Valmet 412 combo 12 ga. shoots high
I have a Valmet 412 o/u combination gun 12ga over 30/06. The shotgun barrel shoots 18" high at 25 yards with 00 buck, pattern is 12" in dia. The barrel does not appear bent. Choke is fixed improved modified. Gun has short wide fixed blade front sight, non-adjustable flip up rear, 30/06 shoots perfect point of aim at 100 yards. The rifle barrel is adjustable for windage and elevation. I suspect the shotgun barrels choke was bored incorrectly. The shotgun barrel is chrome lined and too small in outside diameter (.800") for thin-wall choke tubes. I tried to contact some local (within 100 miles) shotgun card shooting gunsmiths to ream or sleeve the choke, but can't get anyone to respond. Brownells has a piloted expandable reamer that is inserted from the breech. The reamers instruction manual explains how to hone or sand away the chrome lining. Anyone have experience correcting point of impact by reaming a choke with a tool like this? Anyone know a Gunsmith that can perform such an operation?
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Let's go about this from a different direction. You can regulate the rifle, vertically and horizontally. Try adding some temporary amount of material to the front sight to see how much is needed to bring it to the shotgun point of aim. You can do this without firing a shot by bench the shot gun and look over the sight and add material till it points 18in lower on the target. Then do some test firing. Remember different shot loads will pattern differently. Not much height is needed when your dealing with front sight to bring point of aim lower. . If it turns out to be a small amount you can add metal to front sight (explain later) , then move the 06 to This new point of aim with rifle regulator.
If you would consider a detachable valmet scope mount then things go even easier. You can leave the 06 as is and being scope reticle to 06 point of aim.
With such a thin shot barrel a briley adjustable point of aim choke is out and with the shot barrel muzzle attached to the rifle regulator I would consider any work there as a last resort.0 -
I would not be so quick to blame valmet for boring the shotgun choke off. A 00 load of buckshot is a heavy load and shotguns will throw the pattern in respect to recoil, butt plate angle and even the individual shooters weight. You many find that altering the butt plate angle (in your respect ///increased drop) will keep the pattern lower. Remove the butt plate and make up some temporary changeable drop and see where you are going.
Experiment before you go making a permanent change. For example will the rifle barrel allow you to correct the 18in your about to make?. I will explain later how to make a permanent front sight increase. 12 in pattern with 00 buck is fine I would not mess with that choke. Many have found that # 4 coyote buck patterns best, the largest buck that moves thru a choke. And it may land differently than your 00 loads.0 -
I have shot slugs, small shot #4,#5,#6 1 1/4 oz. thru 1 5/8 oz. mag. loads as well as different buckshot loads. It throws a 95/5 or higher pattern no matter what load is fired. I have removed the barrel and sighted the rifle sights on an target and then looked down the shotgun bore and the target is centered in the bore. Raising the comb or butt plate will only make the shotgun shoot higher. If I Lower the comb or butt plate I will only see the back of the tang. Bending the shotgun barrel is not an option as the barrels are joined at the muzzle, forend and monobloc. Adding to the front sight may correct the shotgun problem at the expense of screwing up the rifle. I don't think it is possible to to get 6 foot of elevation regulation at 100 yards. The only way I can see to fix this condition is to open the choke up. Figuring out how to do so true to the bore, not the choke has got me stumped. 0 -
Based on a 28 in barrel I calculated that front sight would need just under .5 in of height
To correct. You could then regulate rifle to this . Your rifle barrel regulator moves the barrel and a small amount will result in a large change. I was figuring on tilt cut the butt plate, giving you more drop of comb. A small amount may do it. I recently moved a 12 ga 6 in to the right by tilt cut the butt plate to the left . I don't see how you can correct 18 in at 25 yard with a thin barrel unable to alter choke position.
I have one other suggestion, since your problem is on the vertical plane , a low power scope 1x or 2x at the most, with multiple reticle marks. Utilizing one mark for the shotgun and another for the rifle.0 -
Hello IMHO Jaegermister has the best suggestion Mount a scope this will allow you to adjust both barrels to have the same POI I have no trouble at all with shooting flushed game with the scope I have even killed two turkeys in the pouring rain with lens cover over both ends from section of tire tube over complete scope. Just swing and let scope tube be aiming point. I have 3 receivers and 7 Barrel sets Scopes from 1.5-5 to 3-9 I have one receiver set up for Shot barrels only. one 20Ga over 20 Ga one 12Ga over 12 Ga and one 12 Ga over 12 Ga. sporting clays with full choke tube set. The combo receiver has double triggers with adjustable rifle trigger I got direct from Finland. along with a full set of wedge shaped butt plate spacers that allow you to change pitch etc.
see picture
picture is of one bird shot on hill side 125 yards away with 243 echo caused rest of the flock to flush and one fly my way crossed at about 30 yards and I got that one with shot barrel I mainly hunt with this gun my favorite long gun other then my Flintlock.long rifle. This receiver has 3 barrel sets. 12 Ga. over 243 12Ga.over 30-06 & 12Ga.over 9.3X74R I have scopes on all 3 Combo barrel sets With steel rigs I modified and made a part to fit into the half moon notch in the rib. Never had a problem in over 25 years of use. . The third receiver is 12Ga. over 243 I plan to give to my grand son.0
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