Sig P220ST Jams at the Range

[Digex2]

I took my Sig P220ST to the range today to give it a workout. I fired one hundred rounds of FMJ without a hiccup. I then switched to 230gr Hydra-Shoks to test reliability. Everything was going well until I got to last eight rounds. I fired five rounds with no problem, but on the sixth round the Sig would not discharge after pulling the trigger. Pulled the trigger again for a double strike and still no discharge. I removed the magazine, and attempted to clear the Sig by racking the slide. The slide would only move back about 1/4 of a inch! Locked tight! Needless to say, I spent about two minutes going through an abbreviated tap/rack drill, with the Sig pointed down range of course. Finally, I decided to ask a range officer for some help (I've never experienced this type of jam before). I explained what had happened and he saw for himself how locked up the Sig was. He then suggested that I try firing it now. Well, to my surprise the damn gun discharged! The range officer told me that apparently the abbreviated tap/rack drills may have reseated the round to enable the firing pin to strike the primer. I went ahead and finished up the last two rounds and called it quits for the day.

What concerns me is 1) Did the abbreviated tap/rack cause any damage to the inside of my Sig?, and 2) How could a round that was mis-aligned with the firing pin and improperly seated to the point where it couldn't be ejected, discharge nonetheless?

 

[TooTech]

What was the brand of 100 rounds of FMJ you fired first?

Not surplus-steel-cased or Wolf-brand ammo by any chance?

 

[Digex2]

What was the brand of 100 rounds of FMJ you fired first?

Not surplus-steel-cased or Wolf-brand ammo by any chance?

It was 230gr CCI Blazer FMJ.

 

[Old Fuff]

I am going to grasp at straws. Maybe the 100 rounds of ball left enough fowling in the chamber to tie up the Hydra-Shocks. Clean the barrel, and the next time try the Hydra-Shocks in a clean chamber and see what happens. The only reason I'm suggesting this is is because I can't think of anything else other then dirt in the chamber that would cause this. If the pistol wasn't fully in battery I don't think the firing pin block would fully release it. So the hammer fell, but the gun didn't fire.

 

[Fed168]

Looking at the Sig manual for troubleshooting, there are several reasons: shooter error, bad ammo, a dirty weapon and a dirty chamber, or a weak or broken recoil spring.

Sounds like we can eliminate the shooter error and ammo. The solution to the others is to clean (and lube where necessary), or replace the recoil spring.

It sounds like the gun needs a bath in the chamber area. My 220ST was coated in grease when I got it- helped the gun get dirty faster, too, even after a good cleaning. It doesn't help either that Sig recommends a "wet gun", lots of spots to be lubed.

You are correct about the gun not firing when not in battery. The disconnector is doing its job.

 

[4v50 Gary]

Thankfully the disconnector was working. (it's a little tab on the trigger bar in case you wanted to know where it was). You absolutely don't want it to discharge while unlocked. That'll ruin your gun & your day.

Now, jams. Could be ammo, dirty gun, lack of lube. I suspect lack of lube but try some more of that same ammo to preclude the it as being the source.

 

[greyhound]

Not dealing with Sig but my Ruger .45, the last two times I've been at the range I've had a FTE after approx. 150 rounds. I'm pretty sure since its been after a lot of rounds that the dirty chamber has something to do with it.

Clean the gun real well, and see if the problems go away.

 

[hksw]

As Old Fuff mentions, since the hammer fell, the disconnect did not disconnect but the firing pin stop did work.

It sounds to me, as others have said, the round did not fully seat, i.e., the slide was not fully forward, and the firing pin stop in the slide and the firing pin stop lever in the receiver were not lined up so the stop worked. Fouled chamber or oversized cartridge. By tapping the slide forward, you eventually got it to move forward enough to line up the stop and the lever and fire the gun.

 

[Old Fuff]

I would be surprised to find a too-tight chamber condition on a SIG, but it isn’t unusual to find Colt 1911 clones that have “match barrels†also may have FTF problems after the chamber gets fouled. If one really has a match barrel the chamber is made on the deliberately tight side. This has a beneficial effect on accuracy, but not necessarily on feeding. In my view any pistol that’s intended to be used as a weapon should have a service-specification chamber. It is also prudent to make sure that any carry-gun is always kept clean and properly lubricated. The reason for this observation should be obvious.

And yes, if the pistol is almost but not quite in battery the disconector may allow the hammer to fall before the firing pin lock is fully disengaged. This is the way it’s supposed to work, and another good reason to carry a SIG.

 

[45R]

Case may have been a wee bit out of spec.

 

[1911Tuner]

I vote for...

Dirty chamber not allowing the round to seat. Can't think of anything
else that wouldn't allow the slide to be racked AND cause a misfire.

Fluff...I've noticed the trend toward tighter chambers on 1911s too.
When I drop a finishing reamer in these, I always get some chips.
Thing is, I can't tell any difference in before and after accuracy...
not enough to see without a sandbag anyway. That just might
explain all these broken extractor hooks that have surfaced
recently...even on good extractors.

