tech related ?'s

[rukh013]

I'm looking to put a UL frame from a proto pmr on a super thin custom rail

How far down from the top edge (where the body sits) to the RT sear pin?

is the sear needed, can I just trip the on/off with a pneumatic piston?

What is the front of the sear for? not the "bolt hook", the nose

What would be the easiest way to make the concave rail top using a drill press?

[OPBN]

Rail specs and tolerances are pretty tight. Honestly, I would just contact Luke and have him mill up what you're looking for.

[knownothingmags]

Rail specs and tolerances are pretty tight. Honestly, I would just contact Luke and have him mill up what you're looking for.
i would +1 this more then once.

luke is your guy for mags for sure.
XMT as well.

just make sure what you are asking is specific. being general is dno good when tight specs are involved.:

[rukh013]

I was hoping not to spend to much, I guess I'll pm Luke on the rail, what about my other ?'s

[knownothingmags]

I'm looking to put a UL frame from a proto pmr on a super thin custom rail

How far down from the top edge (where the body sits) to the RT sear pin?

is the sear needed, can I just trip the on/off with a pneumatic piston?

What is the front of the sear for? not the "bolt hook", the nose

What would be the easiest way to make the concave rail top using a drill press?
UL frame question for you,

are you jumping on the band wagen?

or are you getting it for comfort?

the reason i ask is because its been done.

yes you can trip the on off all on its own, but make sure you spec this correct it.
***if you dont you will mosly likely destroy many on/off's before you get it right.

[rukh013]

I love the ergonomics, had a pm5 w/ a UL

Trying to mate the body lines on a chord body with the pmr UL frame using the thinnest rail

[athomas]

I'm looking to put a UL frame from a proto pmr on a super thin custom rail

How far down from the top edge (where the body sits) to the RT sear pin?Search the tech info. I think its in a sticky. You can find a cad drawing. It will have the dimensions I suspect.

is the sear needed, can I just trip the on/off with a pneumatic piston?Yes, the sear is needed. It holds the bolt from going forward due to the pressure in the front chamber. The on-off is used to close the air path to the front chamber before the bolt is released by the sear.


What is the front of the sear for? not the "bolt hook", the noseThe front of the sear prevents the sear from rotating forward until the bolt has fully reset. The ensures the bolt is reset before the on-off can open. If the on-off were to open before the bolt was reset, the air flowing into the chamber would prevent the bolt from resetting and wouldn't allow the sear to catch the front of it.


What would be the easiest way to make the concave rail top using a drill press?Use a ball nose mill bit and a cross sliding vice or table. If your drill press does not have good side to side rigidity, then it won't work well. You won't have good tolerance. If it does have good rigidity, then it is the same as a mill.

[rukh013]

So with help ive got my tooling method and concave size (1.125")
can't find the spacing on the top of the rail to the center of the sear pin (both classic and RT)