I'm looking for the maximum COAL for some AR 308 mags. From what I found from searching the net 2.83 seems to be the average, are there any others that exceed this? Also, can anyone tell me what the inside length of a 308 lower receiver is?
AR 308 magazine maximum COAL
- Thread starter Masczek
- Start date
Others that exceed what? What mags and what gun do you have. Also what load are you trying to spin up?
KAC and Larue LR/SR25 mags allow 2.871. Only mags to use in a large frame AR10. Expensive but built like a tank.
C products are supposedly close to kac and larue internal dimensions but their reliability has been questionable I think.
No loads developed or gun yet, just doing some research before purchasing anything.
This may be a dumb question, but do all AR 10s, and AR 308 style rifles except LaRue or KAC mags, or do some have too small of a magwell?
The Larue's work in my Mega Maten, DPMS LR-308 & Ruger RPR. Aside for that I would be speculating... but I haven't heard of any compatibility issues.
Just a FYI, the D&H Indus. SR-25 patterned mags that Brownells sells do not accommodate the same COAL rounds like true KAC mags. I did a side-by-side comparison and the D&H mags will take smaller COAL rounds. If you want to accommodate larger size rounds, you have to pay for the KAC (or Larue per others).
Which setup and load was the 6 mm Creedmoor?
Keep seeing feeding issues with 105+ grain bullets in autoloaders. Interested if Larue's are GTG for such a setup.
I have never missed a target do to cartridge aol or, a lawyer chamber shooting 2.80 aol .308 win ammo. If your gun will not group a 1/2moa or better shooting stock length ammo, either your ammo, the gun or your shooting ability is lacking. If your looking for bench rest groups yes changing aol with setting depth will help, but if your field shooting your better off learning how to read mother nature an the a/o than getting rapped up with trivial stuff.
Mega Maten with a 26" barrel I got from Rainier Arms. Loading, IIRC, 41.3gr of H4350 behind a 105 hybrid. I got about 200-250 rounds through it including one match. Due to the short OAL this chamber has I have about a 2.75ish OAL and because of that I just used 10 round p-mags during the match. But did also use the Larue's while at the range. Never had a feeding issue with any of the mags.
Thanks for the info!
Have been curious about that barrel. Rainier just got back with me and said they are using the PTG Absolute Accuracy reamer with the 0.183" freebore. Wonder if that matches your barrel or if they changed things up. Would think 2.81" would be about right with that reamer if I am remembering by creedmoor spec correctly.
ACS mags will load to 2.865 according to the mfg website. Would be a good way to get quite a bit of extra length over a standard magpul pmag, and even some room (.030) on the M118LR mags, without breaking the bank. Many places have the ASC mags for $15 per. Im gonna pick up a couple with weekend and see how they do.
I am waiting for the rest of my Reloading equipment to arrive. Therefore, subscribed.
I have a LaRue AR10 308/762 with LaRue lower. Kicking myself for not ordering more LaRue mags at half price with the rifle.
I have a LaRue AR10 308/762 with LaRue lower. Kicking myself for not ordering more LaRue mags at half price with the rifle.
I'm very curious about this myself as I have a .260 to get started with. Currently have Pmags and Hexmags.
Many years ago when I had the M1a and Springfield Armory magazines, I standardized on an OAL of 2.815".
Load was 175SMK, 42.2gr IMR-4064. Still shooting that in Savage 24" 11FV, and may soon also be shooting 168 HPBT-Match and 42.8gr of IMR-4064 in the soon arriving 20" PSA PA-10.
Greg
Load was 175SMK, 42.2gr IMR-4064. Still shooting that in Savage 24" 11FV, and may soon also be shooting 168 HPBT-Match and 42.8gr of IMR-4064 in the soon arriving 20" PSA PA-10.
Greg
What is the actual I.D of the ASC mags and the max COAL you could achieve? Having a hard time justifying $90 KAC mags compared to the ASC. Makes the Larue’s at $79 seem like a bargain.
KAC > everything else. If you shop around you can find them for $75/ea brand new. I've bought larger lots of them and gotten them for as low as $50ea and you can dump the extras you don't need to idiots on barfcum for $90/ea.
I love my KAC mags..I had good luck with the e lander 308 mags..the floor plate and follower look just like KAC ..
www.brownells.com
Primary arms has the none waffle ones for 15 to 16 bucks
Brownells - Serious About Firearms Since 1939
Brownells is your home for firearm accessories, gun parts, gunsmithing tools, reloading and shooting supplies backed by our 100% satisfaction guarantee.
www.brownells.com
Primary arms has the none waffle ones for 15 to 16 bucks
E-Lander 7.62 NATO/.308 Win 20-Round Steel Magazine
DetailsEvery good rifle needs to be supplemented with a stock of high-quality magazines. Magazines are often the primary source of a rifle’s malfunctions, and poorly made magazines can easily stop a firearm in its tracks. When seconds count, there’s no reason to take the risk with low quality...
www.primaryarms.com
They both allow longer coal..hope this helps
I sold a DPMS 243 and sent the ASC along with it. I bought several KAC mags for $65 shipped. Shop around and don’t settle for less.
I have to agree with redneckbmxer. The kac mags are just amazing. Hard to believe they are as good as they are until you handle them in person.
I just got some Gen 3 PMag SR/LR for an Aero M5 and the max length I can fit is 2.815" and there is no way 2.830" over-all length will fit.
I am glad I found this post as I have been looking for a mag with a longer COAL for my 308 and Nemo Omen.
Seeing the lack of things currently out there, I contacted a friend in the industry and asked if he thought he would be able to make a magazine for both platforms that would work and he said yes.
