In my opinion, I think you may be going about this all wrong. What's the purpose or purposes of this rifle?
I'd pull the Picitiny rail off .... & add a nice scope with a set of Ruger rings, since the receiver is set up for them
Nothing wrong with that but that's one of the main features / advantages of the rifle, to have the forward-mounted scope. Any turnbolt can do that... So, *so far*, you don't 'need' a Ruger GSR rifle to do what you want to do. PM me if you want forward-mounted scope ideas - they really are a benefit, IMO. In other words, leave as is, is what I'd do, and use that feature.
replace the flash hider with a compensator
Why? To reduce recoil? It makes the gun extremely loud, and the point of this gun is actual field use under varying conditions, for various purposes, where you will not have hearing protection on. You don't want a loudener on a gun like that. The flash hider you just might want in a night shooting situation (however theoretical). A .308 doesn't recoil that much. As for muzzle flip - meh, you have to cycle manually anyway - during the time it takes to cycle, the muzzle is back down with no additional marginal time.
And you could thread almost any rifle for that, so again, you don't really 'need' the GSR so far.
also anyone know how hard it would be to convert one to use the M-1 magazines like the Mossburg does ???
Do you mean M14 mags?
& one more... does Ruger offer lower capacity magazines... I like to casually shoot off the bench on my personal range, & the 20 rounder I think sticks out too far to shoot how I would normally.
Now you're on the right track and asking the right question... But perhaps not yet the BEST question, which is, does Ruger have a rifle that doesn't take ANY mags but just has a fixed floorplate? The answer is yes of course, and that's my roundabout way to ask - why on EARTH would anyone want a detachable mag on a turnbolt, ever? It's just something to lose and get in the way and it offers no advantage over a fixed internal mag. None. When are you really going to switch mags out? Would that ever really happen? If if you find yourself in a firefight, since by definition, you've just *found yourself in a firefight withOUT a semi-auto fighting rifle*, the only point is to escape and evade (i.e. retreat)... so you only need to fire some suppressive fire to allow for displacement, or if fighting a lone enemy, end the engagement decisively in your favor - 5+1 of most turnbolts should be way more than enough to do that, and if it's not, then you should be retreating. I understand the theoretical concept of needing more ammo, but I think it's solely theoretical, and that's *including* far-fetched (but not impossible) SHTF-WROL scenarios.
But, having said that, if you DO buy into the idea that you will need that full mag (and extra mag) for a firefight (SHTF-WROL), then you're back to a situation where the OTHER two features that you plan to do away with would become indispensable (potentially): The flash hider to hide your position, and the forward mounted scope to get off shots on moving enemy targets who are shooting back while seeing the big picture with huge forgiving eye relief, not a little exit pupil with a narrow eye relief window as on a traditional scope.
See what I'm getting at? Either you go all-in with the concept or get a regular turnbolt, seems to me. And you also give up bbl length with that rifle. I'd rather have at least 18" or 20". And the stock weight doesn't match the bbl weight.. You've sacrificed velocity with the 16" bbl for a good cause (weight savings), but then used that really heavy stock, eliminating your gains - why?
Even if you do want that short of a barrel, you can cut ANY .308 to 16 with a cut-crown-reblue job. Heck, probably less than $150 for cut-crown-thread-and-reblue.
I'm a believer in the scout rifle concept (except for the detachable mag part), but it seems like you're trying to go out of your way to assemble the worst of all worlds in features. for an all-purpose rifle: Heavy stock, traditional scope placement, loudener, short barrel (make the loudener EVEN louder still), detachable mag.
Sorry, I just don't get it. Nothing wrong with your result - still a pretty good rifle. But for the concept that IS the Ruger GSR, the only thing you should change is one of the things you alluded to - getting a 10-rounder rather than a 20-rounder, for shooting prone, etc. Leave everything else as is and put an IER scope on it.
Oh, and one final thing: 7mm-08 is a better chambering for a scout rifle ... So get the Savage. Sorry, had to.
(although the Savage may not come in 7-08 anymore - used to).
YMMV.
Midway has 3 round & 10 round mags for the Rugers, $29.00 in stock...
Oh, good.
-Savage Hog Rifle. Plain jane, no frills, but the two I've been around are
shooters. No box mag, but a threaded muzzle to attach whatever you want.
The 20" med heavy tube feels just right to me.
Now you're talking. That's seems more like what you want. Or at least what *I* would want in your shoes.
You said you like to shoot casually off the bench. A 16" .308 is very unpleasant to shoot in those conditions, or any conditions really - and that's withOUT a loudener. There's a happy medium between 16 and a 22 or more.
Now, if you took the Ruger GSR, and did two things - replaced the heavy wood stock with a carbon-fiber filled, fiberglass & graphite stock, and converted it to a fixed mag with floorplate, (then added an IER scope), you'd be cooking with butane and have a raison d'etre for your 16" bbl. In my view.