Creating more case capacity in the stock .338 RUM?

ceg1963

Well-Known Member
Joined
Mar 29, 2005
Messages
149
Location
Anchorage Alaska
All big boomer gunsmiths,

There is much discussion about the .338 caliber big boomers like the .338 KAHN (SP), .338 Allen Magnum, .338 Snip Tec, .338-378 etc etc.

My question is this. I want to chamber my next project .338 barrel to the longer cased .300 Ultra Magnum, using a .300 RUM chamber reamer with the proper .338 diameter Reamer Pilot. This will creat an improved case capacity .338-.300 RUM? Then use the .338 neck & throat reamer.

I then want to neck up the .300 RUM brass to .338.

My my gunsmith here in Alaska is extremely qualified and has discussed this project at length. He is on board and has done similar stuff before.

At the end, I want to be able to use more case capacity than the factory .338 RUM offers.

Is this feasible?

If so are there any issues that I need to know about?

Is there a factory/machined reamer system available for something like this?

Is there a better way to build the brass?

Why does the .338-378 not enjoy more discussion on the LR sites?

Thanks for any information.

Charles
 
Yes it can be done and it is a step up from a 338 rum. I am haveing one built. My gunsmith has bulit several with success. Necking up 300 rum brass is no problem, It would be nice to have brass other than remington.
 
screech,

I understand the Edge issue. But isn't that one gunsmith's cartridge? Unless there are publicly available reamers for it and such, I'll have to improvise. I am not too sure if he'd come off the secret.

I think I am on track by necking up the .300 RUM to achieve similar, if not the same performance.

Maybe I'll call it the .338 Super Edge! /ubbthreads/images/graemlins/cool.gif

Please keep the thoughts coming.

Thanks
 
Charles,

I really don't have any secrets. You do want the 338 Edge. It is a 338-300 Ultra, Redding makes dies and has them in stock most of the time. I named it to avoid confusion about what rounds can be chamered in it. The way you are trying to go about it will work but is the hard way. If you want the easy way take a 338 Ultra reamer and set the head space with a 300 ultra go guage, now your done. Buy some dies, load & enjoy. There are some threads on reloading but if you go with H1000, CCI 250's, and 300 SMK's you will be pretty happy. If you OAL is around 3.775" I would start with 90.0 gr and work up.
 
Meichele, Stan Jackson.

Shawn thanks a million! Your way does seem crazy easier! Again, thanks a million. I will execute that way.

Redding Dies it is too.

What about brass? Are they going to produce commercial quality brass for the Edge?

Until then is it best to use .300 RUM necked up, or .375 RUM necked down?

Thanks again. This place rocks!!

ceg
 
I have had no concerns with quality brass in 300 Ultra up. I believe your best bet will be to get the new Nosler custom 300 ultra brass and neck up. Quite honestly I have had no problem getting them to shoot with Rem brass or any other.
 
Charles,

I'm having Redding make me some 338-300 dies. They told me it would take 12-14 weeks to make. I sent my check in on March 27th and they still haven't cashed it yet. Maybe if you order a set, they'll get working on them. /ubbthreads/images/graemlins/grin.gif

Shawn is building me a 338 EDGE. Can't wait till it's done. I can vouch for his work. The gun I sent up to him was a stock 300WM Sendero that he did some accuracy work to. It was an awesome shooter and I'm sure the 338 EDGE that he's now turning it into will be no different.

Devin
 
On specialty dies like that, Redding normally makes 4-6 sets even for an order of one. That way they can have the others in stock and do not have to do the setup for a while.

In other words, might be some 338-300 dies available for someone else real soon without the long wait.

Worth checking on.

BH
 
ceg1963,you can just get a set of 338 Ultra dies and adjust them as necessary for the 338-300.You dont really need specialty dies for the 338-300 whether it is std,S bushing or Comp dies.A neck expander such as used for neck turning in 338 cal will take the virgin 300 brass up to 338.
 
Thanks Shawn.

I am going for your technique of chambering with the 338 RUM Reamer, but using the 300 RUM Go Gauge.

I will then neck up 300 RUM brass to .388.

Thanks again
 
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