Plainfield 12 groove rifle barrel

I initially got into researching the commercial carbines to help Larry Ruth with info for War Baby III. Larry's focus was somewhat limited, and had to be, given all he was researching and working on. So I decided to expand the research and details into what is now M1CarbinesInc.com to add to and complement Larry's work, but not plagiarize it. He and I shared whatever we found, with each other, in a mutual effort to find and document the history.

The time involved in researching the history of so many commercial manufacturers, their suppliers, variations, changes, etc. limited some of the depth of my research into any one manufacturer alone. I'd buy one or two commercial carbines, clean them up, learn, take photos, safety check them, spend time with them on a rifle range, clean them, then sell them to be able to afford one or two more. Obviously I couldn't find, but also couldn't afford, to buy an example of everything, or more than one example of most things.

So I'm no expert at everything, just have limited experience with many. When added to the experience of others, like Larry and folks on this forum, together we likely have more experience than most.

The 12 groove barrels are something I encountered with an early Plainfield and an early Universal. During a time when I was in regular communication with Bob Penny, the founder of National Ordnance. Penny had visited Plainfield, Universal, and others. He'd been in the surplus gun part business for years prior to starting National Ordnance. He was one of the first three commercial carbine manufacturers in 1960.

Penny was my primary source of info on the barrels made by Small Arms Mfg in PA. Several other sources popped up over time. I never made contact with the company as barrels were not my main focus.

As part of my research I bought many back issues of Shotgun News (which I no longer have). The ad below was in their June 15, 1964 issue.



Larry knew of Tri-State Tool in MD but wasn't able to find any info on them. He had info they sold their own carbines. I was able to find the carbines they sold were surplus GI, they made none of their own that I could find. They were involved with buying and selling military surplus during a time when literally tons of it was being sold. I suspect they obtained their barrels from Small Arms Mfg.

Regarding the overall length of the 12 groove barrels and probably other early .30 carbine commercial barrels made by Small Arms Mfg, they were not completed barrels. Whoever bought them, among other things, needed to turn down the front of the barrel for the front sight, cut the opening for the front sight key, finish ream the chamber, create a rear sleeve with correct threading, then create a gas piston housing and install it. The sleeves they created sometimes had the barrel skirt, sometimes not. So barrel length may vary a bit.

Hope someone finds this helpful and interesting.

Jim

Thanks for the information, very informative.

The ad below didn't identify the commercial manufacturer. This one would have been Plainfield or National Ordnance.

Guns Magazine - Sept 1964 - Klein's Chicago advertisement