why the jams?

[Ithabrown]

hello to everyone! for my first post here, i would like to hear the common causes of stovepipe jamming.

i have a Commander in 45 ACP which jams regularly in this fashion: after a fired round ejects, the next round is jammed in a diagonal angle (slug facing upwards).

my guess is the spring. i'm using a "shortened" 18.5 lbs. wolff spring


Ithabrown

[BluesBear]

A stovepipe is when the fired round doesn't eject and the empty case ends up standing straight up in the ejection port.

I'll wager that your slide is riding over the rim and extractor groove and denting the side of the case.

It is doing this with several different magazines?

[1911WB]

What u have is nose-up FTF's. Try a Wolff 18# spring specifically made for the Cmdr. See if that solves your problems.

[MC Peacock]

You may have 2 or three things contributing. The suggestion to use a Commander recoil spring is excellent, try the 18 lb. as previously suggested. But you may also have magazine and/or extractor adjustment issues. Everything happens more quickly with a Commander, so there is less room for error, timing wise. The magazine spring must be stout enough to force the cartridge under the extractor hook, and the extractor must be set up to easliy accept the cartridge, while still allowing consistent extraction of the case from the chamber. I would start simple and try one thing at a time, try the correct recoil spring first. That may cure it by itself. Hope this helps.

[michael t]

I have a Sub-compact Llama that has problems I belive mag spring part of problem. 1.nose up FTF 2 . Round sometimes nose up out ejection port {not stovepipe} 3. Fail to pick up round from mag. Does at least one of above per mag. on 230 ball. Will sometimes fire entire mag if silver tips. Have factory mag and pro? mag makes no difference. Extractor replaced due to breakage no change. Any help?

[1911Tuner]

Howdy Michael,

Your problem is called Bolt Over base...or Rideover Feed. It happens when the breechface catches the extractor groove instead of the back of the rim,
and forces the base down into the magazine...and the bullet nose up. It
usually happens on the last round.

99.9% of the time, it happens because the magazine spring can't get the
round up to feeding position in time, and the slide rides over. If it grabs
the round in the extractor groove, it causes the cartridge to nose up. If
it hits farther up on the side of the case, it jams the slide up pretty solidly.

The slide speed in relation to the magazine timing is the problem.
While a too-heavy recoil spring can make it more likely...it's usually the magazine spring. A Wolff 11-pound mag spring will probably cure it if'you are using 7-round magazines...Wolff 5% Extra Power for the 8-round mags.

Other possibilities are extractor tension or hook location in relation to the
breechface centerline and the distance between the parallel rails under the
breechface, which should be .484 to .488 measured with the
extractor removed...but .484 is the minimum. .490 seems to be where most
smiths want to set the dimension.

Short cycling of the slide can do it...Again, too much recoil spring can cause it, but the recoil spring issue is generally speeding the slide up on the return to battery and outrunning the magazine. If you're using a shock buffer, take it out and see if the problem reduces or disappears. Seen that cure the
problem on more than one pistol. Commanders already have reduced slide travel, and a buffer further reduces it by the thickness of the buffer.

Try the Wolff spring first, though...and do get it fixed. The Live Round Stovepipe can be dangerous. If the case head gets rammed in just the right place, and the primer pressure detonates, you've fired a miniature fragmentation grenade about 2 feet from your face.

Luck!

Tuner

[Ithabrown]

thanks, gentlemen, for the inputs!

here's another problem (maybe minor?): when i rack the slide, the chambered round does not eject as in all my other pistols.

the gun is actually a project, slide assembly is Rock Island Armory and the frame is the Kimber-clone BUL M5 in polymer.

