Easier to get to the critical area to mill out a bit more aluminum for the clearance.  Better ability to access adjustment.  Lighter as well some, which is nice - but mostly for the better ability to avoid contact with the gas-block.  If Ruger didn't screw that part up, I'd still be running their factory handguard, as otherwise it's fine.  Long term, I might put a 12" carbon fiber handguard on for a fully exposed gas block to just eliminate that whole conversation and keep it light.  Current unit is ultralight and cut open along the top.  Mixed emotions since that will allow heat flow there.  6.5CM barrels heat up FAST, so might interfere faster with optics clarity (mirage) more than factory.  We'll see.

A future trip is planned in a couple weeks to an 800 yard gong range, and I'll be able to do some applied long range sustained fire tests then.

As to carbon fiber - one appeal of this unit is the remarkable cost-effectiveness.  Replacing handguards with a unit 30% the value of the gun, kind of undermines that.  

That said, depending on how this goes. Upgrading to a $1500 PLx line at almost half the weight, might be on the table - if this gun  shoot's MOA level. (Well - maybe, new AC, dog got hurt/vet$$ (he's good now - damned good dog), dishwasher just broke, dremel tool just broke, etc - "gah! Motherfucker!?", right?! (its all good, minor mundane shit really)) We'll see on that too.

Fortunately. I happen to have errands to run that will take me by the range also today - so! A couple hour diversion - shall we?

Had chance to take an extended lunch and test some things out.  Some good news and some oopsies.

First off gun was VERY pleasant to shoot.  Much milder and morso thsn a traditional AR10.  I attribute this to the much lighter BCG mitigating slamming around.




Initial group with S&B 140 gr FMJ, which is generally not very great ammo:  ran it at gas 3, per break in instructions



That's pretty damned great, but that was only 50 yards.

So I took it out to 100 yards .  And it did ok at first and then just terrible!  Weird jams.



(Casing wedged between charging handle and bolt face - that's a new one.

Pissed off. I started checking things.   And sure as shit, my gas block was loose!   That's on me, and will scree up everything.  I thought I torqued it good, but I guess not - loctight next time.  

So!  I actually feel pretty good, but don't have the data to prove it to satisfaction yet.  I'll retighten that up (again, that's on me), and try again.

Also, for as typical, 6.5 CM barrels get HOT , FAST!   We'll see what that affects.  Maybe that contributed to my gas block loosening.

Looks quite good. I'm really considering the 6.5cm . Though,  I'll probably set the bolt , fp , and bbl aside for a bit and tinker with putting my 1:9 25-45 bbl in there and try loading 110gr eld-× at 2.5x" .

I don't think you can just do that (BBL swap) with an SFAR.

Bbl swap , bolt swap , and firing pin swap . The mag will be an ar10-15 hybrid ...

* external dimensions of the bbl ext are the same ... ar15 bolt fits bcg ...and POF fp fits also (with mod to remove small collar)

Can you do that?  I have a doubt that will all fit in the reciever and BCG set.  It's literally an AR15 dimensioned BCG.  Amd barrel extension.   And thread pitch to host BBL extension.

The thread pitch is in the ar15 bbl ext and bbl ...no conflict

* it's been shown that you can literally take the bolt carrier out , replace fp and bolt and use it in a ar15
** I've got the POF fp already modded and it fits fine

*** the one difference with the sfar bcg is it's clearenced for the ar10 mag feed lips ...so I'll probably be better off using the ar15 bcg and removing the ar10 feed lips...leaving the ar15 feed lips .

At around 350 rounds with two malfunctions
All handloaded rounds of reasonable QC

For the guys who have changed the handguards out.
Are you getting any additional gas block clearance?

Yes.

I was surprised to see that, because the MI and factory handguard measured the same. I think my factory handguard was bent. I would guess it bent during shipping. It's the flimsiest and cheapest hand guard I've ever seen.

Amazing how Ruger did some really cool things here... Then they have that handguard, the break, and the plastic castle nut.

