Help! Round getting stuck in the chamber

[Carbon_15]

I have been having trouble with my 9mm and .308 rounds. The .308's are being fired in an ar-10.
When the slide or bolt closes on the round it gets stuck about 1/16th out of battery. It locks up and I have to pound it open. I am resizing all the way Down to the shell holder...past cam-over.
The COAL isn't too long.
Ideas?

 

[rcmodel]

You are more then likely buckling the case shoulder when crimping them.
Either on purpose because you adjusted the seating die to crimp and didn't trim every case the exact same length?

Or by accident because the seating die is adjusted wrong and you didn't know it was crimping long cases enough to buckle the shoulders.

The fix?
1. Adjust the seating die properly.
2. Don't crimp them.
3. Buy an L.E. Wilson case gage.
4. Check every loaded round in it.

On the off chance your sizing die isn't adjusted right?
Chamber check a bunch of sized brass in the rifle before you load it.
If that doesn't hang up, see the crimp induced buckled shoulders above.

rc

 

[Certaindeaf]

What are the 9mm's doing?

 

[cfullgraf]

Another thing to consider.

Is it the first time these cases are fired in your rifle? If so, are they previously fired? If so, the previous rifle may have had a slightly larger diameter in the body area and your resize die does not size it down enough. A Wilson case gauge will not check for for the body of the case being a little too large in diameter.

Once fired 308 Win cases from military origin are often fired in a machine gun with generous chambers.

 

[Slamfire]

Many people here do not believe in small base dies, but I am a believer. For decades Mike Venturino claimed you do not need small base dies for gas guns, and then in the July Issue of Guns, the M1a and AR10 he was testing were jamming with his reloads. His reloads were so over sized he could not get the bolt in battery to fire the rounds out and he had to get lumber to beat the bolt open. Ha, ha, sloppy reloading practices will catch up with everyone in time.

I recommend using a Wilson type case gage to set up your small base die.

Regardless, get a case gage.

 

[Carbon_15]

The cases are not over crimped. In fact, the .308's have no crimp...the 9mm has a very light one.
The 9mm rounds usualy have a shinny ring around the base, just above the rim. The 308's sometimes have the same thing and sometimes its behind the shoulder.

His reloads were so over sized he could not get the bolt in battery to fire the rounds out and he had to get lumber to beat the bolt open.

^this sounds like me...maybe my seat die isnt adjusted properly.
I feel like I followed the instructions, but maybe this is my problem?

 

[Carbon_15]

Chamber check a bunch of sized brass in the rifle before you load it.

just checked....yep, its not going into battery with just the sized brass. in 9mm or 308. my die is adjusted to about 1/2 turn past touching the shell holder.

 

[Slamfire]

^this sounds like me...maybe my seat die isnt adjusted properly.


I feel like I followed the instructions, but maybe this is my problem?

No, you believed the instructions.

This ledge is the difference between Go and No Go for the 308 cartridge. The cartridge is properly sized when it drops in between these two marks.



It is a matter of faith that turning the die to the shellholder plus a mystical number of degrees of rotation will correctly size the brass. Faith because sometimes miracles happen and the case is properly sized. Most of the time, no, the case will not be properly sized.

Without gages, you have no idea what is going on, you are just as likely to oversize, especially with small base dies, as undersize, with standard dies, if you follow the die instructions.

What I suspect, if you get the gages, you will find that your die is too long and you will need to remove material from the bottom.

But get the headspace gages.

 

[kingmt]

Sounds odd with 9mm & sounds like the brass isn't sized enough with the 308. you can add a few .001" between the shell holder & head to size them more but I'm thinking it sounds like tight chambers. Unless it works with factory OK.

 

[popper]

1) did you use the chamber brush? 2) COL correct/HS correct? 3) Case gauge works good, but it is not your chamber, yours may be short. 4) small base die set? 5) make sure the shiny ring just back from the shoulder is not a case separation. Paint the empty case with a sharpie and see where it hangs up.

 

[warhwkbb]

I would check the case length first. Should be 2.005-2.015". Much longer and the case tries to get into the chamber then wont release the bullet. Also, you should do a plunk test to make sure your bullet is not seated out too far.

 

[Steve C]

Check for these situations that may cause issues with the round fully chambering.

IN the 9mm the 2 most likely causes are:

The bullet OAL is too long for the particular bullet and chamber. The bullet is engaging the refiling before fully chambering. Solution: seat the bullet a little deeper so it properly chambers. Check using the removed barrel and compare the reload to a factory load when dropped in the camber.

You are not removing enough of the case belling at it is stopping correct chambering in the tapered 9mm chamber. Apply a little more taper crimp.

Possibly the case is being bulged in the bullet seating operation.

For the .308:

Most likely your bullet is engaging the rifling prior to fully chambering. Seat the bullet deeper.

The case isn't re-sized completely and needs a bit of shoulder set back. adjust your resizing die down a bit to set back the shoulder.

 

[Carbon_15]

The bullet OAL is too long for the particular bullet and chamber. The bullet is engaging the refiling before fully chambering. Solution: seat the bullet a little deeper so it properly chambers. Check using the removed barrel and compare the reload to a factory load when dropped in the camber.

You are not removing enough of the case belling at it is stopping correct chambering in the tapered 9mm chamber. Apply a little more taper crimp.

Possibly the case is being bulged in the bullet seating operation.

For the .308:

Most likely your bullet is engaging the rifling prior to fully chambering. Seat the bullet deeper.

The case isn't re-sized completely and needs a bit of shoulder set back. adjust your resizing die down a bit to set back the shoulder

these were all my first thoughts...it does this with just a sized case.

I guess I need to try milling a little off of the bottom of my dies.

 

[cfullgraf]

these were all my first thoughts...it does this with just a sized case.

I guess I need to try milling a little off of the bottom of my dies.

I would get a case gauge to see if the shoulder is being set back within SAAMI specs.

Then I would get a small base die.