300 WM Sizing Issue

[Fishkat]

Over the years I've been reloading for my 6.5 and 308. Recently started loading for a belted cartridge and have an issue sizing I need help with.

300 Win Mag, Norma Brass once fired, Redding FL bushing die, using bushing to yield .002 neck tension, and using the sizing wax lightly as well as the dry neck lube. First loading of brass was not sized but used a neck expander for .002 tension.

Cleaned my fired cases, applied lube, die turned way out so I didn't bump the shoulder to much and could adjust and set die for a .002 bump.

A lot more pressure required than I'm accustom to for case sizing and ended up sizing just a little then backing off and repeating the process until the case was partially sized. Only did two cases and decided something isn't right. Felt like I would pull the case head off if I did it any other way.

Measurements of new, fired and resized cases just above the belt and just below the shoulder.

Above belt: new .508, fired .517, sized .515
@ shoulder: new .490, fired .492, sized .490
OAL : new 2.612, fired 2.616, sized 2.617

Is this a chamber issue, any help appreciated.

 

[MtnCreek]

Sounds like a lube issue. A lot of folks like Imperial, but there's better lubes IMHO. Hornady Unique (in the tub) or Dillon spray (let the solvent evaporate before sizing). Cleaning the die out with solvent then lightly lubing it may help.

 

[para72]

I would suggest picking up a Larry Willis collet die for around the belt area

Sent from my SM-N920V using Tapatalk

 

[Fishkat]

Sounds like a lube issue. A lot of folks like Imperial, but there's better lubes IMHO. Hornady Unique (in the tub) or Dillon spray (let the solvent evaporate before sizing). Cleaning the die out with solvent then lightly lubing it may help.

Thanks, I wish it was a lubricant issue. I have on hand several different lubes including those you mentioned but the Redding wax and dry lube have givien me the best results over the years. Like a lot of things you try many and settle on one. I'm thinking I've got an out of spec chamber and the brass expanded to mimic the chamber and now it's to large for the die.

 

[Fishkat]

I would suggest picking up a Larry Willis collet die for around the belt area

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I looked into the collet die you mentioned and sounds like a great idea and might try one one day but in this case I believe you need to FL size before you can use that die to finish up the sizing down to the belt. Redding has offered to take a look at a few fired pieces of brass and the die and see what they can do. Since the LW collet die works on most belted cartridges I might pick one up for a 7mm RM I have and plan to start loading for. Thanks

 

[airmonkey13]

300 Win and 7mm RM is the same parent case. Would work for both and size what the die didn't. Did you lube just past the shoulder and near the bottom belt? Two hang up spots for me....I had some 270 cases I was doing but had multiple firings, so they were giving me problems like you until I had them annealed..Not sure if that would be the case with your 1x fired.

 

[Fishkat]

300 Win and 7mm RM is the same parent case. Would work for both and size what the die didn't. Did you lube just past the shoulder and near the bottom belt? Two hang up spots for me....I had some 270 cases I was doing but had multiple firings, so they were giving me problems like you until I had them annealed..Not sure if that would be the case with your 1x fired.

Well I'm not ruling out user error but I typically lube the case from below the shoulder to the base. Measuring above the belt gives me a value that is out of spec but I sent a few pieces of fired brass and the die to Redding so maybe they can work some magic. At least they can confirm the issue if there is one. Appreciate your response.

 

[airmonkey13]

Any updates from Redding and what they found?

 

[Fishkat]

Yes, Redding confirmed my measurement of .517 above the belt. The engineer stated the chamber was on the large size, actually gave me the SAAMI spec and allowable deviation but wouldn't say it was out of spec. So it's outside of SAAMI spec.
Redding also, as the engineer said, polished my die to make it easier to size the brass. That was way more than I was hoping for, I've got a custom die built to that chamber. Also there was no charge for any of this, now that is great customer service. The die works great, the rifle shoots extremely well and I'm happy.

 

[Fishkat]

Any updates from Redding and what they found?

Yes Redding worked magic and ground my die to the casings I sent. The .517 above the shoulder is out of SAAMI spec, the Redding engineer said the chamber is on the large size. Redding customer service is outstanding, and what they did was more than I expected. So they made me a custom die, shipped it back to me and all this cost nothing, absolutely free. So the die works very well now, I'm getting a measurement of .515 above the belt and it's real easy sizing now. The rifle is extremely accurate and I'm happy.

 

[Fishkat]

Don't not what happened, the first response gave an error message so I wrote the second post.

 

[Nagol]

you mentioned the overall length of 2.612 saami spec trim to length is 2.610 so it seems your cases are to long. what bushing did you use for neck tension I was thinking of getting the same brass. Thanks hope you get it figured out.

 

[918v]

The sizing effort was high because he did not break the die in. After five cases the sizing effort becomes lighter and smoother. And most chambers are .050” longer than book trim length.