20 Ga slug gun

[hunter4626]

 I am building two truck guns out of some smoth bore barrels.I have finished the 1st one it has an original modified choke 22 inch barrel which I drilled and tapped ans installed a 2x20 shotgun scope.I am having some terrible results in grouping,one shot will be right on target,the next will be 6 or more inch's off the shot after that will return to acceptable poa.I have tried fed,win and rem rifled slugs with same results.I tried some Brenneke last night and am comfortable with the results. Before I start the other barrel which I cut to 18.5 I need to improve this one.Any ideas? should I cut the choke off the barrel?

[bikerbeans]

hunter
 
I would check the scope, rings and rail and make sure nothing is moving on your 22" modified choke.  Also, make sure you have a good lockup on your gun, no gap at the breech and no wiggle, as this will be a problem as well.  Also make sure the latch, latch shelf, breech face etc. are clean and no oil present and that the gun is closed firmly. 
 
Supposedly foster slugs shoot better out of a cylinder bore but there have been tons of deer killed with fosters out of shotguns with just about any choke imaginable.  What range are you shooting?  I know that are some shotguns that are very accurate with foster slugs, but I wouldn't expect foster to shoot better than about 3 to 4 inch groups at 75 yards.
 
The brenneke slugs that are made for smooth bore barrels have always performed better than foster slugs in my shotguns.  This has been true from 410 bore up to 12 ga.
 
If your shotguns are 12GA, this doesn't apply to 20 ga smoothbores, and you reload, the lyman sabots that fit into a 12 ga shotcup have worked very well for me from smoothbore barrels.
 
BB

[MSP Ret]

The modified choke in your 20 should not have a detrimental effect on your groups, as a matter of fact I have had some of my best slug shooting shotguns WITH modified choked barrels. I agree that the first place I would look would be the scope and the scope mounting. I also agree with Brennekes, they have consistently been the best shooting slugs for me out of smoothbore barrels, BUT I highly recommend you use the stanndard velocity 2 3/4" loadings for the best accuracy. Ocassionaly a gun will shoot better with 3" mags, but not often...good luck....<><....

[Savage .250]

Find yourself a new/used rifled slug barrel ....  J s/n.

[hunter4626]

Thanks for the input-I guess I will go ahead with my plans for the cut-off barrel. I already have an extremely accurate fully rifled 20 ga handi but its way to heavy to do a lot of walking/exploring,plus it don't shoot buckshot worth spit. Thus the reason for the smoothbore design-I'm still working on the modified barrel-if it turns out that the cut-off barrel is more accurate, I will go ahead and cut the mod. barrel also.I will keep it posted.

[geartow]

Try the Federal TRU-BALL ammo it has been the best I have found in a smooth bore.

[spikehorn]

I have one of the 22" modified 20ga barrels, All the foster sligs I've run through it have shot between 2"-4" inches at 75 yards. deffinately minute of deer. Winchesters giving the biggest groups and federals the smallest.

[mechanic]

Make sure the latch and latch shelf are dry of all oil, snap the breech shut with authority, verify the scope mount, and try again.  My "extra" slug gun is a 20 mod. with JB welded sights.  About 3" at 75 yds.
 
Ben

[ironglow]

Make sure the latch and latch shelf are dry of all oil, snap the breech shut with authority, verify the scope mount, and try again.  My "extra" slug gun is a 20 mod. with JB welded sights.  About 3" at 75 yds.
 
Ben

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  Ben;
   I know you posted this some time ago..but I hope you still catch it.
?     I also want to put sights on a modified 22"  H&R barrel.  What sights did you put on the barrel and how did you "weld" them on .  Did you have to remove the bluing? did you have to etch the contact surface  on the barrel ?
  With my old eyes, I would like to install either a peep or hi-viz sights..will JB Weld attack plastic to steel O.K. ?

[mechanic]

Ironglow, this old shotgun was a rust bucket anyway, so I sanded lightly the area where the sights were to go, then cleaned with alcohol.  The sights were just some in my "bucket o stuff", that I think came off a 22 bolt.  They have shown no sign of coming loose.  Not so much luck when I tried to epoxy a scope rail.....
 
I sprayed the metal black when I was done, with some Rustoleum.
Ben

[ironglow]

  Thanks Ben, now to find just the sights I need...

[rdlange]

I did a 20ga shorty with Williams WGRS rear and Williams 'shorty' ramp front, hi viz bead.  Don't remember height and had the drilling done by a smith, 'fairly' reasonable for here.  Believe I measured breech and muzzle diameters and did some math to get the heights needed.   Shoots good, but daughter just keeps it close for 'zombies' now.

[gcrank1]

Hey Hunter, are you trying to shoot those groups off a bench? Its way too easy to 'get behind the gun' differently shot to shot on a heavy kicker unless youve had a bunch of practice at it. If you dont the recoil impulse will throw the shot's POI, at least it does for me. Some guys have used a step ladder as a standing rest that will let you roll with the recoil and still steady you up for the aim. I tend to just shoot mine offhand, as I would in the field and see how we do.

[BUGEYE]

I have an unfired youth 20ga modified, laminated and if I were building the perfect all-round gun, this would be the platform. it wears a slip-on pad to make it adult LOP and I've installed swivel studs.
I probably need to move that front stud.
anyhow, you could take anything from a sparrow to a moose.  yes moose...
every deer I've killed, I could have done it with a 22lr, so I would tackle a moose at under 50yds.
I'm referring to head shots here.

[hunter4626]

Well its been awhile since I reread this thread--thanks very much for your various insights and help.I finally found the problem-bad scope the cross hair adj would not hold it changed with every shot. Replaced scope and now have a very accurate slug for my truck-out to 75 yards I can keep  a rifled slug into 3" with no problem.

[gcrank1]

 

[theratdog]

i put a hi viz snap on fiber optic front sight on my 20 guage it is really nice     

[nanuk-O-dah-Nort]

I picked up a 20Ga trackerII barrel

I am interested in shortening it, and remounting the front sight and getting a WGRS rear.

I really like the looks of the shorty shotgun ramp.

I'd be ecstatic with 3"@75 with that.

I was thinking of fitting it to my 357mag SB1, and putting a youth stock on it for a very compact truck gun to have handi during moose season.

.575MiniBalls in the shot cup is supposed to work well, with target loads.

[ironglow]

  For those interested, I have the "aged eyes" problem also..    But as many here, I found that peep sights work well since a shooter lets the rear sight go "fuzzy" anyway.  After buying an air rifle with Hi-Viz sights, I realized how effective they are also..that's why I'm going put 'em on my 20 ga.