Nose dive onto frame ramp, subsequent refusal to chamber

[saltydog]

The loaded round is hitting low on the frame ramp, bounces off and up, bullet hits top of chamber but does not 'roll over'. A failure to chamber occurs with the loaded round caught with the rear against the breech face, case body against against framp ramp, and bullet against the top of the chamber.

Is this a '3 point jam'? If not, what is it?...and what is the fix?

Mags are new Checkmate both the 'hybrid' and their 'GI' version.

Thanks,

salty

[1911Tuner]

Is it a Bolt Over Base misfeed? Or...Does the bullet nose get partway into the chamber and stop? If you can duplicate it by hand-feeding...remove the extractor and see if it changes anything.

If it's a true 3-Point, you usually can't chamber it and put the slide in battery by pushingon it. If it's not a 3-Point...you usually can.

[niemi24s]

If the slide cannot be made to go into battery with a hard push by hand on the rear of the slide, but will go into battery if the muzzle is whacked with a stick (for safety reasons) it's a 3-point jam. With a decent 3-point jam the case will also have a circumferential dent about ¼" back from the case mouth on the case bottom caused by the top of the barrel ramp.

Many are caused by the magazine, some by the ammunition, some by the gun itself.

To narrow the possibilies, we need to know where the jammed case head is in relation to the firing pin hole and/or extractor.

A picture of the jammed case head showing the extractor will be most helpful.

[saltydog]

Tuner,

I don't know that I can explain it any better, but I'll try. If pistol is horizontal, the loaded round would be at a sharp (45*?) angle. Bullet within what could be loosely defined as the chamber, but up against the roof.

Brass body, again at a sharp angle (45*?), against the frame ramp.

Case head, rather top of case head, against the slide breech face bottom.

A push will not chamber the round. 'Roll over' did not accur.

Mags are Checkmate 'hybrid' and the CM version of the 'GI' lips.




Nemi,

No way to post photos.

Case head is well below firing pin hole. Extractor will, reluctantly, hold a loaded round, but at a 'droop'. A not so gentle shake and the loaded round will fall.

I didn't notice any dings, neither was I looking for any. Could be though as the body of the case was up against the frame ramp.

Thanks,

salty

[MoneyTree]

No way to post photos.

Have you tried Photobucket before salty ? It's free and pretty easy to use . As dense as I am it didn't take to long to figure it out ( at least enough to post photos on the site ) .

http://photobucket.com/

Please just ignore this post if you've already tried it , I'm just trying to help out .

[1911Tuner]

Salty...A 45 degree angle makes me feel like it's a Bolt-Over Base. Is the bottom of the breechface on top of the rim...or on top of the case in the extractor groove...or is it pushing on the rear of the case?

[saltydog]

It was pushing on the rear of the case.

I really need to get a camera that has micro potential. Thanks for the advise re photobucket.

salty

edit: I went back to some prior posts looking for failure to feed malfunction posts, and, if I understand them correctly, this wasn't a situtation where the slide was outrunning the mag spring. There was three points of contact: bullet against top of the chamber, case body against the frame ramp at start of bridge, and top of case head against bottom of slide face. Extractor groove in case was not in contact with the face of the slide breech face.

It happenend with 'hybrid' Chreckmate mag and I tried their 'GI' version with the same result. Both times the ammo stack had a couple of rounds left.

I didn't get into it any more. Tinkering with pistols on the firing line is a 'no-no'.

sd

[1911Tuner]

Salty...You've had some of the cussed-est luck with Colts...

If you've got a caliper, take the extractor out and measure between the two breechface guides. You're lookin' for a measurement of .484-.488 inch.

Are the springs in the mags good? Nose-dive usually means that either the feed ramp is too steep, or the mag springs are weak...or the follower angle is bad. Also possible that the mag feed lips are damaged. Look at those. The "GI Version" may need to have the feed lips tweaked for correct release point. About 1 in 10 does need it.

How does the gun feed by hand-cycling, letting the slide snap foreard at full speed? If it hangs up...remove the extractor and try it again to see if it gets better.

