I apreciate all the valuble info on this thread and would like to give many thanks. I am in the beginning process of doing an SBS on my Saiga-12. The Form 1 with paid tax is on the way to the NFA branch of BATFE. I plan to have Tom at Cadiz Gun Works do the job for me and cut the barrel to the factory 16.5' to produce a factory correct Saiga-12 K. He did this gun under warrantee and did such a fine job that the gun runs on 1 oz. low brass Remington with the 19' barrel. The gun was a Vodka special and has three gas ports. I want to use this gun for our monthly subgun matches when we include the shotgun. We only allow the use of low brass bird shot and I would like this gun to continue running the 1 oz. low brass after the barrel is cut to 16.5'. Does two to three inches less barrel make that much difference in back pressure? Any reply would be appreciated.
Yes, a 16.5" barrel will produce less gas than a 19" barrel. There's no way for me to say whether or not it will run a specific ammo. I suggest you tell Tom your intentions when he does your work..