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

Fabricating the Front Trunnion = Part 1

Now with a milled stub, the original receiver was a milled - not sheet metal. The stubs actually give you what you need to make the trunnions! If you compare the stub to an AKM trunnion, you can see the heritage and also where the steel needs to be removed.



The receiver sub was cut with a bandsaw just behind the shoulder. The length of the Yugo stub is now the same as the comparison Hungarian. The next step will be to equally grind down both sides with a groove to accommodate the sheet metal receiver.

When the Soviets moved to a stamped sheet-metal receiver, they still needed the forged trunnions for strength and they wanted to minimize tooling changes otherwise. The inside dimension of an AKM is 1.25". By cutting the stubs to length and milling or grinding the portion of the stub that sits in the receiver to the correct width and length, you are actually creating the needed trunnions from scrap metal. With that said, to be safe, I would recommend still counting the part as foreign made for the sake of 922r just to be safe.

Drilling the Trunnion Holes

To allow for mocking up the build, I decided to use screws as fasteners for the trunnions. True chest beating arguments have ensued on the Internet over the use of screws versus rivets. The fact is that the only proven fastener for the AKM under full-auto combat use is the rivet. Now with that said, many semi-auto civilian AK rifles have been assembled with screws that are locked in place with Loc-tite high temperature thread locking compound and not had any failure.


This article will use screws, but the reader could change the design to use rivets or even later remove the screws one at a time and do solid plug welds with a MIG or TIG welder. As for myself, I decided to do my first screw build and took the time to plan for a result that was as strong and reliable as possible. I had a good secondary motivator as well — the milled front receiver did not have the interior recessed locations for rivets to be squished because the receiver was not designed for rivets. Rather than mill them into place, it further prompted me to try screws.

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

Recommended Articles

See More Recommendations

Popular Videos

Kyle Lamb and Eric Poole talk SIG pistols

Kyle Lamb and Eric Poole talk SIG pistols

G&A Editor Eric Poole and Viking Tacticals's Kyle Lamb talks about 2 new pistols from SIG Sauer and a Lipsey's Special of the P365.

Performance Center M&P Shield M2.0

Performance Center M&P Shield M2.0

From Smith & Wesson, the M&P Shield M2.0 is a great option for a carry gun with optics option.

Ruger introduces Rifles Chambered in the All-New .350 Legend

Ruger introduces Rifles Chambered in the All-New .350 Legend

Two Ruger American Ranch rifles and the AR-556 MPR are now chambered for Winchester's .350 Legend cartridge.

M134 Mini-Gun

M134 Mini-Gun

While filming the 2018 season of Guns&AmmoTV we had the unique opportunity to fire the M134 Minigun.

See More Popular Videos

Trending Articles

The last of Germany's infamous Elefant tank destroyers. Historical

World War II German Elefant Tank Destroyers

Neal S Shera - July 12, 2019

The last of Germany's infamous Elefant tank destroyers.

Want the “Holy Grail” of AR-15 rifles? Brownells has made that possible with their BRN-Proto retro rifle. Rifles

Brownells BRN-Proto Retro Rifle

Patrick Sweeney - July 02, 2019

Want the “Holy Grail” of AR-15 rifles? Brownells has made that possible with their BRN-Proto...

No one can restore receptivity to another Trump term with these disaffected gun owners but the president himself. 2nd Amendment

2020 is Trump's to Blow with Gun Owners

David Codrea - July 09, 2019

No one can restore receptivity to another Trump term with these disaffected gun owners but the...

Rhode Islanders are setting brushfires for freedom once again as they advance a Second Amendment Sanctuary Town movement. 2nd Amendment

SPECIAL REPORT: BIG 2A HISTORY BEING MADE IN LITTLE RHODE ISLAND

John Peterson - May 22, 2019

Rhode Islanders are setting brushfires for freedom once again as they advance a Second...

See More Trending Articles

More Gunsmithing

As someone accustomed to AR-15, M14 and M1 rifles, I can't say I'm a huge fan of the AK-47, but I Gunsmithing

Krebs Enhanced AK Safety

Gus Norcross - May 07, 2014

As someone accustomed to AR-15, M14 and M1 rifles, I can't say I'm a huge fan of the AK-47,...

This fixture holds Mauser receivers and barreled actions in a bench vise, drill press or milling Gunsmithing

Brownells Mauser Receiver Holding Fixture

SGN Online Editors - August 12, 2014

This fixture holds Mauser receivers and barreled actions in a bench vise, drill press or...

Cerakoting of firearms has become hugely popular, more so for decoration than protection, although the finish does both. Gunsmithing

Cerakote - The Hottest Finish in Firearms

James Tarr - February 14, 2019

Cerakoting of firearms has become hugely popular, more so for decoration than protection,...

In Part 2 we left off with our gas system installed, ready to screw on the fore-end tube. Most AR Gunsmithing

Building a Heavy AR-15 Varmint Upper Part 3: Final Assembly & Test Fire

Gus Norcross - January 27, 2014

In Part 2 we left off with our gas system installed, ready to screw on the fore-end tube. Most...

See More Gunsmithing

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW OUR CURRENT ISSUE

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

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