338 Sin

[Dano5001]

Cant wait to see the numbers on this, might be my next Savage build.

 

[Long Time Long Ranger]

Geargrinder, Exactly, your dead on! Because guys with Howa's and many other actions designed for 7mm rem mag size cases can now have a really nice 338 that will work through the action easily. Many magnum actions are shorter unless they are designed to fit the long wby and STW type magnums. That is the reason some companies do not offer the long magnums. Just the 7mm mag- 300 winny length cartridges that were designed to fit on old military '06 action lengths.

 

[sinarms]

Test rifle plans:
#1 Savage ss rum action
Sin Arms ss 26" magnum contour 1/10" with Sin Arms break
Richards micro fit walnut stock

#2 Savage cm magnum action
Sin Arms ss 26" heavy magnum contour 1/10" with Sin Arms break, with nitride coating
B&c duramaxx black stock, karsten cheek piece.

 

[RH300UM]

OK. Another stupid question. Why would you use the same barrel legnth and twist rate in both test rifles?

 

[sinarms]

Because I have them on hand and I want to see the gain of nitride treating a barrel. I think 26" should be about optimal for this cartridge too.

 

[rscott5028]

Will the Savage 12F action handle the pressures and bolt thrust of this cartridge?

How will those pressures/thrust likely compare to the 338 Win Mag, 338 Edge, 338 RUM, 338NM, and 338LM?

I'm not so concerned about the magazine, because my 12 F-Class will always be single shot and I don't even mind removing the bolt to chamber a round.

I just don't want the bolt to give way and blow my head clean off.

thanks!!

 

[geargrinder]

Yes, I've built a couple Edges and WSM's on regular small shank actions. Many others have built Edges on Savage actions with no ill effects.

The Sin will be no worse than that.

Some will argue about the 338 NM and Lapua. Same as with the Remington. I will agree that those sized rounds take the actions to the safe limits of the actions.

 

[sinarms]

Finally an update. I have been working with geargrinder on how to form brass. Finally last night he made a break through and formed some brass. I also did what he did and formed some brass and a dummy round. I will be working on a hydro form die soon also bit here is a preview.

 

[Firecat]

Progress! Gotta love that. Looks like it is starting to take shape. I'll bet you've just about chomped that bit in half. I too am chomping at the bit to see how it turns out. Kudos for establishing your own wildcat.

 

[geargrinder]

Devin,

Did you anneal before you sized? Or, did you get those without?

Looks like you started with 300RUM brass. I did mine with 7mm, but they looked real funny so I ran my 338 expander through them.

 

[sinarms]

Thanks firecat and geargrinder that is 338 rum brass and no anneal I just went for the gold with the once fired brass and it came out nice. New should work even better.

 

[Firecat]

Sinarms, Looks like the 300 RUM brass should be the way to go. Is there any reason that you couldn't use 338 RUM brass? Perhaps you just used what you had on hand. lightbulb

 

[geargrinder]

The 338RUM brass should be the easiest to form because it starts out with the shoulder already .09" shorter than the 7mm or 300.

It's also less to trim off since the Sin is .17" shorter than the 338RUM.

 

[trueblue]

So am I understanding this correctly, this cartridge is being done for the Savage action, so you can shoot the 300gr SMK seated with the BT at the neck/ shoulder junction, and have it fit into the standard magbox of a savage action?
I do not own a Savage action, can you tell me what is different about it that this is required, and a regular 338 RUM will not work.