Initial planning has started and he is confident that he can produce a mag for the AR10 platform that will support a COAL of 2.85" with a goal of getting to 2.9" and our goal for the Nemo Omen is to reach 3.7"
He mentioned the use of a particular stainless or blend of titanium for extreme light weight and strength but I'm not a metallurgist so that part was Greek to me. I just want to find something that will work and hold up even if it means making something new. Bottom line is, I'm footing the bill for him to prove if he can build a better mag for these two platforms that will function reliably with a longer COAL.
I will update once the prototypes are complete and I've been able to test them.
Seeing the lack of things currently out there, I contacted a friend in the industry and asked if he thought he would be able to make a magazine for both platforms that would work and he said yes.
Initial planning has started and he is confident that he can produce a mag for the AR10 platform that will support a COAL of 2.85" with a goal of getting to 2.9" and our goal for the Nemo Omen is to reach 3.7"
He mentioned the use of a particular stainless or blend of titanium for extreme light weight and strength but I'm not a metallurgist so that part was Greek to me. I just want to find something that will work and hold up even if it means making something new. Bottom line is, I'm footing the bill for him to prove if he can build a better mag for these two platforms that will function reliably with a longer COAL.
I will update once the prototypes are complete and I've been able to test them.
After looking into having some custom mags made and finding out the wait time along with expense, I decided to modify a P-mag and see what I could come up with.
I sanded down the front of a 10 round mag and cut a piece of stainless shim stock to fit. https://www.acehardware.com/departments/hardware/metal-sheets-and-rods/steel-sheets/5203930
I used JB Weld to epoxy it to the front of the mag and used a dremal to grind out the inside of the mag, removing all polymer martial exposing the stainless, creating a channel for the tips of the bullet To fit and ride in.
This still allows the magazine to fit in my Nemo and Ascend Armory lowers, though it is a very snug fit and will not drop free.
With the modification, the new interior dimension on the P-mag is 2.906”
I still need to do a little clean up for aesthetics and polish the inside of the metal channel, but here is how it looks.
The pics with the rounds in them are loaded to 2.83” and the mag on the right is a C-mag for comparison.
I cycled a loaded mag with no issues and just need to test fire it now.
I sanded down the front of a 10 round mag and cut a piece of stainless shim stock to fit. https://www.acehardware.com/departments/hardware/metal-sheets-and-rods/steel-sheets/5203930
I used JB Weld to epoxy it to the front of the mag and used a dremal to grind out the inside of the mag, removing all polymer martial exposing the stainless, creating a channel for the tips of the bullet To fit and ride in.
This still allows the magazine to fit in my Nemo and Ascend Armory lowers, though it is a very snug fit and will not drop free.
With the modification, the new interior dimension on the P-mag is 2.906”
I still need to do a little clean up for aesthetics and polish the inside of the metal channel, but here is how it looks.
The pics with the rounds in them are loaded to 2.83” and the mag on the right is a C-mag for comparison.
I cycled a loaded mag with no issues and just need to test fire it now.
If you get the ASC mags make sure to buy the stainless & not the aluminum. The aluminum mags do not allow longer coals. The stainless 308 says 2.866 + or - .002. I load them to 2.86 & have never had any problems. If your shooting competition then the kac is probably the way to go. Also the same goes for the 556 ASC mags, get the stainless with the orange followers not the aluminum. They say the 556 ASC will allow 2.316 or - .002 but I don’t load farther than 2.30. I have had good luck with the ASC & so have most of the guys I know at the range. The pic is of an ASC with rounds loaded to 2.305
Attachments
the mag well size does matter for what I am doing with modifying the P-Mag as it is adding 0.010" to the overall length of the mag from front to back. On my rifles, it is a snug fit and the mag will not drop free but it still removes easy enough that it isn't a problem or concern. I'm doing the same thing to test a mag on my bolt gun as well with a Magpull mag to give an overall cartridge length of 2.95" to see if it works.
I figure if it works and is reliable, it's about 1/3 the cost of quality mags and if it doesn't, it was just a little bit of my time and something I had fun doing.
I'm building an AR10 chambered in 7mm Sherman Short Tactical. Does anyone have any recommendations for magazines/ followers to get good feeding of a short mag? Preferably also able to allow a little bit longer COAL.
Thank you
Thank you
Accuracy Systems makes ar10 short magnums. I would call them & see about buying a mag from them if they modify mags to function better. Otherwise you will just have to try different mags & followers. Asc & kac have the most room at 2.87-.88. Asc is cheap & they work. You could buy wsm/saum follower & replace the 308 follower in a asc mag or try both followers. KAK sells ar10 300wsm uppers & recommends using 10 round pmags. If your going for longest coal, get the ASC mag & play with it. I would definitely call Accuracy Systems & KAK just to see what they say
Curious as well if you built the 7 SST. Which magazines did you go with? Here's a pic of a 2.76" coal 338 Whisper in an ASC stainless mag, and I'm measuring 2.868 on the dial calipers if one wanted to nose drag their cartridges in the ASC. I have a 6.5 SST and a 6.8 Western sitting over there (imagine me pointing at safe across room) but have no intention of shooting them until I've worked my way up getting proficient with the toys I built after the 2020 election so I don't get bored with the "lesser" stuff before I get my money's worth out of them (Disassembled the 224 Valkyrie and waiting on a scope mount before I cerakote and take it out for 1000+ yd fun). Initial guestimate for 6.5 SST laying the bullet next to the brass measurements suggest the 144 berger needs 2.80" which makes the ASC ok, but then I start looking at the 153.5 gr long range hybrid and wonder if I'll be cutting the front off this magazine... but that's a couple years from now my problem.
