FTF first round

[czgunner]

What causes the first round in a magazine to slide straight forward and not feed?
Gun in question is a SIG XO.
Mags are factory and Cobramags.
This happens with all ammo from the slide lock position. Slingshot the slide or release the slide catch, and the to round just doesn't want to pop up into the chamber. It just slides straight into the frame.

[Tom]

When you say "first round", I assume you mean the first round of a topped off magazine. What if you "light load" a magazine, say by only putting in five rounds in a seven-round magazine? Does that feed properly?

Pictures of the problem would certainly be helpful, especially ones from directly above the ejection port. Would like to see where the round is in relation to the magazine lips, as well as the position of the extractor on the case rim.

Since you say this happens with a variety of magazines and ammo types, my only conclusion would be a problem with the gun itself. My first suspect would be the extractor. Have you checked the tension of the extractor?

Go to the Technical section of our Home Page (http://www.m1911.org) and pull up the page on how to check and adjust your extractor. See if that helps at all.

[log man]

While the top round is the hardest for the gun to strip and your problem is rather common, the frame feed ramp should be 31.5 degrees and extend down from the top of the rails a minimum of .360".

LOG

[czgunner]

When you say "first round", I assume you mean the first round of a topped off magazine. What if you "light load" a magazine, say by only putting in five rounds in a seven-round magazine? Does that feed properly?

Pictures of the problem would certainly be helpful, especially ones from directly above the ejection port. Would like to see where the round is in relation to the magazine lips, as well as the position of the extractor on the case rim.

Since you say this happens with a variety of magazines and ammo types, my only conclusion would be a problem with the gun itself. My first suspect would be the extractor. Have you checked the tension of the extractor?

Go to the Technical section of our Home Page (http://www.m1911.org) and pull up the page on how to check and adjust your extractor. See if that helps at all.

Well, I've got the SIG external extractor.
I'll try to post a picture, but the top round of a loaded magazine, from slide lock, slides straight forward into the frame. It doesn't appear to "jump" up at all.

[czgunner]

Here are some pics.
This particular cartridge is a Speeer GoldDot 200gr +P.
This malfunction was reproduced with both the factory and Tripp mags on the first round of a fully loaded 8 round magazine.
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0748.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0749.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0750.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0751.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0752.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0753.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0754.jpg
http://i19.photobucket.com/albums/b183/c_zielsdorf/IMG_0755.jpg

[Tom]

Sorry. I failed to consider your pistol uses an external extractor. So disregard my previous advice on that issue.

It does seem that first round just collides with the ramp head-on and not pitching up and into the chamber.

Again, does this only happen with fully loaded magazines, or would a "light loaded" magazine have the same issue?

Do you have any fine grit (1000-2000) sandpaper? Maybe a light buff with that along the feed ramp may help some.

[czgunner]

It only seems to happen with a fully loaded mag.

[Tom]

Polish the ramp some with the fine grip paper. You're not trying to remove any metal and thereby change the ramp. You just want to polish out any imperfections that may be on the surface.

Just wrap a piece of the sandpaper around your index finger and use that to clean up the ramp surface.

[niemi24s]

I'd advise wrapping the abrasive cloth around something round and hard - such as a wood dowel, etc. This'll help control where the polishing gets done and help avoid any tendency to round over (even it it's just a teeny bit) the upper corner of the ramp where it meets the barrel bed.

CZGunner: Don't break the sharp corner (even a teeny bit) at the top of the ramp unless you want to sabotage your frame!

Regards

[Hammerdown]

That round doesn't look like it would feed even if the ramp was glass smooth. It's diving straight into the frame from WAY back in the feed lips. Either something is major wrong with the lips of the magazine, or the spring is super weak.

Does it feed ok when only loading 7 rounds in the 8 rounder? Maybe 8 rounds is binding something up in the mag tube and not allowing the round underneath to move upward under the top round as its fed from the feed lips, thus allowing the top round to have a big space underneath to dive into.

Can you get your hands on a hybrid lip 7-round magazine and try it with that?

[czgunner]

That round doesn't look like it would feed even if the ramp was glass smooth. It's diving straight into the frame from WAY back in the feed lips. Either something is major wrong with the lips of the magazine, or the spring is super weak.

