One someone happen to know the grade or specifications for the two locking and clamping bolts that lock/hold the LMT MRP barrel to the upper?

The torque specification calls for 140 in-lbs (11.67 ft-lbs) and based on my calculations that bolt is really has a good stress on it.  I am no way doubting the LMT engineers, just digging into the details, as I always do.

Thanks,

77

Have you asked LMT?

Someone a while back was trying to find less expensive alternates and this was discussed...probably not an area to "go cheap" in.

I suspect that LMT might keep the actual spec proprietary just to keep people from making unauthorized substituions.

I don't know the material, but I know they are designed to shear before the upper gets ruined.  That's why I think they are worth the $10 per they charge for extras.  I haven't needed extras yet (knock on wood).

Yes I have, but I did not talk to the right person, I will call them back.  As far as extras, I do know this, this is a special ground down bolt, to an exact dimension, not just any bolt will do, as it is threaded on the end only......this is an engineered bolt....it is designed as a dowel pin, to keep the barrel in exact axial position.  The bolt looks to be .250" diameter, to fit the groove in the barrel extension, which has the same radius as the bolt, my guess the groove is +.001/-.000 bolt radius (bolt diameter/2)

The more I look at the design of the LMT MRP, it is one heck of a good design, no doubt they thought this one through....that is why this brand is my prefered AR, sold my collection to buy jsut LMT.

77