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dons

Nosedive jams - 38 Super

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I've been having some nosedive jams in my 38 Super STI that I've never seen before.  Here's what I've tried:

Magazine bodies, both Gen 1 and Gen 2 STI.

New brass, old brass, and everything in between.

Stock magazine springs and followers: Grams springs and followers.

Overall length 1.225 to 1.245 and lengths in between. I'm using a Zero 121 gr JHP

Does not seem to be a firearm issue as I can duplicate this condition when I download the magazines when they're not in the gun.

To top it off, this pistol and magazine combination has been nearly flawless for literally thousands of rounds. 

So what would change that would cause this issue?  Am I going to have to scrap 10,000 rounds of 38 Super brass and go to 38SuperComp?

 

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Not all, but 6 of 8 so far. This morning I  put 200 rounds through 4 magazines with one jam. Doesn't occur often,  but seems to  happen at matches, including the last hi-cap nationals. 

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I only have that issue when the magazine spring it too weak.  I'd stick with the G2 mags and try ISMI springs.  I've had great luck with them.

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Thanks for that. Four of the magazines, including the one pictured, are new within the last 3 months. So new springs there. I've also installed new grams springs and followers with the same result.  So thats why I'm so puzzled. 

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I know these are typical questions and I'm assuming that you most likely investigated them, but I'll ask anyway in case you missed one: 

1. Have you mic'd the lips? From being dropped they may have closed a bit.

2. Is there any residue stuck on the inside of the mag body? possibly from case lube etc. Could be dragging the follower.

3. Have you tried someone else's mags that work for them? If possible you can do a stare and compare to a know working mag. 

 

Things don't break unless something is changed. From what you said in your post it doesn't seem you changed anything. The above is the only thing I can thing of that would change involuntarily and without your knowledge. 

 

Oh, another thing you may want to try is to bend the front of the very first coil just below the follower up a bit. This theoretically would put more pressure on the leading edge of it bringing the nose up.

 

 

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Posted (edited)
6 hours ago, schaet said:

I know these are typical questions and I'm assuming that you most likely investigated them, but I'll ask anyway in case you missed one: 

1. Have you mic'd the lips? From being dropped they may have closed a bit.

I have, as a matter of fact, bought the tuning tool and set them all per the instructions - still no change.

Quote

2. Is there any residue stuck on the inside of the mag body? possibly from case lube etc. Could be dragging the follower.

No, insides are cleaned and re-cleaned.

3. Have you tried someone else's mags that work for them? If possible you can do a stare and compare to a know working mag. 

I haven't, and will try this.  There are two other 38Super Open shooters in my club, but they shoot SC and use MBX magazines.  I'll see if I can get some time with one of their magazines.  MBX magazines won't work in my gun without modification because of the accurails.

Things don't break unless something is changed. From what you said in your post it doesn't seem you changed anything. The above is the only thing I can thing of that would change involuntarily and without your knowledge. 

You're absolutely right.  I've got probably 20 years shooting open with the 38Super, changed springs regularly.  Doesn't make sense.

Oh, another thing you may want to try is to bend the front of the very first coil just below the follower up a bit. This theoretically would put more pressure on the leading edge of it bringing the nose up.

I've tried this, but the bend only lasts a few magazine cycles.

 

Thanks for your input.  I'm beginning to get very frustrated.

Edited by dons

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My experience with this (I shoot a lot of rimmed super) is that it happens when the mag bodies are too short front to back. It will not feed from MBX mags unless you load ridiculously short with how the cartridges stack in the magazine due to the rim. 38SC does not have the same problem.

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14 hours ago, dons said:

Thanks for that. Four of the magazines, including the one pictured, are new within the last 3 months. So new springs there. I've also installed new grams springs and followers with the same result.  So thats why I'm so puzzled. 

I get it.  Brand new STI springs suck.  Grams are made for capacity.  Try the 11 coil ISMI, they are at least 3" longer than stock STI 11 coil springs. 

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11 hours ago, dons said:

I have, as a matter of fact, bought the tuning tool and set them all per the instructions - still no change.

Thanks for your input.  I'm beginning to get very frustrated.

 

Sometimes the instruction numbers are not going to work best for a particular gun.  You should try working outside the specs a bit and see if you can find the sweet spot.

 

Also, are the inside of the lips where the rim touches very smooth and polished?  I'd suggest stoning and sanding them smooth and making sure that top round at the rear isn't sitting in some kind of depression.

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Salient point to me is that this problem just started. If no variable has been changed, then the only possibility is a "wear and tear" issue on the magazines...…...or the gun. Maybe something with the gun itself changed; mag release worn so mags sit lower (or something equally crackpot.)

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Having been through this problem before I would like to suggest trying an STI follower.

The best day of my open career was when I ditched all other followers and just used these big black tilted followers.

Since then I have had no magazine problems. 

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14 hours ago, NickBlasta said:

My experience with this (I shoot a lot of rimmed super) is that it happens when the mag bodies are too short front to back. It will not feed from MBX mags unless you load ridiculously short with how the cartridges stack in the magazine due to the rim. 38SC does not have the same problem.

Appreciate your observation. What do you consider ridiculously short? 1.220? Thanks

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2 hours ago, jim vaughan said:

Having been through this problem before I would like to suggest trying an STI follower.

The best day of my open career was when I ditched all other followers and just used these big black tilted followers.

Since then I have had no magazine problems. 

 Last test cycle I used only STI followers, still had a jam.  I've ordered new ISMI springs as RangerTrace suggested; we'll see.

