Shaving a sizing die.

[Mtstalker]

Hey guys i picked up a new set of 338 win mag dies and cannot get them to bump the shoulder back it stays the same from before sizing ( shot out of this particular rifle) and after fl sizing. Is it possible to take a few thousandths off the bottom of the die or shell holder to accomplish .001" set back on the shoulder? This is once fired brass and im worried about the shoulder growing over time and hard chambering. Thanks

 

[snert]

Do not assume that one firing has brought that case out to max. In fact it is highly unlikely.

 

[John Russell]

It is not necessary to "bump" the shoulder unless you are having problems closing the bolt.

As Snert said, it takes several firings for the case to completely fill the chamber - you may never need to touch the shoulder in a 338 WM.

 

[M-61]

Before you start cutting up a die you might want to do some research on belted magnums, where they initially headspace and where they headspace after a 'few' firings.

 

[RonAKA]

Hey guys i picked up a new set of 338 win mag dies and cannot get them to bump the shoulder back it stays the same from before sizing ( shot out of this particular rifle) and after fl sizing. Is it possible to take a few thousandths off the bottom of the die or shell holder to accomplish .001" set back on the shoulder? This is once fired brass and im worried about the shoulder growing over time and hard chambering. Thanks

I would not shave down the die. Lap the shell holder on a flat surface like a piece of glass with wet/dry paper. Much cheaper to replace the holder than the whole die, if you change your mind. However, if these case were fired in your gun, and they chamber well, then you might want to hold off bumping the shoulder until after the second firing. If they were fired in another gun, and they will chamber in yours, then again hold off resizing for 1-2 firings.

 

[smoooth]

Exactly! (and I type REALLY slow, apparently)

Why are you trying to bump the shoulder anyway, won't the fired case chamber and bolt close easily?
Does your resized brass chamber and bolt close easily? If yes, you are good to go, fire away.

You don't need to bump the shoulder just because everyone else is doing it.

Your brass will tell you when it needs a bump. You actually want the brass to grow and headspace off the shoulder like a "regular" cartridge. Setting the shoulder back too much will lead to case head separation.

 

[Mtstalker]

Thanks for the input. Ill fire them a few more times and see where it settles in. If i need to i can have a freind who has a machine shop take a few off the shell holder. I was wanting to bump it back for reliability. This is my gun i carry in bear country so reliability is no.1 and accuracy is no.2 it shoots great 5 shots in 1.25" .

 

[Mtstalker]

After resizing there is a tiny bit of resistance while cloasing the bolt with the firing pin removed. Not enough to notice unless i take the firing pin out and there within trim length.

 

[slm9s]

I had a custom barreled 270wby and FL set of rcbs dies where I had to take a "little bit" off the bottom of the FL sizer to bump the shoulder back. Caused no issues and was very accurate.

 

[M-61]

Exactly! (and I type REALLY slow, apparently)

Why are you trying to bump the shoulder anyway, won't the fired case chamber and bolt close easily?
Does your resized brass chamber and bolt close easily? If yes, you are good to go, fire away.

You don't need to bump the shoulder just because everyone else is doing it.

Your brass will tell you when it needs a bump. You actually want the brass to grow and headspace off the shoulder like a "regular" cartridge. Setting the shoulder back too much will lead to case head separation.

1+

 

[snert]

Thanks for the input. Ill fire them a few more times and see where it settles in. If i need to i can have a freind who has a machine shop take a few off the shell holder. I was wanting to bump it back for reliability. This is my gun i carry in bear country so reliability is no.1 and accuracy is no.2 it shoots great 5 shots in 1.25" .

Buy one box of Barnes or Swift factory ammo and carry it for that lonely hungry bear you might have to shoot twice. That box will likely last twenty years, and it will end up being cheaper than buying two dies.

 

[DRNewcomb]

I would not shave down the die. Lap the shell holder on a flat surface like a piece of glass with wet/dry paper. Much cheaper to replace the holder than the whole die,....

This. I once had an '03A3 with a very tight chamber. It would chamber new ammo but my die just wouldn't resize the brass enough. I spent an afternoon lapping the face of the #3 shell holder on an Arkansas stone, down by something around 0.001", after which the brass fit the chamber just fine. Also, read what everyone else said about belted magnums.

 

[ireload2]

You can test your die without modifying anything by slipping a feeler gauge under the case head to jack up the case in the shell holder.

 

[chuckshooter]

You can test your die without modifying anything by slipping a feeler gauge under the case head to jack up the case in the shell holder.

I was just going to say that , nice post

 

[savagedasher]

This. I once had an '03A3 with a very tight chamber. It would chamber new ammo but my die just wouldn't resize the brass enough. I spent an afternoon lapping the face of the #3 shell holder on an Arkansas stone, down by something around 0.001", after which the brass fit the chamber just fine. Also, read what everyone else said about belted magnums.

You can test your die without modifying anything by slipping a feeler gauge under the case head to jack up the case in the shell holder.

many don't have feeler gauges and the don't realize they could cut a drink can with scissors . To make a shim . Larry

 

[Ledd Slinger]

I agree with everyone else. If you're gonna shave anything, shave the shell holder, not the die.

I've had to do this on a couple rifles. One instance was that I got an abnormally thick shell holder, the other was where I bought a used custom barreled rifle and the chamber was a hair too short for the die to bump the shoulder.

Not a big deal to shave the shell holder. Shave the holder down enough to where the bottom of the FL die does NOT touch it when the shoulder is bumped. This will prevent any holder induced misalignment of the die. I just shaved my shell holders down on a bench grinder, then used a flat hand file to clean them up. No precision or machining skills needed to knock down a shell holder because you don't want it contacting the die anyhow. Just keep track of where you're at with a set of calipers. If you accidentally take a few extra thou off, no big deal.

 

[ireload2]

If they don't have feeler gauges they may not have calipers and a micrometer either which leaves them blind.
If they don't have feeler gauges they should spend a few bucks to get a set.

many don't have feeler gauges and the don't realize they could cut a drink can with scissors . To make a shim . Larry

 

[savagedasher]

If they don't have feeler gauges they may not have calipers and a micrometer either which leaves them blind.
If they don't have feeler gauges they should spend a few bucks to get a set.

If it works then the could take the die and a shim to some who could meisure it and cut the die . Larry

 

[ireload2]

But what does he do if his soda aluminum does not work?
At some point in time you have to pay admission to the game or stay home.
The person that does the measuring and cutting might charge way more than the cost of a
set of $4.79 feeler gauges from Harbor Freight.

If it works then the could take the die and a shim to some who could meisure it and cut the die . Larry

 

[dmoran]

Surface grind an inexpensive $5 shell-holder, and don't have to worry about messing up the die.
Any competent machinist can chuck one level and grind it true.
I have them taken down 0.010" (0.115' deck height).
That can be used with any cartridge and die of that size shell holder !.!.!
Easy peasy.... and problem solved
Donovan