Nordic +3 for M2 tactical holds 2 rounds

[trackbird]

I've searched through pages of threads here and I'm sure this information has to exist, but I either missed it or my search skills have failed me this week.

 

I purchased an M2 tactical and I just added a Nordic +3 mag extension. It's very well made and I'm quite impressed with the fit and finish of their machine work. However, they suggest cutting the spring down to be between 10 and 16 inches longer than the mag and extension combined. I started at 18" and worked down to 10" and I am still only able to get 6 and "3/4" rounds of 2 3/4" 12 ga ammo in the tube. I tried both the factory M2 follower and the Nordic teflon coated follower with no change. Will it function with the spring cut down a bit more or am I destined to only get 6+1 in this shotgun? I'm setting up for a 3 gun match and I really needed the additional capacity.

 

Thanks for any input.

[trackbird]

Ok, I solved it. With the spring cut to only 10" longer than the mag and extension, I can get 7 rounds of Winchester 2 3/4" buck in there, but the Brenneke KO slugs are slightly longer than the Winchester rounds and I come up about 1/4 of a shell short by the time I get to #7. So, apparently they do work as advertised (fit as advertised), but you have to watch that you don't have oversized ammo. It's all I can do to get the 7th round in there. There is not more than 1/32" of play. So it's a snug fit.

 

Now I have to get time to go see if it functions.

[shotgunNoob]

You were right in discovering that ammo size can make a difference. For instance, the other day I tried loading 8 rounds of Federal LE 2 3/4" loads into my Mossberg 590 (8+1) and found that, no matter how hard I tried, I just couldnt fit more than 7 rounds into the mag tube. After measuring a round, I found that it was just a bit longer than the purported size; multiply that by 7 rounds and lo and behold, it came up roughly 1/2" to 3/4" beyond what I would have arrived at if using true 2 3/4" loads.

 

Of course, since this is an HD weapon, I now only load 5 in the mag tube anyway (to minimize wear and tear on the spring and ammunition), hence "max capacity," in this case, is a mute point.

[Hookster]

FYI I recently needed a new spring for my M1S90 with a +3 extension. Sure Cycle sold me the spring alone that goes with their +3 for $15. Works great!