Peculiar stovepipe with coated bullets

[konkapot]

New gun. STI Eagle. 

 

Runs factory ammo great. Runs plated reloaded ammo great. 

 

Does not like my 124 coated bullets. 2 out of 100 will stovepipe with a live round; bullet pointed up. Does this when dry and dirty or clean and wet. 

 

Could this be an OAL issue? The coated bullets are a little warmer than the others; about 135pf. Coated are a little longer than the 115 plated, and about the same as the factory ammo it likes. 

 

Mags are Atlas magazines. 

[shred]

Could. What shape are the bullets?  TCs can drag more than rounder ones.

 

[konkapot]

They are in fact TC. Shot 100 of factory just now to make sure I wasn't losing my mind and they ran grrreat. 

[scooterj]

The TC bullets may also be contacting the slidestop, retarding the upward movement of the bullets in the mag. 

[zzt]

Check where the TCs hit the feed ramp.  More than likely you'll have to change the OAL on the coated TCs.  Sound like you are on the ragged edge, since 20% stovepipe.  Also, check the variation on your OALs.  For some reason, I get more variation with the coated bullets I have.  Maybe it is because they are hard cast, not swaged.

[Jim Watson]

Had this happen three times recently with coated roundnose. 

One of the offending magazines had splayed lips, the other was measurably wider across the lips.  I straightened them out and am testing them in practice.  

 

So check your clips.

Edited May 5, 2023 by Jim Watson

[konkapot]

Out of town for a week; back now. 

 

Shot today; same issue; roughly 3 out of 150 stovepiped. Again...bullet is facing up. Not an ejected case...a live round. 

 

@zztMy factory ammo is longer; the plated 115s are shorter. Both a FMJ profile. Should I length or shorten the coated bullets?

 

Any chance this is related to a recoil spring being too light or heavy?

My  support thumb drags a little bit on the slide; could my thumb retard the movemen of the slide enough to cause this?

[zzt]

53 minutes ago, konkapot said:

My  support thumb drags a little bit on the slide; could my thumb retard the movemen of the slide enough to cause this?

 

Absolutely.  Work on that before you make any other changes.  I suspect your problem will disappear when you correct that.  I had exactly the same problem when I put a thumb rest without a side thumb shield on my CZ TS.  The side of my thumb would occasionally touch the slide, slowing it down.  I took the thumb rest off.

[konkapot]

Happened strong hand only today, so it's not that thumb. 

[zzt]

17 hours ago, konkapot said:

Happened strong hand only today, so it's not that thumb. 

 

Then one of two things are happening, maybe both.  You are not gripping the gun tightly and/or consistently  enough, or your load and recoil spring are not compatible.  Got to the next lighter recoil spring and see what happens.

[Baynewrady]

On 5/14/2023 at 3:36 PM, konkapot said:

Out of town for a week; back now. 

 

Shot today; same issue; roughly 3 out of 150 stovepiped. Again...bullet is facing up. Not an ejected case...a live round. 

 

@zztMy factory ammo is longer; the plated 115s are shorter. Both a FMJ profile. Should I length or shorten the coated bullets?

 

Any chance this is related to a recoil spring being too light or heavy?

My  support thumb drags a little bit on the slide; could my thumb retard the movemen of the slide enough to cause this?

To me this sounds like a mag issue, slidestop issue, or OAL issue. Something is causing the round to go vertical once it’s stripped from the mag during cycling. 
 

can you recreate the issue by hand-cycling the gun? 

[jim vaughan]

check the extractor tightness.

[konkapot]

Sorry for not updating this; it was an OAL issue. Stetched them out a bit and it's 100% now.