TargetTalk

Just found this forum. Years on RimfireCentral and Benelli forums but neither particularly helpful with the MP95E/MP90 family. Larry's was always my go-to for questions, parts, etc. Wish I had known about this one. Probably would have saved me my current grief. As noted as a possibility in a number of posts here, the hammer spring tension finally blew out the bottom of the plastic trigger housing. Years of storage with the hammer cocked (yeah, I know - the other sites have no mention of this issue) caused the thing to give up the ghost. I see that Larry's successor, Red Feather Outfitters, has replacement trigger housings for sale. Can those of you here in-the-know advise whether there are any special considerations when removing the parts from the original housing for re-installation in a new housing? My history with this type of thing usually includes the unanticipated launch of some small part across the room never to be seen again. Trying to get ahead of such an occurance with this one. Any advise?

The trigger housings from Red Feather are not tapped for the front takedown pin spring plunger, or either of the two trigger screws. One of my summer projects is to design a 3D printed tapping guide to help with that. One additional catch is that the factory uses undersized taps, so the screws won't come loose. Using a regular tap with a threadlocking compound should work, but many standard threadlockers (like Locktite) aren't compatible with a lot of plastics. I have a contact who may be able to get info on the taps the factory uses. Otherwise, I will try this stuff:

https://www.zoro.com/vibra-tite-threadl ... /G6282109/

You apply it to the screw, and let it dry, so there are no volatile chemicals to attack the plastic (I hope). I will test this on a dead housing at some point.

As far as launching parts, do it all inside a dry cleaning bag.

Drilling and tapping tiny little screws? In a trigger assembly? Puts it well beyond my "armorer" (parts replacer) classification and approaching "gunsmith". Maybe I'll call Benelli "customer service", see what they have to offer. That has only been marginally successful in the past with their shotguns. Something they don't even import any longer? Yeah, right. Not optimistic there.
Thank you for the input Gwhite. I appreciate it. The replacement housings from RFO are cheap enough. Maybe I'll get 2 or 3 with the first 2 being sacrificial experiments.

Benelli USA currently provides no support for the pistols. If you can wait a bit, I can at least provide a tapping guide that can be 3D printed. That would make it pretty trivial for a gunsmith to fix, especially if I can figure out the threadlocker situation.

I've got four that exploded over the pandemic. I usually make sure they are fully de-cocked before they get stored, but the college where I coach kicked us out of the range on very short notice in March of 2020. When I checked things out last fall, the damage was done.

Gwhite wrote: ↑Sun Jun 05, 2022 7:40 pm Benelli USA currently provides no support for the pistols. If you can wait a bit, I can at least provide a tapping guide that can be 3D printed. That would make it pretty trivial for a gunsmith to fix, especially if I can figure out the threadlocker situation.

I've got four that exploded over the pandemic. I usually make sure they are fully de-cocked before they get stored, but the college where I coach kicked us out of the range on very short notice in March of 2020. When I checked things out last fall, the damage was done.

Bummer. Maybe we can convince Benelli/Italy to let us do a group buy of the MP90 housings. :-D I understand that they're aluminum.
Thanks for the offer. Keep me in your loop. I'll see if I can't go ahead and make a purchase for some replacements up front anyway.

One problem with the current MP90 housings is that they changed the way the front pin is held in place. In the old design, there is a spring loaded plunger that engages with a groove in the pin. They have gone to a fancy pin with a folding latch, and the spring loaded plunger that would work in the older pistols is absent. I bought one of the new triggers before I found this out. We haven't tried it yet, but I suspect the older pin will "walk" in one direction or the other. If that is consistent (right or left), machining a pin with a head would fix it. If that doesn't work, I'll have to drill & thread the housing for the plunger screw. I'm not sure all the MP95 trigger parts will work in an MP90 housing. Most of the parts are the same, but the trigger adjustment screws are different.