Good calls all!
Tuner

 

[Old Fuff]

The original National Match chamber specifications were developed at Springfield Arsenal back in 1955 when they were building accurized target pistols for military shooting teams and for use in the National Trophy Match at Camp Perry. They were met to be used in bullseye shooting and nothing else. As such they used every possible modification they could do within the allocated budget to enhance accuracy.

When "combat shooting" (the game that is) came along many pistolsmiths, not a few of which had retired from the services, started using match barrels in their combat guns. While they had a clear understanding of how to build an accurate .45 they didn't necessarily understand what it took to make a good combat gun - especially the kind for real. Today most of the more expensive clones usually specify they have match barrels. Tuner has the right idea. I use a service-spec. finishing reamer too.

 

[1911Tuner]

Old Fluff Said

When "combat shooting" (the game that is) came along many pistolsmiths, not a few of which had retired from the services, started using match barrels in their combat guns. While they had a clear understanding of how to build an accurate .45 they didn't necessarily understand what it took to make a good combat gun - especially the kind for real.

Old Fluff mah fren, if we ain't brothers from another mother, we gotta
be cousins at least. I've had a TIME tryin' to get that point across that
I'm about to give up. There's a big difference between a fighting tool
and a toy. A toy is used for playing "Let's Pretend". A tool is for
more serious things, when a failure to feed or extract may be the last
malfunction a man ever has.

Witness the proliference of broken extractors, lately. If a 1911
pistol is built to proper specs, the extractor has a soft job because
it rarely is called on to actually yank a fired case out of a chamber.
Its job is more of a positioner and a guide to the ejector than an actual
case extraction device. IF...the gun is ordnance spec, and IF the ammo
is ordnance spec, the pistol will run pretty well with the extractor removed.
I've won bets on this point. Several things come into play on this, but
the chamber dimensions are probably at least half responsible for broken
extractors. And the problem isn't limited to MIM extractors. I've seen
Wilson Bulletproof and Brown Hardcore extractors break with relatively
few rounds fired.

An ordnance-spec 1911 is not a loose, rattlebucket when all tolerances
are in-spec. It's looser than a match-tuned pistol, and less accurate, but when new, the WW2 GI pistols were generally much more accurate than
the men firing them.

Pistols that will run without an extractor rarely break one, and more rarely need attention beyond initial set-up. Pistols that won't run without an
extractor seem to break them as you wait. I can do without one-hole groups as unrealistic distances in exchange for reliability...Every time.

Keep screamin' buddy! I'm behind ya.

Tuner

 

[Old Fuff]

Well we do find points of agreement ....

Partly that's because we've both built guns, and understand the pistol as a machine - what makes it work, and why it does or doesn't. It's sort of like automobiles. There are a lof of fine, experienced drivers who don't really understand the mechanics of what they are driving. This has no bearing on their ability too drive however.

A truely fine target pistol is a work of art. The same can be said about a great combat weapon. But the "arts" are different between the two.

 

[antsi]

Digex2: By any chance is this a NEW pistol?

SIG packs their pistols from the factory in a gummy preservative goo to protect them in storage and shipping. This stuff is notorious for causing brand new guns to jam until it is fully cleaned out (of the gun and the mags) and replaced with proper lubricant.

 

[Digex2]

Digex2: By any chance is this a NEW pistol?

As a matter a fact, the Sig is brand new. I did take it apart and wipe it down before taking it to the range. Also, ran some patches through the bbl.

 

[antsi]

quote:
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Digex2: By any chance is this a NEW pistol?
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As a matter a fact, the Sig is brand new. I did take it apart and wipe it down before taking it to the range. Also, ran some patches through the bbl.:

You may have your answer then. SIG's gummy preservo-goo is pretty adherent stuff and like I said, it's notorious for causing malfunctions if you don't get it THOROUGHLY cleaned out. I'd go after the whole pistol with a toothbrush and some solvent. Disassemble the mags and do them too. Then take it back to the range and see if it doesn't start acting like a SIG.

 

[1911Tuner]

Cosmoline on Sigs

Welp...The ol' man learned a little somethin' about Sigs today. Seems
like they'd tell the buyer about that gooey stuff in the owner's manual.
Spread the word!

Good call antsi. Kudos!

Tuner

 

[Jim Watson]

I have a 1969 NRA Handloader's Guide with SAAMI chamber and cartridge drawings. Although there are separate drawings for .45 ACP standard and match, the dimensions are the SAME! So are the tolerances, but certainly a responsible target barrel maker will work to the low end of those.

Beware of anybody dealing in "tight match chambers." There is no such thing, they are selling *undersize* chambers so they can advertise a tiny bit smaller group out of a machine rest. Read the description of a KKM Glock barrel in Brownell's if you want to see just how far this nonsense has gone.

