Bud Hyett
posted this
15 December 2016
This is what I have read. Dr. Hudson, a renowned single--shot shooter, experimented with gascheck and was promoting their usage in Schuetzen before WW1. However, WW1 interfered with the shooting sports. After the war, there was a decline in the Schuetzen sport except for isolated areas such as Davenport, Iowa Gas checks were used on military rifles such as the Lyman 311284 with the .30 US Army (Krag) or the .30-'06 Springfield..
With the birth of the ASSRA after WWII, the choice was plain-base because that was what was in the literature and in people's memory. The soft lead bullet and breech-seating are the modus operandi with a single-shot rifle. The plain-base class in CBA and the ASSRA / ISSAS matches have a dedicated following and are fun. I do this because I enjoy the challenge and the sport.
I am not against experimentation, but I am also stuck on tradition. One is beginning to see bolt action rifles used in the Plain-Base class with a breech-seater looking like an oversized bolt. I suppose these could be used to seat a gas-checked bullet into the rifling for experimentation. And there would be no reason they could not compete in any class except plain-base.
As to the function of hte gas check; it is there to clean the bore and have consistent bore condition from shot to shot. If you recover a bullet in an oiled sawdust box and examine it, you will find a thin ring of lead on the leading edge of the gas check. This is where the sharp copper edge scraped the bore clean of lead deposits asit went down the bore.
Ed Doonan and I shot many bullets into an oiled sawdust filled recovery box in an attempt to answer this question. The same bore condition from shot-to-shot is a factor in accuracy. We adjusted velocity, lube amount and shot several rifle barrels with a range from new to worn-out in this search. All the gas checks showed at least a little lead on hte leading edge and helped formulate this theory.
Farm boy from Illinois, living in the magical Pacific Northwest