Strange pattering problem

[joker]

This all started when I got my guns (835 with fiber optic sights and browning gold with FFII red dot) out this year to make sure they were on. When I took them to the range they were both shooting to the left by about 7" at 40yds. There was no wind and I could see that the sights had been adjusted off center to make both gund shoot to the left. I did not have the tools with me to sight them in so the next day I went to the range set both sights to the center and both guns shot dead on at 40yds. I thought maby I sighted them in last year when it was windy but I didn't think so. About two weeks later I took the gold out and shot it at 50yds. I shot two shots and they both were about 6" to the right. I adjusted the sight back off center where it was befor and it shot dead on (@50yds). I then tryed it at 20yds and it was about 3" to the laft. I now think that I may have sighted both guns in at 50yds last year and they shoot more to the left at closer ranges?Has anyone else seen this or had this problem?

Steve

[mightyjoeyoung]

Nope.

Are the barrel nuts TIGHT?  Could be the reason for the sights "floating"?

[joker]

Nut is tight. I tightened it real tight beffor last year and marked it. I haven't taken it off sence. I cleaned the bbl on the gun.

The sights haven't given me any indication that they are "floating" They seem to consistantly shout more to the left at closer distances.

[mightyjoeyoung]

Maybe it's one of those guns you can shoot around corners...or in this case trees?  The Germans had something like that in WWII I think

[Jourdan_D]

What type of rest are you shooting off of?  Are you right or left handed?

[TheTwistedOne]

One thing that can reek havoc with POI is choke tightness.  A loose choke can also be dangerous.  Choke tightness should be the first thing you check if POI mysteriously changes.

That being said I'd suspect a bore cleanliness issue and a deep cleaning may help.  Stuff you can't see in the bore can do goofy things.  An oily residue in a shotgun bore is not a good idea.

Might not be the problem but I've found the barrel nut tightness isn't as straightforward as you might think.

After you tighten it down it's a good idea to let the action slam shut a couple times and check the tightness again.

The reason for this is it is sometimes possible for the barrel to loosen in the receiver after being subject to the shock of the action slamming shut.  This looseness can occur without the barrel nut moving at all!  Having sights on the barrel itself doesn't eliminate the problem because the barrel can move in the receiver after you pull the trigger before the pellets ever leave the muzzle.

It's also a good idea to check the tightness the first shot after reinstalling the barrel.

[joker]

Thanks for the help guys. The nut and choke were tight, I am always checking them after each shot (its a habit). I did take it apart and clean it real good last night. I took it to the range but with 25mph winds (I had about 5mph at the house) I couldn't shoot it. I have shot it off of snad bags (right handed) and in a lead sled. I thought that it may shoot more to the right with sand bags shooting right handed but It seemed to shoot the same either way.