 

[1911Tuner]

Chamber Specs

Jim, the chambers that I've been finish reaming seem to be tapered
toward the shoulder. I don't get chips until about the last 32nd of an inch or so, and mostly from the leade. Makes me wonder if the tooling used to cut the chambers might be out of spec. Not likely that they would ALL be bad, though...

A trend maybe? FWIW, I had my reamer made to .0005 over
the high side of tolerance, and can tell no difference in accuracy,
but a big difference in reliability with a dirty chamber.
Might be worth investigating...assuming that the barrel makers will
reveal all.

Tuner

 

[Jim Watson]

I'll have to ask my FLG where he gets the most cutting these days.

I know that I watched him ream a very accurate, but very frustrating Brand "W" barrel with a standard Clymer and get out what looked like a hat full of shavings from all along the chamber. I think it was all new surface when done. It works now and is just as accurate as ever. But not with the same loads, not if you go to the trouble to clamp it down in the Ransom Rest.

He reamed a factory Brand "S" barrel and brought out only a few chips. You could look in the chamber and see the bright spots where the metal displaced by a really heavy rollmark had been cut down.

Standards tend to drift. I recall reading that in the '30s that the War Department found that guns being made by Colt did not match the official drawings kept for issue to supplemental contractors - as was done to Singer, Remington Rand, and Ithaca - and parts would not have interchanged. I don't know whether they did more updating on the guns or the prints. Some of both, I think.

My FLG gets very frustrated when some brand of aftemarket part quits fitting like it used to. Do they let their dimensions kind of float with time? Do they change subcontractors? Do they make new molds and dies and not keep them the same as the previous set? Pity we seem to be out of real GI surplus. A local vendor has a stock of GI extractors which I think are rejects. They work just fine, better than most commercial, but the dimension from the retaining groove to the rear surface is short and they install a little below the back of the slide instead of flush or a bit high as seen on a new properly fitted gun.

 

[1911Tuner]

Floating Specs

Howdy Jim,

Could be any or all of the above. Ditto on the GI surplus. Wish I
had my time to do over when the show vendors were practically
givin' it away. I remember a "Magazine War" at a show not too
many years ago. I bought 25 GI mags for 30 bucks. Wish I had
bought a hundred. I remember extractors as cheap as 3 bucks
each...in the original paper! Right now, a new GI extractor that fit
below flush wouldn't bother me at all on a range beater or a
carry gun. I don't worry too much over pretty.

I spoke with Ned Christiansen about the tight chamber issue. He's
noticed it too...and he said that they seem to taper starting
anywhere from the halfway point to about where I've noticed.
He reams far more chambers than I do, so his experience would
tend to be more accurate than mine.

Ahhhh! Progress...

Take'em slow and easy...
Tuner

 

[Old Fuff]

Well I see some folks are discovering some things --- Good!

The first person I know that first noticed feeding problems with fouled "match" chambers was none other then Jeff Cooper, way back in the early 1980' at Gunsite - his training facility. Bullseye shooters knew it earlier then that. It was standard practice to run a dry bore brush through the barrel between matches, and sometimes between strings.

Anyway, I think each manufacturer is using their own dimensions, and probably don't check for wear on their reamers even though they are working on stainless steel more often then not.

The length they were supposed to hold is from the back of the hood to the headspacing sholder at the front of the chamber. If it's too long the cartridge can seat into the barrel ahead of the breachface. If it's too short the slide won't go fully into battery.

And yes, I too think that undersized chambers are tearing up extractors, even the best ones.

As for accuracy. According to Bob Day, some Air Force MTU pistolsmiths took several .45's off the training line that had bores that looked like sewer pipe. They put them through the usual accurizing process, but did nothing about the bores. Then they tested them with G.I. match ball at 50 yards in a Ransom rest. All shot within 4 inches (extreme spread, center-to-center) and some stayed inside 3 inches.

 

[1911Tuner]

Chambers

Yep, Fluff...Fer sure.

After I finish ream a chamber on a barrel that I use, I can often go
1500-2,000 rounds of my old funky cast bullet reloads without a
return to battery problem. Before that, I had several problems with
Springfield drop-in replacement barrels with as few as 100 rounds.
Those barrels are very good for the money, otherwise, but the last
few that I've used needed reaming. One needed to be reamed before it would reliably chamber a round of that ammo, even when it was shiny
clean. 50-60 rounds of hardball would stop it cold. After it was cleaned
up it was fine, and as accurate as any ordnance-spec barrel that I've seen.

Times, they are a-changin. Folks are tryin' to make scalpels outta
machetes.

Keep on reamin'!
Tuner

 

[Digex2]

If I could interject for a minute here.

With all the discussion on out of spec and/or too tight bbl's and non-standard cut extractors...What 1911 manufacturer is sticking to the specs? I've been interested in the Les Baer line of 1911's but haven't gotten around to buying one. And their tolerances are very tight from all that I have read. So that being the case, I wouldn't consider a Les Baer a carry gun. I would however be interested in a 1911 within spec that was extremely reliable without breaking the bank. Thus it's clear why I purchased a Sig .45 for now.