Might work for the 20" models to take the factory handguard and mill out a big window around the gas block like the HBI 16" option.
Not a fan of the huge, finger-trapping windows of the factory handguard, but a little machine and finish work might be a good cost-benefit balance.

Really glad to see you got this going.  Can you confirm what parts swap btwn the SFAR & the POF?  W/ or w/o mods?

I don't know for sure between SFAR and POF as that hasn't been my focus . As they relate to the AR15 I can get a bit closer .

* if you're going to use the ar15 bolt and extension  you're going to go with the pof fp

*If using the ar15 bcg in the pof/sfar you'll need to clearance for ar10 feedlips

* my focus has been ; ar15 bolt and extension  in SFAR with POF fp . Long coals .

* I think between the SFAR and POF you're stuck with paired fp , bolt , and ext .

** some good reading material ; https://mdws.forumchitchat.com/post/ruger-sfar-pof-revolution-ar15-another-rabbit-hole-12776122

I just picked up a Ruger MPR 16” 5.56
The handguard out of the box was cracked underneath the front pic rail section. I’m waiting on the Areo Mod 4 handguard to be introduced so that I can replace it. Should be out soon.

My castle nut is actually steel. Weird that the SFSAR has a plastic one?

Even so, I do plan on picking up a 16” SFAR within the coming days.

A few updates on the SFAR.  where mine is the 20" 6.5CM rifle.  If I had my druthers, I'd prefer an 18" and one cut a little thinner after the gas-block, for this mission, but that wasn't' an option.  

I'm up to maybe 100 rounds through it now, and the gas system really does require a break-in.  I had to run gas at 3 for most of that, but by the end, I was able to drop it down to 2.  Just the standard issue of the rifle internals have enough roughness, that they need to smooth-out by wearing in under fire to smooth out the drag.  A little sloppy on Ruger's part, but then - this is a $900 rifle of pretty incredible capabilities and next-gen technology. I'll take that trade.

To update, here are the main modifications I made to mine.

- Replaced the handguard with one that allows better access to the gas system, and better ability to adjust the handguard to fit and assure clearance of the gas system.  This is a 13.5" handguard.  I also put a light weight plastic pic-rail on the bottom, to support QD bipod usage.  



If I were to actually purchase a handguard, I'd get a 12" handguard and have a completely clear gas system - as I'm older school than current, and one of the few who actually LIKE the old A2 and Service Rifle shooter configuration concept of the where the last 4" and gas system are free and clear for access and bulk minimization.  Also, - yes, a conventional current AR15 dimensioned barrel nut and handguards fit the SFAR.  A small wt savings.  Not shown- but also moved the gas-block forward enough so it's no longer directly contacting the shoulder (like 1/64 of an inch level).


used Aluminum Black to reblacking the hogged out metal to make it fit.  Again, if you go with a 12" handguard (for the 20" rifle length gas system), that eliminates all the screwing around completely.


-Marked the stock location to equal A2 full-sized stock length.  Which is one notch in.  An old competitors item, as inconsistent stock setting means a different addressing of the gun, means a different POI.  

Stock is... OK.  Not my favorite look, but works pretty good.


-Replaced the muzzle device with a smaller one that's A2 FH dimensioned, for size and a tiny wt savings.

The .300BO version does a nice job of cutting the recoil while still being small.  And yes, it's a .30 cal break for a 6.5mm dia gun - and as everyone else says, that's irrelevant and it works pretty much completely the same as well.  That, and any bleed is actually a feature, as that tempers the concussion blast, and I don't actually mind.


Accuracy testing went pretty decent today.  Some junky ammo shot 1 MOA.  Some match ammo did not.  One of those curiosities and I'll need to spend some time figuring out what this gun likes.  The first thing I need to do, now that it's broken in, working, and the gas system is properly secured.

Here's the raw dump.

