I've fully prepped and loaded about 70 rounds of .243 brass (Remington ... I know, I know). This brass had been fired 1-3 times in my Rem 788 and I sized it on my Lee collett die.

I'm taking this brass to an informal shoot tomorrow, so I decided just now to run every round through my chamber. I was reminded of that step a couple of years ago when I didn't chamber my reloads until I was up in my deer tree stand. The first two or three rounds chambered fine, then the next one jammed and totally locked up my action. Big, stupid boo-boo. Ol' Murphy was laughing his arse off, I'm sure.

Anyway, as I ran these 70 or so rounds through the action today, there were 10-12 that took extra effort to close the bolt. On these same rounds I couldn't raise the bolt normally and slide it back, I had to pop the bolt up with some force, only then would the round extract. Didn't have to hammer the bolt up, just pop it up snappily. I marked all those tight rounds with a Sharpie and will use them as foulers or whatever.

My question is this: Any ideas what makes those rounds different from the ones that chamber and extract smoothly? What should I examine or measure to determine why they're different? Is it worth studying, or should I just cull the brass out and not worry about why they're different?

Thanks, guys.

I'm sure it is one of the 75 common accuracy gremlins, but I'd put my wager on those cases having been fired with the warmer loads during workup. It's not reasonable to expect a thrice fired case to chamber like a once fired case.

But, it could be that those cases:

lengthened a little more and are hitting the chamber mouth, or
they have a little less capacity, resulting in higher pressure on the last firings, or
your chamber is out of round a wee bit, and the orientation of those cases was "just so" that they are hard to chamber, or....

In other words, the 75 common accuracy gremlins.... LOL! Dutch.

Since they are made up I would use them as you plan. Usually a tight round will extract easier after firing.

All ammuniton, in general, should be full length sized. The best shooter in the country does it (Tubbs), I do it. So do it. Forget neck sizing unless the load is very light. If your far from your tools then carry a length of brass rod to throw down the bore and knock out a round that sticks from not FL sizing.

Typically after 3 or 4 reloads, brass which is not full length sized will have expanded enough to have a very tight fit in a chamber. This is magnified if the chamber is cut a bit out of round. Many factory chambers aren't perfect so what happens is the tight, slightly oblong round is chambered and it doesn't extract. Add to this a rough chamber and there is your problem.

I neck size about 3 times before setting shoulders back on the brass. You can check dimensions with the use of a tool such as the RCBS Precision Mics, or the tool I use and prefer, the Stoney Point Chamber-All. This gives you very precise measurements of your fired and resized brass and assists in setting the dimensions you want in your brass. What the competition shooters do isn't necessarily the best thing for hunting rifles. While Tubbs may full size his brass, thousands of benchrest shooters do not. I've been using neck sized only brass to hunt with, for more years than I care to tell you and have never had a problem. Just count on having to set the shoulders of your brass back about .001"-.002" about every 3 or 4 reloads and you'll never have a problem.

Have to agree with Bob guys! Every 3-4 firings, depending on load and case design, run them through the FL sizer, and you will remain problem-free as to tight chambering neck-sized ammo. I, too hunt with neck sized ammunition, but always check it before going out...never had a problem. Since I have two rifles apiece for several chamberings and three 30-06's, I have found checking to be important. I try to keep my brass separated according to the firearm I use it in, but you know the story. Sometimes a case will migrate to another location by itself, it seems! LOL. Murphy is an efficient guy when it comes to screw-ups. Regards, Eagleye.

I thought you'd nailed it, Bob, that perhaps most of this brass had been FL sized recently, but that the pieces that are sticking maybe had only been neck sized the last 3-4 times. In most of our guns, the shoulder will definitely creep forward over a few firings.

To check this, I hooked up my Stoney Point case length gauge. I measured the sticking rounds as well as 5-6 of the rounds that chamber and extract smoothly. The smooth-feeding rounds all measured exactly 1.624 from the cartridge base to the datum line. Of six sticking rounds, two measured 1.627, but four measured 1.621, considerably shorter than necessary. I can see where the cases that are .003 longer than normal might have a problem, but four of the hard extracting rounds are too short, not too long. ???

Looking for differences in these same rounds, I checked overall brass length and they're all within specs, so it's not a matter of the necks being long and jamming into the lands. I also measured diameter at the neck (with bullets loaded) and at the body just where the bottleneck starts; again, no differences that would explain the jamming.

Rather than the problem being in the body of the brass, could this be caused by a problem with the rim, like maybe rims that are too thick or maybe bent in some way?

You may have a chamber that is slightly bulged and out of round on one side. The bulged portion of your case could cause the sticking. It's unlikely the thickness of the rim would cause sticking.

On may to check is to take one of the sticking case and either coat it with Dykem, or with a Marksalot. Chamber it and remove noting where the coloring is removed. That should identify the problem. Be careful to index the round as to its orientation in the chamber. Could the chamber be rough and dirty?

Sounds like you may not be "fully" resizing the cases in your resizing die. I think the average 788 chamber is in the minimum range to start with (Sure is in my 222).
Watch loading or any activity that requires much upward presure on the bolt handle on the 788, that seems to be the guns weak spot (sure isn't accuracy ) and bolts are NOT readily available.
LouisB
Just opinions of course.