My friends,

As some of you already know, I am converting a Beretta 411 12 ga SxS into a double rifle in .444 Marlin. The project is reaching a point in which I am almost ready to proof the gun
Now, my questions are:

1) How should I proceed with the proof test? should I load both barrels and shoot them right-left and then check the gun, or should I load one and keep the second barrel empty during the procedure?

2) What load do you recommend? I have at my disposal some quantity of IMR 3031, which is the one I plan to load with, and I was thinking of proofing the gun with the maximun load recommended for this powder/caliber.

Opinions, concerns and experiences are welcome.

Fred

doublegunfan:
You will need to load over the maximum recommended load to prove the gun. General concensus is to achieve a pressure overload of around 25% above maximum factory load. British proof achieves this in medium-bore cartridges by loading a 10% heavier projectile over the same powder charge. You must measure all the critical dimensions, then fire the proof-loads, one in each barrel will do, then measure everything again. If there are no dimensional changes, the gun has survived proof.

A 'cheat' which is often used in Australia, where we have no proof laws or proof-house, is to heavily grease the factory-round with case-lube, then fire it in the rifle. This is generally considered to increase the back-thrust by 15 to 20%, but does not increase pressure as such. Fine for testing the actions of bolt-guns where barrel-wall thickness at the chamber is not an issue, but not very definitive for a double rifle on a shotgun action.

Do you have Ellis Brown's book? He gives some pages to proof-testing...

Marrakai,

I was actually waiting for your comments!

Yes I have Ellis Brown's book, and he mentions that German proof rules state that a 10% increase in bullet weight on top of a standard load could be used to proove a gun. I will propably stick to it.

I am also thinking of shooting a barrel with a primed case on the other barrel to check for "doubling" during the tests. But someone mentioned to me that proofing should be done with both barrels being shot one after the other and only then should the gun be examined. What is the correct procedure?

Fred

"What is the correct procedure?"

I'm not sure, but a word of caution about firing a primed empty case in any double: without the normal pressure of firing, the pin may stick in the primer and make the gun difficult or impossible to open without damaging a firing-pin. If this happens, it will be necessary to drop the floor-plate and manually recock the tumblers in order to open the gun. Graeme Wright mentions having to do this in his book.

Regarding proof-firing, I would probably load a round in the first chamber and fire it, then check. This may not be the correct proof-house procedure, but that way if something is distorting you may catch it before completely ruining the gun.

Thinking about it, a rigorous procedure might be to fire a proof load in the first barrel, then check everything. Repeat in the second barrel, and check again. If all is well, then fire a left-and-right, a couple of seconds apart, then a final check. If it passes that, you definitely have no worries IMHO!

Can anyone give me the secrets to decoding the information engraved on an O&U shotgun made by Merkel. I inherited it from my grandfather and wanted to get some indication of age, model etc.

Any help would be greatly appreciated.

Clark Miller