[Ithabrown]

btw, sorry i erred in writing that instead of a 4.25" Commander, my slide and barrel is of the Springfield compact that comes in 4".

so do i still have to use an 18-lb. Wolff spring? Or follow Wilson's table below:

Recoil Spring Selection Tips (from Wilson Combat catalog)
By Bill Wilson
________________________________________
As a rule of thumb, you should use the heaviest recoil spring possible, which does not interfere with the pistol functioning.
The spring tension requirement is affected by many factors, including the ammunition used, grip pressure, compensators, slide to frame friction, pistol type etc. The following procedure will help you determine what is the proper recoil spring for your gun.
1. First, try the recommended standard spring for your load/pistol combination.
2. Watch for extraction related jams and failure of the slide to lock back. This is an indication of a very heavy spring. Use a lighter one.
3. Use SHOK-BUFF and watch them closely. If they do not last 700-1000 rounds, you have a weak spring
Your recoil spring should be replaced every 2000 rounds.
RECOMMENDED RECOIL SPRING
Gun Light Target Load Full Charge Load
Govt/Gold Cup (stock) #10 #18.5
Govt/Gold Cup (compens.) #9 #15
Govt/Gold Cup (.38SP/9mm stock) #10 #15
Govt/Gold Cup (.38SP/9mm comp.) #9 #13
Delta Elite (10mm stock) #18.5 #24
Govt/Gold Cup (.40S&W stock) #13 #22
Commander (.45 stock) #12 #20
Officers (.45 stock guide) #18.5 #24
Springfield Compact (.45 stock) #20 #24

Full charge load refers to IPSC major or factory hardball. Light target load refers to a download of about 20%.

[1911Tuner]

Howdy again Ithabrown,

Failure to eject a live round can be a couple of things...FIRST...check for
recoil spring bind. When you pull the slide smartly to the rear, do you hear a
metallic "clink" or a dull thud? If it's a thud, you have coil bind and the slide
isn't reaching full rearward travel. Trim a half-coil off the open end of the spring until you hear metal to metal contact.

If you do have coil bind, and you shoot the gun, it will damage the bushing
and the slide quickly...maybe on the first shot.

Is your ejection port opened a little at the front? It may also require a small
"flare" at the front, bottom radius.

If all these check out okay, you may need to shorten the ejector a little at a time until it will eject a live round.

One other possibility is that the extractor hook is too long (too deep) from the wall...where the case rim bears against...and the tip. This depth should
be .032 to .035 inch. If it's more than that, the case gets into a bind between the hook and the ejector as the round twists toward the port, and usually hangs up at about a 45 degree angle.

Luck!

Tuner

[Ithabrown]

Tuner,

Howdy!

I was scratching my head while reading your assessment...wow! I never thought that there were a number of factors to the problem. Let me get beack to my 'smith with these points and in my next post, I will update you accordingly!

Itahbrown

[michael t]

Tuner knows his stuff if you read the other post this section you will see he call my problem right on the money. I proved that by double spring my mag and now it works find. First time since I got the pistol. Now waiting on my new spring so can fix right.

[Ithabrown]

maybe this is the cause of my FTF problem:

PROBLEM #2: THE EXTRACTOR:
"The amount of pressure a 1911's extractor places on a cartridge casing's rim is regulated by the curvature of the part in its channel through the slide. This is a crude system. Too much curvature means too much pressure, and the extractor will not allow a cartridge casing to slip up into place, resulting in a failure to feed. Not enough curvature means insufficient extractor tension, resulting in failures to fully extract and/or eject. Most modern firearms use spring-loaded extractors, a far more durable and reliable system. This is a major improvement in firearms design that seems to have passed by the 1911.
The tension of a 1911's extractor can weaken with use. One sure way to screw up your extractor is to drop a round into the chamber with the slide open then drop the slide on the chambered cartridge. This will force the extractor to bend back and around the case rim, eventually abusing the extractor so much that it will lose its tension or even break off in extreme cases."


The above article can be found in this great site. I tried the test and the bullet really kept falling from it's seat, so now i'm off to the range after adjusting the tension of my extractor. i'll keep you guys posted later.

[BluesBear]

1911 Tuner is a master of extractor tensioning.

But biscuits & gravy is his true calling. :p