First target

Which was mostly S&B 140 FMJ ball.  Which isn't great ammo - and didn't give really great performance.  It did OK.  My mission goal for this gun is 1.5 MOA.  It got pretty close.  Ignore the reported group size of the center (X spot) group - no idea what is wrong with the calculator there, but the reported performance numbers are wrong.  Just discard that one.  The bottom 4 of this target are S&B 140 factory.  The top left is Fusion 140 gr, with one flyer opening it up.  I've noticed in 6.5CM, when switching ammo, it can take a few shots to recondition/settle the barrel, and that might be the flyer.  See next target.   The top right is teh 129 gr SST hornady light power reloads, which did OK.  Acceptable.

Second target - was junky 140 Fusion reloads made with retire-trash brass and loaded with Am Reloading pulled fusion bullets with random Am Rel repack powder.

Annnddd that's the ammo that shot MOA level, in both groups shown.  It really liked that ammo and bullet. Just wow.  It shot really really well, IMHO.


Third target - is some hot 143 gr Hornady reloads (center and top left).  Which historically don't shoot well in my guns, but actually this gun did OK with it.  I ran this at gas setting 2, and it ran great.  

(wait this is actually my last target, I shot the "forth target" before this one, if you're keeping track.

Fourth target - mixed, but mostly my sweet sweet 140 gr Nosler match ammo reloads.  Which it didn't like.  Some work to do here.  Maybe not so sweet


Mixed in in a couple of those targets are some very mild 129gr Hornady SST reloads.   A batch for my MDRx which is a delicate little bitch, and only shoots mild ammo even close to OK.  And sure enough, this gun did pretty good with that too.

So conclusion - is this gun worth it?  
OH HELL YES.
Despite the goofy issues with the gas black, this is a GREAT gun and I consider the most advanced most optimized AR10 platform you can get.  For under $1000??  yes please!  I can get 1 MOA repeatedly with it, with at least one ammunition; and not some compromise ammo that's way downloaded either.   This is going to be a fun gun to have.  Nuances - it DOES require a break-in.  I suspect this also applies to the barrel itself even.  And the gas-system contact issue may need your attention.

I do feel like velocity seems a bit low for a 20", but I need to confirm that.  So when I get a chance in a few days, I'll do some velocity comparisons to prior 20" 6.5CM barrels with the same ammo, to confirm if that's true.

Also, one more note - 6.5CM guns get HOT.  and they get hot FAST.  I was seeing mirage after 15 rounds, in my scope.  If I were to buy a handguard for this gun (vs use one laying around), I'd look hard at a 12" carbon-fiber unit that doesn't have vent-holes on the very top vertical part, but just on the top-sides.  Though that $300 adder kind of tempers the whole "cost effective" part - so I haven't gone that route yet.  

Anyway, if the thought is to load up a stack of 25 round mags and light it up with this gun, bring gloves.  Maybe bring water and fire-extinguisher, because this is going to get really really hot if you're planning on mag-dumps.

Good update lazy, but you are probably going to cost me.  Really wanted a 6.5, but of course we only had .308 when I bought.

Here's my muzzle velocity data.  A bit odd.

S&B 140 gr: 2440 fps.  That is really low for a 20" BBL with that factory ammo, and other 20" BBL's like my FAXON were reporting 2635 FPS with that ammo.  I'm not sure what's going on there, and maybe something was amiss - with my chrony.  I will say, the 2635fps result is similar to what others are seeing on-line when this 65 cent ammo was readily available.  So it's the SFAR number from my GARMIN that isnt' making any sense.  My GARMIN was clocking my 5.56 about right, so I think it's inherently OK, but maybe I had it too close to the muzzle break and that was doing something, or maybe this is just a really slow barrel - not sure.

140 gr FUSION reloads; 2450 fps relatively mild but consistent with all other test barrels for this mild load.  This is with 4064 powder, and my other 20" guns clock it at 2437-2497 FPS, depending on the gun - and the SFAR clocked it at 2450, which is good to me, that's in line with all the other guns.  Again, 4064 is a bit of a fast powder for a 140gr bullet, hence the velocities on all these are a bit low, and all in line with each other, including the SFAR.  So that seems normal enough.