OK, an update. I ordered three replacement MP95 Atlanta trigger housings from Red Feather. After inspecting and comparing the new housings along with a lot of consternation and contemplation of worse-case scenarios, I started punching pins and unscrewing screws out of the original housing, being careful not to launch the tiny little pieces/parts into oblivion. I was able to figure out what I thought would be a reasonable progression of disassembly and things went very well. Gwhite, you are correct that the takedown plunger and trigger adjustment/return spring holes are not tapped. However (this is why I purchased 3 housings) I guessed that tapping the holes wasn't necessary. The takedown pin plunger, the trigger adjustment plunger and the trigger return spring grub screw will simply thread themselves into the plastic housing and essentially tapping and locking themselves into the material of the housing nice and tight. Putting everything back together went along OK. I did launch the sear spring twice (got lucky twice) and had to fabricate a slave pin to put the trigger/sear back in the housing. Function checked everything and all appears well. Well, almost. So far, I have been unable to get the safety selector off the original housing. I'm coming close to stripping the tiny little allen screw heads so I stopped messing with that at the moment. It's my understanding that some models of this gun didn't even have a safety selector and looking at how it interfaces with the trigger a lack of a safety doesn't impede the proper operation of the firing mechanism. I'll continue to work on that since I certainly prefer having the safety since it came equipped with one. Mine is also one of the versions that doesn't have a disconnector as part of the trigger mechanism so that was one little part I didn't have to contend with. As of now, I'm happy that I don't have another expensive paper weight. In the future I'll quit putting it up with the hammer cocked. Now, TO THE RANGE!!

Interesting! Installing the screws without tapping might be the way the factory does it. Given the plastic's tendency to fracture under stress, I hope it doesn't let go at some point.

I'll check the hole sizes. There are "thread forming" taps that basically push the material around to form a thread without removing any material. If the hole dimensions match up with what would be needed for that, it should be OK. That would certainly simplify things considerably.

As far as the safety goes, for a pistol exclusively used for competition, the safety is entirely unnecessary. I believe most target pistols sold in Europe don't have them at all. They are required for import into the US, at least for new pistols. I've seen used target pistols (not Benellis) for sale that were imported with no safety.

The very earliest design of the MP90S used a different safety, mounted on the bottom of the trigger assembly. It slid back & forth, and I believe it blocked the hammer strut from extending out the bottom, preventing the pistols from being cocked. They switched to the lever arrangement in the mid-90s', possibly with the introduction of the MP95. The older frames don't have the clearance milled in the frame for the rotating lever safety, so if you need to install a later model trigger, you have to remove the safely levers, or machine the frames. A previous coach for my team swapped a lot of stuff around, and performed this modification on some triggers. I'm still trying to get all the old triggers matched up with the proper frames, but it hasn't been a priority.

I think the screw may be held with threadlocker. I've only done a few, but always managed to get them out OK. If they do use threadlocker, sticking a soldering iron in the hole for a bit may free it up. I strongly recommend using the best hex keys you can find. Bondhus ones have always worked well for me. Other brands (even some "good" ones) can run undersized, or the ends are sheared instead of ground. That often leaves the end distorted and at an angle, significantly reducing the engagement in the hole.

Yep, the soldering iron method was going to be my next attempt but at this point it isn't a priority.
As far as the self-tapping part, those things went in smooth as butter and didn't require a lot of extra force to get installed. Didn't feel like they were overstressing the housing going in. Once in, they feel nice and tight but will start to come out with about the same amount of force that it took to get the out of the original housing. They aren't things that would be coming out on a regular basis anyway so I'm gonna call it good. Still not a gunsmith. Just an armorer. :-D

Thanks for the additional feedback on the force required. I just went through the numbers, and the hole diameters match pretty closely to what one would use for thread forming taps in metal. Your discovery will save me a LOT of time & headaches.

I think I will still 3D print a guide to make sure the screws go in straight, but that should be very simple.

I've got until September to rebuild four triggers. I'll report back on anything new I learn in the process.

