[CAVman]

It's been a while since I updated the status of "My short cycling Socom 16".

I received the rifle back from S/A with a fitted op rod & test fired. The 'smith flagged all the CMI 25 round mags as having weak springs, did not test them.

I sent the mags to CMI with the request make them reliable or replace them with 20 round mags. I got 6 springs back from CMI and then the mags were returned with the report:

All mags had the feed lips reformed. All followers replaced with a teflon coated piece. No further changes. Except that wasn't true. When returned, the springs in the magazines had one more coil, and the same number as the springs that CMI sent to me; this is a coil longer than the 20 round spring, but thinner. Either way, it didn't work. When purchased new, the magazines had the same number of coils as the 20 round mag - in fact it was the same spring as the stock S/A 20 round magazine; but different, thinner than the USGI spring.

I test fired the Soc16 with the 2 x 20 round magazines I had to the tune of 200 rounds with no malfunctions. I've been trying to cycle the 25 round magazines through (there are 7 of them). Each time I go out, one of the 25 round magazines malfunctions. When I revert to the 20 round magazines, the gun works 100%. Mind you it's not a hugely bad failure rate, but it's now about 1 in every 120 - 150 rounds.

It does appear that the gun works with good magazines and the CMI 25 round magazines do not fit that description. I am close to 1200 rounds through the gun at this point and each time the 25 round mags are introduced, there is a stoppage. Tonight the one stoppage was definitely a feed issue - the round got stripped by the bolt but the nose missed the chamber at the 11 o'clock position. The last time was like a short cycle but IIRC the trigger reset; unlike before s/a worked on it. At this many rounds spent I can't say any of these 7 magazines are serviceable and I would highly recommend anyone thinking of buying these avoid them at all costs. I've spent literally hundreds of dollars trying to verify these mags work but they don't. Roughly every 4th to 5th loading produces a failure to feed of some sort.

If you're considering these Checkmate 25 round magazines, save your money.

I smell another 'SEI Receiver'-Type Thread Coming Here !!!

GI2

Seriously, 'Smurfslayer'---Did You Contact Checkmate Regarding Your Findings As To The Springs?
And You Previously Stated You Asked CMI To Either Fix Them Or Replace Them With 20 Round Mags...Are You Going To Follow Up On That?
Finally, Just Curious...Do You Know If There Was Any Consistency As To WHICH Round In The Mags Was The 'Stoppage'?
Was It The First Round, Last Round, # 17?....or was it just seemingly random rounds?
Thanks!

CAVman in WYoming

 

[Smurfslayer]

I smell another 'SEI Receiver'-Type Thread Coming Here !!!

GI2

CAVman in WYoming

Not from me! The rifle seems to be working like it should using the standard mags.

Did You Contact Checkmate Regarding Your Findings As To The Springs?

Are you talking about the mags coming with the same spring as the 20 rounders? I did do that when I sent the mags to them.

And You Previously Stated You Asked CMI To Either Fix Them Or Replace Them With 20 Round Mags...Are You Going To Follow Up On That?

Yes, I am.

Finally, Just Curious...Do You Know If There Was Any Consistency As To WHICH Round In The Mags Was The 'Stoppage'?
Was It The First Round, Last Round, # 17?....or was it just seemingly random rounds?

There is no discernible pattern. Last night it was round 18. Previous session was mid magazine, maybe 14 or 15.

In fairness, that session I also had a case that didn't extract. It was stuck in the gun good, with a meaty part of the rim nearly ripped off. I don't think it's fair to fault CMI for that one.

Previous to that session, I got one on the 2nd round from the magazine. I then ripped off 200 rounds trouble free from the 20 round magazines (2 of them). Prior to that I don't have anything written down specific to which round, only the magazine numbers.

 

[37489]

You have numbered your mags right?

You have numbered your mags to tell them apart right? Just wondering if all of them act up at random or if there is a subset of bad actors.

Have you taken the final step? Mail them back to CMI with the request for 20 rd replacements. Either way get them out of your house. I had two no-name mags that failed to feed, short cycled etc. Paid $20.00 each for them. Sent one to a member here who confirmed it was crap. Tossed the other one by a different manufacturer in the dumpster and never looked back. It's like day trading. They say the first step in day trading is to write a check for $50,000 and then flush it down the toilet. If you can do that you are cut out for day trading.

Get those magazine shaped objects out of your house and move on bro. And thanks for sending up a flare for the rest of us.

 

[Smurfslayer]

You have numbered your mags to tell them apart right? Just wondering if all of them act up at random or if there is a subset of bad actors.

