[azuredragon]

UPDATE: I think I figured it out and I'm fairly certain this is a problem with the ammo. I duplicated this malfunction with my other two 1911s that have been flawless - a Colt that's been worked over by Wilson Combat, and a Springfield Operator that has been reliable in 2k rounds. Both had failures to feed while trying to chamber the top round off a full magazine and both showed deep indentations in the same place on the case. This happened with multiple magazines as well. This issue did not happen when I tried it with Remington Golden Saber or with my dummy rounds so I think the process of elimination has led me to the right place.
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Hey folks, noob here and I know that there are some fixes to this malfunction but I need some help figuring out which direction to go in. I had a malfunction today chambering the top round off of a full magazine that I'll attach a low quality picture of below.

I decided to try and replicate this a few times and while I wasn't able to recreate the malfunction, all the rounds that I chambered had this distinctive indentation near the edge of the case.

For context, I was using Blazer 230gr FMJ fed from 7rd Wilson 47 magazines. I also fired 14 rounds through the extractor tension test and the ejection pattern was strong and consistent at 4 o'clock. I also checked with a Weigand gauge and I pulled 28 ounces so I'm pretty sure the extractor isn't part of the equation here.

Should more material be taken off the edge of the barrel throat? I've attached a picture of the throat as is as well as a picture of the feedway.

And if there's an issue with the lugs and link, how do I go about checking that and fixing it? Thanks everyone!

 

[Steve in Allentown]

I also fired 14 rounds through the extractor tension test and the ejection pattern was strong and consistent at 4 o'clock

Did you fire these 14 rounds after removing the magazine after each round was chambered?

Do this simple diagnostic to rule out the extractor as being part of the problem.

1. Remove the extractor
2. Seat a fully loaded magazine
3. Attempt to feed the first round

If the first round feeds correctly, the extractor has something to do with the malfunction.

A three point jam is often associated with an out of spec feed ramp which causes the nose of the bullet to impact the barrel ramp hard rather than slipping over it. This pushes the barrel forward which causes it to rise into solid contact with the slide. At that point the cartridge case is in contact with the breechface, the barrel's break over edge, and the top of the chamber all at the same time.

You've already identified and slightly radiused the break over edge. Could it be radiused more? I'd have to have it in hand to answer that.

Here's another quick and easy test.

1. Seat a full mag
2. Either press the pistol down hard against a table top with the magazine in contact with the table top or push up hard against the mag with the palm of your weak hand and release the slide to load the top round.

If it feeds, the simplest solution to the problem may be to drop in an EGW Higher mag catch. This part will cause the mag to sit higher in the well resulting in the nose of each bullet striking the frame feed ramp a little higher. This may allow the nose of the cartridges to lightly skip over the barrel ramp rather than pounding directly into it.

In summary, run the without-the-extractor test first. Then run the hold-the-mag-as-high-in the-pistol-as-possible test.

 

[pistolwrench]

I'm not seeing ANY crimp at all on the case mouth.
Looks like some of the flare remains.

 

[azuredragon]

Thank you Steve! I got off the phone with the other Steve, Steve Owens, who was really generous in helping me walk through some different things to look into. I went to him first since he throated and finish reamed my barrel so I'm really thankful for all his help so far.

To start with, yes, I ran the extractor tension test with no magazine inserted. I also tried racking the top round of a full mag into the gun with no extractor installed and when it came to the Blazer ammo, the same issue cropped up. However, when I tried chambering rounds when pressing up on the mag, it fed much smoother. There wasn't the same super pronounced "kerchunk" of the previous tests. I think I'll have to give that EGW higher mag catch a try.

Also, @pistolwrench, I think you're right! I looked at some of these rounds I had chambered and a lot of these have some pretty bad bullet setback. I measured the OAL of the fresh rounds and they're all around 1.260. I picked one of the rounds I had chambered just once and it measured 1.197.

 

[Steve in Allentown]

. . . when I tried chambering rounds when pressing up on the mag, it fed much smoother.

Okay, the extractor can be ruled out as the problem.

That "kerchunk" is the front edges of the top barrel lugs crashing into rear edges of the slide lugs. The cause is the timing of the barrel moving up and engaging the slide lugs too soon. Because the barrel is moving upward too soon the barrel and slide lugs are not meshing smoothly as they should. Instead the lugs are not correctly aligned when they meet which results in the clunky feeling.

The probable fix is to cut the barrel ramp to a less acute angle. The challenge with doing that is you can only change the angle so much before case head support is compromised. This kind of stuff is probably best left to a professional. Maybe Steve Owens has time in his schedule.

An EGW Higher mag catch may be worth the small investment. FWIW, I put this mag catch in pretty nearly every 1911 even if they don't technically need it. I've found that it smooths out the feeding. Just be aware that depending on the magazines you use, you may have to relieve the underside of the ejector to avoid contact with the magazines. This LINK may be of some use.

I wonder if this might be a case of barrel bump? Pull the barrel out and look at the feet to see if there's evidence of barrel bump.

Here are a couple of pics showing barrel bump:

 

[azuredragon]

Ok so I'm gonna get an egw higher mag catch, take a look at the barrel throat, and look for signs of barrel bump. In the event that I do find barrel bump, what's the proper fix for it? I assume I have to file on the lugs but is there any trick to getting it right? Thanks!

