I'm about to find out! I finished a trigger job on my stainless M77 7.62x39 this week. Hopefully, I'll get a chance to shoot some this weekend if the dang rain holds off.
I don't think this round is inherently bad. You have to consider that 99.9% of people's experience with it is cheap military surplus crap. Fine for shooting tin cans, lousy for award winning accuracy.
Take the article Shooting Times did on CZ's 527 in 7.62x39 two years ago. Surplus ammo was typically awful. However, commercially loaded Federal 123 gr. PSN printed nice 1.69" groups. Handloaded with a Sierra 125 gr. bullet pulled that down to 1.27" groups. Not to shabby for an ultralight rifle.
The problem is the Ruger rifle. Yes, that's right. The Ruger is bored for .308 diameter bullets, and it has too slow of a rate of twist. The CZ 527 is bored for .311 diameter bullets. This caliber is designed for .311 bullets.
The poor quality mil surp and the slightly better Russian commercial ammo are both .311.
The cheap American ammo is .308.
The highest quality American and European factory loads are .311.
Don't blame the caliber. Blame the moron that first thought that is was a good idea to "standardize" on .308 diameter.
EDIT: I apologize if I seem rude. I get very frustrated by the whole fiasco. $350 for that ruger is a decent price, but you must find loads that have bullet diameters of .308 or load your own.
I posted this reply from Davidson's Gallery of Guns website a few months back on this very same topic. It is a reply to my request of the bore size on the Ruger M77 in 7.62x39. As she states, the info came directly from Ruger. Davidson's is located in Prescott, Arizona, same location as the factory that builds Ruger rifles:
Ruger's groove diameter for the 7.62X39 caliber cartridge for either the Mini-30 or model 77's is .3100 - .3115 according to their engineering dedpartment. This is a compromise diameter designed to shoot either the .308 or .313 diameter ammo
that is available.
A .311 diameter bullet would be my choice for handloading applications if available.
I hope this helps!
Rebecca L. Gridley
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