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3 hours ago, konkapot said:

Salient point to me is that this problem just started. If no variable has been changed, then the only possibility is a "wear and tear" issue on the magazines...…...or the gun. Maybe something with the gun itself changed; mag release worn so mags sit lower (or something equally crackpot.)

 

It sounds like you are well versed in evaluating this.  I will say that your photo does not indicate anything with the feed lips.  The last time I faced this (although 9mm which is tapered) was trying to load ammo longer, and the mags didn't like it.  Time before nd was due to weak springs, which were barely used.

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3 hours ago, konkapot said:

Salient point to me is that this problem just started. If no variable has been changed, then the only possibility is a "wear and tear" issue on the magazines...…...or the gun. Maybe something with the gun itself changed; mag release worn so mags sit lower (or something equally crackpot.)

Thanks for responding, it's driving me nuts. The only thing that's changed is the mag release, and it was one of my first suspicions. But I can duplicate the jam with the magazines out of the gun, just trying to unload the magazines.  But I'm still going to try another magazine release.

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5 hours ago, dons said:

Thanks for responding, it's driving me nuts. The only thing that's changed is the mag release, and it was one of my first suspicions. But I can duplicate the jam with the magazines out of the gun, just trying to unload the magazines.  But I'm still going to try another magazine release.

 

My suggestion is to check the magazine body width. If the rounds are stacking too much side to side, they will reduce the spring pressure to the follower. Can you say if it happens during a full mag, half full, almost empty? Any pattern there?

 

You also might want to check out this video, which could help explain your woes:

 

This can help with better feeding. 

 

You see, the magazine bodies get out of shape after being dropped and all of that pressure from the persistent dropping of rounds and then back into the body deforms things over time. You are simply bring them back into specifications. 

 

Also, go with Grams Springs and Followers. They work the best.. by far. Just make sure that the follow is polished and there is nothing scraping the inside of the magazine body. A cloth Dremel wheel is your friend here. 

 

Meanwhile, maybe I will see you at one of the Northern California ranges next year?

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38 minutes ago, Nevadazielmeister said:

 

My suggestion is to check the magazine body width. If the rounds are stacking too much side to side, they will reduce the spring pressure to the follower. Can you say if it happens during a full mag, half full, almost empty? Any pattern there?

 

You also might want to check out this video, which could help explain your woes:

 

This can help with better feeding. 

 

You see, the magazine bodies get out of shape after being dropped and all of that pressure from the persistent dropping of rounds and then back into the body deforms things over time. You are simply bring them back into specifications. 

 

Also, go with Grams Springs and Followers. They work the best.. by far. Just make sure that the follow is polished and there is nothing scraping the inside of the magazine body. A cloth Dremel wheel is your friend here. 

 

Meanwhile, maybe I will see you at one of the Northern California ranges next year?

Thanks for the tips, I already went through this process. I have the Grams products, new springs are on the way.

 

Meanwhile, I typically shoot with Shasta Shooters in Redding, 2nd Saturdays. 

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You could try 100 SuperComp brass and see if that solves the problem. Keep in mind you might have to adjust the extractor to work with the rimless cases. Or not.

 

Question: when the mag is fully loaded, is there a gap between the top round and the one under it? 

Edited by superdude

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16 minutes ago, superdude said:

You could try 100 SuperComp brass and see if that solves the problem. Keep in mind you might have to adjust the extractor to work with the rimless cases. Or not.

 

Question: when the mag is fully loaded, is there a gap between the top round and the one under it? 

Thanks for your comments.  I've ordered 1000 SC brass in my frustration. I may have to go that route. I'm trying some other things first, and I can always sell the brass.

And the answer is sometimes there is a gap, and I know that's bad. I'll be travelling the next week or so and won't be able to do more testing until I get back.

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Does the follower move up and down freely in the mag body with no ammo. Try loading the mag and duplicate the condition. Tap on the mag and see if the rounds pop up

if so they are sticking inside the mag body. Have you changed tour ammo in any way?

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Just went through this with a new Akai open gun and new MBX magazines.  Plus I got a few where the round would flop from side to side and jam on the edge of the feed ramp.  All this a few weeks before the Nationals.  I took a big gulp, made the scary call to change something right before a big match, called dillon and ordered a supercomp plate and 4K brass.   It is SO MUCH BETTER.  Rounds stack properly in the magazine, don't nosedive and feed properly.  I have not had a single malfunction since.  I was trying to use up the the super brass I had (including thousands new), but giventhe time, trouble and expense to travel to matches it is a false economy.  You will probably need a new extractor.

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8 hours ago, sauza45 said:

Does the follower move up and down freely in the mag body with no ammo. Try loading the mag and duplicate the condition. Tap on the mag and see if the rounds pop up

if so they are sticking inside the mag body. Have you changed tour ammo in any way?

Thanks for taking the time to offer your input. The followers of all the mags move freely. I've noted that I can duplicate the condition. And when it jams, no amount of tapping releases the rounds. A true "death jam"

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4 hours ago, bradhe said:

Just went through this with a new Akai open gun and new MBX magazines.  Plus I got a few where the round would flop from side to side and jam on the edge of the feed ramp.  All this a few weeks before the Nationals.  I took a big gulp, made the scary call to change something right before a big match, called dillon and ordered a supercomp plate and 4K brass.   It is SO MUCH BETTER.  Rounds stack properly in the magazine, don't nosedive and feed properly.  I have not had a single malfunction since.  I was trying to use up the the super brass I had (including thousands new), but giventhe time, trouble and expense to travel to matches it is a false economy.  You will probably need a new extractor.

Almost ready to go this route. Will try shortening the OAL significantly first, as suggested. 

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Something to remember, only change one thing at a time or you won't know exactly what solved the issue.

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