Benelli MP90S .32 jamming

Joddi · Post by **Joddi** » Tue Aug 09, 2011 6:50 pm

Hello shooting friends.
I have got some good advise here before and with the previous problem solved I turn to you again. My MP90S jams very frequently, 1-2 out of 5 shots will jam and shot nr 4 almost always jams. The bullet end hits high while the bottom of the case rests against the boltface below the extractor. Your assistance is greatly appreciated, Joddi

Gwhite · Post by **Gwhite** » Tue Aug 09, 2011 6:59 pm

Not sure about the 32, but in a .22, I'd immediately suspect the magazine.

oldcaster · Post by **oldcaster** » Sun Aug 14, 2011 9:51 pm

I think it is very likely that your crimp is wrong because of different lengths of brass. If your brass has been shot several times it will be longer and can be longer on one side than the other. Not only can this cause inaccuracy but if you adjusted your crimp on a longer case, a shorter case doesn't get the crimp it should and you might not notice it and consequently it will fail as your picture shows. I am only talking about roll crimp and I really don't know if taper crimping will fix the problem or not. Dave Wilson thinks it is a good idea and he has been working on this caliber quite a while so give it some thought. Recently I shot some groups at 50 yards with my Benelli. 20 shots with old brass that varied about .006 and with old brass that was trimmed. Untrimmed gave me 4 1/4 inches and trimmed gave me 2 5/8 inches. Next I am going to shoot the same 20 rounds of long brass but I am going to use a taper crimp. After I get the results I am going to take the brass and trim just enough to make sure the end is square but not worry whether the lengths are the same. I want to prove or disprove whether the brass has to be uniform length or just square in the front and or whether taper crimping might make length unimportant as far as accuracy is concerned.

fsmte · Post by **fsmte** » Wed Aug 17, 2011 9:45 am

sorry my bad english. but can be ramp magazine that is just holding the cartridge in the front. then he rises and rises more quickly than it should. Wadcutter for the magazine should be well regulated to properly hold the ammunition. far right is hard to say.