I’m thinking of buying a 1/8 twist 20” 6.5CM barrel for my scar 17. Does anyone have this setup and have first hand experience?

Are they plug and play with ZERO modifications?

Do they have any issues not swapping out anything but barrels?

Do the FN mags feed the 6.5 well? And do the SR-25 pattern lowers feed the 6.5 without issue when using pmags?

Anyone need to modify gas’s jets with the 6.5 barrel for a saker 762 which definitely is a lot of back pressure for the 308, but the jets come over gassed anyways and went to a 1.35 for 16” 308.

Any recommendations on gas jet size for a 20” 5.6CM shooting the standard bulk 140gr American gunner stuff at 4500 Ft in Utah with a saker 762? Temps vary so can’t give an accurate range but just assume all from below freezing to over 90 F.


Any help on whether or not to buy an 1100.00 barrel and drop another 300 on a rail would greatly be appreciated, otherwise looks like I might have to pony up and shoot a review so we have one. I couldn’t find out much detailed review on em.

I picked one up a year or two ago, sometime before the 20S came out. I have to use the piston and regulator from my .308 barrel but I think you can get complete units. Can't speak to supressed use but I jetted mine up so the cheaper S&B would cycle reliably, don't remember what size jet is in there now.

Overall from my experiences it's about a 1 MOA setup on average (sometimes a smidge better, sometimes definitely more) with factory Hornady ammo, with a random flyer about every 10 - 20 rounds. And by flyer I mean it's like 3 - 5 inches away from the group. Still haven't figured out what's causing it. It'll also randomly just gouge the shoulder pretty bad on either loading or ejection, haven't figured that one out either. If you're not reloading probably not a big deal. Honestly at this point I mostly suspect my jetting rather than a defective product.

I also used the KDG Gen 1 rail in conjunction with it. If you're looking at going the same route you're going to have to trim some of the mounting screws so they don't dig into the barrel.

So far as I can remember it's fed fine from the factory .308 mags when the jetting was strong enough to work the action.

From my reloading I've gotten the best results from Hornady ELD-M bullets, and my barrel apparently absolutely hates Sierra SMK's.

That's about all I can think of right now about it. Overall I don't regret getting it but I definitely still have some work to do with it. My goal is consistent less-than-MOA performance out of it.