ARC Mags

Stag556

Sergeant of the Hide
Feb 10, 2017
571
40
28
My followers jamb like that also if I do to them what I saw in the video, yet in 300rnds of live fire, it hasn't done it once.
Is it possible that recoil is driving the tips of your bullets under the feed ramp, due to the increased mag internal length, and then the bolt is tipping them the rest of the way?
That's a plausible idea but I can't say for certain what exactly is causing it. I wish I knew but for now I'll have to stick with my AICS mags. I'll hold onto these in case there is a redesign of the follower.

Due to only being able to recreate the issue under live fire and only having my match gun to test them in, I don't want to put the extra rounds down the tube to try and figure it out.


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LawnMM

Harbinger of Sarcasm
Jul 5, 2009
1,743
130
63
Colorado
www.accuracy-tech.com
Don't own any, figured I'd see how it was panning out first. I've seen similar problems in the past. The follower likely needs redesign to keep it from tilting and shifting. The next issue may be feed lips.

I had some mags from a vendor that rhymes with ralpha and they would nose dive beneath the ramp and jam regularly. My rounds were long. AI Mags...no problem. The difference was how early the ralphas lost control of the round.

AI Mags maintained control noticeably longer as they moved forward before popping free in the receiver. Sold the damn ralphas and haven't had an issue with AI since. Even with my long 308 rounds.

Anti tilt follower, move feed lips forward to maintain control longer... my suggestions. Talk to the MK machining guys. They have a dynamite 3D printing setup. See if they can work up an anti tilt follower.
 

Sig Marine

Sergeant - USMC 1968-1970
Dec 29, 2013
342
18
18
So Cal
Don't own any, figured I'd see how it was panning out first. I've seen similar problems in the past. The follower likely needs redesign to keep it from tilting and shifting. The next issue may be feed lips.

I had some mags from a vendor that rhymes with ralpha and they would nose dive beneath the ramp and jam regularly. My rounds were long. AI Mags...no problem. The difference was how early the ralphas lost control of the round.

AI Mags maintained control noticeably longer as they moved forward before popping free in the receiver. Sold the damn ralphas and haven't had an issue with AI since. Even with my long 308 rounds.

Anti tilt follower, move feed lips forward to maintain control longer... my suggestions. Talk to the MK machining guys. They have a dynamite 3D printing setup. See if they can work up an anti tilt follower.
Feed lips on the ARC are very short when compared with the AICS mags, something like 1/4" or so. I agree with the above as another poster in this thread previously said he switched out the follower and spring assembly from either an AICS or Alpha mag into the ARC and it ran well. Hopefully Ted can make some mods and get these to run. Love the concept and the compact size.
 
Feb 10, 2017
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I think they'll work in the near future. Ted seems like a knowledgeable guy, and I'm sure the follower redesign is already in the works.

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Oct 19, 2011
518
4
18
s.e. iowa
My tikka wasn't feeding well at all. It was skipping over about every other round. I stretched the spring and opened up the rear of the lips so they are parallel to the front around .410 and haven't had a problem feeding yet. Before I stretched the spring it was trying to push the round front to high and was hitting the top of the barrel missing the hole.

 
Dec 16, 2009
158
0
16
Springfield, MO.
It seems the problem with mine is not with the mag necessarily, but with my receiver. The internal length of the magazine is longer than my magazine port. So the last round in my arc mag gets stuck under the feed ramp. I guess the only way to fix it is to either go with aics mags, or inlet the feed ramp. Any one know how to do that?
 

LawnMM

Harbinger of Sarcasm
Jul 5, 2009
1,743
130
63
Colorado
www.accuracy-tech.com
It seems the problem with mine is not with the mag necessarily, but with my receiver. The internal length of the magazine is longer than my magazine port. So the last round in my arc mag gets stuck under the feed ramp. I guess the only way to fix it is to either go with aics mags, or inlet the feed ramp. Any one know how to do that?
That's what I'm talking about with feed lips length and how far forward in the receiver the round is controlled. If they pop free too early they can drop or dive under the ramp. Ideally you want them controlled long enough that they can only slide up the ramp by the time they pop free. The follower can also contribute to this if it tilts. The bolt puts forward pressure on the round, and the follower dives and jams the round.
 
