Benelli MP90S .32 problems

[JiriK]

This is an old Benelli MP90S World Cup in .32 S&W Long WC. Bought it new in 1997.

Last time I tried to shoot with it, it went full-auto. Twice during the first three series in the precision stage of a competition...

I cleaned and adjusted the trigger mechanism and tried again this Tuesday. No full-auto that time but ejector flew off (/broke, I haven´t found the part yet) after 12 rounds. So I ordered new ejector, that little spring that pushes the ejector holding pin and a new buffer. All Benelli original parts.
I ordered new recoil spring from Larry´s guns mid 2012 and replaced it then.

Today I shot 120 rounds, 24 series of five shots. There were maybe two series without a malfunction, but I had two malfunctions in several series so these pictures show what happened on average in every series: https://www.dropbox.com/sh/gvvlplttlf6q ... HhaTJ0jJaa
There was also one case where the bolt could not pick a new cartridge from magazine and instead made a scratch in the shell.

Tried my own reloads and "Magtech" factory loads with both magazines. No difference there.

What causes this? Bad magazines?

Borrowed a Manurhin MR32 Match revolver from a clubmate today for a test - thinking about buying it. Will solve all the feeding, ejecting and full-auto issues I´v had with this .32 Benelli. Also no need to worry about spent .32 shell hitting me in the head after firing.. Happened three times today. Not fun.

[Dipnet]

JiriK,
I don't know about the MP90, but I had the same thing happen to me with a Walther GSP 32. It turned out that I had the trigger pull weight adjusted way too light and suspect that recoil alone caused the sear to disengage and fire the next round. Five rounds can disappear very fast (I was grateful it didn't happen at a match).

Any rate, increasing the pull-weight of trigger pull solved the problem. Dipnet

[JiriK]

Thanks, I already cleaned and re-adjusted the trigger mechanism. No doubles or full auto so far.

Tried to shoot again today. First three series ok, no malfunctions. Then one or more malfunctions in every series.

Noticed at the range that my magazine is cracked a bit just behind part that throws the shell out. Tried the other one but no help there. Looks both magazines have a crack forming at the same place..

https://www.dropbox.com/s/03cbntvq5hqwt ... 01_Pro.jpg

[Dipnet]

JiriK
Sorry to hear that, but it sounds like you've discovered the cause.

I think I've seen a listing for MP90 mags for sale in recent month or so on Target Talk (can't remember whether they were for a 22 or 32). If you can't find what you need, I would place a WTB query for 32 Benelli mags. Best, dipnet

[Leon]

You can buy just the magazine housing from Larry's Guns....

[JiriK]

You can buy just the magazine housing from Larry's Guns....

I didn´t find the part in their website, but emailed them. We´ll see if they have parts.

[Leon]

You can buy just the magazine housing from Larry's Guns....

I didn´t find the part in their website, but emailed them. We´ll see if they have parts.

Good luck -Larry's were able to supply me with a Benelli .22 magazine body. They weren't advertised either.

[JiriK]

They have .32 magazine body in stock - so I ordered two.
http://www.larrysguns.com/Products/32-m ... _097P.aspx

edit: That was fast! Ordered 2 x magazine body last Friday. Received them today (Tuesday) USPS and Finnish postal service performed brilliantly! Will test tomorrow.

[JiriK]

Ahh.. the ejector broke again. What am I doing wrong?
https://www.dropbox.com/s/zceh0u5loyl1i ... o.jpg?dl=0

Feeding and ejecting worked ok after I bought new magazine bodies, but now.. I could still finish the practice session.
Last competition of the season is this Sunday. We´ll see how well the pistol works this time.

I bought the 14-2 revolver I asked about in that other thread. But I still need to make a proper grip for it.. so I´ll shoot this competition with Benelli.