Here's the issue. I have the above rifle, a ZM Weapons LR300. It uses a charging handle that is very similar to, but also very different from, a standard AR-15 charging handle.

I would like to have a new one milled out of 7075T6 because mine was damaged. Fortunately, I still have mine available for comparison and measurements.

Does anyone have knowledge of a verified good CAD file for a charging handle? Ideally, I would love an ambidextrous charging handle, but I'm concerned about clearance issues at the rear, because the channel is cut high and back further in order to clear the taller gas key.

The plan is to start with a basic charging handle, and modify the file from there. Then I'll need to find someone to make it for me! I know that this is a big project.

Any and all suggestions or pointers are welcome. If anyone knows anyone willing to assist, please let me know.

Thanks for the help guys!

I'd just draw the CAD from scratch.  A charging handle would be a really quick an easy thing for an experienced person to draw.  Also, not horrible as a first project if you don't have experience.   Fusion 360 is free for hobbyists.    Get a set of calipers and go to town.

I'm not a machinist, but the hardest thing I see is getting the radiuses right.

Sweet rifle.  I always wanted one of those but just couldn't justify the cost of them back in the day.

Even more so after playing S.T.A.L.K.E.R Shadow of Cherynobl

The best set of drawings would be the ones from the TDP (Technical Data Package).  I don't know if anyone (other than Colt) has made a CAD file.  You can start with that and make changes based on measurements taken from yours.  But, you'll have to do all of the drawing.

I wound up buying a CAD file from rifleconnection.com, and had a friend (who also has one of these rifles) work on it to try to come up with a file for this charging handle. We currently have a file ready for printing or CNC work.

He came up with the idea of 3D printing one out of polymer to test the fit and dimensions, anyone know who could provide the service like that?

If the 3D printed plastic one works out, then I would just have to find a machinist willing to make it, I have a couple of possible leads for that locally. I'm planning on having three total made out of 7075T6 aluminum, one for him, and two for me.

I could print you one.  Wouldn't cost anything but shipping.  If you wanted to save on shipping though, lots of libraries and such have printers.  Should be plenty of local hobby people with a a printer also.

I called around a few places today, and I'll call a few others tomorrow. But I sent you a message! Thank you

No problem.  Only takes a few minutes to set up and print.

Got it going now, should take a couple hours.

Attached File

Got it printed.  The dimensions match the CAD drawings you sent, at least as far as a set of cheap calipers goes.  Should be close enough to verify fit and function.

Attached File




Only thing I spotted that might need to be changed is the fillet around the top that starts where the circle is.  I think it could be deeper.  For that section, it might be best to slightly overestimate the depth rather than go under.

Attached File


Let me know where you want it sent and I'll get it mailed out.

I think these were made under contract by Yankee Hill Machine

Thank you so much!



Yes they were, and that was one of my first phone calls. They told me that they don't have access to the files anymore, as when Para USA bought the rights, they lost access.

Did the charging handle fit?