Have you taken the final step? Mail them back to CMI with the request for 20 rd replacements. Either way get them out of your house. I had two no-name mags that failed to feed, short cycled etc. Paid $20.00 each for them. Sent one to a member here who confirmed it was crap. Tossed the other one by a different manufacturer in the dumpster and never looked back. It's like day trading. They say the first step in day trading is to write a check for $50,000 and then flush it down the toilet. If you can do that you are cut out for day trading.

Get those magazine shaped objects out of your house and move on bro. And thanks for sending up a flare for the rest of us.

You know it! The gun is very fun to shoot and I know a lot of posters here aren't fond of the Soc. sights but I really can't complain accuracy wise. Also in fairness I have a 2 moa aim point on an ultimak upper but anyway.

Each of the magazines - one is blank, but the remaining 6 are numbered 1-6 and all have malfunctioned. 3 have the spring that came back from CMI as replacements, 3 have the springs that came back in the magazines, 1 has a Wolf +5% spring for a 20 round mag. All of them have malf'd at least once. They get about 3 loadings each and choke, give or take a loading.

I've let friends punch some holes with this gun and quite a few have the same goofy smile as putting some rounds through a machine gun. GI5

I didn't find a lot of feedback on the 25 rounders when I bought them, but I found a lot of good CMI feedback. To their credit, they've stood behind the product so far. I'd like them to work but they just don't.

 

[patriot armory 308]

I have four CMI 25 Rnd mags for my scout rifle and have fired hundreds of rounds without a single problem.

 

[CharlieEcho]

Good advice! "Get those magazine shaped objects out of your house and move on bro. And thanks for sending up a flare for the rest of us."
Thanks

 

[Seventh Fleet]

I agree send them back and get CMI to replace them with 20 round mags. You've definitely gone the extra mile in trying to make the 25 rounders work, so cut your losses and move on...

7th

 

[Mocos]

I have maybe 5-6 thousand rounds through my socom and early on had some of the problems you described. All my mags are now cmi's and the all work 99% of the time. I have a couple of 25 rounders and 4-500 through them with no failures yet.. Ammo? all milsurp and a lot of wolf. Early on I had problems like you described and after installing a new Tubbs op rod spring the failure rates dropped significantlly.

suggest you consider:
>some of the problems sound like weak op rod spring related..
>if you use the magazine as a vertical grip does change the feed angle and maybe more so with the 25 rounders...more leverage
>do the failures occur when the gun is cold or warmed up or hot...you mentioned something about the 3rd loading or so....like after 50+ rounds of slow fire, sustained medium fire or mag dumps...
>are the catch hole in the front of the mag and the welded catch tabs on the back of the mag the same as the 20 rounders....
>check the op rod spring guide for wear on the tip that hooks into the front of the magazine.

other use for them if not for your socom.....use them for despensers for a bolt action, you can carry them bullets up in your mag pouch..

If all else fails you can send those mags to me and I will gladly dispose of them for you...I will even send you a fedex tag ...just pm me...lol

 

[Smurfslayer]

suggest you consider:
>some of the problems sound like weak op rod spring related..

It's been to S/A twice already and I won't rule out the op rod spring, I would point out that in the previous thread I linked I suspected that the op-rod was dislodging and hanging. They refit the op-rod ( apparently for no disassembly, you need a freakin' crowbar to get it out now ). This was the last trip to S/A and since then even the 20 rounders work flawlessly. The first trip to S/A it was short cycling with even the 20 round mags.

Not that I can disassemble it anymore, but what's the length of the spring supposed to be?

>if you use the magazine as a vertical grip does change the feed angle and maybe more so with the 25 rounders...more leverage

No. I don't use them for a rest, or a forward grip. I have an AFG2 mounted well forward.

do the failures occur when the gun is cold or warmed up or hot...you mentioned something about the 3rd loading or so....like after 50+ rounds of slow fire, sustained medium fire or mag dumps...

No pattern I can point to other than -most- of the failures occur in the middle of the magazine and it doesn't seem to matter if I'm shooting fast, or slow, or whether the rifle is cold, warm or hot.

are the catch hole in the front of the mag and the welded catch tabs on the back of the mag the same as the 20 rounders....

They are the same visibly.

check the op rod spring guide for wear on the tip that hooks into the front of the magazine.

ok.

 

[Mocos]

It is tough to measure the catch hole and catch tabs accurately....another way to measure...is to see if you can insert a fully loaded mag with the bolt closed...and see if the 20 an 25 rounders have the same resistance and if you really have to rock it back and forth to leverage in .....do it with dummy rounds if at home. It's subjective but if the "feel" is the same for both mags and when they are fully inserted do they lock up without much wiggle. If you're satisfied with the uniformity...I would tend to think it is more a gun problem than a mag problem. If there are discernable differences in feel, that should hint where the problem might be.

as far as ammo....I can't comment as I don't reload 308 yet...and what I do use does't run 100% but close to it.

again.. I will gladly dispose of them for you....

