STI feeding issue - 38 Super

[vscorsa]

Hi All,

I have a 2011 Framed STI race gun which has fired under 1000 rounds. Up until this weekend the gun has performed flawlessly with no issues at all, I have run the same 125gr conical proj with the same powder for all of its short life.

This weekend I headed down to the range for a practice run on friday and the STI wouldn't cycle properly. The symptoms are:

- Load mag with the usual 10 rounds (restricted in Australia.)

- Slide mag into STI, click off the safety, rack the slide using the rack bar.

- Slide comes all of the way back manually, let go of the racking bar.

- Slide moves forward picks up the back off the shell and pushes it forward into the ramp at the breach.

- Round stays against the ramp until I either apply light pressure to back of the slide or use a screw driver to lift the front of the proj a little bit.

- Fire the first shot, STI cycles the slide then as the slide comes forward it does the same thing with the round hitting the ramp.

It does this with every round in all five mags, every so often it will get a run on and may cycle two or three shots but this was very rarely across the 150 odd rounds I fired.

What has me clueless is that i haven't changed anything from the previous weekend when the pistol ran really perfectly. The only thing I did was clean it the same way I always have.

Anyone have any suggestions on what to look for?

So far I have:

- Checked the total length of the round, I usually run this at 1.250in it had snuck out to 1.265in so I brought it back. Didn't fix the issue, but may have improved.

- The brass has been reloaded 3 or 4 times so tried some brand new brass. Didn't fix the issue.

Thanks for any advice.

Cheers

[al503]

Try a new spring of the same weight or try a heavier one. If you started off with a light recoil spring, 1k rounds can wear it in enough to the point that it will be too weak to do what it needs to do.

Edited June 12, 2011 by al503

[GrumpyOne]

Check the feed ramp and the breech face, see if they are smooth with no burrs or carbon build up. Clean the rails on the frame and slide, and apply some good oil/grease (slide glide).

[ParaGunner]

It could be a mag issue to,need new mags springs.

[10ring]

It sounds like the Extractor tension has increased, or the round is catching on the extractor hook. Could the Extractor Tunnel have some build up so that there is more force required to move it out of the way?

[vscorsa]

Thanks for all of the feedback.

No burs on breech or ramp face, both spotlessly clean and unmarked.

I initially thought that it may be a mag issue however it is doing it with all 5 mags and started with all 5 mags at the same time. After thinking the odds of it being an issue with all 5 mags being slim I checked the mag well and it doesn't appear to have been moved.

The extractor is something I hadn't thought about until you guys mentioned it. I can hold a round and manually pass it through the gap between the extractor and the breach face. If there was an extractor issue would this still occur? What is the best way to check?

I am currently running Super comp brass, as a trial would just normal 38 super brass make a difference for the extractor if there was an issue? The pistol is setup with an Aftec extractor.

I took it out today with the shorter length rounds and freshly cleaned again with no success. It still won't push the round through when you initially cycle the slide, every so often it will. It seems to get better as you manually cycle through the rounds in the mag until you get down to the last few. When shooting no change just jams every shot.

I have been wondering whether it has been a combination of the spring becoming lighter and not enough powder to pull the slide back to the stops before coming forward. I have been running 8grs AP100 (Austalian powder which should chrono at 1400fps without compensator) with a 125gr Conical.

[vscorsa]

Hi All,

I fixed the issue, i think it was a combination of something fouling the ejector and the grease I was using on the slide wasn't allowing it to move properly.

I gave the slide and ejector a really good clean with action blaster and cleaned off all of the Tetra grease on the slide. Then I used engine oil as lubrication which was suggested by my gunsmith and it hasn't missed a beat since.

Thanks for all of the help and suggestions.

Cheers

[andy2011]

Hi All,

I fixed the issue, i think it was a combination of something fouling the ejector and the grease I was using on the slide wasn't allowing it to move properly.

I gave the slide and ejector a really good clean with action blaster and cleaned off all of the Tetra grease on the slide. Then I used engine oil as lubrication which was suggested by my gunsmith and it hasn't missed a beat since.

Thanks for all of the help and suggestions.

Cheers

I had the same thing,the Aftec extractors are tuned for supercomp

[shooterbenedetto]

Supercomp has smaller diameter rim than 38 super!

definitely different tension...try one of each on the slide.

if you use 38 super case, extractor will be tight and will

hold the brass and wont let it go up the ramp.

Edited July 13, 2011 by shooterbenedetto

[CocoBolo]

Hi All,

I fixed the issue, i think it was a combination of something fouling the ejector and the grease I was using on the slide wasn't allowing it to move properly.

I gave the slide and ejector a really good clean with action blaster and cleaned off all of the Tetra grease on the slide. Then I used engine oil as lubrication which was suggested by my gunsmith and it hasn't missed a beat since.

Thanks for all of the help and suggestions.

Cheers

I had the same thing,the Aftec extractors are tuned for supercomp

AFTEC makes a 38 Super extractor and a 38Super Comp/9mm extractor, depends on which one you buy. In a good running gun with an AFTEC when it starts not going into battery the first thing to do is to clean the extractor tunnel that is probably full of caca. Since its out might as well clean that firing pin tunnel at the same time.

I use RIGG grease on my open guns, however, I always give the slide rails a small shot of CLP to thin the grease down. A 10# recoil spring helps a tight open gun run more reliably than a 9 or an 8.

Glad to hear you got it running.

[lcs]

FP10 Oil only! Do not use grease on an open gun slide. Your OAL should really be around 1.232.

[CocoBolo]

FP10 Oil only! Do not use grease on an open gun slide. Your OAL should really be around 1.232.

Absolutely if you have a gun that has Acc-u-rail.

Non Railed:

Actually the combination in the right places works very well for me. This is Texas, a very harsh inviornment, with blowing sand extreme temps but NOT COLD. I've been thru Ohio, I had to stop at an auto parts store and buy a higher temp thermostat so I could get the ice off the inside of my windshield.

I never used grease till my GUNSMITH the guy that built my OPEN GUN told me to try it. By the way the slide to frame fit is tighter than Dick's hat band.

Edited July 13, 2011 by CocoBolo

[Bob DuBois]

The Extractor and tension are the heart of a 1911-2011 style pistol. Been running then starts acting up usually trash build up in the extractor tunnel or tension has changed. I pull the extractor and clean the tunnel using Q tips about every fourth cleaning.

Fan of Mobil 1 5W30 synthetic, petroleum motor oil will gum up the works.

[calishootr]

Dump using the grease, at least during the winter months, I have some really cool bearing grease a machinist friend of mine gave meto use, and it works great!!!!....till the temp drops into the 40's....then a 3 toed tree sloth is quicker than my slide, like was said earlier, clean the extractor tunnel of accumulated CRAP, with grease it will build up in there quicker, if you still want to use grease, at least cut it a lil with light machine/gun oils in the winter months