First off, I am not using a 750, this is in regards to a 7400 but I thought this would be the best place for this issue. If not, please let me know where to go.

I bought a 10rd magazine for my 7400 off of eBay. The brand is National Magazine Company. I don't if that's a good brand or not. But the issue I am having is that it causes jams almost every shot. From what I can tell, the magazine is not fully seating in the front causing the round to jam below the barrel entry.

Is there anything I can tweak on the magazine? Is it just eBay junk? Just a lemon magazine? Any input would be appreciated.

I have two 10 rounders for my 742, manufacturer unknown. I think I got them from Sportsman guide though. No problems. Natchez SS may have some. But from time to time I come across web posts of folks with problems. Compared to the factory mag, the three most likely causes:

1. Latch points. Does the 10 rd mag lock in the same? If it's too far up, down, angled, loose, wobbly, or tight and binding in the mag well... You might be able to add electrical tape, or carefully file to improve fit. If you DO or DON'T push up on mag when firing things change?

2. Feed lips. Not at correct angle or curve. Very hard to correct by bending.

3. Dirty or sticking spring & shell follower. I don't think they can be disassembled without permanent damage. Spray solvents or brake cleaner may dissolve follower. With 3 hands or a vise, push down the follower, clean inside as much as possible with bore solvent, lube with silicone spray, wipe dry.

On my 10s the bolt lock tab was removed from the follower because the longer mag has no bolt release lever.

Maybe this will help.

I messed with this pile for about 2 hours one night. I tried to get it looking as close to the factory 4rd as possible. I was able the slip the plastic "carrier" out and clean out the housing. I even stretched the spring a little. I finally got it doing solid dry runs, just pulling the bolt back and releasing. But then I went and fired it, still jammed. I was able to get about 4 or 5 rounds out without problems but every round after that jammed.

I'm thinking I'm going to have to scrap this one and try a different brand.

Good luck. Post up what you come up with, worky/no worky

I don't know about the newer models but I am working on replacing the "roll pin" that retains the front recoil spring guide rod. That pin has to drifted out to clean the rod and at least to easily clean the bolt, carrier, and operating rods while still in the receiver. That way you don't have to pull the barrel as often, which isn't fun, requires a special wrench, and may affect scope zero.

I have special ordered some cotter less clevis pins from Grainger. .187 dia x 1" long. I'll get them at the end of this week and see how well they fit. If this works I'll post up in the 742 section. I will have extras available.