shotgun slug grouping problem

[rml127]

I posted months ago about a problem I'm having with a 12 gauge mossberg 500 trophy slugster. It has a cantilever barrel and scope. Last season it was hitting real high and I never did find the problem. This year I decided to swap a different scope onto it because the old variable power scope seemed to change the point of impact when I turned the power up. I spent several hours yesterday and today trying to get it to group at 50 yards without any luck. I'm using lightfield sabots and I also tried remington copper solids. The gun used to shoot very good when I bought it years ago. My groups ar anywhere from 5-10" at 50 yards right now.

I checked all of the screws and went over the gun again and can't find anything wrong. When I first bought the gun I didn't know any better and I shot alot of regular rifled slugs thru the rifled barrel. I decided this morning to give the barrel a real good cleaning to see if there was any lead in the barrel. Well, long story short is I spent an hour scrubbing and swabbing and It's still not clean. I think the barrel is full of lead and I'm having trouble cleaning it all out.

I havefour questions I hope someone can answer,
1- what is the best cleaner to remove lead?
2- can this problem cause terrible grouping with sabots?
3- is there any way to determine if a scope is broken or bad?
4- what is parralax and how do I tell if thats a problem?

[Wingbone]

1. Because the slugs are surrounded by a plastic sabotthere should be no lead in your barrel. It could be plastic from thesabot.
2. Unless you can see a lot of buildup on the lands, I doubtbuildupis a problem.
3. Put the scope on another rifle you know to be on and shootit. If it groups well, its not the scope.
4. Parallax should not be a problem at 50 yd.s

Unless you've got areally cheap scope, I doubt the scope is the problem.

[UncleNorby]

Get a good wire bore brush and some solvent that will remove lead, like Butch's Bore Shine, and go at it until those grooves are free of lead.

Then you can begin to worry about other things that can affect accuracy.

I'll bet that is your problem.

[rml127]

I'm really hoping this is my problem. I spent 10 more minutes this morning scrubbing with a bore brush and swabbing with hoppes #9. Everytime I use a clean patch it comes out dark gray. I'm almost out of hoppes, I'll have to see what else they have at the store that might clean it a little faster. If I look down the barrel it looks shiny like a mirror but it is obviously still coated in lead.

Is your bore brush clean? I clean mine out with brake cleaner and still there is junk on it. Don't use the borebrush and see what happens.

Also, don't be dipping your brush in the hoppes. Contaminates the whole bottle and makes it appear real dirty.

[stubblejumper]

While hoppes#9 does remove powder fouling it is pretty much usless for removing lead or copper deposits.Try shooters choice lead remover.

http://precisionreloading.com/shooterchoice.htm

[338]

I just had the same problem with a deerslayer that I put Ithaca's rifled barrel on. I never got it to group with any slugs, checked all the screws, locktited the barrel to the reciver, cleaned it with butches bore shine then swapped scopes. And it still won't shoot. So I orderd a 11-87 and will put the old barrel on the Ithaca put it in the safe and sell the rifled barrel .. Hope you have better luck than me ..

[sybigbuck]

Isnt the mossberg a smoth bore, If so dont shoot sobots you have to use rifled slugs. remember rifling negatesrifiled slugs,thats Right from the Manufature dealer.

[700bdl870exp]

i agree stublejumper shooters choice works great and also break free does too.