You need a standard set of 7.62X39 head space gauges (go and no-go), these will be more costly than the mosin gauges because 7.62X39 head spaces of the case shoulder, which requires more complex machining to make.
Your best bet would be to take it to a gunsmith, unless like previously posted, you want to collect these rifles and can justify the cost of the gauges.
Also, checking head space on a semi-auto is more complex than a bolt action, The bolt needs to go into battery properly with the go installed, and must not go into battery with the no-go installed, and must not fire out of battery.
NRA Lifetime Member Since 1999
"I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason
Last edited by iraiam; February 25, 2013 at 04:20 PM.