Ruger NO 1 in 30 Viper?

Anybody ever heard of these? I was looking up ser# of some of my No 1s and this came up. ser# 132-57560 30 Viper Shipped in 1984 model # 01349
ser# 132-57555 30 Viper Shipped in 2006 model # 01349
There was a bunch of them in consecutive ser#s

Got this off the Ruger Site!

It does indeed show that on the serial number look up. Never heard of this.

I think they were No.3's and were a military training aide for rocket launchers, or something like that. Lane Pearce wrote an article on them in an old RCA Journal. They were not rifles and only used the action and some other parts.
CLN

Actually, I think the caliber was 30 Carbine and it was called Viper.
CLN

30 VIPER RECOILLESS RIFLE TRAINER

Developed during 1976 as a lower cost sub caliber training device for the VIPER shoulder-fired assault weapon. The first tests were done at the Pomona Division at General Dynamics and utilised commercial 22 Hornet cases loaded with 5.56 M196 tracer. Various other combinations were tested at Eglin AFB but it was the 7.62mm M62 tracer that gave the best stability at the reduced velocity needed. During 1979 these M62 tracer bullets were loaded in 30 Carbine cases. The first specimen is one of the first loadings that were done on commercial cases with the M62 bullet with orange tip. It was seated to the cannelure to confirm seating depth, set up tooling for loading as well as "show-and-tell" for General Dynamics management. I FOUND THIS

30 VIPER RECOILLESS RIFLE TRAINER (SHORT CASE)

During late 1979, there were concerns that standard 30 Carbine ammo could be chambered in the VIPER trainer and cause malfunctions or extend the range of the trainer. This led to the chamber being shortened so that normal 30 M1 ammunition could not be used and the cases were trimmed to 1.10'' The bullets were loaded to the cannelure to give an OAL of 1.880". A small lot was made up using 150gr. Hornady bullets with orange tips. The cases were once-fired and hand trimmed to the shorter length. There shorter cases were however not necessary and no further development was done.