Very hard ejection (pun unintended)

[BoyGlock]

2 comped guns of different mileage. .38super/comp. Sti framed custom. 1 kkm barrel, 1 sti barrel. Functioned reliably for about 40k rounds between them of ipsc major pf >160. Powder is n340, head 125gn coated. Brass are armscor Rimless (SC) Chambers are clean. Aftec supercomp extractors. 

Almost simultaneously began FTE jamming intermittently after some 20-40 rnds fired in a clean chamber, with the shell stuck hard inside the chamber. Extractor hooks slide over the rim but at times stays with the rim. I have to pry hard with a flat head screw driver to remove the shell. I tried cleaning the chambers judiciously without any success.  
 

Thought at first it was the ammo since it happened on 2 barrels of different guns. But the load is basically the same since about 30k rounds ago. Its just recently that this hard fte happened. And Im out of 2 Open guns until this is resolved. Shot the same ammo in my 3rd open gun with Schuemann hibrid barrel and it ran 100% for 200+ rnds. 
 

Have you experienced or saw this happened before and what/how was it resolved?

Edited August 22 by BoyGlock

[Grendel]

Did you change anything with the way of preparing the brass? I've had Hard ejection with brass wet tumbled with too much lemon acid, they became bone dry, change to Lyman turbo sonic solution and now very smooth ejection.

[BoyGlock]

1 hour ago, Grendel said:

Did you change anything with the way of preparing the brass? I've had Hard ejection with brass wet tumbled with too much lemon acid, they became bone dry, change to Lyman turbo sonic solution and now very smooth ejection.

No. I also wet tumble and use Armor All Wash n Wax with water then home brewed brass lube after drying for as long as I remember. Thank you 

[mmc45414]

Wondering about wear on the sizing die?  Does a unloaded sized round slide into the chamber OK?

[BoyGlock]

43 minutes ago, mmc45414 said:

Wondering about wear on the sizing die?  Does a unloaded sized round slide into the chamber OK?

They gage ok. The first few times it started FTEing I collected the empties to chk if it was the round or it was an isolated issue. Resized them later at home and they gaged wirh decent clearance to spare. 

[BoyGlock]

The only thing I did to both chambers out of the ordinary starting a few months back was clean them with a stainless chamber brass for my .357 revo cylinders. I just brushed them lightly knowing its a bit abrassive. It coud have abraded the chamber walls?

Edited August 22 by BoyGlock

[mmc45414]

40 minutes ago, BoyGlock said:

The only thing I did to both chambers out of the ordinary starting a few months back was clean them with a stainless chamber brass for my .357 revo cylinders. I just brushed them lightly knowing its a bit abrassive. It coud have abraded the chamber walls?

Maybe try different ammo?  Maybe something a friend loaded?  Might point to the pistols instead of the ammo/reloading. 

ETA: Maybe shoot your rounds through a friend's gun?  All of this assumes you have a trusted friend... 

Edited August 22 by mmc45414

[shred]

N340 is a pretty fast powder for major loads so pressure is going to be up there and the brass will probably get hammered. Tried some new or different brass to compare?  Drop-checked a bunch of these rounds in the problem-chambers?

 

[lefty o]

id lean towards the brass, or spitballing here how much wash and wax do you use when brass tumbling? quite possible you are getting a waxy buildup.

[BoyGlock]

3 hours ago, mmc45414 said:

Maybe try different ammo?  Maybe something a friend loaded?  Might point to the pistols instead of the ammo/reloading. 

ETA: Maybe shoot your rounds through a friend's gun?  All of this assumes you have a trusted friend... 

I fired the same ammo in my third gun and did not jam in 200+ rnds. 
 

 

3 hours ago, shred said:

N340 is a pretty fast powder for major loads so pressure is going to be up there and the brass will probably get hammered. Tried some new or different brass to compare?  Drop-checked a bunch of these rounds in the problem-chambers?

 

Agree n340 is in the faster side for major Open load but some of the jams were with new brass. 
I will try a slower powder next time around if i havent resolve this in a few tries. 
 

 

2 hours ago, lefty o said:

id lean towards the brass, or spitballing here how much wash and wax do you use when brass tumbling? quite possible you are getting a waxy buildup.

Been wet tumbling with same mix in water of 2-3 caps per wash for some 30 thousand  rounds now and havent seen any wax build up in any of my reloading dies especially in resizing where it would surely gunk up. It FTEd even in clean chambers. 

Edited August 22 by BoyGlock

[BoyGlock]

I plan to polish the chambers with grit 800 and 1000 sand paper if nothing changed for the better. 

[rishii]

5 hours ago, BoyGlock said:

The only thing I did to both chambers out of the ordinary starting a few months back was clean them with a stainless chamber brass for my .357 revo cylinders. I just brushed them lightly knowing its a bit abrassive. It coud have abraded the chamber walls?

I hate SS chamber brushes, I know they’re supposedly softer than the barrel, but a steel brush on steel bothers me

i would check your chambers for scratches, look down your barrel at a slight angle,  rotate and look for dark marks

Instead of sandpaper, I have used a felt polishing bob coated with red rouge in a dremel to polish chambers before.