[saltydog]

Yeah, I know what you mean Tuner. If this was a race, I'd have been laped by the pace car.

I'll measure and post again tomorrow.

Thanks,

salty

[saltydog]

I've had a nap and morning coffee, so things are looking better. The Dremel remains un-plugged.

Best I can measure is .492.

Thats slightly over your previously stated max.

Thanks,

salty

[1911Tuner]

Best I can measure is .492.

Thats slightly over your previously stated max.

Won't hurt anything.

Slip the extractor back in and look at it from underneath to see how much of the bottom corner...the area that the rim first hits when it starts to feed.
How much of that corner is protruding beyond the guide wall?

[saltydog]

If I understand right, you are asking how much of the .492 distance between the guide walls would be taken up if the extractor is installed?

If so, with extractor installed, distance from the flat aft of the extractor hook and the opposite wall is .450. That'd mean the extractor intrudes .042.

Kinda misleading though as the lower portion of the extractor is beveled. That beveled portion is the first to contact the case head. Don't know how to measure that...

salty standing by.

[1911Tuner]

If so, with extractor installed, distance from the flat aft of the extractor hook and the opposite wall is .450. That'd mean the extractor intrudes .042.

That's a bit much. Is the bottom of the beveled portion in the way of the rim...or is it flush with the guide?

[saltydog]

It APPEARS to be flush with the guide.

Had to have a little flashlight help and two pair of reading glasses to see that.

Extractor will hold a loaded round with a little 'droop', but will release the loaded round with a bit of not so gentle agitation.

sd.

[saltydog]

I don't wanna sound rude, but may we continue this a bit later?

I have an appt for an 'Old Geezer's Physical' that I definitely am NOT looking forward to.

Talk later?

Thanks,

salty

[niemi24s]

That's a bit much.
A little arithmetic shows the mid-spec value for extractor intrusion to be as shown below and the pic'll give you & Salty something to refer to (if needed) when he returns from his ordeal:
http://i129.photobucket.com/albums/p232/niemi24s/P087090001b.jpg
Looks like it intrudes about 3 times more than it should - assuming I did the math correctly.

Cheers.

[1911Tuner]

Good illustration, Dan. Thanks much. If Salty's measurement is accurate, I'm thinkin' that either the channel is either angled or too far to port...and likely the former. There could also be a problem with the thickness of the front pad, especially if somebody has cut it down too much, and let the extractor move in too far.

Hey Salty! Take the extractor back out and measure the thickness of the front pad. You're lookin' for .130-.135 inch.

Dan...You'll want a little more than the mid-spec dimension of .0145 inch. Otherwise, the tensioning wall may not even touch the rim and apply tension. With today's pistols and the willy-nilly specs...ya really can't go by ordnance prints, and I usually wind up havin' to adjust the extractor's position to compensate. There was a time that replacing an extractor was a simple matter of set tension...drop in...go. Those days are gone for the most part. About as often as not, the extractor is a hand-fit operation.

[niemi24s]

..You'll want a little more than the mid-spec dimension of .0145 inch.
About how much protrusion do you try to get when fitting an extractor?

[saltydog]

The front pad.

If we're on the same page regarding terminology, its the 'kinda-sorta' oblong area immediately aft of the hook. Not the pad mid-ship?

If so, the aft area is oblong, meaning that its longer than wide.

Looking at it as though it was installed, at the tallest point, it is .168 tall. It is .138 thick.

Apples and apples?

sd.


edit: What is the 'tensioning wall'?

thnx
sd.

[niemi24s]

What is the 'tensioning wall'?
Here's a drawing with all the gory details & dimensions.
http://i129.photobucket.com/albums/p232/niemi24s/P8290001d.jpg
There's also a blueprint of the extractor in our Technical Issue section.

Cheers

[saltydog]

Lord luv a duck, you're good!!!

I recon the 'tensioning pad' (Item F) is what Tuner referred to as the tensioning 'wall'?

I don't want to sound kinda pickey, but I need to get the nomenclature right before I can follow the posts.

Thanks,

salty

[1911Tuner]

About how much protrusion do you try to get when fitting an extractor?

