THe Beretta 391 and the shims it comes with

[swipter]

I have read on other forums that the 391 shoots high and the shims will correct this. Can someone please explain this to me? I can't not seem to understand the concept.

Thanks

[esldude]

Okay the stock connects to the receiver, with a shim between the two. A flat shim in there will point the stock straight back. A shim a bit thicker on the right side, will angle the stock to the left. One thicker on the high side will angle the stock down. So these shims in a sense let you angle the relative position of the stock to fit the gun to you. Pretty good concept.

Hope this make some sense.

[Dave McC]

Using the shims in connection with patterning will dial in the shotgun. Takes an hour or so but well worth the effort.....

[swipter]

So do you dial it in, if necessary, at a rifle range or do you do it at a skeet range? I would be shooting stationary targets at the rifle range.

[K80Geoff]

Usually shotguns are "Dialed in" on a pattern board. Stockfitters use pattern boards to properly set up a stock.A pattern board is a large metal sheet usually with a hole in the center for aiming that is coated with a white paste. When you shoot at it the shot bounces off but leaves a mark, which can be smoothed out.

You can set up your 391 patterning board by obtaining large sheets or a roll of butcher paper. Set up a target backer (Pallets on edge will do) and stapling a sheet of 3'x3' paper to the pallet. Mark a center target (I use stick on orange circles ) to aim at.

Mark off 16 yards, put in a full choke.

Then mount the gun as if you were shooting at a bird and shoot at the center orange target on the paper. Do this 5 times. If you are mounting properly you will have a large hole somewhere on the sheet of paper. Measure from the center of the hole to the center of the target. Get the measurement in inches. Every inch from the center corresponds to 1/16 inch in stock adjustment. If the hole is to the left shim the stock on the left side to move the stock to the right (Cast off) to impact the center. Check on a fresh sheet after you shim.

This will get you shooting where you look provided you mount to the same place consistently. When mounting do not "Crawl" the stock, in other words do not move the gun or your cheek around to improve your sight picture. You should be able to mount the gun and hit the center with out adjusting the stock or your shooting position.

Of course you might have other problems such as too long or too short stock or need the pad canted to fit your shoulder. These problems require help from someone knowledgable.

[Ruger4570]

Ditto, K80

[swipter]

THank you. I will be printing this for later.