Long Distance Gun Fitting

Hi Professor,

I am trying hard to make my 391 shoot straight. Out of box p.o.a was 3 inches left of center @ 16 yds. After increasing cast off with Beretta shims provided, p.o.a is not any better. I then added a additional shim that I shaved down to the form of a wedge increasing cast off. No luck, I,m still 2 inches left. I fear that adding more shims could weaken stock head @ receiver and cause problems. Any suggestions?

Knowing that you can’t actually fit anyone via internet here is my physical description hoping it might help in your suggestions. I am 6′ 1″, 255lbs., thick chest and wide shoulders. I’ve noticed that I tend to mount my gun further out almost on the shoulder and arm joint. I also have a full face (what the hell I got fat cheeks). I wear 32″ shirt sleave.

I’ve even ordered a Wenig stock for the 391. Their American Style model. comes with parallel comb, 1/4″ offset comb and a 3/8″ toe out (no off set at heel). Stock feels great. I,ve lowered comb to my height but with this stock you cannot use beretta’s shims. Point of aim with this stock is also 3 inches to left. My question here is can you make the stock butt end slope one way or the other to create cast the same way pitch is altered? I feel like my chest and shoulder mass forces the gun left when I flush the butt to my shoulder. Looking for help.



Dear Kevin,

Professor? Geez, I love that. It sounds so learned, so erudite. Oops! Come to think of it, most of the professors I know are Commie dweebs who salute with their left hands. Who you calling a Commie dweeb? See what kind of advice you’re going to get.

Here’s the deal on gunfitting- it’s a combination of shooter style and shooter physical makeup. You can’t separate one from the other. That’s why a fitter/coach has to see someone shoot before he can hope to come up with the right dimensions. The amount that your turn your head into the stock when you shoot and how upright you hold your head have a lot to do with determining cast, just as does shoulder and face structure. Stock fit also has a great deal to do with how square you stand to the bird vs turning to your side a bit like a rifle shooter. It’s all a matter of degree. You say that you shoot “almost on the shoulder and arm joint”. I’m not really clear exactly where that is. I’d have to see that and I’d also want to see how far to the side you turn your body.

I’m going to assume that your shooting style has gelled and that you are pretty much fixed in the way you mount a gun so that the point of impact feedback you are getting is consistent.

The next thing I’m going to assume is that you already do have some guns that fit you and that you shoot well. Have you compared the stock dimensions on those guns to your 391? What are the differences? Do they all have a lot more cast than the 391 or are they similar? Do you get the same sight picture when you mount? If you get the same sight picture, but not the same point of impact, then look to something mechanical in the barrel alignment. If you can’t get the same sight picture, then look to the stock.

First thing is to eliminate any mechanical deviation in the gun. 391s are mass produced and it’s possible that the gun simply shoots to the left. Test by doing what you have to do to sight directly down the rib with beads lined up. Does the gun still shoot to the left or is it now correct? If it still shoots to the left, it’s a gun problem either with a crooked rib or an incorrect mating of barrel into receiver or incorrect bead alignment.

If the gun shoots straight when you get the beads lined up, then its a fitting issue. We’ve eliminated shooter technique and mechanical problems as the cause. So now it’s just a case of getting the stock cast off far enough.

Go easy on the shims. As you surmise, too much shimming will bend the magazine spring tube too much. I used to screw around with this on my Remington 1100s all the time and managed to bend the tube enough to bind the link. The Beretta tube is much stronger and really, really doesn’t like to be bent too much. I’ve seen a number of people get away with double shims, but I wouldn’t go further than that.

If shims won’t get you over far enough, then you have to remove wood from the stock. Pure and simple. Just get out the rasp and sandpaper and have at it until you get the sight picture you want. Brutal, but effective. Just remember, when removing wood, cut a little and shoot a lot. Then do it again. And again. And again. Once you get it right, refinish and you are done.

Stocks with adjustable combs are only partial solutions to cast as only the comb moves. You say you mount out on your shoulder, so you really want to move the whole thing out. If wood removal alone won’t do it, then it’s back to Wenig for a stock with considerably more cast-off.

Sooner or later this is going to cost you some real money. I’d really advise spending it on a decent gunfitter first. As you can see by all the questions I’ve asked, it really is just about impossible to analyze gunfit over the ether. A good gunfitter who can actually see you mount the gun will be able to spot the problem in less time that it took me to write this and make all my guesses.

After the above professorial ramble, now to your other question: yes, there are a number of ways to “fake” cast by angling the recoil pad. None of them really alter cast of course, but they do alter the way the gun sets up on the shoulder. I’ve got a box of hacked up recoil pads with toes ground off, toes ground at an angle and inside rear edges beveled. All of this affects where the gun seats on the shoulder, not how the cheek fits the gun. I use recoil pad mutilation more to affect barrel cant than cast.

Since you have a heavy chest, you might try rounding the toe of the pad considerably. Kickeez has a “rocker” design pad that is worth a look. http://www.kickeezproducts.com/rocker.php  Just a glance at it will show you what they are trying to do. I like to work with Kick-Eez pads because they are solid and can be cut any way you wish without penetrating the egg crate voids of other pads. This pad essentially increases pitch in only the lower half of the pad. Worth a try if you feel that the toe is digging in enough to move the barrel to the left. Of course, if your shooting left were caused by mismounting due to the recoil pad, you should be able to see that in your rib alignment and you didn’t mention it.

That’s why these things have to be done in person or we just keep doing around in circles. It’s like writing out an instruction manual on tying a shoe lace. It’s so much easier just to show the person. Gun fitting is the same.

Best regards,

Bruce Buck
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)

This entry was posted in Shotgun related and tagged . Bookmark the permalink.

Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.