Feb 14, 2017
99
5
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It seems the problem with mine is not with the mag necessarily, but with my receiver. The internal length of the magazine is longer than my magazine port. So the last round in my arc mag gets stuck under the feed ramp. I guess the only way to fix it is to either go with aics mags, or inlet the feed ramp. Any one know how to do that?
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I loaned my mag that has 400 rounds through it now to my buddy to try in his Defiance. Same mag, same caliber, same 2.800 OAL rounds, the only difference, my feed ramp is clearanced, his is not. His would feed the first time, but jam the second. Didnt matter if the mag was full, or if it was the last round. When his bolt closes, the first round drags the lower round forward, and under the feed ramp. When the upper round clears the feed lips, the lower one pops up and the nose is already stuck under the ramp. Google Rem 700 feed ramp notch and that should get you the info you need. If not, Pm me. The reliable fix in these mags for people who don't want to clearance their feed ramps is probably going to be a spacer of some type in the front of the mag to keep the rounds rearward.
 
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Apr 17, 2014
86
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Ok I thought I would follow up on my experience with these mags so far as I had a few hiccups this weekend same as many others... 1. feeding at home no live fire perfect 2. Live fire at the range concrete covered 60rds perfect 3. Practical match on a range outside little dust perfect 4. Weekend camping 120rds dusty dirty desert shooting= 7-8th round nose diving under feed ramp out of 120 rounds maybe 5-6 misfeeds. Same problem many others experience with the follower hanging up in the front of the magazine. It does pop up freely quite easily so I think this could be fixed without much trouble. Ted did say they need to be kept clean but they have only had 3 outings... I'm thinking the problem is when recoil happens the rounds move forward then feeding becomes a problem. Spacer or longer feed lips may be the trick
 
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LongRifles Inc.

Gunny Sergeant
Mar 14, 2010
4,643
89
48
46
Sturgis, S. Dakota
www.longriflesinc.com
Maybe I can help here...

Yes, the COAL that the ARC magazine accommodates is longer than some receivers will allow for without modification. If we go back 5,6,7 years this was a "big deal" here on the hide. Seemed like everyone was whittling away on receivers to make stuff work. This seems to be an intermittent problem.

The ARC magazine is no different.

I've already done a few actions like this specific to this magazine. Not a big deal. There are points to consider and I will share with you what I've learned.


IF you are doing this work, understand first that just notching the lower feedramp won't cut it. You have to think about how the cartridge behaves as it travels upward through the "gauntlet" of the magwell and into the feedlips. It is an arc movement. That means the projectile tip is drawing part of a circle as it moves to present itself to the face of the bolt.

The notch has to be widened for the whole system to function properly. It's a simple enough toolpath to create on a cnc. Manually it'll be a little more work, but not impossible. Ignoring this will create the condition where the whole thing falls apart. the tip of the bullet gets hung up.

$75+shipping and we'll knock it out. Day or two rotation in the shop. I want the whole gun. I'm not going to do this unless I can qualify the work on YOUR setup. Me cobbling stuff together here on odd/end parts to check just won't cut it. It might cost a little more, but it costs a whole lot more to ship it 2 or 3 times. . .

Happy to help.

C.

LRI
 
Feb 13, 2017
192
0
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Ran a match on Saturday with my TL3 MPA 6mm Comp Match Improved (6mm Unicorn) not a single issue. The ARC mag was able to get my COAL with 115 JLKs to where I need them to be 2.851. It was perfect. Dad ran same setup running 6mm Lapua. No issues at all. To date neither of us have had a single fail to anything with the ARC mags.
 

ZY100

Sergeant
Oct 13, 2007
202
17
18
VA
PDC custom Chassis and Defiance Deviant...smooth-smooth in two different rifles.

Mag catch was just a hair tight, but easily fixed with three strokes of a file.
 

ddavis

Sergeant
May 26, 2011
888
4
18
Texas
UPDATE:

Ran through a club match with the ARC mag (with original ARC follower with tabs filed down) in a Mausingfield action and I had typically 1 failure per mag. I believe it was when I was down to the last 3 rounds. Bolt would ride over round, and I'd have to pull bolt back, push round down level in mag and run bolt again. A minor annoyance that didn't cost me any points, but definitely something that needs to be fixed. It had just rained the night before so very little dust. Mag was clean. Not sure what to do about this beyond what I've done with the file already.

