Gentlemen!

This might sound like a stupid question but what's the difference between the 6.5 SAUM/GAP 4S and the 6.5 PRC? Which one is better in your opinion and why?

Also, how is the recoil of a 6.5 SAUM/GAP 4S vs a .308?

If my memory serves me correctly i'll try and give what I know.

George Gardner of GAP developed the 6.5 SAUM 4s it was designed to be the ultimate short action cartridge as well as offer optimal ballistics for the PRS series which has a velocity cap of 3200ft/sec I believe. Part of the design philosophy was to run long barrels with slow powders(H1000) to get the velocity rather than wringing the performance out by high pressures which ultimately attributes to excellent barrel life in proportion to the performance delivered. The one caveat of the 4s is currently hornady is the only brass available (some form brass from 7 saum norma brass and ect...)

The 6.5 PRC to my understanding was a Hornady/Ruger project that George of GAP helped work on. it too is aimed at the PRS market and is built with similar design principles of the 4s but uses the RCM (ruger compact magnum) as it's parent case rather than the SAUM. The 4s has slightly more capacity over the RCM.

For general purposes there so similar you could likely flip a coin and choose one. The big difference that I see is the RCM is backed by Ruger and Hornady so it could potentially go further in the market just due to the backing of such a giants. don't get me wrong the 4s has it's followers but most who run the 4s have to coin to spring for the best. the PRC could bring a new crowd into the ever growing sport especially when off the shelf guns like Ruger RPR hit the market.

In short the 6.5 PRC was in my opinion designed to pick up where the 6.5 creedmoor leaves off and offers maximum performance within the rules of the game (PRS). It should be an interesting year when they hit the market. and with the BC wars going on and offerings like the new 150smk with its touted .713 G1 BC the velocity the PRC/4s can deliver will be a game changer.

As to recoil there are so many variables it's hard to compare. (weight, braked vs non brakes, ect...)

Thank you for the very helpful reply! So out of a 16-20 inch barrel, which do you think would be a better round out of those two?

In terms of recoil, I was referring to having a Remington 700, with a fluted heavy barrel with maybe an AAC Brake and the barrel length at 16-20 inches long, in a Manners T6A stock. How would those rounds compare to a .308 in this set up?

Also, will it fit into my Manners T6A Remington 700 SA stock? It has an AICS for a 308 in there.

Thanks again!

your looking at the wrong tool for the application IMO. with a 16-20" barrel you will be better served with a plain jane 6.5 creedmoor or even the 6.5x47 lapua. part of the 4s/PRC's design parameters is slow powders with long barrels. doing that with a short barrel is likely going to yield equal to possibly lower velocities than the other cartridges mentioned and with a lot more blast. granted you could run faster powders and ramp up the pressures and still pick up some velocity over the others but at what cost? a lot of wasted powder and likely some serious throat erosion. you also will likely run into load density and es/sd issues vs the appropriate sized cartridges for the task.

I don't personally own a 4s/prc but if I had to venture a guess I'd say recoil would likely be more than a standard .308 load and probably along the lines of a heavy .308 (think 208gr) or 30-06 from a hunting weight rifle no brake. again purely a guess. an efficient brake and heavy setup really can tame recoil.

unsure about the mag compatibility. I've never looked for aics pattern short mag mags.

Don't know much of the PRC, but I do have a 4S. It's 9 lb 15 oz all up and with a Dead Air brake it doesn't recoil any more than a 308. Purely subjective, but the recoil impulse is a very mild shove.

If you want a magnum 6.5 I would go no less than 22-24" on the barrel, instead change up the contour if weight is a concern. I'm running a Brux #5 on a M70 in a McM Game Scout and it handles great. If you end up with a typical precision rig (15 ish lbs) recoil will be a non issue, especially with a brake.

I have a floor plate but as for mags Accurate WSM mags are the go to IIRC.