Hard chambering after sizing

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flashman2

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I'm kind of stumped... so I have a new Remington Seven 7mm-08, and about 60% of my resized cases are hard to close the bolt on.

It's not a seating depth issue, it happens with empty brass.
It's not a neck sizing issue, I'm FL sizing.
It's not a case length issue, they're all at trim to length.
It's not a die issue I don't think, I've tried FL sizing with both Lee and Redding dies.
It's not a pressure issue - I'm at starting charge weights or below, using H4895 to duplicate 7x57mm loads.

It's with PPU brass, and the unfired cases chamber just fine. No issue with hard extraction on the freshly fired cases either, nor obviously any pressure signs. MVs are also right where they should be. I'll measure headspace length on the fired cases tomorrow, but still... once fired brass shouldn't be hard to chamber even with just neck sizing.

Thoughts?
 
You either have a very tight chamber or you are not closing your dies all the way. Giver your dies another half a turn in and see if that does anything.

I have also taken a few though off the top of a shell holder to get my shoulders where i wanted them.
 
Sorry.... Should have added dies are all the way in.

Even then, I've never had fired brass be as hard to chamber as this resized brass is... There really shouldn't be any reason FL sizing is even necessary on once fired, let alone hard to close the bolt on. It might be a tight chamber, but it's in spec - new unfired PPU brass fits just fine.
 
I must have a bejeezus tight chamber - like under SAAMI spec tight. Sized brass is 1.627 to the headspace datum, which is exactly SAAMI cartridge minimum, and .003 under SAAMI chamber minimum. I'll try shaving the shell holder, thanks.
 
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Thanks for that.

Duh, of course it's obvious in hindsight... Guess my chamber is super tight and the dies are pushing the shoulder forward a bit too far. Well, seems like I have another project tomorrow.
 
I tried that too, with no change in headspace length. I'm away from home though so I'm stuck using a hand press for the time being. But I wailed on the press as hard as I could 'till things were squealing with no improvement.

I've got a few new unfired brass at 1.622 so I'll measure those after firing to see what the rifle headspace is. But I'm figuring it's around 1.625 as the odd case that's 1.626 is easier to chamber.
 
flashman2 said:
I tried that too, with no change in headspace length. I'm away from home though so I'm stuck using a hand press for the time being. But I wailed on the press as hard as I could 'till things were squealing with no improvement.

I've got a few new unfired brass at 1.622 so I'll measure those after firing to see what the rifle headspace is. But I'm figuring it's around 1.625 as the odd case that's 1.626 is easier to chamber.
Click to expand...

If you see any gap or daylight between the shell holder and die when sizing with your hand press your not sizing enough.

I wanted to do the same thing with a hand press and watch a movie on TV and no joy. I ended up sizing the cases with my trusty RCBS Rockchucker press and the cases were sized without chambering problems.

Hand presses work OK when neck sizing only, "BUT" if you have a die at minimum body diameter the sized cases "grow" in length more and a good press is needed.

Note pausing at the top of the ram stroke for a few seconds reduces brass spring back making the brass stay put after sizing with more uniform shoulder location.
 
Just giving some insight because I recently went through this issue. Probably a no brainer to long time reloaders, however it was a learning experience for me and might be for the OP as well.

Had several hundred once fired Lapua brass for a Savage I owned, recently made the switch to a Coyote. Upon first firing with the Coyote I had no issues using Federal gold, chambered and extracted flawlessly. When I made the switch to my own loads, the rounds required excessive force to chamber and extraction was showing signs of over pressure. Once fired in the Coyote and FL sized again, the issue went away. Obviously (obvious now) the issue was the case had just expanded in one chamber, and now it was going into what I can only imagine is a slightly tighter chamber so giving me some struggle. I've since bought a small base die, and after sizing with that they're fine.
 
Yes, absolutely - you must FL size if you're using cartridges in different rifles, or using brass fireformed in another rifle (unless it has a tighter chamber of course.)

The issue here though is FL sizing brass for use in the same rifle it was fired in. It's actually more of a rifle issue; SAAMI chamber minimum is 1.630, so a case sized to 1.627 should fit perfectly. The fact it doesn't tells me the chamber must be under spec. Be interesting to measure headspace on a fired case after the next range session. I got lazy this time and didn't bother doing it right away, and it bit me.

Anywho, a switch to Imperial wax has solved the issue, letting me apply enough force with this hand press I'm forced to use at the moment.
 
You can try two things with brass fired in another chamber that is causing chambering and extraction problems.

1. Pause at the top of the ram stroke for 3 or 4 seconds, this will greatly reduce as much brass spring back after sizing.

2. Use a small base die that returns the case back to minimum SAAMI dimensions, and thereafter use a standard FL die.

NOTE, on a semi-auto the full length resized case should be .003 to .005 "smaller" than its fired diameter. This allows the case to "spring back" from the chamber walls a extract reliably.

I buy bulk once fired Lake City 5.56 and 7.62 brass and all of it is sized at least once with a small base die. And again this reduces the case to minimum SAAMI dimensions and insures the resized case will chamber in any rifle. And small base dies are not the end of the world as many reloaders think. The small base die will also push the case shoulder back approximately .003 "more" than a standard die. So care must be taken when adjusting the die for proper shoulder bump to prevent case head separations. Example I use Redding competition shell holders and use a +.004 shell holder that pushes the case .004 "less" into the resizing die for my .5.56 cases. This gives me .003 shoulder bump and if the standard RCBS shell holder was used it would push the shoulder back .007.
 
Yup, the Lee. It's alright. Turns out some nice ammo, it's loaded consistent .6-.7
MOA .270 Win for me. Can't complain about that. Sure is a pain for any volume though. Still, can't wait to get my regular presses set up again.

For some uses I've come to like it though, it's another tool in the box. Literally, in this case - I'm reduced to loading out of a toolbox.
 
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Just for info, I recently switched shell holders for my Rock Chucker, the old one I had was tight on some brands of brass, new one is much better. Anyway, I try to bump the shoulder back to 1.627" for my .243, using an RCBS FL die. 1.628" is slightly tight, I'm happy with 1.626"-1.627" measured from case head to shoulder at .400" diameter.
Freshly fired unsized cases out of my rifle measure very close to 1.626" on average, when resized using the new shell holder in the press they came out at 1.630". I knew the shell holder was thinner than the old one, so this wasn't unexpected.
I put two marks on the die lock nut and the thread and started turning the die down a tiny bit at a time until the brass came out consistently between 1.626"- 1.627".
If in doubt whether or not the shoulder is being pushed back by the die, measure the head-shoulder distance of a fired round, then turn the die out 1/4 turn and resize it. It SHOULD get longer at the shoulder after sizing if the shoulder isn't being bumped back. Then turn the die in a little at a time until you get the length you want. You may or may not have to trim afterwards depending on where the case is stretching.
I trim to 2.035", but not until the case length exceeds 2.040". I usually get 2-3 firings before I need to trim.
This is relevant to full length dies, which is what I use.
I've never run into the situation where the die bottoms out before I get the length I'm looking for.
 
THIS ISSUE COMES UP A LOT ON HERE. THE LENGTH IN YOUR CHAMBER IS A BIT LONGER THAN THE "DIE" LENGTH. FROM BASE TO SHOULDER, SOOOO THE SOLUTION IS EITHER SHORTEN THE DIE ABOUT 0.020 or remove some from the shell holder. You simply have to move the shoulder back a bit.
Enjoy.
 
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