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POI different for bottom & top barrel

17K views 33 replies 20 participants last post by  Ernroe 
#1 ·
I have a Beretta O/U w/ Wright Chokes that shoots different points of impact. The bottom brl shoots 50/50 and the top brl shoots 90/10 POI. Have any of you seen this before? What is the solution? I would like both brls to shoot 70/30.

Ernie
 
#4 ·
Just the recoil will make the top barrel of an over and under shoot higher. No good solution unless you get a special custom choke to lower the POI of the top barrel to match the bottom barrel and then raise the comb to get both barrels to shoot where you want. The special choke would have to be locked in place.
 
#5 ·
Ernie, I'm guessing, but it sounds to me like you are counting pellets above and below the line while you are shooting close (say 13 yards). Knowing at what yardage you shot at and how high in inches the POI was above POA would be a great help.

I had a Gold E combo that drove me crazy until I tested and found out what was the problem (actually, problems). The first thing you want to check is barrel regulation.

To do that, set up on a bench somewhere between 15 and 20 yards in front of a grease plate or pattern board. Pick one barrel and shoot each choke tube, several times, at the plate. Aim the shotgun like it was a rifle and shoot enough times that you can say with confidence that this choke hits say 3" high and 2" right. Move on to the next choke in the same barrel. Hopefully, you will find two ore more that shoot to the same POI. You don't care yet what that POI is, only that some of your tubes are consistent.

Now move to the next barrel. Use your tightest known good tube and shoot for POI. On your O/U that will tell you how well the barrels are regulated. Do the same for the single barrel. You will then know how well your barrels are regulated, and which tubes are good. After that, you can decide how to correct any deficiencies.
 
#7 ·
zzt's post makes the best possible case for deep-sixing the whole "percent high" madness and switching to the far more informative "inches high" description.

If he has diagnosed the situation correctly - and I'll bet he has - we might have heard one barrel shoots a bit, maybe an inch or two up close, higher than the other and we could all breath easier.

and if we knew is was determined off-hand and/or with but a shot or two, we'd not worry at all.

Neil
 
#8 ·
Assuming you have done what you need to establish a general 'POI" in context of aiming point - and say, 4" high, Briley makes eccentric chokes which have always worked for me.

Having said that the eccentric chokes don't work as well in moving POI for open chokes (as you might imagine). Hw will tell you 3-4 inches is about max expectation
 
#10 ·
"Should work to my advantage in Doubles, but hasn't so far"

Why should it be an advantage? Sure the first bird is rising, but not that much faster than the singles bird. If the bottom barrel shoots higher that what you use for singles, I can't see it being an advantage at all.

When you say "very high" what do you mean, in inches, and at what distance?

Neil
 
#11 ·
I remember back in the late 80's I bought two Winchester Classic Doubles shotguns. One with 28" barrels for hunting, and another with 30" barrels for Sporting Clays. At this time in England, "Smoker" Smith was kicking butt in sporting there. The gun felt right so I order these two shotguns.

I struggled big time with these guns. I knew better, but I didn't check the POI before shooting them a while. I was surprised to find out that the barrels were so far off that I could never adapt. The top barrel shot 50/50 and the bottom barrels (both guns) shot 15 inches high at 30 yards !! I gave these guns to a friend to sell for me.

I had another friend that shot a Winchester Pigeon grade Unsingle at a event where you could try out all different guns and related gear. He had to have one. I asked if he bought the gun he was shooting there, as he said he couldn't
miss with it. But no, he didn't even try to buy THAT GUN as he could buy a similar new gun at wholesale, which he did.

Well, that gun was a disaster. Just the opposite of the first gun. He couldn't hit hardly anything with it. We finally checked the POI and found out that it shot about 24 inches high at 20 Yards, yes 20 yards. We renamed this gun a "Buzzard Grade" He traded it off.

I had a similar problem with a Browning Citori trap with 32' barrels that I bought after the Classic Doubles fiasco. I bought it at the 1989 Arizona State shoot. On a lazer both barrels shot to the same place, so I bought the gun. Took the gun home and attempted to shoot it, couldn't hit anything. Took it to the pattern board and found with a figure 8 sight picture the barrels (both) shot 24 inches high at 30 yards.

I talked to Tom Wilkinson about the problem and he said he could add a rib to it with reverse taper and get it to shoot anywhere I wanted. He installed the rib so the gun would shoot where I wanted it to and that gun has been the best all around shotgun I have ever owned. I can change the chokes and shoot skeet, sporting, or trap or anything else, love this gun.

After Tom's work I have had Briley thin wall chokes installed in both barrels, as well as Spears's double releases, and my buddy Phil Simms built the stock, and I have had Tom Wilkinson install a hunk of brass rod in the stock (17 0z.) that was rifle drilled so I can get the stock off/on without having to remove the weight. It weighs a little over 10 lbs. recoil is almost nil, even with heavy 1 1/8th shells.

Merry Christmas to all.


Tom Strunk
 
#12 ·
What I call Monday regulated shotguns can come from any manufacturer!! One barrel shoots where it's supposed to and the other is out in left field or extremely high. Too much vino over weekends can cause those guns to slip out to the buying public it seems on Monday productions.

Learning how to handle a properly regulated set of shotgun barrels is tough enough without having one off-set any great degree! A couple inches is understandable but not a foot or more difference! There's VERY few shooters that could master such a contraption in my view.

