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Arca / Rat Atlas mount

Way_ky

Sergeant of the Hide
Full Member
Minuteman
Jan 13, 2020
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New to the MPA chassis. Got an Atlas PSR with Arca Lock clamp coming from a trade tomorrow. Will it work on the RAT rail or do I just need to trade the mount to a quick detach?
 
It's their own dovetail cut ARCA dimension. It is not the same as RRS, which anybody can use, and even get templates for. MDT is one company that has chosen to go with the RRS standard. I'm sure there are others.

I have taken my RRS clamp with bipod and made it slip on my MPA chassis. Can't remember what it was I did testing it, but I have heard of people have gear slip on them in competition. I can try the exact same thing with a RRS rail and it not budge. Have yet to try my MDT rail for my Oryx but it's cut to RRS so I doubt I'll have issues.

There is no actual industry standard. There is RRS, and what anybody else wants, like MPA. The consumers im sure wish it was standardized to RRS.
 
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Pretty sure only the early MPA's had the wonky spec'ed rail. I think just about everyone these days goes with the RRS spec ARCA dovetail. I certainly don't have any issues with mine, and its several years old.
 
Pretty sure only the early MPA's had the wonky spec'ed rail. I think just about everyone these days goes with the RRS spec ARCA dovetail. I certainly don't have any issues with mine, and its several years old.
mine was castle cut with inclinometer and lug lock so pretty recent still. had bipods fall off on barricades. slip prone. and thats cranked tight

i hear there might be a new product coming out to help with hand tightening A419 and RRS clamp knobs
 
My RRS clamp locks 100% solid on all 8 of my MPA chassis.

Edit, I have used it on 7 of 8... #8 I have not tried but see no reason it wouldnt.

All mine have Castle cut also I believe
 
It's their own dovetail cut ARCA dimension. It is not the same as RRS, which anybody can use, and even get templates for. MDT is one company that has chosen to go with the RRS standard. I'm sure there are others.

I have taken my RRS clamp with bipod and made it slip on my MPA chassis. Can't remember what it was I did testing it, but I have heard of people have gear slip on them in competition. I can try the exact same thing with a RRS rail and it not budge. Have yet to try my MDT rail for my Oryx but it's cut to RRS so I doubt I'll have issues.

There is no actual industry standard. There is RRS, and what anybody else wants, like MPA. The consumers im sure wish it was standardized to RRS.

thats interesting to hear. I just assumed the ARCA was the standard that everyone machined their stuff to. Didnt realize RRS was the standard. I thought ARCA was a cross industry item since it started in the photography side of things or am I confusing that with something else.

I have an MPA in the mail right now, Im curious what the dove tail will be milled to now
 
Arca is just a loose term for a rail with dovetails cut on either side, no specific dimension. That’s why screw knobs were so popular with photography companies. Since they wouldn’t share info with each other since they are still all tight competitor