Met a guy at the Tulsa gun show about 25 years ago. He had the table next to mine. He had several sniper rifles for sale. He told me that he did work for the USMC and he welded the scope mounts on several of their rifles because that was what they required. The guy look somewhat Oriential. Does anybody on here know if what he said was true or not. He had several snipers including Winchesters, Remingtons, and 303 British. All with the scope mounts welded on.
After the Vietnam War, the USMC analyzed the M40's performance in the field and they identified areas of improvement for the weapons system. One of the upgrades that was requested was a more solid scope mount, so the early transitional M40A1's had welded Redfield scope mounts.
The M40 used a Redfield 40X scope base and Redfield low rings (with 4 top screws), whereas the transitional A1's used either a Redfield 40X or 700SA scope base and Redfield medium rings (with 2 bottom screws). Even though the scope remained the same (matte green Redfield), they increased the barrel diameter and needed the medium height rights to ensure clearance of the objective lens housing. The Corps also purchased more Redfield scope bases with the new medium height rings, these were the 700SA bases (the original USMC M40's only used the Redfield 40X base).
The first few welded Redfield bases/ring sets were very poorly done, and the early welded mounts had random sloppy welds, pinned rings and epoxy filling in gaps. The welded mounts were soon standardized and had 4 welds per scope ring (the scope base's windage screws weren't welded). The 700SA mounts needed a channel milled into the front side of the front ring, which allowed access to the front receiver screw hole. All of these modifications were done by the 2112 armorers at the RTE shop in Quantico. These welded Redfield mounts were used from the mid 1970's to about 1982, when the Corps started receiving their new Unertl scopes and mounts.
In 1980, the Corps received 25 Unertl mounts for testing, but Unertl mounts didn't exist yet. So, these first 25 Unertl scopes were used with the welded Redfield mounts. The Unertl mounts were actually based on these welded Redfield mounts, but with added features like the integral clip slot and bullet nose lugs. As a note to collectors and rifle builders/cloners, if you can't find a Unertl mount for your early A1 rifle, weld the correct Redfield base/rings into a mount and use that instead. Hundreds of these welded Redfield mounts were used for the better part of a decade (with both the Redfield and Unertl scopes), so there's plenty of historical precedence and your clone A1 will still be correct.
I have about 2 dozen original USMC welded Redfield mounts, the vast majority have 40X bases, only 5 of them have 700SA bases. The earliest welded mounts have sloppy welds and other unique characteristics, whereas the rest of the mounts are very standardized in the way they're made. One of the best known photographs of a welded Redfield mount being used by Corps was featured on the cover of Gung-Ho magazine in April 1981. In this photo a Scout Sniper is using an M40A1 with a very early welded Redfield mount (we know it's an early mount because of the sloppy welds) and a prototype Unertl scope.
I actually have this exact welded mount in my collection! If you compare the welds on the front right side of the mount (where the front ring attaches to the base), you can see that the magazine cover mount and the mount in my collection are the same one. I acquired this welded mount from Colonel Chandler about a decade ago, so it's provenance is solid.
Here's one of the welded mounts when they became standardized with the 4 welds per scope ring, this one has a 40X mount (notice how the front receiver screw hole isn't obstructed by the front ring):
Here's one of the 700SA welded mounts (notice how the front receiver screw hole is partially obstructed by the front ring):
The 2112 armorers had to cut a channel in the front ring in order to access the mount's front receiver screw. Normally, the base would be screwed to the receiver, then the rings were attached. However, this obviously wasn't possible to do with everything welded together, so this is an absolutely necessary modification when using a 700SA base on a welded mount. The cut in the front ring was done before the ring was welded to the base, here's a photo of this modification:
@black1970, I have no idea if the person you met was an old USMC 2112 armorer, but if he was a 2112 in the late 1970's, there's a chance he could have made welded Redfield mounts (and possibly even the ones in my collection that are shown in these photos!). I'm not sure if I answered your questions, but I hope this information helps in some way!