Loading for my grandsons marlin xs7 in 243 win. Using once fired Hornady brass and 100 grain hornady bullets along with new Hornady dies. Full length sized 100 cases, cleaned, charged and seated bullets like I have been for 40 years. Rounds won’t chamber. So, I made some dummy rounds, full length sized and trimmed to 2.030, seated bullet, round won’t chamber. About the only thing I can figure is this rifle will require a small base sizing die, but very open for suggestions as I have never experienced this in many many years and many multiple calipers. Am I missing some this simple.

How much did the case head to shoulder distance change from before sizing to after?

See if a resized brass will fit prior to powder and bullet. If it will, then your bullet is jamming into the lands preventing the bolt from closing. The last rifle I bought was super short throated. I have to seat those bullets WAY down in the case.

CKAT. Thanks, I already thought of that and initial seating depth was slight below a factory load. No luck, but that suggestion makes perfect sense

Maybe measure the "width" of the neck without bullet and with bullet? Thick neck/slightly over diameter bullet combination?

A few thousandths

Which way? If it shortened then that shouldn't be the problem.

Problem solved guys, thanks for all the suggestions. For 40 years I put the sizer die down to touching the shell holder. In this case, I finally touched the shell holder then turned the die down another half turn. Chambers perfectly. Now I have to pull 100 bullets and do it all over,

If you have a 308 die [better yet 7mm08 or 260] pull the expander/decapper out and run the loaded rounds into this. This will move a bunch of the shoulder, maybe enough to chamber.

You didn't say which rifle the once-fired brass was fired in. It sounds like the brass was fired in a different rifle. Always try the sized brass in the chamber before going farther in reloading, especially if the brass came from a different rifle. You can buy a shell holder that will allow brass to enter the sizing die farther.

Which are those? The Reddings are made in increments of increasing height which correspondingly decrease how far the brass goes into the die.

I have done this with my 308 die.

My 308 die does double duty as a 7-08 body die, my 7-08 die ... as a 260 & 243 body die. Works great.

I had the same problem when I bought a Ruger Hawkeye ultralight 7mm-08. I have had a Rem 7600 for several years and the brass from the 7600 wouldn't chamber in the Ruger after I FL resized it. A 1/4 turn down with the die solved the problem.

If one encounters this issue in the future, a solution is to use a shell holder from the same manufacturer to match the dies, or one with a lower height.
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I believe Redding used to catalog shell holders of varying heights, or one can machine a few thousandths off the current unit.

Or, if you don't have access to a lathe or mill, fasten a piece of 1500 grit wet/dry sandpaper to a piece of flat glass and slowly work the top of the shellholder down, measuring frequently until you achieve the needed shoulder bump.

Ed

That's a typical 243 problem. If some of your rounds still don't chamber, it's because the inside of the neck needs lube. The 243 has a long sloping 20 degree shoulder, when the ball pulls back through the neck it pulls the the shoulder forward if that makes sense.

A Redding Body die would allow you to bump the shoulder back, without having to pull the bullets...

or you can do the suggested using a 260 or 7/08 die with the spindle pulled out... like us cheaper guys who figured out that after buying a couple of Redding Body dies...

Try a neck sizing die.

Most reloading manuals suggest 1/8 or 1/4 cam over when setting up your FL sizer. 1/2 a turn is probably a bit extreme. But hey, if you're happy with that go for it.

Seem's to me the directions with dies have said to cam over for years. I suspect with a tight chamber it is needed, I did it myself for years. and doing that will resize any case to fit pretty much any rifle. Problem came in for me years ago shooting a 7mm Rem Mag. Had a sloppy chamber, lot of belted cartridges and rimed cartridges had that problem. Then following the direction actually allowed the case to fit all rifles but the sloppy chamber contributed to case head separation. That is when I learned about partial sizing. The deal is even with chamber's for rimless cases the chamber in each rifle can vary a bit. But even with the variance the case will still work in the chamber of most rifles. The ones then that separate the head are said to have excessive head space Th chamber is actually out f spec. It can be fixed by moving the barrel back and rechambering or can usually be fixed with partial sizing. In partial sizing the die goes down to the shell holder also but then is backed off. Then the die goes down only far enough to allow the case to fit properly in the to long chamber. But, you can size the suggested way and the ammo will normally still fire in that long chamber but case life will be decreased. That rifle you just did probably has a tight chamber but is SAMMI spec. To neck size with the FL die, the die doesn't touch the shellholder but is taken down to where you can see it stops on the case before touching the neck. Problem with that is that you'll fire a couple rounds and have to FL the case to get it to chamber again. Problem being, if you call it a problem, is your chamber is a bit longer than SAMMI Spec but still falls within it! By partial sizing you simply resize the case to fit the chamber of that gun.

I have two 243's and I partial size both. One rifle will shoot the ammo loaded for either rifle but the other rifle won't. Nothing wrong with the ammo, just the cases sized to fit individual chamber's. One chamber is tight and one not but both are within Spec. The theory behind making the case fit an individual chamber is that it better lines up the bullet with the bore, I don't know that for a fact but maybe it does. I do it out oh habit left over from trying to make a hunting rifle a match rifle!