Feeding problems: Tungsten guide rod?

[feralcat]

Hi folks -- Long story, quick version: has anyone had problems with feeding and a tungsten guide rod/ISMI spring?

I bought a new G35 in August of last year, and started shooting it in LTD/LTD-10 class, USPSA.

I made the following modifications: Tungsten guide rod/15-lb ISMI spring from CGR, Dawson/Henie sights (ditto), RSotelo trigger kit.

In September and October, I probably put 2k through the gun, with no problems, using factory 15-rnd and 10-rnd mags.

Fast forward to the end of November and December: I started getting some really nasty feeding problems, where the bullet (Zero<tm> 180gr JHP @1.142 OAL) would hang just below the feed ramp. *Usually* this happened only within the first couple rounds in the mag. *Usually* this occured more often when I started using Dawson +5 extension's on my 15-rnd mags. *Always* when this happened the weather was chilly -- 35-45 degrees F.

Changes and things I ruled out:
1) Limp-wristing? Nope.
2) Mag springs? Replaced the extra power springs in the mags. Also, I began having feeding problems with the 10-rnd mags.
3) Thumb dragging slide? Nope.
4) Feedramp? Polished with 600gr and steel wool
5) My reloads? No -- this happened, too, with WWB factory 165gr JFP's.

Finally, yesterday I pulled everyting that wasn't stock out of the gun, except for the sights, and took it to the range. 300 rounds not one problem.

I noticed my tungsten guide rod now has some "grooving" in a couple spots. The wear appears to have increased since I first installed it (there was some wear almost initially, but I have heard that's normal in tungsten guide rods).

Anyway, here's my hypothesis: the ISMI 15-lb spring was binding on the guide-rod just enough to occasionally slow the slide and cause feeding issues....This problem became exacerbated with more wear on the rod, or colder weather??

Sound reasonable? I guess I'll keep shooting the gun stock. A shame, as I liked the little bit of extra weight on the muzzle, and Ralph's trigger job is nice addition, but at this point, I'm really gun-shy (ha). It's no fun shooting six matches, and having problems on almost every stage. <fume>

[tous]

Do this test:

Move slide fully to the rear. With the barrel pointed skyward, ease the slide forward until it is 1/2 to 3/4 of an inch from battery. Release slide. The recoil spring should pull the slide into battery. If it doesn't, then we need to diagnose the problem.

Does this problem occur with all magazines? Does it occur with all profiles of bullets? Does it occur with bullets set at different COLs?

Eliminate once suspect at a time. <c>b

[RandySmith]

Finally, yesterday I pulled everyting that wasn't stock out of the gun, except for the sights, and took it to the range. 300 rounds not one problem.


This is a very common occurance. We jokingly call it 'the awakening'. ;)


Anyway, here's my hypothesis: the ISMI 15-lb spring was binding on the guide-rod just enough to occasionally slow the slide and cause feeding issues....This problem became exacerbated with more wear on the rod, or colder weather??


Yes, the metal recoil rod is most likely your problem. I have seen these things cause failures on many occasions.

I cannot say I have seen the problem increase with cold weather. Do you use a heavy lube (grease) on the slide rails? Just looking for another contributing factor.

Randy

[Custom Glock Racing]

The grooves are likely normal. The long rods get a groove where they ride at the end of the slide. Did you oil the rod? Did you check that the spring moves freely on the rod? What exactly is happening when you get your jams? Did you try any other spring weights (testing is often needed as there is no magic weight that is always right)?

Feel free to call me at the shop and we can probably clear it up.

[feralcat]

Matt -- called your shop tonight, and left a message. I'll try to catch up with you later in the week.

I haven't been oiling the rod, really, though I clean it pretty regularly, after spraying it and the spring with BreakFree CLP.

I truly can't think what the problem would be, at this point, except for something with the rod/spring. The rod has a couple of grooves in it -- the deepest is 1/3 way from the end, but there are some other small areas of wear...I have not tried any other recoil springs of the same or different weight.

When the jamming occurs, I notice the slide is stuck partially open. If I slingshot the slide, the round always chambers, w/out problem.

