6.8 Rem SPC build

[Southpawmark]

I am considering buying the 6.8 SPC from LMT as i really like their products. But i have a question:

What caliber ammo can be fired from the 6.8 SPC?

Does anyone make a polymer magazine for the 6.8 SPC?

TIA

[Grizzman]

Don't worry at all about hijacking the thread.

The camera in your cell phone is pretty impressive. I never would have guessed they were taken with a phone.

I've never used MI BUIS, but I can definitely recommend Troy.

As long as the Omega rail locks solidly onto the delta ring (and I'm sure it does), it looks to be a good solution, and really easily installed.

It may take a while, but it may be possible to trade your EoTech for one with the side buttons. Besides the upgrades you've mentioned, the only additional one I can think of is to mount a QD sling mount on the rail to completely take all external forces off the barrel. I've used MI, DD, GG&G, and Gear Sector with satisfactory results for all of them.

I'm glad you're getting your AR to the point where it's exactly like you want it, cause that's part of the AR's allure.

[Grizzman]

Originally Posted by Southpawmark

I am considering buying the 6.8 SPC from LMT as i really like their products. But i have a question:

What caliber ammo can be fired from the 6.8 SPC?

Does anyone make a polymer magazine for the 6.8 SPC?

TIA

An LMT would be a nice choice.

6.8 Rem SPC ammo is still fairly limited, but it seems to be getting better each month.

Silver State Armory (SSA) offers the widest range of bullet options that I'm aware of. Remington and Hornady both offer a couple different options. I see that even Corbon offers a couple of options, one of which is a 115 grain subsonic load. If I'm going subsonic, I'd choose 130s over 115s.

As far as component bullets for handloading is concerned, the selection for .277 isn't quite as complete as it is for .264, but it's not bad. Any bullets for the .270 Winchester will work, but they're not ideal due to the velocity difference. The Sierra 110 grain Pro-Hunters I'm using for barrel break in seem to be working fine, though I haven't mounted a magnified scope on it to see how well they really do.

I picked up a box of 110 grain Nosler Accubonds from Bass Pro yesterday, and should receive a box of 110 grain Sierra MatchKings by Thursday. I also plan to pick up some Barnes TTSXs some time.

As far as I know, there aren't any polymer magazines offered for the 6.8. I've got two 25 round C-Products magazines so far, and they've been completely reliable. I've also had 100% reliability with their 308 mags.

Here's a thread I found on ARFCOM: http://www.ar15.com/forums/topic.html?b=3&f=17&t=501311 that may be useful. I still need to read it myself. I'm still in the market for a shorter 10 round mag for bench work, and I'm not sure at this point which one I'll try.

[Southpawmark]

Got the LMT 308MWSE coming hopefully later this week, it will have the same extras as the 5.56 did.

Will post pics when completed. Still pondering the thought on the 6.8 Congratulations on your build!

[Grizzman]

The build is now 100% done, hopefully at least for a while. After a bunch of research, I ended up selecting a lower parts kit from G&R Tactical. I chose the option with the Magpul trigger guard an no trigger, hammer, and disconnector. The kit went in with no issues, and I ended up putting a Bill Springfield modded trigger group into it.

The Mega lower has a polymer tipped screw that presses against the upper to eliminate all movement between the two. It took a few minutes to get the pressure correct....too much and the rear pin won't move without a bullet or punch, and too little and there's noticeable wobble. I've got it set for zero play and moving the rear pin only requires a little extra pressure.

I've put 75 rounds through it so far, with the remaining 25 break in rounds to go down the tube tomorrow.

I loaded up 25 rounds with 115 grain SMKs over Reloder 10x tonight, which I'll try out in two or three weeks.

I bought a couple PRI 15 round magazines to try out for load evaluation sessions from the bench. I've never used a PRI mag before, but these will likely not be the last ones I buy. Not only are they significantly shorter than the C-Products 25 round mags (imagine that) they are obviously built to a higher standard.

The PRIs were a little over twice as expensive as the C-Products, so the higher quality wasn't a gimme. I just grabbed a C-Products 308 mag out of my closet, and it is welded in a completely different manner than the 6.8s. The 6.8s are spot welded, and the .308s seams are butt welded together and done with adequate precision. Unfortunately, the 15 round PRIs seem to be the cheapest option, with all others running about $10 more. I may end up getting a few of those if I find them on sale, since they look and feel different from my other aluminum AR mags. This isn't a big deal, since I primarily use P-Mags for the 223 and 308.

Since pretty much the only visual difference is the lower's roll mark, I didn't take any more photos.

I'll probably post the results of the first accuracy tests, and maybe a short comparison to my 308, which is likely a better competitor to it than my cheap(ish) 223. It really needs to cool off some. I don't like working up my handloads in 90 plus degree heat, and the increased pressure and lack of barrel cooling (and sweat) the heat causes.

[wxl]

The PRI mags are my favorite for the 6.8. They also allow the longest cartridge OAL for reloading.

[Grizzman]

Thanks for reminding me to mention the increased overall length. The maximum length in the C-Products mags is approxfimately 2.280". The PRIs should allow for 2.300", and that's another reason to only use one mag type.....don't want ammo that I can't use in half my magazines.


It really needs to cool off some. I don't like working up my handloads in 90 plus degree heat, and the increased pressure and lack of barrel cooling (and sweat) the heat causes.

I received a couple 25 round PRI magazines a couple days ago. They're built to the same standard as the 15 round magazines and are the exact same length as the C-Products 25 rounders (and also USGI 30 round 5.56 magazines).

Last night I went to put some ammo I loaded with Remington 115 grain FMJs to 2.300" OAL into one of the PRI 25 round magazines. They went in, but there was heavy bullet tip drag along the front face of the magazine. It took conscience effort to keep the top couple rounds pressed all the way back against the rear of the magazine, and the 2nd or 3rd round in needed to be forcibly snapped down past the front face of the mag. They might function in this manner, but it's not worth the extra care needed to load them. I shortened them to 2.290", and at that length, they loaded in more easliy and should function 100%.

[allrockabilly]

Just thought I would give you a quick update on what I have done with my M4. Well I traded my Stag Arms Model 2 for a New Daniel Defense DDM4 V4.
Love it. I have already put the MagPul MOE pistol grip, Stubby front vertical grip, BAD lever - Magpuls Battery assist lever (just got it, need to practice), Magpuls front and rear Gen 2 flip up Back up sights (I will eventually get Troy).
The rifle came with a Magpul MOE Buttstock, Magpul Edvanced trigger guard. Free floated DD Omega X 9.0 quad rail. DD low profile Gas Block...etc

Here is some pics. I do have some things I will do to it but this is excellent for now especially for a 5.56 M4.













I will tell you more details on it soon but I got to run off to work.
Better pics to come. I am now trying to decide if I want to build or get a 6.8 SPC upper or get a .308 in an AR platform still now sure.

-Ryan S