This one was originally a USGI Springfield M1 Rifle and converted to "Tanker" configuration by Federal Ordnance who roll marked "Tanker" on the left side of the receiver and on one of the receiver legs. I got it very inexpensively -- because it was highly unreliable. A Springfield Inc. built rifle should be more reliable than this was.
The rifle fired quite accurately, but had constant failures to extract. Ripped the rims of some cases and merely bent others. The rifle had the roughest chamber I've ever seen and the gas system apparently let way too much gas thru the port. The bolt was trying to extract the cartridge while there was too much gas pressure in the chamber and the case was stuck to the rough walls. I spent a year with this "Hobby" rifle getting her running well. Polished and polished the chamer, and used a McCann adjustable gas nut to bleed off excessive gas pressure.
Once I got her running well she sent me to the poor house shooting .30-06 at 25¢ a shot. At the time good surplus 7.62mm NATO was under 10¢ so a couple of cases of the same ammo I already shot from my M14 paid for a new 7.62mm barrel (fitted by Smith Enterprise).
The Smith muzzle brake in the photo was necessary shooting .30-06. Just left it on after the caliber conversion.
This was a fun project. I've got more money in her than she's worth, but still fun.
-- Chuck