I don't shoot for any particular measurement. It's pretty much up to the gun, and what works.

Looking at it as though it was installed, at the tallest point, it is .168 tall. It is .138 thick.

Not the width, Salty. The thickness from the back of the extrator to the front of the pad. That pad determines how far from the breechface centerline the hook sits.

[1911Tuner]

I recon the 'tensioning pad' (Item F) is what Tuner referred to as the tensioning 'wall'?

The tensioning wall is the area that bears against the rim of the case.

Recon? I think ya meant "reckon" there Dan. You ain't from around here...are ya?
:D

[saltydog]

Dang, It wasn't him that can't spell Tuner, it was me. I can't hep it.

sd.

[niemi24s]

I recon the 'tensioning pad' (Item F) is what Tuner referred to as the tensioning 'wall'?
These are two different things.

In the drawing in Post #20, the tensioning pad is F and the tensioning wall is D.

[1911Tuner]

Dang, It wasn't him that can't spell Tuner, it was me. I can't hep

Now, Salty...You's a southrun boy. You ought to have knowed how ta spell reckon...

:D

Dan...The pad is known as the "locating" or "positioning" pad. It locates/positions the hook relative to the breechface centerline.

[niemi24s]

...The pad is known as the "locating" or "positioning" pad. It locates/positions the hook relative to the breechface centerline.
OK, that's a better term for it - as it really doesn't have anything to do with the amount of tension the extractor puts on the case rim - which is really a compressive force on the case rim anyway.

Cheers

[saltydog]

Item F, Niemi24s's dwg, measures .143".

I really want to thank Niems24s for the illustrations. Having a picture to follow along with the words helps this stump headed DA understand.

Thanks,

salty

[niemi24s]

Item F, Niemi24s's dwg, measures .143".
OK, that means the positioning/locating/tensioning pad is good.

How about the thickness of the tensioning wall, item D, (measured from side-to-side as the extractor would be inside the slide)? It should be between 0.072 and 0.078 inch.

[saltydog]

Item D measures .082".

That .082" is consistent for the length of the groove/slot (?, again correct terminology?)

That length, as best as I can fit the jaws of the dial caliper into it, seems to measure .103". ( Looks like Item H on the dwg.)

Incindentally, I didn't ask, but should have, I have printed Niemi24s' dwgs. Guess that was OK? Not going to use them except for a bit of personal understanding.

salty

[1911Tuner]

Item F, Niemi24s's dwg, measures .143".

Somethin' strange...

If the pad is at the maximum end of the tolerance...and you've got .042 inch of the wall protruding beyond the guide...somethin' is definitely strange. Are you sure of the measurements?

[saltydog]

Yes, as best as I can measure. The jaws on the dial caliper that measure the inside distances are a tight fit, but I think I got it right.

What is it that seems strange? Maybe its an aftermarket extractor. I bought this Combat Cmdr used, so I don't know what is in it or who put it there.

salty

edit:

The extractor is a tight fit in its tunnel. I had to get the tip of a popsicle stick to pry it out.

sd.

[1911Tuner]

What is it that seems strange?

With the locating pad being .143 inch thick, about the only way you could have .042 inch of protrusion would be if the extractor channel is mislocated.

Does the flat side of the extractor sit flush with the slide? If so...Has the firing pin stop's slot in the extractor been cut? If not...has the FP stop itself been cut? How wide is it?

[saltydog]

'...flat side of the extractor...'

If I understand right, you're asking if the extractor protrudes beyond the end of the slide? No.

The firing pin stop measures .477" across. Some of the finish is worn off the 'tracks' that fit into the slide cut. The bevel on the bottom of the firing pin stop does not appear to be as rounded as in a stock Colt FPS. The FPS does NOT fit nearly as snugly into its channel as does the extractor.

Am I making any sense at all?

sd.

[saltydog]

OK. I think I understand now. The flat side of the extractor is NOT flush with the milled hammer pathway. Using the dial on the calipers as a yardstick, eyeball guestimate would be maybe .010" to the right of the hammer pathway.

salty

[niemi24s]

Case head, rather top of case head, against the slide breech face bottom.
Must have missed this from Post #4. Almost sounds like the magazine spring's not popping the back end of the cartridge up when released by the feed lips?