-Dan
 

Sheldon N

Blind Squirrel Finds a Nut
Sep 24, 2014
2,458
317
83
Pacific Northwest
If bolt is over riding round then you don't have enough case presentation to the bolt head. Either something to adjust in the mag latch to get the mag to sit higher (not exactly sure how) or open up the feedlips a bit so the case sits higher and gives more to present to the bolt face.
 

ZY100

Sergeant
Oct 13, 2007
202
17
18
VA
Did you file the mag or the catch?
The Mag...my AICS, Alpha and Magpuls all fit fine. The ARC fit, but you had to very deliberate and firm....so much so I could see it raise its head at the worst time. I will say the ARC mag locks in rock solid. ZERO play.
 

ddavis

Sergeant
May 26, 2011
888
4
18
Texas
If bolt is over riding round then you don't have enough case presentation to the bolt head. Either something to adjust in the mag latch to get the mag to sit higher (not exactly sure how) or open up the feedlips a bit so the case sits higher and gives more to present to the bolt face.
I think it was due to the follower sticking in the mag. All I'd have to do to fix the issue was stick my finger in the action and push the rounds down and they would pop back up to full height, solving the problem.
 

nexusfire

Secks fi millimeet
Sep 9, 2010
1,485
86
48
46
Mesa, AZ
My issue is when I rack the first round, round below it gets pushed forward and won't load after shooting the previous round. I have to use my finger and push it towards the rear of the mag. Too much spring tension? 6.5cm with lapua brass.
 

superde

Gunny Sergeant
Nov 7, 2003
1,107
13
38
Bryan, Texas
A lot of people seem to be having problems with these mags. I have 3 and they have run flawlessly in 2 rifles - 6BR (defiance) and 243 (impact), both in AIAT chassis. I did file down the follower wings a little from the get go just because of what I read here. I need 5 more, so if you don't want them, send me a PM - it will save me a few $.
 
I bought an extension kit for my arc mags and they also run flawless. per the instructions it says to measure the spring, then stretch it. pulling on it didnt really do it, i had to bend it at the bends to acheive this. Needed a little tuning but they run fine now. Also run in a defiance. If any one doesnt want their mags feel free to send them to me!
 
Mar 27, 2012
508
18
18
28
Newark OH-IO Go bucks
Any updates on the reliability of these magazines? My rifle gets dirty and I don’t want issues to arise due to a delicate magazine. Does Ted intend to release a gen2 model that corrects the feeding issues some of you have experienced?

thanks
 

Pusher591

Gunny Sergeant
Jun 18, 2009
2,476
41
48
33
Gaston County
Any updates on the reliability of these magazines? My rifle gets dirty and I don’t want issues to arise due to a delicate magazine. Does Ted intend to release a gen2 model that corrects the feeding issues some of you have experienced?

thanks
No updates as I know but Mark Leupold did say the follower re-design was in the works a while back but haven’t heard anything else about it.

Im gonna try to run them in my 6.5 PRC. If they work, great. If they don’t I’m gonna put a MPA mag extension on it and run the AICS 10rd spring in it to see if I can get away with it. If that doesn’t work I’ll just swap over some 5rd AICS mag springs/follower and be done with it.
 

ddavis

Sergeant
May 26, 2011
888
4
18
Texas
Mine seems to work fine now. I can't remember if I took it apart and sanded the follower a bit more, or if it just got "broken in" after my initial filing, but the last few hundred rounds have had no problems. IIRC when I spoke to Ted on the phone a couple months ago he basically said he shouldn't have jumped into the mag making business, it was a lot of trouble. He didn't say what the future holds for ARC mags. It seems like a simple follower re-design would solve the issues.
 
Mar 27, 2012
508
18
18
28
Newark OH-IO Go bucks
IIRC when I spoke to Ted on the phone a couple months ago he basically said he shouldn't have jumped into the mag making business, it was a lot of trouble. He didn't say what the future holds for ARC mags.
That doesn’t exactly build confidence. I picked up 2 that are slightly used and will give them a try with the 6creed. I’ll be sure to post back how they work whether good or bad.

