Nose high jam caused by... ?

[prickett]

Hi,
I went shooting yesterday and one of my guns had a number of nose high jams (resulting in failure to feed). These were reloads.

Is a nose high jam symptomatic of a reloading error? e.g. OAL too long or too short? Or, is there something else to blame?

I had the jams with multiple magazines, so I'm doubting they are the cause.

TIA

 

[Furncliff]

Best to ask in the Reloading section if you suspect it was an issue with your hand loads.

 

[orionengnr]

A few more details might be helpful as well...

 

[wally]

Pretty much impossible to do anything but guess without photos.

Did factory ammo work with this gun and these magazines before and/or after trying these reloads?

 

[chhodge69]

High-angle feed jam usually indicates a weak mag spring. Hot loads will exacerbate the problem. Extra recoil will shake the top round loose so it rattles around in the open breech.

 

[The Lone Haranguer]

Feeding angle stoppages are usually caused by the magazine, but the use of reloaded ammunition introduces another variable. Shoot it some more with factory ammo. If the problem goes away, look again at your reloads.

 

[rcmodel]

Bullet shape or short AOL would be the two leading suspects.

Most semi-autos are based on the Browning design, and feeding is controlled by the round sliding up the breach face and under the extractor hook.

While that is going on, the top of the bullet ogive starts to enter the chamber at the barrel hood, and the bullet nose holds the round down until it is fully in line with the chamber.

A short OAL, or a bullet with a short ogive design doesn't contact the top of the chamber soon enough to get it going in the right direction.

Perhaps if you could give a few details?
Like what kind of gun you are talking about?
What bullet design you were loading?
And how long the OAL is?

Only then could we get more specific on what your problem is caused by.

rc

 

[1911Tuner]

Did it look somethin' like this?

 

[prickett]

Did it look somethin' like this?

Yessir. Exactly like that.

 

[newbuckeye]

My sig 1911 did that w/ SJHP factory loads..... It only liked ball FMJ or FJHP like the fed high shocks.

 

[prickett]

Bullet shape or short AOL would be the two leading suspects.

Most semi-autos are based on the Browning design, and feeding is controlled by the round sliding up the breach face and under the extractor hook.

While that is going on, the top of the bullet ogive starts to enter the chamber at the barrel hood, and the bullet nose holds the round down until it is fully in line with the chamber.

A short OAL, or a bullet with a short ogive design doesn't contact the top of the chamber soon enough to get it going in the right direction.

Perhaps if you could give a few details?
Like what kind of gun you are talking about?
What bullet design you were loading?
And how long the OAL is?

Only then could we get more specific on what your problem is caused by.

rc

The gun in question is a CZ-97 .45 ACP.
I'm shooting a cast lead truncated cone (cast using the Lee TCN mold). The OAL is 1.151"

The powder charge was near the top of the recommended load (i.e. it was relatively hot).

 

[1911Tuner]

Yessir. Exactly like that.

That's called a Bolt Over Base misfeed, and it's a magazine spring problem. Normally doesn't happen until the last round or two in the magazine. The slide literally outruns the magazine and catches the case in the extractor groove instead of at the rear of the rim.

Look closely at the picture. Notice where the breechface is in contact with the case.

 

[BADUNAME37]

I have an old .22 LR that I refinished. I cleaned it all up and the bullets would do the same thing coming out of the magazine.

I had to adjust the magazine lips by making a little tool of a piece of square stock (an old doorknob steel rod with a cut in it with a jeweler's saw). I could see that adjusting them a bit each way was improving the feed problem until I had them just so.

If the magazine has been dropped onto the feed lips onto a hard surface, that would cause the problem. More than likely the feed lips need to come out just a bit.

 

[BBDartCA]

1911 Tuner - great info. Thanks. What if you get this type of misfeed with cartridges that are not the last ones in the mag. In other words, I have experienced this kind of misfeed on the 3rd cartridge in a 7 round mag. After clearing the misfeed, it cycles OK. Springfield 1911 in this case. Thanks

 

[rcmodel]

Lee's TCFP .45 bullet ogive is goofy.

I bought that mold several years ago, and both my 1911's that will feed empty cases and any Lyman & H&G mold wadcutter had minor problems with that Lee bullet.

I quit messing with it before I figured out what was so different about it.
But it seems to me the OAL got too short by the time you seated it short enough to miss the rifling leade in my guns. The nose hits the feed ramp late and bounces it up too high, & then hits the top of the chamber late and fails to push it back down soon enough.
Three point jams like yours result.

The OAL is 1.151"

Thats awful short.
Try seating it out as far as you can and still miss the rifling and see if it helps.
BTW: Hornadys 230 TC seats 1.200". Their 200 TC seats 1.240".
GI RN hardball is seated 1.271".

Of course, if the slide is hung in the extractor cut like Tuner posted the photo of?
It is not the bullet.

rc

 

[1911Tuner]

What if you get this type of misfeed with cartridges that are not the last ones in the mag.

It can happen at any point after the first round or two. It just happens most often near the bottom of the mag. Other possible contributing factors or causes include too much recoil spring and short-cycle caused by light ammo or too much recoil spring.

If you can get it to happen again, don;t clear it. Look to see if the forward edge of the center rail is in the extractor groove. If not...try seating the bullets out to about 1.200-1.210 OAL.

 

[MCgunner]

Caused by the fact that you weren't shooting a revolver.

 

[prickett]

Thanks everyone for the input.

I reloaded a batch with a slightly longer OAL. The one I mentioned was a mistake - that was for a different bullet. The OAL I actually used originally was 1.19". I loaded up a batch at 1.21" and reduced the powder.

100 rounds attempted. 100 rounds successfully loaded and fired! 100% success.

Thanks again for the suggestions.