Building a Hybrid Yugoslav M70B1 from a Stub with Screws
December 30, 2011
George Spafford is building a replica of the Yugo M70B rifle using a stub parts kit. A new installment will appear here every Friday
Range Testing & Results
The hybrid M70 is secured in a rifle stand that is safely pointing into a berm at the range. A heavy magazine bag is holding the rifle down and a string is tied to the trigger. The rifle functioned flawlessly.
Once the rifle was assembled and function tested, I took the rifle to the range and shot about 90 rounds it. I started with a single round loaded in the rifle manually and the rifle was secured to a stand with weights over it. A proverbial string was tied to the trigger. From behind a tree I pulled the string and the rifle tested just fine. I carefully inspected the spent case. The primer indentation looked fine and the case did not bulge. I did this careful inspection for three rounds and then I started loading multiple rounds into the magazine testing feeding, ejecting, etc.
The cases of the first three rounds were carefully inspected after each firing. I wanted to make sure the firing pin didn't pierce the primers and that there wasnÃt any bulging of the cases. No problems were detected with the first three or over the course of several hundred rounds. It highlights the value of taking oneÃs time, doing things the right way and not skipping safety checks such as ensuring the headspacing is correct.
With this build it ran flawless. It also really highlighted how fast the screws loosen up without Loctite. To be honest, I expected them to loosen but not that fast. I was testing with an Allen wrench and found screws coming significantly loose within the first 20 rounds. It further reinforced the benefits of rivets in the AKM design.
Recoil started to loosen the bare screws within 20 rounds highlighting the need for Loctite. In the author's opinion, this highlights why heavy use AKs use rivets to create secure mechanical connections between the sheet metal receiver and hardened forged trunnions.
Not too bad for 20 rounds at 50 yards fired from a bench. The tighter cluster of 14 rounds is about 4 inches and spreads out to 8 inches. Bearing in mind the very worn state of the barrel, using Golden Tiger off the shelf ammo and that I am using iron sights, I am pretty happy! I forgot my front sight adjustment tool that day so correcting the sights had to wait for another day.
In short, I was very happy with the build. The heft and balance of the rifle are a delight. Recoil was trivial and accuracy was actually better than I expected given the barrel. The trip to the range allowed me to verify that everything was right and the rifle was ready to move on to the next step — securing the screws and refinishing the rifle.