Something weird going on here...

[EXPRESS]

Tonight I was loading up some .300 win mag ammo to try out tomorrow.
Brass was once fired and full length sized Lapua.
First lot were Barnes MRX and everything went to plan, as usual.
I had the rifle on the bench to obtain and double check overall length on each load.
Then some Lapua Scenars. I loaded 5 up and while I was running them through the rifle to see if the bullets were engraving, one round stuck.
It was a bit hard to close but I put it down to the bullet still seated too far out.
The bolt came back out without the cartridge and I had to tap it out with a cleaning rod.
Confused, I decided to try it again. This time it was tough to close the bolt, but I figured I see if it would grab the round and extract it. It stuck again.
I put that case aside and continued to check the others. A few trials later, another round stuck, same thing.
I grabbed my calipers and started checking for anything out of spec.
Nothing was out. It seemed that maybe the shoulder on these cases was contacting the chamber more than it should but it's hard to tell.
Still not satisfied I ran a boresnake through the chamber and barrel in csae there was anything in there and tried the sticky cases again. They stuck, and had to be tapped back out.
I measured them again, nothing out of the ordinary.
After that I got called away from the reloading shed, I'll probably just pull the bullets and re-size the cases, but it was truly strange.
Any ideas?

 

[KQguy]

Are you using a headspace guage when resizing your brass?Try bumping the shoulder back a little more and see what happens.

 

[6mm Shooter]

I just got my 7mmSTW back from the smith. My throat somehow shrunk. When he cleaned it out he said it looked like some kind of baked on cleaner or something. I figured it out a few days later. I have been using gun juice after cleaning the barrel and it has been building up in the throat. I push a wet patch through and the excess is squeezed out in the throat and I have not been wiping it out but I am now.

 

[steve4102]

Are you using a headspace guage when resizing your brass?Try bumping the shoulder back a little more and see what happens.

#1 Ditto!

 

[Winchester 69]

Just a thought. If your cases are too long for the chamber, such a scenario might play out.

 

[Innovative]

Read my website (below), and you'll see the cause of your problem right on the home page. Our website is devoted to helping shooters make the best handloads possible. I also made a special resizing die designed specificly for belted magnum calibers.

- innovative

 

[kraky2]

I've got one of Larry's dies and it works wonderfully and has helped me reclaim a quite a bit of weatherby brass from a couple of my buddies custom rifles. (That's why I made HIM buy it!)

But..if you haven't had trouble with that gun and that set of dies before (I'm assuming a once fired was in THAT GUN?) I would wonder if the bulge above the belt is the culprit. A quick check of your ammo....at least a check that' worked for me is as follows: measure just above the belt if you have a measurement greater than .5135" just above it you may have the dreaded bulge. If not I would say that's not the problem.
One other thought is if you keep your headspace to a near minimum and might have had an expander go through a pretty dry neck and pull the shoulder and neck up past the headspace dimension?

 

[4xforfun]

I am a little confused, as usual. If you are loading for a 300 win and your dies aren't set up right and , say, you are bumping the shoulder back too far, that shouldn't affect head space what so ever. Belted rounds are designed to head space off of the belt. I neck size only on all of my hunting guns, so I head space off of the shoulder, so after the first firing the belt is useless to me. If the brass had been fired in that gun I can't see how it is possible that the brass could be too long. What I have seen on three different factory guns is the chambers are reamed "out of round". On two of them, the chamber was wider on the north south axis than on the east - west. So, the only way the rounds would fit was if they were rechamberd the same way that they were fired. I could make them fit if I rotated the brass until it fit. I never had a chamber cast made, but it was plain as day what the problem was when I measured fired rounds. I tried to fix the problem by FL sizing the brass, but that didn't work. The brass was bad right from the belt and I couldn't iron it out. The funny thing was that Remington didn't have a clue....after three months with the guns, they sent them back with two of their own new brass, which they had fired in the gun. "No problem found. Gun shoots fine". I called them and tried to re-explain the problem and that the brass that they sent back would only fit in the gun when rotated to a certain point. They just couldn't grasp the concept...."but.....the gun shot fine, our ammo chambered w/o any problem, we can't help you"

So, try that. Measure your once fired brass, before you run it through your press. Or try and re-chamber the brass at the range. If it chambers rotate it 90 degrees and try it again.

Now if this is a gun that you have had for a while, and the problem just mysteriously started....well....then.......a......NEVER MIND

 

[4xforfun]

What happend

Just curious if you ever cleared up your little mystery????

 

[yellowjacket]

The several times I have seen this problem, the solution has been very simple. Try raising your seating die up a little. You should feel no sudden increase in pressure at the bottom of your stroke seating the bullet. As a general rule you will need a space about the width of a nickle between the case holder and the base of your seating die (with no case in the shelll holder) at the bottom on your stroke. When you have the seating die set to low it can deform the shoulder of your case and this may not be corrected by resizing. Since you changed bullets before the problem showed up increases the odds that this is your problem.

 

[Stevewix]

I've had the issue yellowjacket speaks of, caused by too great of case tension when seating bullets, resuting from a buildup of copper in the sizing die that needs polished out. On my brass, a ridge was formed where the shoulder meets the body, it's barely detectable, but has caused me a few headaches. It can also be caused by the 'seating button' in the seating die having some kind of bur and not wanting to travel up, causing the illusion of an overabundance of neck tension.

 

[.280Rem]

Are you using a headspace guage when resizing your brass?Try bumping the shoulder back a little more and see what happens.

Ditto.

 

[4xforfun]

Yep....spot on with the seating die. I had that problem once, about 15 years ago. A guy learns his lesson in a big hurry after loading 100 rounds. Carefully weighing each powder charge. Good thing I wasn't on a hunting trip somewhere. It was bad enough pulling 100 bullets.

Anyone ever run across an "out of round" chamber??