 

ddavis

Sergeant
May 26, 2011
888
4
18
Texas
That doesn’t exactly build confidence. I picked up 2 that are slightly used and will give them a try with the 6creed. I’ll be sure to post back how they work whether good or bad.
Just be prepared to file the "ears" down on the follower if it doesn't work right. That will likely solve any issues.
 

Natestreo

Full Member
Feb 15, 2017
243
1
18
Anyone have 2-3 of these that they're having trouble with and want to sell? I'd like to try them in my setup. Willing to dremel the hell out of them and make it a project if necessary lol. PM me
 

Sheldon N

Blind Squirrel Finds a Nut
Sep 24, 2014
2,458
317
83
Pacific Northwest
Update on my ARC mags. I've got a pair that I've used for about a year now without issue. Filed down the ears off the follower when I got them and they've been trouble free for thousands of rounds... until a couple weeks ago at the Quiet Riot PRS match.

Very dusty conditions, gritty/sand dust. Had my mags go into full lockup, refused to feed. I had even seen them start to hiccup and had wiped them out and wiped off all my rounds and reloaded the mag, but that didn't help. Cost me several stages worth of points, had to borrow a mag to finish the match.

Nothing to do with the follower, it's the geometry of the double stack constricting into a single stack feed. There's a lot of pressure on the side walls of the mag from the brass, and this friction can overcome the upward pressure of the spring, even though the spring is really strong.

They work okay in normal conditions, but my advice is if you are going to shoot in dusty environments I would steer clear.
 

lash

Swamp Rat
Sep 28, 2012
3,046
756
113
59
Central Florida
Update on my ARC mags. I've got a pair that I've used for about a year now without issue. Filed down the ears off the follower when I got them and they've been trouble free for thousands of rounds... until a couple weeks ago at the Quiet Riot PRS match.

Very dusty conditions, gritty/sand dust. Had my mags go into full lockup, refused to feed. I had even seen them start to hiccup and had wiped them out and wiped off all my rounds and reloaded the mag, but that didn't help. Cost me several stages worth of points, had to borrow a mag to finish the match.

Nothing to do with the follower, it's the geometry of the double stack constricting into a single stack feed. There's a lot of pressure on the side walls of the mag from the brass, and this friction can overcome the upward pressure of the spring, even though the spring is really strong.

They work okay in normal conditions, but my advice is if you are going to shoot in dusty environments I would steer clear.
Well that is disappointing to hear. I use AW mags in my Stiller and like them a lot for their short size, very solid construction and consistent performance. I am awaiting a Nucleus action that will not accept AW mags and have been considering the use of ARC mags due to the similar size.

It sounds like I need to reconsider and go in a different direction for feeding this new action.
 
Apr 15, 2017
56
1
8
I have two mags purchased from LRI about 8 months ago. I only use factory Hornaday 6.5 Creed 140 ELD's in my RPR. I have about 1000 rounds through the mags. The mags have never failed to feed, extract, or eject. I can even rest the gun on the mag with no problems feeding new rounds. However, I have noticed occasionally that after chambering a new round after 2-3 seconds I could hear the remaining rounds shift up in the mag indicating that they were stuck for a short time. This happened when the mags were fairly new. I haven't noticed it in the last 500 rounds though. Seems like something was a bit tight but ran in. The mags now work great. After several matches with them they still work great when cycling the bolt fast or slow. The only thing to be aware of is if you get any grit in the mags, they will begin to hang up. However, Ted makes it clear that they need to be kept clean. And for what it is worth my RPR has never failed to feed, extract, or eject in the 2600 factory rounds since it was new with PMAGS, AICS mags, or ARC mags ( I did have some problems with someone else's reloads once). The ARC's are the best because they are short and feed real smooth.

