MPA RAT base slips on MPA chassis

[LC 6.5 Shooter]

MPA rat base slips on MPA chassis when loading bipod. I get it on as tight as I can by hand. The only way to get it to not slip is to use a 4.5mm allen wrench to tighten it. Anyone else have this problem and a solution?

Just a note. When I run it on the spigot with a rat base instead of my magneto I dont have that problem. Its like it doesnt fit the chassis as good.

 

[ToddM]

Might need to contact MPA, sounds like one or the other is a tiny bit out of spec. I only takes a tiny bit in these dovetail systems and they simply won't hold. JP had problems with their prototype chassis slipping and evidently all it took was getting the amount they compensate for paint -vs- anodizing wrong.

This is IMO why the Arca/RRS/dovetail rail system(s) are problematic, it only takes a tiny bit out of spec across the manufacturers and even within the same manufacturer and things slip when loaded. I've seen bipods fall off at shoots after the user had not noticed them slipping during the day. Dovetail provides quick adjustment and a fairly non-obtrusive (compared to a full length pic rail) that allows full forearm use, but it's prone to slippage. Someone really needs to make a new combination something like a dovetail rail with shallow spaced scallops so you get the advantage of full adjustment, but the solid lockup or more than just a wedge.

Also none of these "knob" dovetail QR work well, RRS had to change their knurled knob on their bipod plate because people could not get them tight enough to stay and IMO even the new knob is a poor bandaid. What they really need to use on these things is the camming style QR used in mountain biking wheels/seats, some clamp tight enough you can snap the steel bolt.

Low profile short QR levers will never provide as tight of a lockup as hex bolts/nuts will, knurled knobs are even worse. It's the reason Geissele will not make a quick release optic mount.

 

[chrismartin]

That's the reason Aera 419 came out with their ARCALock rails and clamps. They use a sawtooth pattern on the edge of the dovetail to mechanically engage with their clamp.
Luckily, I don't have an issue with my MPA and RAT Harris Base

 

[Eric32]

AREA 419 arca lock rail solves that issue

*Beat me to it*

 

[ToddM]

Yep that's the way to do it, figured it wouldn't take the shooting world long to figure out Arca by itself was a poor application under recoil, the problem now is though is will they adopt it as a standard, license it to other companies, and will those companies pay to use it. Otherwise it's just one company making a very limited product suite.

 

[HogsLife]

Area 419 Arca Lock Rail. Solid piece of gear and ZERO slip.

 

[65shootmoor]

Only issue I've had with mine is the knob seems a little undersized to really torque down. I've had mine slip because of that, I didn't get it as tight as I'd like. Wish it was a lever instead of knob.

 

[anginaprinzmetal]

I hadn’t had any issues
I own three of them
Matter of fact only issue I had was w Area419 Arcaloc and pins not well aligned (I know that’s an user issue, but the system works as intended only if the locking pins are perfectly aligned)

 

[jwood1284]

I’ve had the original knurled knob RRS clamp on my Atlas for over a year, and have never had it slip. It has been on a RRS plate, Sawtooth plate, and a MPA chassis. I’ve used it in 7-8 matches without issue.