Even More On Balance


Dear Bruce

I really enjoy reading all your comments on this web site. You have already answered many of my questions through reading the archives.

I have been shooting sporting clays for about 1 1/2 years . I am becoming more interested in gun fit. I have a good idea what effect cast, pitch, comb, heel and LOP settings have on a shotgun.

My question is on shotgun balance, how important is it and how would one go about checking for correct balance and correcting for it if need be?

Current gun is a AL 390 sporting, mine also has hit me in the face, I have filed the comb down to 1 1/2 and the heel measures 2 1/4 with the 60 DX shim installed. I only have about 200 rounds thru it with these measurements but it doesn’t seem to hit me in the face anymore.

Any advice on 390 and info on balance would be greatly appreciated.

Thanks in advance.

Kerm

Dear Kerm,

Congratulations on taming the 390 sporter stock. I was never able to come to terms with mine and sold it. I would have kept it if I could have bought a 390 trap stock for it, but – as usual- Beretta didn’t have any in stock so I stuck with my trap stocked 303s. If you can get the 390 stock to fit with a little hacking, more power to you. Handsome is as handsome does. The 390 sporter would have given a lot less face slap to a high percentage of their owners if they had made that comb more parallel. That is the biggest complaint that I hear about the gun. It would be a great opportunity for an aftermarket producer to address since Beretta has shown no interest in doing anything about it.

As to gun balance, that’s like picking a wife or making chili- it’s REAL personal. There isn’t really a right or wrong. I have always felt that K-80s balanced like a pig on a snow shovel, especially in the longer barreled versions, but there are people out there who love them and are far better shooters than I am. Personally, I wouldn’t mind the weight and inertia for trap and perhaps not for American-style skeet, but for sporting I would prefer a better “feel”. In Europe, they can’t give the K-80s away. In America guys will trade their first born to get one. Go figure.

Generally I find that 30″ and 32″ SOLID CHOKE Belgian Brownings and Mirokus often balance to my taste. I am of the “long and light” school, within bounds. I have trouble with many of the current mass-production Beretta/Japanese Browning O/Us with the factory screw chokes. In many cases, I feel that the addition of these chokes has put a blob of weight right in the front of the barrel, just where I don’t want it.

I don’t mind barrels with a bit of weight for target shooting, but I don’t want the weight all in the same place. I want it strung out along the barrel. There is a big difference in the feel of a solid choke barrel built to weigh, say, 1.65 KG and a 1.5 KG barrel with a .15 KG weight stuck in the middle or on the front.

I have covered this “moment of inertia” problem before, but it never hurts to repeat myself and bore you to death. Our search engine is tough to use. Consider a broom stick with a brick on either end. It balances in the middle, but is hard to start or stop swinging because of the weight at the ends. Take the same stick and bricks and put the bricks together in the middle. Same balance point, but now the stick is too easy to start and stop swinging. Now grind the bricks up and spread them out along the stock equally. Same balance point and weight, but a much better balanced swinging. That is, crudely, sort of how it is with adding weight to gun barrels.

Now to your gas gun. At first many people found the A390 sporter too heavy up front due to the heavier (and loathsome) stepped rib and also due to the heavy steel forend nut. Beretta actually listened to the shooters and reintroduced the sporter with a flat rib and an alloy forend nut. Now some people think that the front is too light. Depends on what you want.

If you want to experiment with a touch more weight up front, you could get one of the old steel forend nuts. That will add a couple of ounces (albeit in one place). I have seen some people use one of the mercury recoil reducers that screws on in place of the forend nut, but they usually don’t seem to stick with them.

The biggest problem usually occurs when someone has that .723″ Beretta 390 barrel backbored to “improve” it. A backbore of a single 30″ .723″ barrel out to .735″ will pull about 1.65 ounces. That is a surprising amount of weight and many find that their customized barrels are now too light up front. Adding an extended choke may build back in .5 oz of that, but to many it still feels funny. Other seem to think it is just fine.

I wouldn’t begin to tell you what correct balance is. It is what feels right to you and what produces a responsive, yet stable, gun. Proper balance can reduce the perceived weight of a heavy gun. Improper balance can also make a light weight gun even more difficult to shoot. If you use the broom stick and brick analogy, you will see that “balance point” really doesn’t determine what proper balance is. What counts is how the weight is distributed along the gun.

Bottom line: I can’t tell you how you should balance your gun. You are just going to have to experiment or borrow guns to find what you like. Maybe someone has a “formula”, but I don’t.

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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