M870 Euro Grip - FAQ

Is it safe to run my M870 on HPA?

So long as you run around 100-120psi, it should be fine. Expect HPA to cause more wear and tear on the replica since it’s expected to run at lower pressures. Inspect and maintain all the seals at regular intervals.

How do I fix the small leak between the grip and my M870?

If a leak occurs upon installation, check both faces the o-ring butts up against for any burrs or damage. If a leak occurs later on, it’s likely the same o-ring (#104xN70 Buna) that’s been damaged, or the grip may have loosened.

Do clone MR2 regulators work?

We’ve found that most of them work. It’s important to inspect all components and verify that all seals are good and the components are machined to tolerance. It’s highly recommended to disassemble, remove the factory oil, and regrease them with TechT. There are a few that have been more reliable than actual Polarstar MR2’s due to the more robust Body ID o-ring, but we would still recommend using the real thing. 

Why is my regulator spinning?

Although this happens most commonly with the Polarstar MR2, the CAT5 is also prone to this. Usually, the setscrews haven’t dug into the body of the regulator enough, or they have backed out. 

For the CAT5, tightening the set screws should be sufficient. 

For the Polarstar MR2, it’s recommended to swap the cone-type #4-40 x 3/32” setscrew for cup-type or, even better, knurled cup-type. 

For clone MR2s, it’s recommended to swap the flat-type M3x4 setscrew for cup-type or, even better, knurled cup-type.

If you purchase a clone MR2 from us, we’ve already QC checked, relubed, drilled divots into the regulator body, replaced setscrews, and installed stainless steel thread inserts to mitigate any issues.

It is recommended to avoid bottoming out your tank to prevent the regulators from locking together and to lubricate your tank O-rings with PTFE grease. 

For more information, please refer to our lifetime warranty or contact us.

Instructional video in progress