changing beretta shims

declan1980

have any of ye lads that own beretta 391's ever changed the shims on them?
my gun is shooting high and to the right and i'd like to try changing the shims to bring it into line.
is there anything i'd have to be careful of, or should i get a professional to do it?

zeissman

I changed mine years ago when I got my gun.
From what I remember I think it was easy enough.
I just followed the instructions in the manual.
You will need a tube spanner or socket set with a deep head to fit over the nut and bolt inside the stock though.

clivej

declan1980 wrote: »

have any of ye lads that own beretta 391's ever changed the shims on them?
my gun is shooting high and to the right and i'd like to try changing the shims to bring it into line.
is there anything i'd have to be careful of, or should i get a professional to do it?

Very easy to do yourself.

Take off the butt plate and get a socket (not sure of the size 13mm/15mm) on an extention and remove the nut. The stock will come off with a metal shim plate thats inside the stock. Now you can put on or replace the action to stock plastic shim.
NOTE to use the same plastic shim and metal plate shim with the same numbers and same way round so that they match up.

I found on my 391 that when I put up to the cheek that I could see over the rear to much (seeing to much of the front bead), shooting high, and I put 2 plastic shims on to let down the stock more (but only used one in the stock metal shim plate). Now when I bring it up my eye follows the bead/rib down the barrel far better.

FISMA

Declan,
When you shoulder the weapon, are you able to see the length of the rail, from beginning to end, as if it is a ramp sloping upward? If so, that would be at least part of why you're shooting over targets - that's where the gun is pointing!

The rail should appear flat - you should only see the end. The end as in cross section of a rectangle.

I would try a shim thicker at the top than the bottom, which should pitch the end of the barrel downward.

However, as someone said, it is probably best that you read the manual.

As for shooting to the right, I am unsure. Often when you have a right handed trap shooter they have difficult shooting the right most station. They can nail the left ones and the center, but the right causes problems.

This is often because when a right handed shooter shoots the right station and a clay is going to the right, the stock comes off of your face. When moving to the left, the stock pushes your face so you do not have this issue.

When face and gun leave alignment, you have problems.

declan1980

FISMA wrote: »

Declan,
When you shoulder the weapon, are you able to see the length of the rail, from beginning to end, as if it is a ramp sloping upward? If so, that would be at least part of why you're shooting over targets - that's where the gun is pointing!

The rail should appear flat - you should only see the end. The end as in cross section of a rectangle.

I would try a shim thicker at the top than the bottom, which should pitch the end of the barrel downward.

However, as someone said, it is probably best that you read the manual.

As for shooting to the right, I am unsure. Often when you have a right handed trap shooter they have difficult shooting the right most station. They can nail the left ones and the center, but the right causes problems.

This is often because when a right handed shooter shoots the right station and a clay is going to the right, the stock comes off of your face. When moving to the left, the stock pushes your face so you do not have this issue.

When face and gun leave alignment, you have problems.

cheers for the advice, i'm guessing that the gun is shooting to the right because when i shoulder the gun it twists slightly to the right as it sits into the pocket of my shoulder and as a result the barrel is slightly off center to where i'm looking.
would you think this is possible?, or is it because of having the shim that's in the gun thinner on the right hand side?

FISMA

declan1980 wrote: »

cheers for the advice, i'm guessing that the gun is shooting to the right because when i shoulder the gun it twists slightly to the right as it sits into the pocket of my shoulder and as a result the barrel is slightly off center to where i'm looking.
would you think this is possible?, or is it because of having the shim that's in the gun thinner on the right hand side?

Hmm, shims for a RHS pull - I do not honestly know. I am no expert here, however, I would first suspect shouldering problems.

Try setting up a video cam to watch yourself and you may see the problem.

Here's how I teach newbies to shoulder a shotgun. So much easier when it is seen rather than explained. Basically, you open the shoulder, seat the firearm, and then close the shoulder - allowing the shoulder to hold the firearm like a third hand.

1) Point your hands as if you were a five year old playing cops and robbers pointing a handgun: two hands clasped, outstretched in front, arms parallel to the ground. This is a closed shoulder.

2) Now rotate your arms back to your body 90 degress so that you look like the letter T or t. That is the shoulder open position.

It is in #2 that you want to seat the firearm and then close up. That is "cuddle" the firearm with the shoulder until you are ready to fire.

With a firearm in hand, try opening, and then closing to get the proper fit.

You will notice that this is also a more consistent way of seating the shotgun.

When you shoulder a shotgun on a shoulder that is almost or someone closed, it seats differently - variance = bad.

Clothing such as a heavy winter jacket or summer t-shirt cause further variance = bad. Opening and closing is a nice way to minimize variance.

If anyone has shimmed for lateral movement, please advise.

declan1980

i just changed to shims and spacer on the gun, it was set up for 50-dx, and i changed it to 65-dx. it already feels better and i'm looking flatter along the rib up to the bead. i'll check it on a pattern plate tomorrow to see if it shoots flat.
i'm also practicing FISMA's shouldering technique to see if it will help bring the pattern into the center