MPA chassis, play in recoil pad assembly?

[mark5pt56]

Just got it in and curios about something before I call. It's the Lite version, set screws to secure the pad and cheekpiece. The recoil pad screws(4) are tightened and it has a wobble to it, stemming from the pad assembly that attaches via roll pins to the two adjustment shafts. Is this normal? Kind of irritating if so. To be clear, the wobble IS from the the loose fit of the roll pins, either the holes in the shafts or the pad assembly are to big. The wobble almost sounds/feels like when you shoulder a loose fitting AR stock.

Appreciate the replies and I really don't need any dickhead responses.

 

[Bandit31]

I had a Hybrid for a very brief amount of time that had the same issue, so maybe it is normal for certain models. I don't have any experience with the other chassis MPA has available as the Hybrid was a one and done deal.

 

[mark5pt56]

Wonderful, so it's a common issue then it sounds.

 

[ChaseCO]

Mine is the same. Initially I was annoyed by it, but now I’ve totally forgotten about it. I was going to just Rocksett or Devon them in place since they should never come out anyway and that would probably take care of it.

 

[Lonestar1027]

My hybrid with roll pins has the same wobble

 

[chavezz556]

Standard

 

[mark5pt56]

Ok, thanks. Looks like I live with it or do a fix. Makes my decision easier when I finally do the Vudoo and will do the Ax chassis instead.

 

[BANG...ping]

Mine is the same. Initially I was annoyed by it, but now I’ve totally forgotten about it. I was going to just Rocksett or Devon them in place since they should never come out anyway and that would probably take care of it.

I found this annoying. I fixed it by taking the butt assembly off and placed locknuts on the threaded rod to tighten it up.

 

[1moaoff]

Simple fix, yes it shouldn't be an issue and it really isnt. I have 5 or 6 of them and I dont really have the issue because I take the threaded part out. I simply set it once and run it.

 

[Meety Peety]

If you have a bag rider, slide it back far enough to put a little pressure on the butt pad and then lock it down. It will take all of the wiggle out of it and also serves as a stop shim for if you ever need to take it off and want it to go back on in the same spot.

 

[BANG...ping]

If you have a bag rider, slide it back far enough to put a little pressure on the butt pad and then lock it down. It will take all of the wiggle out of it and also serves as a stop shim for if you ever need to take it off and want it to go back on in the same spot.

That will only work if you have a short length of pull.

 

[Meety Peety]

That will only work if you have a short length of pull.

Yes at some point the bag rider runs out of room in the slot to move rearward. On all 3 of my MPAs it could probably run out to around 14 1/4" LOP or a hair longer. Folders can get a good amount further since the out of the box LOP is longer on them.

 

[BANG...ping]

Yes at some point the bag rider runs out of room in the slot to move rearward. On all 3 of my MPAs it could probably run out to around 14 1/4" LOP or a hair longer. Folders can get a good amount further since the out of the box LOP is longer on them.

10-4 that. I am 6’ 4” so the LOP is an issue to me. I run the stock all the way back, probably past its intended max LOP, but it works.

 

[bornhunter04]

My hybrid is the same. Glad to hears its not just mine.

 

[Anderson_A]

My hybrid did the same thing I fixed it with a couple o rings but I run it all the way in. my second option was to drill those holes a little larger and put a fastener that would tighten that fit up. I agree those roll pins are not the best way to do that but I guess they were trying to save an oz of weight? otherwise really like the chassis

 

[sharpdoug]

Get the extended bag rider it looks way cooler anyway ?

 

[mercracing]

I have a hybrid on the way. I’ll have to keep these fixes in mind.

 

[MarinePMI]

Mine does that when the set screws aren't tightened down. Once the set screws are...set, the wobble goes away.

 

[mark5pt56]

The Lite doesn't have the adjustment wheels and the set screws are tightened. I wonder why they just didn't drill the holes in the body the same size as the ones in the shaft portion?

 

[Rthur]

Simple fix.
Place stock in vertical position and put red loctite at the top of the joint where the housing meets the shaft.
Wiggle around a little to allow penetration into joint.
Leave in vertical position over night.
No rattles to be found.

R

 

[mark5pt56]

Simple fix.
Place stock in vertical position and put red loctite at the top of the joint where the housing meets the shaft.
Wiggle around a little to allow penetration into joint.
Leave in vertical position over night.
No rattles to be found.

R

Yeah, was thinking of waking green, but have red also.

 

[mark5pt56]

Did the red and it's solid now, thank you. As a side note if you wanted to "mark" and repeat the position of the cheekpiece or recoil assembly, #31 o rings work great. Just have to stack them accordingly, this is a safeguard if screws loosened by chance.

• 9/16 in. O.D x 5/16 in. I.D. x 1/8 in. wall

https://www.homedepot.com/p/DANCO-31-O-Rings-10-Pack-96745/100258186

 

[ChaseCO]

Was going to say after you started this post that I decided to put a drop of loctite 609 (green) at the junction of the rod and chassis. Let capillary action draw it into the joint. Stood it up in the safe overnight, and now it’s locked up tight. Perfect. Glad to hear the red worked as well.

 

[mark5pt56]

Great, glad it helped!

 

[ShtrRdy]

This is an old thread but I came up with a solution to this problem.

I punched the roll pins out of the butt pad assembly and then used an 8-32 tap to thread the holes in the butt pad plate. Thread the holes on both sides. I originally thought I would have to drill the holes out but they are close to the correct size for a 8-32 tap.

Then insert one of the steel rods into the plate so that the original holes lined up and install a set screw and tighten it so the set screw is located on the hole in the rod and it's pushing the rod to one side. Do the same with the other rod. Then install set screws into the opposite side to add a little security.

Pre-installed the butt pad assembly into the chassis and secure the rods with the set screws in the chassis. This gives a solid connection.