Recurring issue with 170mm mbx mags

[yekcoh]

I had two of my 170mm mbx mags fail on me in an identical fashion at a very big match

 

I would like to know if others have experienced this and found a remedy

 

On a 24 round stage, After shooting about 23 rounds (I load to 28 rounds and never max them out), a round gets lodged with the follower causing the remaining rounds to get loose inside the mag subsequently causing a jam. 
 

My friend suspects weak spring which is what I think too. He says mbx follower and spring arent great and get weak quickly and recommends grams. This is the first time happening to me so I’m very frustrated 

I do change mag springs periodically and stretch them when I clean from drops

 

If anyone has experienced something similar and found a solution, please shine some light on me. 
 

The first failed mag had a new spring 

second one had spring replaced in july so they arent old

Edited August 31 by yekcoh

[aandabooks]

First thing I do with a MBX mag is buy Grams follower and spring.  The MBX followers are soft and wear quickly.  Usually just hit up Shooters Connection.  Spring and follower were less than $20 last time I bought.

[shred]

What pistol/frame?  MBX makes 170s for 2011. CZs, etc.

 

[jpeters11]

I’ve ran stock followers in my gen 1 MBX 170s for years and really don’t worry about replacing the springs, they’ll last over a year without issue.
 

Do your mags have the new ultra max follower? I saw that was a thing, didn’t understand why since mine do 30+1 when I need it 

[IVC]

Do you clean magazine tubes? Here in the desert any magazine that drops in the dirt pile will quickly exhibit the behavior you describe if you don't run a brush through the tube between stages. 
 

Do you wet tumble your brass? Squeaky clean looks nice but is not as slick as dry tumbled brass. 
 

Anything that adds a little friction by the magazine wall will exacerbate problems with weaker springs and suboptimal followers. 

[yekcoh]

My brass is wet tumbled. And I brush when they drop. 
 

So if it isnt the spring issue, could it be the degradation in the followers?

 

both mags arent a year old and are only used during match. 

 

do followers need to be replaced?

[BoyGlock]

If the mag body is a bit large inside and/or the follower is a bit narrow, these will create clearance enough for the round and follower to bind inside resulting to a salt-shaker condition you experienced. Try other followers of same or different brands that might have wider body.

1 hour ago, yekcoh said:

My brass is wet tumbled. And I brush when they drop. 
 

So if it isnt the spring issue, could it be the degradation in the followers?

 

both mags arent a year old and are only used during match. 

 

do followers need to be replaced?

 

[zzt]

I don't buy the statement MBX springs and followers wear out quickly.  I'm still using the same followers that originally came with my 155s and 170 mags.  The only thing I did was bend the springs so the followers were a little more horizontal.  That cured the round slipping under the follower when a partially filled mag was dropped.  As far as springs go, I replaced them after three seasons, just because I thought I ought to.  I replace them yearly now, just in case.

 

BTW, stretching mag springs only lasts about one loading.  If you are having to stretch your springs, it's time for new.

 

BTW2, MBX followers and springs work better in MBX mags than Grams guts do.  Tried it.  Not good.  Atlas springs and followers do not work in MBX mags at all.  Tried that too.

[Rnlinebacker]

The MBX follower always has excess material on it. Take a Dremel to it on the sides and back two corners. Go until the follower runs smoothly throughout the mag tube without sticking. 

 

Follower should sit pretty close to the top of the magazine been and you will be able to load 30rd by hand. Will also be reloadable with 30.

[yekcoh]

On 9/3/2024 at 12:25 AM, zzt said:

I don't buy the statement MBX springs and followers wear out quickly.  I'm still using the same followers that originally came with my 155s and 170 mags.  The only thing I did was bend the springs so the followers were a little more horizontal.  That cured the round slipping under the follower when a partially filled mag was dropped.  As far as springs go, I replaced them after three seasons, just because I thought I ought to.  I replace them yearly now, just in case.

 

BTW, stretching mag springs only lasts about one loading.  If you are having to stretch your springs, it's time for new.

 

BTW2, MBX followers and springs work better in MBX mags than Grams guts do.  Tried it.  Not good.  Atlas springs and followers do not work in MBX mags at all.  Tried that too.

wow it’s amazing to see how every reply has been different and conflicting to one another. 

some people noted follower wears which is something I didnt think was a thing. mbx has worked fine this year until last week. 

 

so Im gonna start fresh and switch both springs and followers and not stretch spring after each use.

 

 

 

[zzt]

11 hours ago, yekcoh said:

wow it’s amazing to see how every reply has been different and conflicting to one another. 

some people noted follower wears which is something I didnt think was a thing. mbx has worked fine this year until last week. 

 

so Im gonna start fresh and switch both springs and followers and not stretch spring after each use.

 

 

 

 

Most of the problems are from using the wrong MBX components.  Followers are Gen specific.  Although Gen 1 followers will work in Gen 2 mags, the reverse is not true.  The Gen 3 springs do not require the week or two of 'conditioning', the previous Gens did.  My last replacements dropped right in and were fully reloadable from day one.  I reused the original followers.

[MikeyScuba]

I only got 30 with the Taran basepads and even then I had to slam the mag into the gun.  Otherwise no issue.

[yekcoh]

From digging the forum here are some of my findings:

 

1. MBX tubes have wider internal which people have reported issues when the rounds are moving from the double stack to the single stack region. This is probably a similar issue I am facing.

 

2. People reported grams followers work well in MBX tubes while Grams founder doesn't recommend it...

 

 

Edited 2 hours ago by yekcoh