M70 LA with remington .308 barrel

[JMBD2112]

I went with a buddy of mine to pick up a Matthews bow he had found on CL and it was at a pawn shop here in town. They had a few rifles on the wall and one in particular caught my eye, It had what seemed to be a benchrest stock, wood, maybe walnut, not to sure. The forend at the base was was maybe 2 1/2 to 3 inches wide. Here's the kicker, it was a model 70 long action with a Remington stamped barrel chambered in .308. The barrel had a rather large diameter, definitely bigger than my 5r that has a .850 bbl. The guy at the counter told me it was an actual M24 barrel, which I'm not to sure about. I didn't see any engravings that said US M-24 or the USMC with the ordnance symbol like on the M40's. I've talked to a couple other friends that said they had heard in the Vietnam era their were some rifles made that may have been slapped together like this one. I'm curious if this maybe something worth while, or if it's some franken rifle. Any input would be greatly appreciated.