It's just a slower way to shoot. :)

Randy, I'm not sure what the cold weather has to do with the issue, either. It's possibly coincidence?

[Vanek Custom]

Test and make sure the slide is going all the way back.

Use a felt pin and put a mark on the frame and slide holding the slide back as far as you can using the ISMI spring and rod. Do the same with the stock rod/spring. I've had as much as a 1/4 inch difference of the slide movement and it will cause feeding problems. BTW - I use slide glide on all my recoil rod.

[Glock-N-Fun]

feralcat,

A freind had the same wear ring near the end(1.350 from end)of an extended tungston rod on a 34 .After examining it and taking some measurments,in the case of his 34 there were no wear marks at the end of the slide anywere,it look like the wear was caused by the spring ID.The rod OD measured .245,the spring ID measured .257,this leaves a .012 differance,which isn't much.The Aro-Tek SS rods that i use measure .230,and have never bound or have never had wear rings.It would appear the cause for the wear rings is the rod being just a tad to big for the spring ID,or the tungston not being hard enough,or both.

[feralcat]

Glock'nFun -- my measurements were about the same as your friend's. Here's the same picture of the rod I sent to Matt at CustomGlockRacing, where I bought it, a couple months ago.

After 3 range sessions with the factory rod and spring back in, I'm closing in on 1k rounds, without a single failure to feed. <shrug> At some point I might try to buff-out the areas of wear, and re-polish the rod, or play with other springs, but at this point I'm just ready to have some matches w/out malfunctions.

Charlie -- interesting test. I made two pencil marks on the frame, with the slide back on both recoil rods/springs, and they were identical. I'm trying to convince myself I don't need one of your triggers. :)

Steve





http://bellsouthpwp.net/f/e/feralcat1/tungstenrod.jpg

[RandySmith]

After 3 range sessions with the factory rod and spring back in, I'm closing in on 1k rounds, without a single failure to feed.


Yep!

Welcome to stock-glock reliability.

Randy

[Vanek Custom]

I would almost bet that if you would try a 15 lb. Wolff recoil spring the problem would go away. I use both ISMI and Wolff and I let the gun decide which one it likes the best.

[Glock-N-Fun]

feralcat,

Try to borrow an Aro-Tek rod or any other manufacturers rod that measures closer to Aro-Tek's .230 diameter to see if this eliminates the problem,if you fell it might be the rod.As you've all ready stated,your glock ran fine with the factory rod,due to these facts im thinking the larger diameter of the tungsten rod and the ring may be the problem.

[feralcat]

Figured I'd post an update.

First, thx, Matt, at CGR for offering to inspect the rod and/or replace if I wanted. Kind offer, but I think I'm ok for now. Here's what I'm finding.

1) If I run my G35 completely stock, I have zero problems.

1)a) this assumes good mags: I seem to have a problem with one of my magazines -- it is an older 15-rnd one marked "LEO Only". What happens when I use this magazine, is that sometimes the round won't get picked up: the extractor claw does not grab the rim.

I miked the metal lips and noticed they're much close together than on my lastest-generation magazines. I don't know if this is normal or not but regardless -- this particular magazine was a compounding factor in problems I had.

2) I chucked the rod in a drill, wrapped some velcro around the trigger, for a poor man's lathe, and sanded the rod with wet 400 and 600gr paper. I didn't remove much metal, but it's significantly more smooth. Oiled it with a few drops of 80W gear lube, and no problems feeding -- maybe 500-600 rounds at this point. I'm thinking as long as I keep a occasional eye on the rod, don't run it dry (as I had been doing), I should be fine. Possibly I'll try a Wolff spring, too -- I believe they're not as square-edged?

3) Final problem, unrelated to the above, is running a reduced-weight striker spring (part of a trigger kit I have installed). With Winchester small pistol primers in my reloads, I have consistent light-strikes. This is a fairly new issue, since the reduced spring *used* to work. I've seen a suggestion to check the channel liner, but how could it be damaged? The gun is only 6-7 months old. I'm thinking it's some combination of light spring + hard primers (perhaps a particular batch of WSP's?)+ variable primer depth in reloads and used brass.

In any event problem 3 goes away with the stock striker spring -- just thought it was odd.

Thx all