ASC and KAC steel AR-10 Mags - what's the max OAL round length for each?

[ReaperDriver]

For those that run the ASC and/or KAC steel mags in their Large frame rifles, as the thread title says, what is the max length you can load to and still reliably function? I've got a bunch of Pmags but they are very limiting for the longer 6.5 bullets. I like the price of the ASC vs a almost a Hundy for the KAC mag.

Are there any other mags out there on the market that accommodate longer OAL's than the 2.800 pmags?

 

[NukeMMC]

I get 2.815" with PMag, 2.830" with DPMS, 2.875" with ASC and 2.880" with KAC.

With that said, I max out my loads at 2.850" COAL and use ASC and KAC magazines. DPMS didn't work in my Mega. I'll use PMAGs for FGMM or M852/M118/M118LR.

I had feed issues with 2 of the 6 ASC mags, called thm up and they replaced them, no issues.

 

[Longshot85]

A lot of people don't realize the specific m118LR pmag exists

Part # MAG577

OAL up to 2.830

Click product description to read details

PMAG® 25 M118 LR/SR GEN M3® Window

GEN M3 25-round magazine for SR25/M110

magpul.com

 

[ReaperDriver]

I get 2.815" with PMag, 2.830" with DPMS, 2.875" with ASC and 2.880" with KAC.

With that said, I max out my loads at 2.850" COAL and use ASC and KAC magazines. DPMS didn't work in my Mega. I'll use PMAGs for FGMM or M852/M118/M118LR.

I had feed issues with 2 of the 6 ASC mags, called thm up and they replaced them, no issues.

Thank you, that's very useful!

 

[Longshot85]

Thank you, that's very useful!

And if you buy any second hand look for the "M118" marking as seen here

 

[ReaperDriver]

I get 2.815" with PMag, 2.830" with DPMS, 2.875" with ASC and 2.880" with KAC.

With that said, I max out my loads at 2.850" COAL and use ASC and KAC magazines. DPMS didn't work in my Mega. I'll use PMAGs for FGMM or M852/M118/M118LR.

I had feed issues with 2 of the 6 ASC mags, called thm up and they replaced them, no issues.

Did you do anything to mod your ASC mags? I loaded my .260 Rem rounds to 2.850 and they were inconsistent feeding. Several of the bullet tips (130 Berger AR Hybrid) dragged on the inside of the mag front wall and hung the follower up. I have 3 brand new ASC mags and they all did the same. I wonder if ACS changed the internal spec. I now load to 2.847 and they seem to work fine.

 

[NukeMMC]

Did you do anything to mod your ASC mags? I loaded my .260 Rem rounds to 2.850 and they were inconsistent feeding. Several of the bullet tips (130 Berger AR Hybrid) dragged on the inside of the mag front wall and hung the follower up. I have 3 brand new ASC mags and they all did the same. I wonder if ACS changed the internal spec. I now load to 2.847 and they seem to work fine.

Mine are about 3 or 4 years old.

 

[ReaperDriver]

Mine are about 3 or 4 years old.
View attachment 7586149

View attachment 7586150

Yup, I measured mine as well when they arrived and got the same measurement. However, no way is a round going to fit at that length. I even tried 2.865 to give it some room and no worky. I finally ended up at 2.847 just to give it come clearance. Otherwise the rounds even at 2.850 drug the nose on the front of the wall. I just shot all my loaded rounds yesterday, but I'll load up some soon and post a pic to show the actual bullet clearance.