MDI SLR receivers come loose.

Armedsask said:
Lock washer on a flat washer completely negates the lock washer.
Click to expand...

Typically, A lock washer is never used directly on bare metal part, like a nice smooth anodized surface, as it will gouge.

Part > Flat washer goes on smooth side down(Yes look at a washer, one side is smooth all the way around to the other side which has a edge from being stamped, put it on incorrectly and it will leave a ring mark as you tighten down) > Lock washer on top > Screw

Most people never bother with this but if you are assembling parts going into a corrosive environment, do it wrong, and the part is SCRAP! If you have inspectors and QC people watching and recording they will slap your pee pee for this rookie mistake.
 
Last edited:
Sqr said:
I am beginning to think that a number of issues is with owner error and not the product.
Click to expand...

Not sure how you can owner error a bolt when he says he tightened it. Maybe not everyone has gotten an identical product.

Glad to hear a few more positive stories hopefully the bolt backing out is limited to just a few units.
 
Beater said:
that's a great lookin rifle Uisge did you have the dreaded loose bolt problem? I'm around 400 without that problem. I have only ran 55 and 62 gr so far
Click to expand...

No, no problem there. Only got about 100rds though it though. I may try to spin down a nord lock as suggested above though, unfortunatly the smallest one I have is a little bigger than the bolt dia. So it may not be possible without a trip to the bolt shop. The takedown bolt does not have a very large surface under the head to work with.
 
Well I spun one down, was tricky, had to take a lot of material off. It works but not as good as an unmodified one, I am going to try and find a box of the right sized nordlocks.
 
I'm wondering how common the issue is...?

I remember when everyone was freaking out about XCRs losing parts and really the issue was people not using a torque driver properly. Is this the same issue? Will torqing to a certain spec prevent loosening or is the design prohibitive to long term bolt/screw retention? How common or wide spread is this issue?

Personally I don't see loc-tite or locking washers as anything more than a band aid solution but if I can torque to spec and avoid the issue I'm totally ok with that. Did you guys with the issue get a torque spec from MDI? Did you use a calibrated wrench? Any info you could provide would be greatly appreciated for those of us still on the wait list
 
Last edited:
I beat mine like rented mule regularly. I've got nearly 1000 rnds through it since August and I've never had to tighten the take down bolt once.
 
What is wrong with locktite? As long as the bolt doesn't budge it's not load bearing. I agree pins would be better...but if it stops it from rattling loose.
 
b_w. said:
What is wrong with locktite? As long as the bolt doesn't budge it's not load bearing. I agree pins would be better...but if it stops it from rattling loose.
Click to expand...

It's a stop gap - if I can torque the set screw to spec and not have it come loose that's one thing but I shouldn't have to use adhesives to keep my upper/lower together.

If I already owned one I'd probably put up with it but at the moment I still have the option of the MS. I'll have to do some mulling and make the call sooner rather than later.
 
b_w. said:
What is wrong with locktite? As long as the bolt doesn't budge it's not load bearing. I agree pins would be better...but if it stops it from rattling loose.
Click to expand...

Locktite is likely to take the heli-coil with it when removed. You might get away with blue, but red on a clean dry heli-coil can cause heartache.
 
Uisge said:
Locktite is likely to take the heli-coil with it when removed. You might get away with blue, but red on a clean dry heli-coil can cause heartache.
Click to expand...

The OEM bolt is polished which also has a small diameter head that can be switched out for a regular pistol grip bolt of the same length. These bolts have a rougher texture and a larger head that will not fall out past the capture screw.
 
The owners of MacDef are deleting comments about their design flaw on the slr builders FB group. Figures. Shady greedy losers.
 
You must log in or register to reply here.
Back
Top Bottom