[shred]

2 hours ago, BoyGlock said:

I fired the same ammo in my third gun and did not jam in 200+ rnds. 
 

That just tells you whatever is causing the problem doesn't show up in that gun.  Could be it has a larger chamber, smaller chamber, smoother chamber, different lockup, larger bore, more freebore, narrower breechface, etc.. who knows?

 

Have you drop-checked these rounds in the 'bad' chambers?  That will at least tell you if the problem occurs is before or after firing them.

 

[BoyGlock]

12 hours ago, shred said:

 

Have you drop-checked these rounds in the 'bad' chambers?  That will at least tell you if the problem occurs is before or after firing them.

 

Yes and they passed

[yigal]

I went through several guns that had similar problems with a final chamber  reamer  and polished  chamber after this . The problem disappeared.

[Toolguy]

Have you checked to see that the powder charge is correct? Maybe the powder measure somehow got bumped up to a higher charge, causing more pressure?

[IVC]

Analytically thinking... Something changed. The brass is stuck, so there must be additional friction holding it in the chamber, especially if you have to pry it out. The fact it works in other guns is inconclusive since those are different chambers. To create extra friction, either brass is expanding more, of there is change in the surfaces that contact either other (brass-chamber). 

 

To eliminate each, I would start by checking powder level (affects brass expansion), trying new brass (brass can lose elasticity), inspecting brass exterior for smoothness (affects friction). One important check would be to look at the brass that was actually stuck and inspect its exterior for any scratch marks. This would indicate small burrs in the chamber from rough cleaning. If the same happens with new brass and factory loads, then it must be the chamber. If the FTE brass looks smooth, it could still be very small burrs. Next would be to check the throat for any damage that could prevent proper head-spacing. Can you over-insert a round? If so, case mouth could be getting stuck, something you can inspect on the actual FTE round. 

 

Just throwing some ideas from the top of my head... 

 

 

[BoyGlock]

Ive checked all the possible causes I could think of but found nothing. The powder charge, ammo components, clean chamber are all within usual specs. For about 3 yrs now n340 is quite reliable accurate and consistent to me. Until very recently began fte jamming in my matchgun. Initially very infrequent and intermittent until suddenly in my last major it jammed heavily in same match gun. Match chrono was 169. Now I could not finish a magfull without a jam. And its in my two guns now! Although its much less in the 2nd gun. I collected the affected brass and thoroughly inspected them. I still believe its the ammo. I looked in the chamber in good light and magnification.Nothing to my untrained eye. I consulted my local gsmiths but didnt get a workable solution yet.

 

Now, is it possible for a pistol chamber to expand in prolonged normal use with major pf? I havent seen, known or read it to be but its the one i havent checked yet coz I dunno how to, short of chamber slugging. I inserted the fired problem brass unresized to the kkm chamber, it goes in but not in the sti barrel/second gun. Is the kkm oversized? But the sti barrel also had fte’d although to a lesser degree. 
 

And how is this problem happen in two separate reliable guns in almost same time?

 

[BoyGlock]

Thank you for your inputs. Helps a lot in viewing this differently. Hope to stick with you until its resolved. 

[CHA-LEE]

Check the crimp on the ammo. If there is excessive crimp the leading edge of the brass can get past the back edge of the chamber. When that happens the brass can get stuck in the chamber. Post pics of the loaded ammo as well as the brass that is getting stuck. 
 

If this issue is happening on two different guns then its 100% an ammo issue.

[BoyGlock]

Its lightly crimped im sure

On 8/26/2024 at 1:22 AM, CHA-LEE said:

Check the crimp on the ammo. If there is excessive crimp the leading edge of the brass can get past the back edge of the chamber. When that happens the brass can get stuck in the chamber. Post pics of the loaded ammo as well as the brass that is getting stuck. 
 

If this issue is happening on two different guns then its 100% an ammo issue.

 

[BoyGlock]

I polished the kkm chamber with no. 800 and 1000 grit. Testfired yesterday. Same ammo. In 175 rnds its 100% no fte of any kind. Its a bit low round count but encouraging. Will test more later. Goal is at least 500 rnds without cleaning the chamber. 

[yigal]

2 hours ago, BoyGlock said:

I polished the kkm chamber with no. 800 and 1000 grit. Testfired yesterday. Same ammo. In 175 rnds its 100% no fte of any kind. Its a bit low round count but encouraging. Will test more later. Goal is at least 500 rnds without cleaning the chamber. 

[BoyGlock]

Update. 
500+ rounds after, kkm barrel is 100%, not a single FTE! Can say polishing its chamber worked!

 

Will do the same with the STI barrel next.  And testfire it as above. 

 

[BoyGlock]

Its still a mistery that needs to be understood then resolved. The sequence of events logically said its was the ammo definitely. I looked hard for whatever clue in the ammo but found nothing so I looked in the chambers and decided to polish the one that had the worst FTE. As I polished, I didnt even believe that this was the solution so it was kind of experiment out of nothing else to try to solve the problem. Even as I test fired, I was expecting it to fte jam. But lo n behold! It kept on feeding and extracting positvely until I reached my goal of 500 rnds. 

So what was it? Im still looking…