The answer depends on whether your rifle has an adjustable gas block.

I don't have this rifle, but I do have a Swedish AG42b Ljungman and reload for it. I fabricated a gas block adjuster in order to use Rel 22/Vihta Vuori N165 for the reloads. These slow-burning powders are ideal for the Swedish Mauser but anathema for the Ljungman. The Ljungman's designer, Erik Eklund, told the Swedish ordnance authorities that his rifle would require special ammunition to prevent excessive port pressure i.e. "over gassing." The Swedish bean counters said "hell no" and so the AG42b rifleman was issued an oil bottle and was instructed to oil his cartridges.

Slow burning powders are correct for heavy bullets and fast twist rifling. Their advantages are lower initial chamber pressure and high-density case fill. The disadvantage is excessive port pressure that will damage the rifle's gas system.
If your Zastava does not have an adjustable gas block, stick with service ammunition or equivalent reloads.

 

@Leon
it has indeed a adjustable gas block (0 to 3) and i left it in the lowest (position 1) level but still workable as semi - auto.
How will this "overgassing" manifest on the ejected brass cases?
regards

 

@Leon
it has indeed a adjustable gas block (0 to 3) and i left it in the lowest (position 1) level but still workable as semi - auto.
How will this "overgassing" manifest on the ejected brass cases?
regards

Again, I can only speak from experience with the AG42b Ljungman. Ejected cases flew 75-110 feet/ 22-35 meters downrange and had badly chewed up rims that made them useless for reloading. With my home-made adjuster, brass lands nearer to the firing line and in reusable condition. The original Ljungman would require frequent replacement of the extractor. The "b" upgrade beefed up the extractor, but the rifleman's kit included two spare extractors and the tool needed to remove them from the bolt.

I don't know how the M76's gas regulator is calibrated. I presume it has a "standard" setting and one or more adverse condition settings for fouling or inferior ammunition. If you are using the smallest gas port setting with standard ammo, proceed with caution.

 

@Leon
you can reload the once shot brass a second time = but thats it. After this the brass is not safe to shoot anymore after what i observed with the ejected brass cases. Ejection is acceptable without having the feeling that there is too much pressure behind. Cases are likewise more or less sooted. I am using a light lee factory crimp to insure the bullet will not be pushed deeper inside the case while loading inside the chamber.
I will try to use a less slower powder like N140. As soon i have results to compare i will post them.
Gunboards is great - watch your six always

 

Re "Cases are likewise more or less sooted." Is the Zastava M76 chamber fluted like the PSL's? If so, then sooty cases are to be expected, and desired.
Your Zastava M76 has a long-stroke gas piston system. The inertial mass of the reciprocating components helps absorb some port over pressure, but there is a limit. I have an M1 Garand with the Criterion 6.5x55 barrel. In order to use my standard Swedish Mauser loads, I installed a Schuster adjustable gas plug.

 

I am a fan of the M-75 sniper ammo. That is what I shoot in my German snipers and replicas. A good rifle can do sub-MOA. How much improvement in accuracy can one expect with hand loads?

 

if this ammo is available it would be an option but in Germany Surplus Ammo has to undergo a likewise expensive pressure certification before it can be sold to civilian market. So reloading is the more better option.

 

Those are some good results. Thanks for sharing.