33 SHERMAN MAGNUM

[300 Driver]

How efficient is this compared to an Edge? I think these are similar velocities to what others saw in 338 Edge with 98gr powder.

No matter what the powder load is, this is awesome!

 

[elkaholic]

How efficient is this compared to an Edge? I think these are similar velocities to what others saw in 338 Edge with 98gr powder.

No matter what the powder load is, this is awesome!

Reached 2756 with N565 today which I think is about max. No x mark but bolt had a little stiffness (300 gr)
I loaded up some RL26 also and guessed where Max might be. I didn't get a read on the first, but I think
it was max. One grain more clocked 2842 but had an x mark and stiff bolt so max is likely near 2800, which makes sense with N565 making 2756. Im pretty impressed with what its doing with a 24" barrel!
Downside was, I shot various charges for group and it looks more like a shotgun than a rifle group!
I think I must have a scope problem or?? This same barrel shot ragged holes when it was on my 338 sherman for about 400 rounds.
Ill try to figure that out this weekend.

 

[300 Driver]

Not knowing all your specs, could I rechamber a 338 Win Mag up to 338 SM without setting the barrel back?

 

[elkaholic]

Not knowing all your specs, could I rechamber a 338 Win Mag up to 338 SM without setting the barrel back?

Pretty sure you could. the case length on the Sherman is 2.550

Not knowing all your specs, could I rechamber a 338 Win Mag up to 338 SM without setting the barrel back?

yes, you could

 

[WeatherBugHiker]

It's amazing to see all of these new rounds being made and I'm still sitting here learning how to speed up my reloading process lol

 

[Pdvdh]

Pretty sure you could. the case length on the Sherman is 2.550

yes, you could

Rich,
Wouldn't the belt diameter within a 338 WinMag chamber be larger in diameter than the case web on your 338 SM?

 

[elkaholic]

Rich,
Wouldn't the belt diameter within a 338 WinMag chamber be larger in diameter than the case web on your 338 SM?

No, I think the web is .530

Rich,
Wouldn't the belt diameter within a 338 WinMag chamber be larger in diameter than the case web on your 338 SM?

I think the belt is the same diameter as the case head on the SM at .532

 

[Earnhardt]

How many grains of N570 with the 250 & 300 grain bullets?

 

[elkaholic]

How many grains of N570 with the 250 & 300 grain bullets?

I don't know that you can pressure out with N570 and a 300 but I will try it this week hopefully. It still might make a useful load

 

[Earnhardt]

Ok, how many grains of what powder are you using, and with what bullet?

 

[BPollard]

View attachment 209369

The new 33 Sherman Magnum is here and ready to be spun up and ready for elk season. It is based on the 30 SM simply necked up. This baby promises to be a Hammer and the 28 and 30 versions have shown outstanding accuracy!
No data yet but you can be the first. I expect the 285 to reach 2800-2850' and it will likely run a 250 Berger to 3100'.
Phil Allen has the reamer and Hornady is currently cutting dies.
This will be a very strong performer on a std magnum bolt and no rebated rim.

Phil Allen
MCM Firearms
www.mcmfirearms.com
208-406-5000

Keep us posted this looks like it might be interesting

 

[elkaholic]

Ok, how many grains of what powder are you using, and with what bullet?

Im just getting started really, but I reached 2800 with a 300 grain Berger with RL 26. I tried it because I felt it would give top velocity. I ran one up to 2842 but it left an x mark and some stiffness in the bolt. N565 reached 2756 with the same bullet.
RL26 also ran a 250 Berger up to 3105 with no x mark and very minor bolt lift. I figured it at max though.
This is with a 24" barrel.
Ill be trying to find time to test a little for accuracy and maybe try some more powders this week. I had a scope mount problem that I have corrected so well see how it goes.

 

[300 Driver]

Rich,
Any updates? Really curious what powder charge you're using. If you don't want to give specifics, I'd love to know if you're using 80-ish or 90-ish grains of R26 just for comparison.

 

[elkaholic]

Rich,
Any updates? Really curious what powder charge you're using. If you don't want to give specifics, I'd love to know if you're using 80-ish or 90-ish grains of R26 just for comparison.

No time to shoot but around 80 grains for the 300 gr