I took one apart, and I can see where the plastic is pushed back out around the hole from one of the rear screws. That wouldn't happen if they used any sort of conventional thread cutting tap. I'll try to get a good photo or two tomorrow.

Things just got a bit weirder. I've been working on making 3D printed guides to make sure the screws go in straight, and I discovered that only ONE of the six housings I bought from Red Feather is unthreaded. (Just my luck to start working on that one...) That means I can go ahead and fix the four pistols that have already exploded, and have one spare that is ready to go. I have no idea why Benelli sold the two different versions unless the unthreaded ones were a mistake, or they are from two different shipments, and they decided to change what they were providing.

The team I help coach has ten MP95E's total. The ones that exploded are mostly from pistols with serial numbers below 2000, so they are quite old. We have three that have serial numbers over 9500, and those will probably be OK for a while. We have one trigger that let go that was in a pistol in the low 6000 range, but it's quite possible the trigger got swapped with an older pistol at some point.

Interesting. I purchased 3 and all were unthreaded.
As to my safety lever removal, that didn't go well at all. Just short of stripping them I did the heat application thing to no avail. Ended up drilling the screw heads to get the lever out of the housing but there's no putting it back into the new housing. As you noted the gun works just fine without it. On a whim, I've ordered a couple of the housings without the safety lever slot just to see if it will all go back together in that housing and function properly. The OCD in me dislikes having the un-filled hole in the housing and none of replacement parts appear available anywhere.
My gun is in the 4500 range so is an older one as well. I purchased it new in December of 1995.

I've rebuilt one trigger completely, and have been working on detailed notes on the process. I will do the other three using those notes and see how it goes. I did thread the one unthreaded housing I have. The first stage adjustment screw is REALLY short, and starting that straight is tricky. In order to help get the threads started straight and save wear & tear on the real parts, I used longer (2 cm) hardware store screws to start the threads, and then finished up with the actual parts.

The one safety I've removed gave me no trouble with the screw. I'll see if any of the others give me grief. I also found a bag of safety parts removed from 2 triggers so they could be used in the older frames, and there was no sign of heroics applied to the screws. I'm not sure why yours put up such a fight.

Losrobles: Please check your private messages (in upper left). I put together an extensive step-by-step procedure for doing a trigger rebuild, and I'd like your comments on it before I go public. You are the only person I know who's also been through the process.

Thanks!

After re-building 4 triggers and re-assembling them into pistols, I've cleaned up my notes for those who may follow in my footsteps... I've attached a PDF with detailed instructions on how to transfer all the parts to a new trigger housing. Red Feather Outfitters did have some in stock, but it's not clear how long they will last. If you don't mind skipping the safety, they do have a fair number of housing without the holes for that feature.

https://www.redfeatheroutfitters.com/search/101p/

Many thanks to LosRobles for providing the inspiration to tackle this problem, and especially for his discovery that the three screw holes don't need special taps.

While re-organizing our parts collection, I found another exploded trigger. I'll provide an update if I find any more short cuts when I rebuild that one.

I cleaned up my notes a bit, and added an Appendix with drawings on how to make nice tools to do the threading & magazine catch work more easily. It JUST fits under the forum 513 kB file size limit...

what a fantastic write up - great work!

Thanks! Now that I am mostly retired, it's nice to have time to document stuff like this properly. Fixing one problem once is useful, but there's a lot more to be gained if I can write it up. Given that I had 5 of these to fix, it was a no-brainer.

I may have to revisit this in 5 years for the team I help coach, and at my age, I will have forgotten half the details. If I get hit by a bus, somebody else will have to deal with it, and there's no point in reinventing the wheel. Being able to put it online to help others is an added bonus.

I love shooting & part of that is working with precision equipment. It was really gut wrenching to open up the team safe after the pandemic and find four of our pistols in pieces. Now that I know they are relatively easy to fix, I (and others) won't have go through that in the future.