300 H&H help

[meangreen75]

I need some help for the 300 H&H experienced guys. I am using an RCBS FL to decap and resize my extremely limited amount of brass. I resized piece #1 and got a bulge halfway down the neck. I brought the die down and the bulge got smaller, so I brought the die all of the down to the base and tried again. As you can see it's still there. Any ideas on what I can do to eliminate this? The neck is measuring at .333, the area right above the shoulder is .340. It is fitting into the chamber but I would rather the case look like my once fired and be completely the same size. I appreciate any help I can get.

 

[MagnumManiac]

When you screw the die in with the ram fully up, are you screwing it down until it touches the shell holder?
If you are, take a case and size it with the handle all the way down, then look and see if there is a gap between the shell holder and bottom of die…if there's a gap, that's your issue, the case is not sizing all the way.
What does your shoulder measure now?

 

[meangreen75]

I've got the die all of the way to the plate. It's probably possible to lower the plate and screw the die down more but it's pretty close to max. I've never sized with the die screwed in more than when it hits the plate.

Shoulder to base is 2.361 (resized), once fired is 2.3625.

 

[MagnumManiac]

I've got the die all of the way to the plate. It's probably possible to lower the plate and screw the die down more but it's pretty close to max. I've never sized with the die screwed in more than when it hits the plate.

Shoulder to base is 2.361 (resized), once fired is 2.3625.

When you say 'plate', are you referring to a progressive of some sort?
If so, then maybe that's all the sizing you will get on the neck.
I load for 375H&H now, had 300H&H 20+ years ago, never had your problem, but I did have case head separations after the third sizing almost every time. I only ever used WW-SUPER brass and no matter how I sized, it never stopped, even neck sizing only.
It will make no difference if the neck isn't sized down to the shoulder, will just look odd, but this is how I size anyway.

Cheers.

 

[KsKevin]

Could you be sizing the neck too much? What is ur neck diameter of a loaded round? 0.333 neck seems a bit small unless you have really thin brass or are neck turning. With a 0.308 bullet this is only 0.025" of brass thickness total.

Just grasping at straws…

 

[Digger0519]

I have seen this twice. Once with setting my .338 lapua for .002 bump on my Forster co-ax. Another time setting the same bump for my neighbor's 260 rem on his new Dillon 550. If using a press that uses traditional style shell holder, you can get competition shell holders that will help you get closer with headspace.

I was using Redding dies, he was using RCBS. In both cases, the die manufacturer was contacted and described the issue. The dies were sent in and they were able to machine a few thousandths off the bottom of the die to get where we needed to be.

Good luck!

 

[Dean2]

You are over sizing the neck or your rifle chamber is overly large in the neck area and allowing the neck or the cartridge to expand a lot, which means when you size it, there is still part of the neck that is at chamber size due to the slow taper on this cartridge.. Measure a loaded round, measure a fired round, fired round should be .004 to .006 larger than the loaded round. After sizing the neck should be no more than .004 smaller than the loaded round.

 

[meangreen75]

Could you be sizing the neck too much? What is ur neck diameter of a loaded round? 0.333 neck seems a bit small unless you have really thin brass or are neck turning. With a 0.308 bullet this is only 0.025" of brass thickness total.

Just grasping at straws…

Factory loaded is .335, once fired is .340, resized above the bulge is .333. I'm using a Dillon 550 for resizing, decapping and seating. RCBS FL die.

 

[meangreen75]

I have seen this twice. Once with setting my .338 lapua for .002 bump on my Forster co-ax. Another time setting the same bump for my neighbor's 260 rem on his new Dillon 550. If using a press that uses traditional style shell holder, you can get competition shell holders that will help you get closer with headspace.

I was using Redding dies, he was using RCBS. In both cases, the die manufacturer was contacted and described the issue. The dies were sent in and they were able to machine a few thousandths off the bottom of the die to get where we needed to be.

Good luck!

Thank you. I'll email RCBS and see what they can do. Much appreciated!

 

[Dean2]

Factory loaded is .335, once fired is .340, resized above the bulge is .333. I'm using a Dillon 550 for resizing, decapping and seating. RCBS FL die.

Those sound to be pretty much spot on, so I think Digger is the one that nailed it, case is not going far enough into the die before the bottom of the die hits the shell plate on your Dillon. If you want to verify that size some in a regular Rock Chucker style press. If you size on a standard press you can also use comp shell holders rather than trimming the die.

 

[Culpeper]

For 300 H&H I use a regular Lee FL die and a Willis collet die for the web as needed. The FL die needs lube in the neck as well; I use a chucked nylon bore brush. Try to find NOS brass. Keep your MV below max. I crushed my share of brass on the learning curve.