Hmmmm.....

[I'm thinkin' - and my head hurts!:D ]

[saltydog]

I dunno. Both mags are Checkmate. One 'hybrid' and the other is CM's version of the 'GI' mag.

I guess its possible for the springs to have been kinda wimpy. But the mags are dang near new.

I have some extra power springs in several Metalform mags that I can try. It'll be a couple of days before I can get to the range.

CM and Metalform both make good stuff, so it shouldn't make any difference.

Maybe it just don't wanna play nice with Ranger ammunition, or the planets were't lined up just so-so. Too dang many possibilities. Its gotta be something simple that I am overlooking.

Wish I lived closer to Mayberry.

Thanks,

salty

[niemi24s]

. . . I have printed Niemi24s' dwgs. Guess that was OK?
OK by me. These (and all the others I've posted) are in the public domain anyway.

[1911Tuner]

The flat side of the extractor is NOT flush with the milled hammer pathway. Using the dial on the calipers as a yardstick, eyeball guestimate would be maybe .010" to the right of the hammer pathway.

Hmmm. Not likely that small amount means much....even if it's due to the channel being angled and not just a spec tolerance issue with the butt-end of the extrator.
See if you can get a more precise measurement than with an eyeball micrometer, Salty.

[saltydog]

OK. Did that, but the measurement assumes that the hammer pathway is straight and perpendicular. Thats a large leap.

With FPS in place to prevent 'clocking' of the extractor, measurement across pathway with top of firing pin hole as a reference is .315". Measurement across pathway with middle of firing pin hole as a reference is .336".

That could just be the mfg tolerence of the extractor, and not the extractor tunnel to be off a bit, right? I guess I am grasping for straws, I'll shut up and stop guessing and listen to you guys.

salty

edit at 0945 local CST.

I have to leave for a while. Be back Fri eve or Sat am.

sd.

[niemi24s]

In trying to get a mental picture of the jammed gun I went picking for clues:

From Post #1:
A failure to chamber occurs with the . . . case body against against framp ramp . .
From Post #4:
Brass body, again at a sharp angle (45°?), against the frame ramp. and
Case head, rather top of case head, against the slide breech face bottomand
Case head is well below firing pin holeand
. . . the body of the case was up against the frame ramp.
From Post #7:
. . . case body against the frame ramp at start of bridge . . .

I end up seeing a jammed cartridge with:

• its case body against the frame ramp - perhaps not flush against it, but at least not against the top of the barrel ramp;
• (the bullet nose against the top of the chamber);
• the top of the case rim on the breechface - somwhere between the bottom of the disconnector rail and some distance below the firing pin hole and;
• the case rim never getting close to the extractor.

Then asked myself "Self, how does a 45ACP cartridge end up like this?" and got no answer.

Then asked myself "Self, can a 45ACP cartridge end up like this?" - again, no answer.

Then asked myself "Self, if a 45ACP cartridge cannot end up like this, how about a 45GAP cartridge?".

Zebra? :)

[1911Tuner]

Then asked myself "Self, how does a 45ACP cartridge end up like this?"

How about a Bolt-Over Base misfeed? That's what it's startin' to sound like...

Salty...Is it caught between the barrel hood and the slide...with the breechface against the side of the case?

[niemi24s]

Back in Post #6 you'd asked . . .
Salty...A 45 degree angle makes me feel like it's a Bolt-Over Base. Is the bottom of the breechface on top of the rim...or on top of the case in the extractor groove...or is it pushing on the rear of the case?
. . . and he replied . . .
It was pushing on the rear of the case. . . . Extractor groove in case was not in contact with the face of the slide breech face.
To me, this implies the chamfered edge of the case head was against the lower part of the breech face - and not under the disconnector rail.

I've never seen one, but wouldn't a bolt-over-base jam leave a little dent on the top of the case just in front of the extraction groove?

Sure be nice to have a pic of the jam, eh?