Does it feed ok when only loading 7 rounds in the 8 rounder? Maybe 8 rounds is binding something up in the mag tube and not allowing the round underneath to move upward under the top round as its fed from the feed lips, thus allowing the top round to have a big space underneath to dive into.

Can you get your hands on a hybrid lip 7-round magazine and try it with that?

Where can I get a hybrid lip magazine?

[niemi24s]

Where can I get a hybrid lip magazine?Brownells has genuine Colt 7 round magazines in their Factory Gun Parts section. This is a hybrid lip magazine.

Regards

[czgunner]

Is part number 160-114-451 a hybrid?
So the Crobramags aren't hybrid? Not sure of the brand that ship with the Sig pistols, but these aren't either?

[niemi24s]

The only one I know for sure is a hybrid lip magazine has a Brownells Stock # of 160-114-450DE (Colt Fac. # SP53355B) because I ordered one.

Whether or not the number you gave will get you a hybrid lipper I can't really say for sure.

Perhaps somebody else knows.

Regards

[John]

Check the inside of the magazine lips, although since the pistol jams with two different kind of mags, I don't think it is the mag. Have you replaced the recoil spring with a heavier one? How does the pistol work with FMJ? And load one of your magazines to capacity and let it stay that way for a night. Test it next morning to see how it works.

If all the above fail, I am afraid this baby needs to go back to Sig Sauer.

[carsten1911]

Hi,

this one sounds and looks bad.
I suspect the magazines to be positioned too low.
Niemi, our wizard of numbers and data, do you have any measures for the position of the cartidge e.g. relative to the upper side of the frame rails or barrel bed or anything? Or simply a pic that shows a "good" position for the rounds, frame only, loaded mag in the frame?

Might also be that the angle at the bottom of the slide is the culprit (angled surface too big):
The round is expected to nosedive a bit and then bring the nose up, but in this case it looks like the round is FORCED to nosedive and wedged in solidly...and yes, I suspect the stub nose of the bullet "helps" this jam.

(Important note: These are just two amateur guesses...although I have seen problem number one myself and it wrecked the nerves of the gunowner.)

Certainly a try with tapered or hybrid lipped magazines (and FMJ ammo) is worth it and should be a starting point.

Carsten

[czgunner]

Mags have all sat loaded for at least 24 hours.
This jam occurs with ball and defensive ammo, handloaded or factory.
Pistol has maybe 600 rounds through it.

[Tom]

Then as John suggested, this sounds like a job for Sig.

[niemi24s]

Hammerdown had mentioned the possiblility that both magazines are applying way too much pressure to the cartridge column when filled to capacity.

If you find the 8th round extraordinarily difficult to load into the magazine, it's a sign that either the spring is compressed to its solid length or the follower is bottoming out.

If this is occuring inside the magazine, try those magazine (filled to capacity) in another 1911 and see if the same thing happens. If it does, I'd say it's a magazine problem - with both of them.

Seems like most feeding problems are caused by magazines anyway - especially extra capacity magazines.

Regards

[niemi24s]

Hi Carsten:. . .do you have any measures for the position of the cartidge e.g. relative to the upper side of the frame rails or barrel bed or anything? Or simply a pic that shows a "good" position for the rounds, frame only, loaded mag in the frame?Got both: http://i129.photobucket.com/albums/p232/niemi24s/P089030003etxta.jpg http://i129.photobucket.com/albums/p232/niemi24s/P089040001b.jpg Both are with a Colt hybrid (tapered) lip 7 round magazine.

The drawing depicts the amount of nosediving endured by the top round in this magazine when it's full.

Regards

[John]

You are asking Niemi if he has measures???? Are you serious???? He has measures of anything you can think of. And of course, he has pictures to support his measures!!! LoRL, Niemi you are a treasure.

[1911Tuner]

There are only three things that it can be.

The gun. The ammo. The magazine.

Since it only happens on the top round, the first two have been eliminated. That leaves the magazine.

Cheers...

[Tom]

That leaves the magazine.
But wasn't it stated the problem happens with multiple magazines?

Mags are factory and Cobramags.
This malfunction was reproduced with both the factory and Tripp mags on the first round of a fully loaded 8 round magazine.

[1911Tuner]

But wasn't it stated the problem happens with multiple magazines?

Correction:

It's the magazines...

[Tom]

Correction:

It's the magazines...
LOL Fair 'nuff. :D

Like everyone else, I'm anxious to see how this ends up.