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 Trunnion - Part 2

The smooth-sided milled receiver lies nice and flat. It's easier to drill it before shaping the sides and making it irregular. Center punch the hole locations, use good cobalt bits and plenty of cutting oil. The big hole is where the barrel pin goes.


A screw pattern similar to a Hungarian was center punched. The top rivets followed the centerline of the barrel to absorb recoil. I purposely relocated the lower back holes up in the trunnion so they went through thicker parts of the trunnion wall, allowing for more threads and a more secure screw.


With the decision to use screws made, I proceeding with the build. The two front holes on each side were drilled using a #10 drill for 10-32 button-head alloy screws. The rear lower hole on each side was drilled using a #3 drill to accommodate º-28 button head alloy screws. Larger screws were use to accommodate the torque expected during recoil. I did not tap the holes yet, as the receiver will need its holes drilled and the easiest way is to do that with the receiver on the trunnion. Rather than risk the threads being damaged, they will be tapped after the receiver is drilled.


Also, spend some money and buy quality drill bits and taps. The quality in cheap imports can vary dramatically at your expense. I wait for them to go on sale at http://www.use-enco.com and then load up. Shopping at industrial supply stores/websites can save you a bundle while also delivering quality.

In case you are wondering, I drilled the holes at this point because the receiver is flat sided and easier to support compared to after the shaping is done and the sides become irregular. For me, when I can think of it, simpler is better.

Recommended for You

CZ-USA's handy CZ 527 7.62x39mm bolt gun now accepts a sound suppressor. Rifles

Suppressor-Ready CZ 527 Review

David M. Fortier - July 22, 2019

CZ-USA's handy CZ 527 7.62x39mm bolt gun now accepts a sound suppressor.

Sturm, Ruger & Company, Inc. introduced three models of the Ruger American Rimfire rifle with Go Wild Camo I-M Brush stock and bronze Cerakote finish. Rifles

Ruger American Rimfire with Go Wild Camo I-M Brush Stock

Ruger Firearms - July 10, 2019

Sturm, Ruger & Company, Inc. introduced three models of the Ruger American Rimfire rifle with...

CRKT makes 17 different knife models exclusively for Ruger, from fixed hunting knives to tactical folders, and many of their models are offered in several different styles. Accessories

Ruger CRKT Knives Review

James Tarr - July 08, 2019

CRKT makes 17 different knife models exclusively for Ruger, from fixed hunting knives to...

See More Recommendations

Popular Videos

Springfield Armory Saint Victor in .308

Springfield Armory Saint Victor in .308

The Saint Victor in .308 features a 16" light weight barrel, M-LokĀ® free float hand guard and included flip-up sights.

M134 Mini-Gun

M134 Mini-Gun

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

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.

See more Popular Videos

Trending Stories

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.

If you want to keep the peace, keep and bear arms. Don't give up your guns. Any other choice would be ridiculous. 2nd Amendment

Is Red Dawn Really Just Ridiculous? If Not, Who Would Citizen Disarmament Help?

David Codrea - May 29, 2019

If you want to keep the peace, keep and bear arms. Don't give up your guns. Any other choice...

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 Stories

More Gunsmithing

AGI's Certified AR-15/M4 Riflesmith Course includes DVDs with Complete Disassembly and Reassembly, Gunsmithing

AGI AR15/M4 Riflesmith Course

SGN Online Editors - July 06, 2014

AGI's Certified AR-15/M4 Riflesmith Course includes DVDs with Complete Disassembly and...

On the bench in front of me was a customer's M&P Shield he'd dropped off complaining about the Gunsmithing

Apex M&P Trigger Kits

Gus Norcross - July 11, 2014

On the bench in front of me was a customer's M&P Shield he'd dropped off complaining about...

Melonite is very resistant to corrosion and is claimed to be a better treatment then hard chrome. Gunsmithing

Sarco Melonite Finished M4 Barrels

SGN Online Editors - April 30, 2014

Melonite is very resistant to corrosion and is claimed to be a better treatment then hard...

See More Gunsmithing

GET THE MAGAZINE Subscribe & Save

Temporary Price Reduction.

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW OUR CURRENT ISSUE

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

×