Skip to main content Skip to main content

Building a Hybrid Yugoslav M70B1 from a Stub with Screws

Building a Hybrid Yugoslav M70B1 from a Stub with Screws

George Spafford is building a replica of the Yugo M70B rifle using a stub parts kit. A new installment will appear here every Friday

Installing the Rear Trunnion

Here is the unique Yugo M72 rear trunnion. An M70 trunnion would have a spring loaded crosspin that blocks the recoil spring base's channel until depressed. This prevented the heavy Yugo cover from jarring loose under the extreme recoil of a rifle grenade launch. Since I never plan to launch rifle grenades, using a M72 trunnion that lacks the retaining pin was not a concern.


I bought an aftermarket RPK rear trunnion, as they are readily available from a number of sources including Apex and R Guns. I drilled its two rivet holes out with a #3 bit and then used the AK-Builder trunnion jig to locate the holes for it. Honestly, my only regret with this jig is that I didn't buy it sooner.


In terms of screws, I'd definitely recommend using at least 1/4" screws in back to resist the recoil they will take. You can run a smaller tap and screws, but the connection would be too weak, in my opinion.

Tapping the rear trunnion using the drill press to ensure the tap is vertical to the work piece. With a 1/4" tap, you can get it started, but the torque required will likely make you choose to use a hand tap wrench partway through.

Next, with the #3 holes drilled into the rear trunnion, I tapped the holes in the same manner as the front trunnion using my drill press to hold the tap square as I manually inserted. Note — do not apply any Loctite yet. You'll want to do that after testing. I'll mention this again later, but when you do want to finalize the screws, use Loctite Red 2760 as it is impact resistant and makes a very solid bond.




GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

Popular Videos

FN 509 Tactical

FN 509 Tactical

Patrick Sweeney Reviews the FN 509 Tactical

New from Rival Arms

New from Rival Arms

Tyler Kasper of Rival Arms talks about the 2019 offerings from the manufacturer.

Diablo Double-Barreled 12-Gauge Handgun

Diablo Double-Barreled 12-Gauge Handgun

Patrick Sweeney tests the Diablo double-barreled 12-gauge handgun by American Gun Craft. Also, see his full review in Firearms News Issue #1, 2021.

See All Videos

Magazine Cover

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW OUR CURRENT ISSUE

Buy Digital Single Issues

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Firearms News App

Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get the top Firearms News stories delivered right to your inbox.

Phone Icon

Get Digital Access.

All Firearms News subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now