Bang
 

lash

Swamp Rat
Sep 28, 2012
3,046
756
113
59
Central Florida
I have two mags purchased from LRI about 8 months ago. I only use factory Hornaday 6.5 Creed 140 ELD's in my RPR. I have about 1000 rounds through the mags. The mags have never failed to feed, extract, or eject. I can even rest the gun on the mag with no problems feeding new rounds. However, I have noticed occasionally that after chambering a new round after 2-3 seconds I could hear the remaining rounds shift up in the mag indicating that they were stuck for a short time. This happened when the mags were fairly new. I haven't noticed it in the last 500 rounds though. Seems like something was a bit tight but ran in. The mags now work great. After several matches with them they still work great when cycling the bolt fast or slow. The only thing to be aware of is if you get any grit in the mags, they will begin to hang up. However, Ted makes it clear that they need to be kept clean. And for what it is worth my RPR has never failed to feed, extract, or eject in the 2600 factory rounds since it was new with PMAGS, AICS mags, or ARC mags ( I did have some problems with someone else's reloads once). The ARC's are the best because they are short and feed real smooth.

Bang
See the part that I bolded in your post. That's the rub for some of us. I mostly shoot in Florida, where fine sand gets into everything eventually if you do anything other than bench shooting. If I am going to have to worry about keeping the mags spotless during practice or a match, then it's a problem. I may try one and use other mags as backup, if I can get one from the PX reasonably.
 
Apr 15, 2017
56
1
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See the part that I bolded in your post. That's the rub for some of us. I mostly shoot in Florida, where fine sand gets into everything eventually if you do anything other than bench shooting. If I am going to have to worry about keeping the mags spotless during practice or a match, then it's a problem. I may try one and use other mags as backup, if I can get one from the PX reasonably.[/QUOT
Yes, fine grit seems to be a problem. I was at a match in North Carolina a few months ago and it rained hard all day. I kept wiping my hands off as much as I could but the fine grit seems to get everywhere
See the part that I bolded in your post. That's the rub for some of us. I mostly shoot in Florida, where fine sand gets into everything eventually if you do anything other than bench shooting. If I am going to have to worry about keeping the mags spotless during practice or a match, then it's a problem. I may try one and use other mags as backup, if I can get one from the PX reasonably.
Yes, grit seems to be a problem. At a match in North Carolina a few months ago it rained hard all day. No matter how hard I tried, I could not keep fine grit off my hands. Eventually, my mags got dirty and when loading new rounds into the mag I could feel that the rounds did not move freely up and down when I pressed down with my fingers. I then switched to my spare PMAG. No problem. That is why I mentioned in my previous post that the ARC mags feed so smooth. I had become so used to the smooth feeding ARC mag that the first round with the PMAG required so much more effort that I thought there was a malfunction! But as I said, when clean they always work in my RPR. Seems like a small bit of fine tuning will make these great mags better.

Bang
 

ultrarunner7

Quiet Professional
Nov 20, 2012
944
15
18
Williamsburg, VA
Fellas. I ordered one of these mags and it doesn't fit in my AXMC or my Short Action Customs rig with a Manners stock. I called ARC and all they told me was "it should fit". I measured the rear and its longer than my AI mags. I'm pretty disappointed. Fits in my MPA Chassis.
 
Jun 17, 2009
676
165
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30
Houston, TX
Update on my ARC mags. I've got a pair that I've used for about a year now without issue. Filed down the ears off the follower when I got them and they've been trouble free for thousands of rounds... until a couple weeks ago at the Quiet Riot PRS match.

Very dusty conditions, gritty/sand dust. Had my mags go into full lockup, refused to feed. I had even seen them start to hiccup and had wiped them out and wiped off all my rounds and reloaded the mag, but that didn't help. Cost me several stages worth of points, had to borrow a mag to finish the match.

Nothing to do with the follower, it's the geometry of the double stack constricting into a single stack feed. There's a lot of pressure on the side walls of the mag from the brass, and this friction can overcome the upward pressure of the spring, even though the spring is really strong.

They work okay in normal conditions, but my advice is if you are going to shoot in dusty environments I would steer clear.
One of my squad mates had an ARC mag that failed in that same match. Had the LRI follower. He ended up throwing that mag as far as he could after a bad stage, not sure if he ever got it back....
 
Feb 13, 2017
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You have to grind the top of the mag catch down on the ARC's to work with most BM's. Compare it to an AICS catch and you'll see what I mean. Most BM's are designed so AICS mags don't over-engage.. or seat too deeply in the mag well.
 
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