HAP
 
#13 ·
That's what I was getting at, Hap. But before we put this away, I hope we hear from Ernroe on _where_ this gun shoots, in inches, not "percentage high." And how he shot the patterns to find out, and how far back.

As drgondog says, offset chokes from Briley do what they say they do and shoot well, but a few inches is all they they can correct.

Neil
 
#15 ·
ernie, you just pick a distance to test your POI at. I like 13 yards, but others work. It's just hard to tell a pattern center at 40 yards and you need a whole big sheet of paper for each shot too. Closer you can get the information you need and take several shots on the same sheet of paper and that's what you want, several shots.

Then you just measure - really, estimating is close enough if you are close - the distance between the point you were shooting at and the place the center of the pattern seems to be.

You might find a typical "two inches high at 13 yards" which is "somewhat high" and a popular place to have a gun shoot.

Or you might find something else.

The point is, you have a "where" you can pinpoint in your mind. Or tell others about. Or fix.

What ernoe has told us, "90% high" really doesn't tell us anything about "where" that upper barrel is shooting since we don't know how far back, or "free-hand" (always suspect) or how many shots. You need at least a few in about the same place before you can be happy (or start to worry.)

The linked website above goes into more detail.

Neil
 
#16 ·
.


"When you say "very high" what do you mean, in inches, and at what distance?"

.


Don't have my detailed notes with me...

But my memory is that...

The MT6 bottom barrel shoots between 5 and 6 inches high at 13 yards from a rest and between 15 and 18 inches high out at 40 yards (a whole pattern high).


This was measured using Remington factory STS 1-1/8 ounce of #7½ at 1145 fps with a Perazzi factory #6 choke (Modified).

Using the same factory load and shooting conditions but a Perazzi #10 choke (Full) in the upper barrel, the pattern was between 1 and 2 inches high at 13 yards and maybe 3 to 4 inches high at 40 yards.

This patterning was with the factory stock. The gun now has a Wenig stock which may affect the absolute barrel POI but don't think it should materially affect the relative POI difference of the two barrels.

.


I am a very slow Doubles shooter. The second target has begun to fall by the time I get to it. This is why I am thinking the Perazzi ought to be better for me for Doubles.

But I have been getting better Doubles scores with both my Browning Citori XT and with my K-80 Trap Special. Both of these guns have over/under barrels in which the two barrels shoot to similar (same) POI.



.
 
#17 ·
Hey Guys, great input and it is appreciated. It is obvious from reading the responses that I have not done enough patterning to fully determine the problem. Until a few yrs ago I was a skeet shooter and never patterned a gun. I know that is hersey in the world of trap but I always shot the same K gun and and never thought about it. However, I have shot enough clay targets to know when something is not right w/ a gun as was the case with this gun. So I decided to shoot it at the pattern board. At our club we have a roll of white paper on a spool w/ a cutter. I rolled off enough paper to cover the board and clamped it in place. Then I placed a "Shoot n See" reactive target (abt 18"x18") in the middle of the paper. I then backed up 30yrds (measured) and aimed at the bulls eye (free hand) in the middle of the reactive target. The bottom barrel placed about 50/50 above the point of aim. I repeated it and it was the same. I did not count the pellets but it was visually apparent that it was close to evenly divided. I repeated the same procedure with the top barrel. The result was about 90/10 split. That is when I decided to seek input from this group because I was sure that somebody on here has had the same type problem. I have had some very useful suggestions and intend to use them in the next week or so and will report the results back to this thread. BTW, I bought this gun to shoot doubles with but so far it has not worked out.

Thanks again for the input.

Ernie
 
#18 ·
Do your O/U Bbls have a replaceable Hangar such as is on K-80, KS-5, KX-5 so you can regulate your POI.

You may need to replace your Lower Bbl Hangar as they have the following hangars

0-1-2-3-4, ) being the highest shooter, and the #4 the lowest shooter, you will need to find out which one you need by testing the POI w/different Hangars


Gary Bryant
 
#19 ·
Haven't seen a Beretta with bbl. hangers. I do recall a lot of complaints some years back with combo sets not being even close bbl. to bbl. on Beretta guns. I recall some Browning superposed O/Us that, I believe Simmons, removed the side ribs and installed hangers but this would be more expensive than trading guns.
 
#22 ·
Hammer1, perform the test again using your #10 choke in the bottom barrel. If, after 5 or 6 shots you find the POI was the same as with the #6 choke, you have a barrel regulation problem. If different, you have what may be an easily correctable choke tube problem. To find out, so as I suggest in my first post on this thread.
 
#23 ·
I'm at the patterning board a couple of times a week with customers. I have noticed that with Beretta's, you have about a 50/50 chance of having one that shoots perfectly straight, with both barrels. Browning on the other hand, you have near 100% probability that the barrels shoot straight. Out of the box, for lower end OU's, it's hard to beat a Browning.

Just my experiences.
 
#26 ·
I bought the TMX used in 1987 and since I liked the rib I figured a DB-81 would be just perfect for Doubles. I found a used DB-81 and bought it and the bottom barrel was just right it shot about 8" high and straight left and right but the Top barrel shot dead flat and 6" to the left of POA. I couldn't shoot Doubles with that gun so I eventually traded it back to the store I bought it from. Even P guns can have a barrel regulation problem.
 
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