6.8SPC/.224 Valk magazine question

[TrueBlue711]

This question is more directed at the .224, but since the casing is a necked down 6.8 SPC, I figured I'll have better luck with getting an answer involving both calibers.

I have plenty of standard 5.56 AR mags from multiple different companies. I'm just a barrel shy of finishing my .224 Valk build and wanted to know if anybody has experience shooting their 6.8 SPC (or .224 for the few who may have one by now) trying out different kinds of mags. I know there are magazines specifically designed for the 6.8 SPC cartridge. What's the difference between that and a standard mag? Have you had issues shooting 6.8 out of a standard mag? Right now, 6.8 mags are going for $35 a pop and are getting harder to find. I'm just wondering if it's worth spending that much for a mag that I may not need if standard mags work fine.

[bedlamite]

Just get the correct stainless steel 6.8 magazine. You can get a couple into a 5.56 mag, but you can expect it to jam.

PRI, CPD, ASC, and Barrett all make good mags and are readily available anywhere.

[TrueBlue711]

but you can expect it to jam

Do you know what causes the jams? Is it the case size or the bullet size difference? I'm wondering since the 224 is using a 22 caliber bullet, feeding will work fine. But if it's the casing that's causing jams, then I'll definitely get 1 or 2 6.8 mags.

[ed308]

Regular 5.56 plastic mags will work but only up to around 5 round before they develop a bulge. They can also have feeding issues. I have four 6.8 and use either PRI waffle mags or LWRC Six8 Pmags. Both are excellent. The LWRC Six8 mags only work with LWRC Six8. Most of the other 6.8 metal mags will work but may need to be tweaked. I've read Barrett 6.8 mags are also good. I have 12-15 PRI mags and have not needed to tweak any of them. But they're not cheap. I've purchased some on sale at $25. PRI's 15 round mag is my favorite.
I also use them for 6.8 and 6.5x47 Lapua cats.

Cavityback has a good selection of PRI mags. They even have some with the fronts cut out to load longer. But $34 to $35 each for the regular mags.

http://www.cavitybackbullets.com/category-s/124.htm

[TrueBlue711]

Thanks for the info. I was cringing the whole time while doing it, but went and bought a PRI 15 rounder 6.8 mag. $35 is a lot for a mag, but at least I only need one or two for this kind of build.

My first batch of 224 ammo arrives tomorrow, so I'll play around with all my other mags and see what works and doesn't work as far as fit is concerned. The only thing I'm missing to finish my rifle build is the barrel, which is on order...but about another month wait. Once that arrives, I can really test what mags the ammo likes or doesn't like and I'll post the results.

[bfoosh006]

IMHO, one of the most important aspects will be the feed lip width.

A 5.56 mag will be narrower... so the cartridge might not rise far enough up to feed.

I bet a Google search " Will a 5.56 mag feed a 6.8 ? " would answer a lot of your question.

[ed308]

I've never experience a feeding problem with a 5.56 Pmag in my 6.8. But I've only used one when in a bind and only with 5 rounds in the mag. Bulge is the biggest problem with a 5.56 mags in a 6.8. A regular Pmag doesn't have walls thick enough to keep the side wall of the mag from bulging outward. If you stuff more than 5 rounds in the mag, you can't insert it into the magwell due to bulge. LWRC and Magpul solved that problem by designing the Six8 Pmag as a larger mag and by increasing the interior dimensions of the magwell for the Six8. The Six8 Pmag has much thinker plastic compared to a regular 5.56 Pmag. (If someone comes out with a metal Six8 mag, you'll see LWRC Six8 start flying off the shelves. That will allow you to load longer than 3". Keeping my fingers crossed that happens. But tooling to manufacture mags isn't cheap.)

If you need to adjust your metal 6.8 mags, usually opening up the top of the mag a little or filing some off the front of the mags solves 99% of all problems with mags and the 6.8.

Hope your barrel is 1:6.5 and instead of the 1:7. That twist will be better suited for the heavier bullets in the .224 Valkyrie. I plan to buy a barrel from ARP when they hit the market out later this year.

[stagpanther]

I plan to buy a barrel from ARP when they hit the market out later this year.

Harrison say he would actually do that? Doesn't make sense to me since he already makes a superior 5.56 x 42 spc.

[ed308]

Harrison say he would actually do that? Doesn't make sense to me since he already makes a superior 5.56 x 42 spc.

People want it. Summer 2018. Available brass sells for a lot of people. He was initially offering one in the 1:7 twist. But had second thoughts and canceled since that twist isn't the optimal for the heavier bullets. But like you suggest, the .224 Valkyrie is basically the same as the 5.56x42 but with the shoulder bumped back just a little more.

[Mobuck]

I figure if the makers thought any old common mag would work, they wouldn't have gone to the expense and trouble of designing 6.8 specific mags.
Sometimes mags work for cartridges outside their design. I had good results using Thermold .223 20 rd mags for 5.45x39 as long as I kept fewer than 10 rounds in the mag. Oddly, 5.45 doesn't seem to work at all in 6.5 Grendel or 7.62 mags.

[Big Shrek]

Originally Posted by TrueBlue711

Thanks for the info. I was cringing the whole time while doing it, but went and bought a PRI 15 rounder 6.8 mag. $35 is a lot for a mag, but at least I only need one or two for this kind of build.

My first batch of 224 ammo arrives tomorrow, so I'll play around with all my other mags and see what works and doesn't work as far as fit is concerned. The only thing I'm missing to finish my rifle build is the barrel, which is on order...but about another month wait. Once that arrives, I can really test what mags the ammo likes or doesn't like and I'll post the results.

When you branch out away from AR's, you'll find that $35 for a mag is NOTHING...

S&W 1000 series mag starts at $50, if on sale. Current average regular price is around $70-75.
Same for the Star Megastar in 10mm...you pay to play in the 10mm Leagues.

Wilson Combat and other top end 1911 mags start at $30...

I saw an Erma KGP68 mag for $180 on Ebay the other day...
wondered if it came with a backrub & a happy ending,
as they sell for $55 each at TK...

[TrueBlue711]

When you branch out away from AR's, you'll find that $35 for a mag is NOTHING...

Yeah, I have many pistols too and I know their mags are not cheap. Never understood why, but that's just the way it is. I also have a SCAR 17 and their mags are $40. I just cringe when it comes to the AR & AK platforms since their mags are normally around $15, even for quality ones.

Ironically, right after the PRI mag I bought arrived, MidwayUSA just got a bunch of their AR Stoner 6.8 mags back in stock for $15 each (5, 10, 15 & 25 rounders). So I picked up a couple 10 rounders too.

[stagpanther]

PRI and ASC mags are among the better--never a waste of money IMO.

[ed308]

Just saw where Cavityback Bullets got a shipment of PRI 6.8 mags. He's got them in 10, 15 and 25 rounds. He's also got 10 round mags where the front is opened up for loading longer than 2.3"

http://www.cavitybackbullets.com/category-s/124.htm

[stagpanther]

Cavity back's mags that PRI makes for them are great--I have quite a few of them--I wish they made some of the front cut-out models for the 308 platform as well. About the only slight nit I have to pick is that they advertise they work equally well with grendel cases--my experience has been not quite as reliably as a dedicated grendel mag.

[ed308]

Isn't the follower in a Grendal mag different from the one in a 6.8 mag?

[stagpanther]

Isn't the follower in a Grendal mag different from the one in a 6.8 mag?

I believe both follower and mag width are slightly different--though in a pinch can be used interchangeably.