't as uncommon as you think. The last thing you want to do is bend the barrel to correct a bad choke.

[RickinTN]

I shoot and teach the clay target disciplines. I have worked with many shotguns over the years, both mine, and students' guns. Many choke tubes are not concentric and will throw a pattern. The first thing I would do is to try another choke tube, no matter the constriction, and see if it shoots to the same place. I don't recommend bending a barrel under any circumstances. If you find it patterns to the same place with several choke tubes is simply means your rib is not in line with the centerline of the bore. Other than having the rib re-attached in the right place there is no fix. I doubt you would have any luck having Mossberg correct the problem. There are more shotguns out there that don't shoot where they look than do. In turkey hunting you are using your shotgun in the only instance where a shotgun would be "aimed". Shotguns are made to be pointed and most people shoot better with the front bead removed.
Good luck,
Rick

[Boolit_Head]

Try a different choke but the fit of a shotgun effects the location of your rear eye and that can effect the aiming. High end shotgun sports mostly involve shotguns that are fitted to the shooter.

[rmcc]

Carlson choke

[redhawk0]

It is a Carlson choke....are you indicating they are known to be good or bad?

[redhawk0]

I shoot and teach the clay target disciplines. I have worked with many shotguns over the years, both mine, and students' guns. Many choke tubes are not concentric and will throw a pattern. The first thing I would do is to try another choke tube, no matter the constriction, and see if it shoots to the same place. I don't recommend bending a barrel under any circumstances. If you find it patterns to the same place with several choke tubes is simply means your rib is not in line with the centerline of the bore. Other than having the rib re-attached in the right place there is no fix. I doubt you would have any luck having Mossberg correct the problem. There are more shotguns out there that don't shoot where they look than do. In turkey hunting you are using your shotgun in the only instance where a shotgun would be "aimed". Shotguns are made to be pointed and most people shoot better with the front bead removed.
Good luck,
Rick

I agree Rick...they are definitely meant to be pointed. I've killed a lot of game with this gun down through the past 45 years....but I think this is the first time I've ever patterned it. I can't remember if I did 25+ years ago while turkey hunting then or not....I've never gotten a turkey but I seem to recall shooting at a stump to see if the gun was "on"....haha I can believe that the rib not being centered might cause a left/right shift to POI...but likely not the shooting low. I'm more inclined to believe its either the choke or the barrel itself. I remember falling with the gun about 15 years ago. I was able to keep the gun out from under me when I hit the ground like a rock (a big rock...I might add)...I got my feet tangled in a slash pile after the logging company came through the area. I remember coming down with my right arm under me and the row of shotgun shells in my vest pocket were between my arm and my ribs...guess which gave first...yeah...I had trouble breathing for 6 weeks after that one. It might be possible that the barrel was bent at that time...but again...its just speculation. Since I'm a lefty I was able to control the position of the shotgun when I fell. There is no visible bend when looking down the tube.

I'm just trying to eliminate all possibilities before attempting a correction. I appreciate you guys' knowledge.

redhawk

[cub45]

you can very lightly file the muzzle at an angle to move the shot to where you want it to hit.

[MrWolf]

I would also look at the stock. Be surprised what an ill fitting stock will do.

[pietro]

Before you bend the barrel, try a different choke. I have sent chokes back and gotten them replaced because the choke itself was causing the problem. This isn't as uncommon as you think. The last thing you want to do is bend the barrel to correct a bad choke.


+1

I once had a Browning BPS that, while the choke tubes were OK, the section of the muzzle threaded for them was off kilter (I knew because the issue stayed when I changed choke tubes)

I would suggest calling Mossberg Customer Service & see if they'll stand behind the barrel.

.

[toallmy]

Is the bead knocked over ?

[Cap'n Morgan]

The easiest way to check the choke is to loosen it half a turn and see if the POI changes. (a few shot will NOT harm neither choke nor barrel)

[redhawk0]

Is the bead knocked over ?

Nope...i have a hi-vis bar sight on the front. Its parallel to the rib.



The easiest way to check the choke is to loosen it half a turn and see if the POI changes. (a few shot will NOT harm neither choke nor barrel)

I had thought of trying that...but haven't yet. I wasn't sure if it was a good idea. I'd hate to mess up the threads on the only barrel that I have with threads. I do have the original 28" Mod choke barrel that came with the gun...maybe I'll give it a test firing too just to see if I can narrow this down.

redhawk

[gnostic]

A gunsmith at Oak Tree Gun Club in LA bent the barrel on my brand new BT 99, it shot low and left. Now it shoots where I'm looking with my cheek on the stock. You can't see it's been messed with. Brownells has the jig to bend shotgun barrels...

