A Semi-Auto Scout Rifle?
I would pretty much echo Jmr40's comment.
By the way, here's the link to a Forum dedicated to Cooper's Scout Rifle (SR), it's theory, practice, and accessories, and about anything else that's relevant and "Scout-ish."
http://www.scoutrifle.org/index.php
Savage is upgrading the stock on its scout rifle, and it now looks like this:
https://www.range365.com/savage-110-...-accufit-stock
For me, the problem with Savage's Scout variant was my range experience with their very earlier first entry. While not junk, I thought the one an acquaintance at our club allowed me to examine and shoot was flimsy, fragile-feeling, and not terribly accurate (at 100-yds), although that had nothing to do with the forward-mounted Leupy scout optic. It was probably the ammo. While I definitely liked the receiver mounted aperture sight, it looked easily broken if somehow bumped hard, let alone if the weapon was dropped while hunting in the boonies. As far as I recall, it wasn't stripper clip loadable. I wanted to like it but decided to pass.
That said, Savage's newer version, as well as Ruger's GSR entry, both look to be sturdier, more robust specimens of what a field-practical Scout rifle should be.
In fact, had I not pursued trying to adapt most of the attributes of Cooper's
bolt SR to a
semi-automatic platform, I'd probably already have one or the other, or maybe a custom.
Instead, coming from a Service Rifle/Match shooting background with the M1 Garand and the M1A, and having already spent a few thousand rounds behind my 18" 7.62/.308 Tanker, I felt the M1 provided a 'Scout-ish' platform I'd prefer over a bolt - at least for now.
I'd already seen a full size M1 ('06 chambering) at our range that had been outfitted by the owner with Ultimak's forward rail mount, on which he'd attached a LER pistol scope in QD rings for hunting. After watching him run three or four 5-rd "hunting" clips through it and seeing how it grouped at 100-yds, I was convinced the mount was rock solid and the platform had merit. But it would need to be shorter and lighter to be of practical use. The upside consideration, of course, was that the M1 weapons-system already has the best and sturdiest battle sights ever fielded anywhere in the world, and the Ultimak set-up eliminated the need to modify or remove the rear sight to mount an optic. Obviously it was clip fed, again without interference of a receiver-mounted scope.
I was aware of S.A.'s 16" SOCOM with the forward rail, but I already some old "beater" M1s for doner rifles (being old DCM 'Rack Grade' M1s I picked up for cheap long ago). So those ended up getting re-purposed into 'Scout' configuration.
Shuff's Parkerizing built me two 16" Mini-G faux-'Scouts' using Ultimak forward rail mounts. One of the RG's had a salvageable USGI barrel, so I retained the '06 chambering, and essentially it's become my dedicated "hunter" Mini-Scout. On the other, the GI barrel was a tomato-stake anyway, so Shuff re-barreled it with a 16" Criterion in .308. Super accurate, that one is my "all-around" Mini-scout.
Either Mini can run a 2.75x Burris or 4x Weaver scout scope in QD rings on the Ultimak, or a RDS, or just go it irons-only. Both are great shooters, although the '06 is a bit blasty, but for the one or two shots needed when deer or hog hunting, it's not bad. The gas systems on both are regulated by Schuster Mfg.'s adjustable gas plug, which allows you to 'tune' the gas-driven op rod to the particular load you're shooting and achieve reliable cycling.
What's the downside to a semi-auto Scout built off an M1 (or an M1A, for that matter)?
Well, it'll never make Cooper's weight specs. Possibly 'Scout-erizing' an
M1 carbine might, but I've never been a fan of the .30 carbine cartridge, so that sort of project never interested me.
The use of a detachable mag as part of the SR set-up is more of a personal choice, IMO. Both of my Minis, being clip-fed, are 50-states legal.
Plus, where a state's hunting regs permit use of a semi-auto, most (though not all) have mag-capacity limits. So the ability to use 5-rd en bloc clips, like the stripper clips used to feed a bolt gun's 5-rd internal ('box') magazine - which is what most of Cooper's early Scout variants were - keeps the weapon legal in the boonies.