OK, 140 gr HPBT reloads - with slow burning 4350.  SFAR clocked 2530, which is pretty low, but faster than the other loads.  My 20" PSA with a FAXON BBL (because I had shot out my PSA BBL and replaced it ... I shoot a lot).  was clocking 2630 fps.  that's a big difference, 100 FPS.  Could this be a case of slow-powder and SFAR bleeds lots of speed somehow?  Or is it just experimental error?  Don't conclude anything from this, as this is a small and noisy data set, I'll keep looking at this.  And the trend isn't even consistent between these 3 brands, so again, this could just be experimental error.  

So here's my question - does anyone else have SFAR 6.5CM velocity data, and notice any comparison or trend vs other 20" 6.5CM BBL's?   I don't think anything is wrong, just curious.

@ the NRA show yesterday, I picked up a POF Rogue 16" - no sights, but under 6 lbs.

My Rogue has been good to go.
Could be better, but isn't that true of any gun?

Shot my 16" 308 SFAR today for the first time.

Recoil is not bad for a lightweight .308, even with a flash hider vs break.  

It ran good unsuppressed on setting 3. Suppressed on setting 2. Ejecting pretty consistently from 2-3 O clock.

2-3 MOA with PMC 147Gr X-TAC.

One malfunction while suppressed.

I want to install an A2 stock on one of these, but I'm not sure what would be needed.

I assume that i could just get a delerin insert or some quarters to fill the rifle tube so that it's the same interior depth as the SFAR tube, and then the factory spring and buffer would be fine.

Anyone know of a more elegant solution than quarters?

CFA Francs.

I would think you'd get yer length set w/ quarters, then replace most of em w/ a chopped broom handle.  Fine tune w/ quarters, electrical panel slugs, etc.

I could be mistaken bit doesn't the sfar use a standard ar15 carbine buffer and buffer tube? If it does just use a standard rifle buffer and buffer tube with the a2 stock.

If nothing else, the spring is definitely different. Way stiffer (That's what she said)

No, they are unique and particular.  Buffer is standard, but tube and spring are not.

Might be close to a5

Will an A2 fit against the lower correctly?

If so, it's a solution to all the weird fuckery that Ruger did with what appears to be cheap plastic castle nut and end plate.

Otherwise, you can just throw on any endplate if your grip of choice doesn't use a beavertail, or an extended endplate for any other grip.

Yeah I'll probably replace mine, when I get around to it.

[Dpuble]

Sounds like the bore dimensions are okay, but a shallower leade or longer freebore.

Yes, now that maybe 80-100 rounds in, I'm going to do a deep clean and measure lead.

Mine blasts 147 Hornady factory ammo at 2540 fps.  Oh and blows primers doing it lol

Brass colored primers?

https://www.thingiverse.com/thing:5896188

3d printed buffer spacer. I made one for my 9mm AR. If you can determine how long you want it to be,  i can make it any size.

For my personal SFAR.  Will be shooting 85gr TSX, 85gr Speers, and 90gr AccuBonds.  18" barrel, rifle gas, 6.9 pounds.

Tony

You have a mill.  You can go lighter.  

I bet it shoots lights out.

Once I knew how many quarters it took, I cut a #4 rubber stopper to the same thickness.

FWIW, I would never actually run quarters.  That sounds like a dissaster waiting to happen as soon as one falls over and the buffer slams into that.  

Magpul makes a nice insert for the UBR Gen 2 stock, amd buffer tube, which is A5, with the insert for those running a carbine sized (non A5 buffer).  That might be close.

He's already lighter than Wilson's 16" Ultra Light Ranger .243 . What a time to be alive .

Quarters are only used for a temporary solution, just to establish the depth.  But, I don't see how one could fall over when the spring is pressing them against the rear of the tube.