 

[MrShmitty]

I wondering if CMI has been able to work out the kinks since then. I would really like to run with 5 25 round mags for my Socom. Is there other springs we could use to help reslove this problem? Like an after market Wolf spring that is plus maybe 15 to 20%? Just a thought. I mean I would be happy with my 20 rounders but if you can fit 5 more rounds per mag who would ever need an AR again?

 

[Smurfslayer]

I wondering if CMI has been able to work out the kinks since then. I would really like to run with 5 25 round mags for my Socom. Is there other springs we could use to help reslove this problem? Like an after market Wolf spring that is plus maybe 15 to 20%? Just a thought. I mean I would be happy with my 20 rounders but if you can fit 5 more rounds per mag who would ever need an AR again?

It may have been that. I’ve bought 2 separate mags recently and both have tested out successfully. At one point CMI sent me a batch of springs, so it appears I’m good for replacements for a while too. I tried the available Wolff spring, but it’s for a 20 rounder. It wasn’t reliable in the 25 round mag body.
<knock wood> my current rotation of mags have all checked out nicely.

 

[RSConsulting]

I wondering if CMI has been able to work out the kinks since then. I would really like to run with 5 25 round mags for my Socom. Is there other springs we could use to help reslove this problem? Like an after market Wolf spring that is plus maybe 15 to 20%? Just a thought. I mean I would be happy with my 20 rounders but if you can fit 5 more rounds per mag who would ever need an AR again?

That's funny...

If I have to put 2-3 5.56Nato rounds into an opponent to BE SURE they stay down, versus a SINGLE 7.62Nato (theoretically speaking, of course - LOL) - then a 20 Round M14 mag = a 60 Round AR-15 mag.

ADVANTAGE = M14.

Theoretically speaking of course.

And I'm NOT selling my AR's, just because I fell in love with the M14 platform (starting my 3rd M14 build). I just recognize the "tactical superiority" of a platform that can take someone out of their sneakers at under 100 yards (and leave the laces tied) and still push their face into the dirt effectively @ 7-800 yards.

I'm surprised there would be so many "conformity" issues with the 25 rounders. You would think it wouldn't be too difficult to simply "extend the box" and put a longer/stronger spring in, to accommodate the extra 5 rounds.

OTOH - I did have to trim all the followers on my SAI stamped/NIW mags to accommodate round 20 and lock in my Sage/SEI - even though they all worked fine in my Sage/SAI. Instead of looking at dimensional differences between receivers and stocks - I took the easy way out and trimmed the followers.

I've got one OLD CMI 25 rounder in the closet - I guess, based on this - it goes on THE BOTTOM of the "ready pile"...

Rick

 

[Smurfslayer]

old doesn’t necessarily equate them with a bad batch, unfortunately the only way to know they work is test them and that gets darned expensive. With this kind of cost, I like to see 3-4 full mags worth of trouble free function under varying conditions.

 

[m1476251]

Have you tried loading the 25 five round mags with say 10 rounds and then test? Then 15 rounds, then 20? Try to narrow down if the mag is reliable up until a certain number of rounds are loaded - or not.

 

[Hiram325]

I bought one CMI 25 just to try, I have a few dozen 20's. No problem with the 25 so far but this certainly puts the 25 in a different light.

 

[Smurfslayer]

What I have done is 5 rounds, then 10, then 10 again, the 3 x 25 rounds.
When ammunition didn’t require easy financing plans I wanted at least 5 x a full mag count plus some lesser round counts.

I will test slow fire, controlled pairs & 3 (controlled) shots at speed, but I’m not bump firing or the like to test them.

 

[kabanchik]

There IS a REASON, you know, as to why the US Armed Forces, and other users of 7.62mm battle rifles around the world, only issued 20rd magazines with their weapons. The rounds are just too heavy for RELIABLE functioning in magazines larger than 20rds. One can argue that the Brits used a 30rd mag, successfully, in their L4 BREN LMG, but in THAT weapon the magazine fed downward into the action, NOT upward.

 

[jbrooks]

The title of the thread is a little misleading. When I saw it, I thought that there had been a study performed showing some problem with "all" 25 rounders...

When CMI first developed the 25 rounders, they used the standard 8-coil 20 round mag spring. It was replaced at some point with a 9-coil spring which provides the proper force on the ammo. CMI will replace any older mag springs for free.

I have 5 of the 25 round mags, and they have performed flawlessly in my SAI pre-ban rifle. Better in fact, than the 20 rounders which tend to not keep the bolt back due to a mis-shapen follower.

Probably need to run other potential problems with your rifle to ground.

JWB