hard chambering

Use a sharpie (black or blue works best for me) on a couple cartridges, marking them totally head to neck. After chambering and extraction, that should help you see where they're tight at.

How many times have they been fired. They could be work hardend and need anealing.

Necks in bottle neck cartridges will thicken over time.
With a bullet seated the neck is being squeezed in that part of the chamber. If that’s the case the neck needs to be outside reamed.

My best guess is that they weren't full length sized even though you thought they were. If the shell holder doesn't touch the base of the die on the up stroke you haven't full lengh sized the case. The cause can be inadequate lubrication of the case.

A less likely possibility is that you need a small base die.

In loading thousands of rounds I've never had thickened necks be a cause of hard chambering. Likewise, I've never found work hardened brass to be a cause of hard chambering though it is a cause of split necks.

I would try sizing, rotating the brass 1/4 turn and sizing again. Just make sure the press is camming over with the brass in it to make sure it is an actual FL size operation. Then try the brass before loading it first.

readjust your seating die. test a empty case to see if you are bumping the shoulder down. if cases are old trim them and aneal them.

Jeff Flannery said:

redding comp shell holders and worked from .010 and settled on .04 when some of them chambered easily.

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Use a standard shell holder to fl size. Forget the Redding competition shell holders.

3 common causes for the feeling of hard closing bolts:

1) Jamming over-length seated bullets into the lands

2) Crush fitting an over-length shoulder for headspace

3) Wedge fitting an oversized case base

The first two are hard to mess up, easily diagnosed, and easily fixed - lowering your seater plug and your sizer body, respectively. The 3rd is more difficult to identify, and may only be remedied by replacing your die - especially in consideration of minimizing shoulder set-back while still sizing the base sufficiently.

Make sure your chamber is clean and a piece of crud is not lodged in there somewhere.

Jeff Flannery said:

mute point to use the redding (competition) shell holders

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SAAMI tolerances- A maximum (large) rifle chamber and a fl die that sizes the brass to the maximum (smallest) amount may leave a chambered cartridge with as much as .015" head clearance. Not good.

Most chambers and fl dies are cut some where between maximum & minimum specifications.

Your fl die is just a few thousandth smaller then the rifles chamber, because it almost works with the .002" competition shell holder. Almost a perfect march.

So this time, the competition shell holder may not be needed for this rifle?

The cam over difference between a hard vs a light cam over may make a thousandth difference in shoulder bump/set back when fl sizing.

As brass work hardens, it may require a standard shell holder? Time will tell.

Always see if 3 empty fl sized brass will allow the bolt to close easly.

Fired brass may take 3 or more firings to fully expand to the chamber. https://saami.org/

Jeff Flannery said:

Thanks i'll try that. I have no idea what else to do to get them to chamber easily

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Jeff
Lots of good input, and to be clear I’m NOT posting in contradiction to any other post,,,, if I may add that it sounds like your brass are now fully fire formed. You have a great opportunity to adjust your headspace by sizing a few more thousand and note exactly how much sizing is happening. When I first set a die to touch I find about .010 between the the top of the ram and the bottom of the shell holder, After recording the datum of a fully formed case I’ll size using a (full stroke )then record a base to datum number for comparison , if no difference I’ll change feeler gauges and adjustment the die down a couple thousand at a time until I record change then sneak up on the final number you seek. All I personally need is enough sizing to chamber freely.
A case gage I find to be a very useful tool as well.
Take your time and measure as you go.
J

Understanding that this thread is a dog whistle for Mr Guffey

I’ll say - Define good cam over in thousands ??

Jeff Flannery said:

I checked headspace with my Hornady comparator and it they were with in sammi specs.

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The Hornady comparator that you are using does not necessarily measure headspace to the same datum that SAAMI measures to, so that isn't the number that you should use.

Instead, use the comparator to get a measurement from a case that chambers "snug" - but not using force. Check that measurement and record the number. Set your die to size THAT case .001 to .002 shorter using your gauge. If the bolt now closes easily, you have your number.

Again, because your measurement tool is not the same tool that they use, the SAAMI number does not rule - your chamber rules.