Cheers

[1911Tuner]

I've never seen one, but wouldn't a bolt-over-base jam leave a little dent on the top of the case just in front of the extraction groove?


Sometimes. Sometimes not...

Sure be nice to have a pic of the jam, eh?

Yup. This is like a doctor tryin' to diagnose the cause for a headache over the phone.

[niemi24s]

Hi Salty. When you get back from your trip, tell us which of the following pics most closely resembles your jammed case head and the breech face.
http://i129.photobucket.com/albums/p232/niemi24s/P087110034a.jpg

[niemi24s]

And, just for chuckles, here's a drawing of the extractor, breech face and breech face guide blocks with some mid-spec dimensions for your amusement:
http://i129.photobucket.com/albums/p232/niemi24s/scan0011d.jpg
Hope you had a safe trip.

Cheers

[berkbw]

It's hard to see the "groove" in the dummies, but we all know where it would be. Do the jams with live, factory ammo look like these pix?
b-

[berkbw]

How much vertical play does your empty mag have?
b-

[niemi24s]

It's hard to see the "groove" in the dummies, but we all know where it would be. Do the jams with live, factory ammo look like these pix?
b-
The round in the pics isn't a dummy - it's a nickel plated handload with a 200gn LSWC. The lighting I used just made the groove look "washed out" (over-exposed).
How much vertical play does your empty mag have?
In the pic on the right, the mag had to be removed to get the case head to stay in place on the breech face. These are re-creations of what these 2 different jams would look like, and the recoil spring had to be removed to stage them. Ole Bessy's a slick-feeding thing. Never had either type of jam in the 44 years I've had her! :D

Cheers

[saltydog]

Got back last night. Had a nap, got next to some soap and water and a cold beer. The world does look better in the morning.

regarding the two photos posted by neimi, the angle of the cartridge in the left photo seems about as severe as I rember the failure to feed/chamber. However the position of the case head on the slide bolt face as it appears on the photo on the right is correct.

Re the 45 GAP zebra mentioned by neimi, the ammunition was factory Ranger 230 JHP in Plus P flavor. Maybe reduced mass short short slide didn't wanna play nice with the Plus P Ranger. After one failure, middle of the ammo stack, in each of two new/like new mags, I boxed up my toys and headed for the house.

No additional magazine/ammunition combinations were tried, or have been tried to date.

The feed ramp does NOT appear to have been modified, but there is more distance from the top of the feed ramp to the lower face of the barrel than 1/32". I don't know how to measure that distance, but its more than thumb nail thick. How critical is this distance?

I do very much appreciate your posts and suggestions. Thanks for the insight and a different perspective.

I still think its something simple that I'm missing. Maybe the forest is getting in the way of the trees again.

salty


edit:

Printed another of your dwgs neimi.

sd

[niemi24s]

How critical is this distance?
Not too critical at all.

Too little and its too easy for the bullet nose to hit the bottom of the barrel ramp after glancing off the frame ramp. This can knock the back of the barrel forward and upward (due to the link) and lead to a 3-point jam.

Too much and if the contour of the barrel ramp has also been maintained and moved forward it will increase the amount of the case that's not supported by the bottom of the chamber. This can contribute or lead to case blow-outs. Not good at all!
Printed another of your dwgs neimi
Be my guest. They're all in my public Photobucket folder anyway.

Cheers

[niemi24s]

Here's a (hopefully) clearer one that includes a change in nomenclature for the area labelled F: http://i129.photobucket.com/albums/p232/niemi24s/P078290001e.jpg

[1911Tuner]

Dan...Salty has notified me via phone message that his computer has crashed and he'll be unable to respond to the thread until his problems are resolved.

[niemi24s]

Thanks Johnny: Salty must've got one of those dang square electrons stuck in it somewhere. They can be such pesky little critters! :D

Cheers

[saltydog]

My 'puter wasn't repairable and all efforts to recusiate the gerbil failed. New stuff was ordered and plugged in.

Ken Crawley has the mis-behaving Cmdr. Hopefully he can get it to play nice with JHP ammunition.

The way it was, I simply did not have any faith in it. Maybe that'll change.

Thanks for you help and suggestions.

salty