 

[azuredragon]

Followup question, if the “kerchunk” happens on guns that have been reliable, don’t have barrel bump, have proper extractor tension, and have throated barrels (in both cases by Wilson), does that just sorta point to the ammo as the core issue? And is crimp a big part of the ammo problem? Sorry I’m just trying to wrap my head around this!

 

[seagiant]

Hi,
Going back to what PistolWrench mentioned, and what I know from experience.

If this is handloads you are using, (could not figure that out from your post?) then...

You HAVE to use a dedicated Taper Crimp Die, (set correctly) as a last step or you will have feed problems!

 

[azuredragon]

Hello Seagiant, these are Blazer 230gr FMJ! factory new ammo

 

[seagiant]

Hello Seagiant, these are Blazer 230gr FMJ! factory new ammo

Hi,
Thanks, yes, best to find a problem, with factory, and rule out a reload problem, in the mix!

 

[Steve in Allentown]

In the event that I do find barrel bump, what's the proper fix for it?

Carefully file, stone, and/or sand the contact point to eliminate the contact. Mark, file, test fit as many times as it takes. Don't get heavy handed.

Seagiant's post made me remember something. During an extended 3 day magazine test that I ran a couple of years ago certain magazine / pistol / ammo combinations would result in the dreaded "kerchunk". If you have more than one brand of magazine on hand, you might want to see if the "kerchunk" happens with each of them.

 

[azuredragon]

Unfortunately I only have the 7rd Wilson 47 mags on hand but I’m gonna try and get some different brands of ammo to see how things work!

 

[Viper_29]

Ya I agree that when I've seen this sort of 3 point jam it was because of my reloads and not enough taper crimp. Hard to cope with that with factory ammo though but I do like the EGW higher mag catch, I use one and it might help you overcome poor ammo like that.

 

[Magnumite]

Try running some of the problematic Blazer ammo through the seat/crimp die. If the problem goes away...bimbo, nailed it.

 

[azuredragon]

I would if I had one Magnumite! but that's a great suggestion that I'll keep in mind for future ammo issues. Thanks!

 

[seagiant]

Hi,
Just throwing things on the wall and see if anything sticks but...

If you are running good Wilson Mags, they should not be a problem?

The other thing is that even though that is factory ammo, as was noted, the case mouth on the ammo does not look good.

Might want to try, some more ammo and yes the higher mag catch as mentioned, would probably be a better mousetrap.

Also, if you have a protractor you might want to check the angle of the frame ramp.

Although, not as much of a problem as years ago, still happens.

Ramp angle, should be 31.5 degrees.

 

[Magnumite]

Many moons back I shot a match. Ended hideously embaressed, not by my shooting but by gun and my backup gun. Similar issues to OP’s. Both guns did it. Went home and a couple other guns did it. Same sytle weight bullet, the load always ran well in the guns. I couldn’t figure it out because that style and weight bullet always worked. Well I settled down after my unsettled mood and did the investigative thing.

Here’s what I determined. Same style and weight bullet that I typically used. Same diameter bullet. Same firm crimp, even heavy. Same process used during reloading. All loaded a couple days before the match. But these bullets were plated. And slicker than slick. They setback even under heavy crimp...on work hardened cases used many times. Flash back occured to 44 Magnum bullet creep and chronograph data showing wide extreme spreads and high SD.

Cardinal sin...changed something and didn't prove the change. I will still use plated bullets but only with low reloading cycle brass...or as practice fodder. So precictably I prefer jacketed first then lead projectiles.

 

[seagiant]

Hi,
Probably 30 years ago was shooting local IPSC Matches at my Gun Club.

Was having the same problem as the OP not every round but enough to be a problem.

Talked to a more experienced friend of mine, and he asked if I was taper crimping with a dedicated die.

I was not, and when I started, that problem went away.

Taper crimp for me is .469-.470 at the end of the case mouth, measured with the thin end part of the caliper jaws.

Have also been using Wilson mags in all my 1911's and have had no problems except a weak spring which is easily fixed by putting in a Wolff Extra Power spring.

 

[azuredragon]

Alright so I talked to Steve some more (really grateful for his generosity and help by the way) and I touched up the barrel throat and feed ramp. No dremel, just some 320grit sandpaper wrapped around a pencil to hit the rollover edge on the barrel throat and to get out some of the machine marks on the frame ramp. I followed up with the same technique with some 2000grit sandpaper (those were the only two types of sandpaper I had!). I also took care to preserve and not touch the top edge of the ramp on the frame. I don't want to push my luck too hard, especially with the concern for case support, so I stopped here and took some pictures with the end of the case flush with the end of the barrel hood. I know the next time I shoot, I'll be inspecting my brass for bulges to be safe.

As before, the Golden Saber and dummy rounds chambered very smoothly with no hesitation. However, when I switched to the Blazer, it was the same issue with the indentations on the brass, bullet setback, and weird hitch-y feeding sensation. I also checked for barrel bump and unless I'm missing something, I'm not seeing anything.

I guess at this point, I'm tempted to just chalk this up as bad ammo, especially since it choked on my railed 1911 that has been really good to me for 2k rounds of various other brands and the same mags. So if anyone is looking for 750 rounds of Blazer and some change, I'll be throwing that on the Classifieds on addicts pretty soon lol.

 

[seagiant]

Hi,
If you have a friend that reloads or you might want to get started by buying a used press and dies.

I bet, if you taper crimp that ammo, as it should be, it will feed.

I love buying and refurbing old presses!