Yea. Probably wouldn't I guess.

You think these are going to be a good platform long term? Curious on your thoughts about the whole system.

Pretty sure the 9mm guys run em all the time.  If you need to make a phone call or need a Coke hit up someone w/ an AR-9, they probably have a buck fifty in there.  

AR9 was my first use of them.  It took 5 to get the bolt to stop where I wanted.  I thought it was a bit funky tho, and went to the rubber stopper cut to length.

I got to a shoot a friend's SFAR this past weekend, and a question came up, and none of us had an answer. I have researching the topic this week and have found....nothing.

How would one go about SBRing an SFAR? I am not aware of anyone producing SBR-length barrels, etc.

No experience with it - but if you want to get a fix on the cheap, here's a 12" Rail for $40 on sale.  

For those with 20" full rifle length units and rifle length gas system, this is a quick&easy (&cheap) way to eliminate the gas-block issue completely, as it'll end just short of the block.  12" of rail is plenty, I'm personally not a fan of rails longer then that - just added mass and bulk in a place you're never going to use.

https://www.primaryarms.com/ghost-firearms-no-logo-m-lok-handguard-black-12?quantity=1&custcol_pco=Orphan



If anything shows up on their Memorial Day sale else that I want, I'll probably toss one of these on there - though in my case I've already modified my other handguard, so not sure if I'm going to bother.  But, not a bad idea to have for other 20" gas length projects I suppose...

file form 1. Not sure how fast eforms are these days, but I've had them approved in a week in the past.

pull the barrel. send it to a smith to get chopped and threaded.

12.5" is probably as short as you'd want to go with the midlength gas system.

Install a shorter handguard. Any AR15 handguard will do, especially if you change out the gas block to something lower profile.


12.5" midlength 308 POF Rogue SBR
Attached File

How short?  You can cut down an existing barrel, being considerate of gas system length.  Nobody is "producing" SFAR barrels at all on the secondary market that I am aware of.

Paladin, MosTek, maybe Tromix, are all rebarreling using your existing barrel nut.

1) Buy appropriate twist barrel blank;
2) Pull SFAR barrel;
3) Pull locating pin from barrel extension;
4) Send blank, barrel extension, & bolt to Paladin Machine of South Carolina with specifications;
5) Profit.

good advise.  One complication is the SFAR relies on improved metallurgy to run 6.5 Creedmoor force, in 5.56 dimensioned bolt and barrel extension.  That's not a casual thing, as that's a serious increase in the amount of force that amount of metal is expected to hold back.  Not just anybody is able to bang out that metallurgy and assembly practice right now.  They're going to need the right super-stainless improved metallurgical barrel extension to do it.  Which is going to slow 3rd party options for a little while.  For right now, I'd only go this route by using the provided barrel and just modifying/cutting that barrel, to assure retention of the correct barrel extension, and whatever systems they did to attach the barrel to that barrel extension (maybe it's standard, maybe it's not).  

Also, these rounds tend to be designed for long barrels and have a substantial gas reservoir to keep pushing that bullet to acceleration in the longer barrels.  Running a 12" SFAR .308 or 6.5 CM is going to be some seriously blasty business.   And as noted in some other threads, don't be surprised if you end up eroding out that barrel surprisingly quick when that tanker truck volume of high-pressure gas gets released at full pressure of just a 12" barrel when the bullet (plug) leaves and all the high pressure gas instantly accelerates and leaves the barrel - which is going to erode the crap out of the barrel.  (High velocity gas is intensely erosive, hench 10.5" BBLs have shorter lives than 16" BBLs)

If you're a reloader, that will help, as you can just make up loads with really fast burning powders to mitigate some of that.  

But as S4Su says, your gas settings will likely need to be tweaked.  The good news is the SFAR design concept is an oversized gas port throttled by their great big gas block, so maybe you'll still be OK.  

Sounds like a fun project, Start a thread if you do it, I'd love to see how it goes.