[NSB]

The easiest way to check the choke is to loosen it half a turn and see if the POI changes. (a few shot will NOT harm neither choke nor barrel)

This is true and it won't hurt the gun at all. I remember that I did that with a Briley Extended choke based on their suggestion and the POI did move. Also note that there is a DISTINCT difference between "aiming" a shotgun vs. point shooting with a shotgun. You're definitely aiming and since it's a turkey gun that is what you want it to do, hit POA. Point of fact is that you can remove the choke from your gun and shoot a couple of shots with no harm done. I used to shoot 1500-2000 rounds a month shooting clays and I've seen people do it frequently. Some with some very expensive guns....mine included. None were harmed in the process. The shot's still in the wad until it leaves the barrel.

[Cap'n Morgan]

Speaking of chokes, this is what can happen when interchangeable chokes are neglected.

Some time ago I noticed a very nice 32" Beretta 692 in the "used guns" rack in a gun shop. The gun looked like new, and yet the price was fair - too fair, actually. The owner of the gun shop explained that both the chokes could not be removed, probably because the previous owner had been shooting large steel shot in the gun (both chokes were IMP MOD) On closer examination you could actually see tiny bumps and bulges in the tapered part of the chokes. He had tried to work them loose, using both penetrating oil and force, but was afraid to ruin the barrels and decided to sell it as a "permanet choke" gun. Strange as it may sound I didn't fell any urge for any more shotguns, and passed on the the offer. Later I told a friend about the gun and mentioned that the chokes could probably be removed if one would accept to destroy the chokes in the process.

A month later my friend showed up with the gun and a pleading look in his eyes. I took pity of him and promised to give it a try. Using an original choke to get an idea of the profile I clamped the barrels in a five-axis mill, aligned each barrel separately and carefully drilled two tracks opposite each other in each choke using a 3/8" end mill, keeping as close to the barrel walls as I dared. Finally, after an hour of clammy hands and much measuring, the chokes would finally give in... and come out.

As you can see in the picture, the problem was not only caused by large steel shot but also by a scary amount of rust. At some point water must have gotten between chokes and barrel to wreck havoc over a long period of time - all while the owner was keeping the exterior of the gun spotless clean!


https://i.imgur.com/KYmYrEA.jpg

[redhawk0]

Yikes...that says something about removal for greasing every now and then. Looks like a painful removal for sure.

redhawk

[Greg S]

Aside from fitting the stock, as mentioned above probably, stocks are universal and one does not fit all. With a shotgun, the sight g eye Is the rear sight and as with firearms, to move the point of impact you need to move the eye. To raise the point of impact, add shims, tablet backs of cardboard to the top of the comb and shoot at a patterning bored till the pattern hits where the eye/bead is looking. In europe, when you buy a shotgun, the better places offer fitting and stock bending.

Once the amount of correction is figure out, you can purchase an ez-comb foam and plastic covered self adhering comb pice to attach to your stock.

[Tokarev]

I am almost positive that the chokes could have been removed with just the right amount of heat and w/o any milling.

As to the point of impact, the screw in choke can be ruled out by twisting it in incompletely by 90 degrees and checking if the POI moves to the opposite side of POA.

[M-Tecs]

Through the years I fixed POI on7 or shotgun barrels. First couple I did I just used 3 full shot bags. Having a fixture like below makes the job easier.

http://castboolits.gunloads.com/showthread.php?372348-Shotgun-barrel-bending-jig-change-POI

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

http://forum.accurateshooter.com/threads/shotgun-barrel-bending-to-change-poi.3966405/

[M-Tecs]

https://www.youtube.com/watch?time_continue=337&v=B90fJ2RAZ8g&feature=emb_title

[W.R.Buchanan]

Shooting Slugs is where you see this POA vs POI problem most. With a bead You are essentially stuck with whatever you've got and must use Kentucky Windage to correct for POI.

This is why I have rifle sights on all my slug guns. Open sights on a Turkey Gun wouldn't be wrong at all. At least you could adjust them if needed.

My Ithaca M37 came back from Ithaca after rebluing and was not even close. it was shooting 3 feet high at 20 yards! Apparently according to Ithaca this is not an uncommon thing and the reason why is the way the barrel is held in the gun. Too much tension on the mag cap with put upward pressure on the barrel and as it heats this increases bending the barrel upward.

Proper tension is to tighten by hand until thumb and fore finger tight and then back off one click.

I sent it back to Ithaca and they bent the barrel down and now it shoots where it is aimed.

The operative point here is,,, that "THEY" Bent the barrel down!

"They" actually know what they are doing!

And this is something I would only attempt under the most dire of situations.

This gun is way too nice to bubba! So "They" got to fix it!

This would be far easier to screw up than fix right, and everyone should just know this!.

Randy

[ulav8r]

One of my instructors at CST said the only tool needed to change point of impact was a tire on the vehicle you drove to the range in. He said to whack the tire with the barrel, force and angle determined by the direction and amount of change needed. Doing it at the range allows you to check and repeat till you get it right. I have never needed to try it.

[wch]

Try different ammunition; if you;re adamant that you want to use the shells that you have, then bend to barrel or change the tube.