I'm a noob to the forum and hope someone will help with some questions. Shotgun is an M1 pistol-grip, 18" tactical, about 15 years old.

I'm trying to get this gun to cycle reliably with a little added weight, specifically the four-shot extension and a light and mount which weigh about 10 ounces. I only want it to cycle light magnum 2 3/4 " OO.

At the range, it successfully cycled a couple tubes of Win XX, loaded 7+1+1. I guess I got a little confident and tried some lighter buckshot and skeet loads, and problems developed. There were all sorts of failures, FTE, failure to return to battery, stovepipes, etc., even when I went back to the XX's.

I now have the receiver completely torn down, and it is slightly dirty, but not gummed up. I'm going to replace the recoil spring and have the following questions:

1. Should I use a heavier spring, such as the Wolf, or just a standard-weight?
2. Should I replace the bolt inertia spring and the firing pin spring?
3. I have some spare magazine tube springs I bought from Beretta for a 1201FP ( basically the same as an M1). The Beretta springs are 3 " longer than the old M1 spring and slightly smaller in diameter. Think I'm OK with one of these?

Any other advice will be GREATLY appreciated. Thanks much.