300 Sherman Shortmag (SS)

[GREATSCOTT!]

My 22" is 40 rounds deep:
200 grain Berger Hybrid
62.5 grains of RL16
3068 fps unsupressed and slowly speeding up
One large hole with 3-shot groups @100 yards
10.9 MOA gets 2" groups @ 640 yards

 

[Gstew1930]

Mine is 40 rounds deep:
200 grain Berger Hybrid
62.5 grains of RL16
3068 fps unsupressed and slowly speeding up
One large hole with 3-shot groups @100 yards
10.9 MOA gets 2" groups @ 640 yard

What's your barrel length?

Edit: never mind I'm an idiot lol. I see it

 

[cjl2010]

My 22" is 40 rounds deep:
200 grain Berger Hybrid
62.5 grains of RL16
3068 fps unsupressed and slowly speeding up
One large hole with 3-shot groups @100 yards
10.9 MOA gets 2" groups @ 640 yards

What's your COAL?

 

[GREATSCOTT!]

What's your COAL?

COAL - 2.985"
Base to ogive - 2.257"
I like the 200's better in this cartridge, it assures the boattail will be above the donut-prone area thru the life of the brass.

 

[Gstew1930]

COAL - 2.985"
Base to ogive - 2.257"
I like the 200's better in this cartridge, it assures the boattail will be above the donut-prone area thru the life of the brass.
View attachment 288002

**** I might have to get one of these

 

[GREATSCOTT!]

Yeah, and I'll probably back it off speed-wise. Anywhere from 2900 to 2950 is plenty for me; and elk, moose and deer don't know the difference between 3050 and 2950 when 200 grains of lead smashes thru them.

 

[Gstew1930]

Yeah, and I'll probably back it off speed-wise. Anywhere from 2900 to 2950 is plenty for me; and elk, moose and deer don't know the difference between 3050 and 2950 when 200 grains of lead smashes thru them.

I agree. I'm impressed you're getting those kind of speeds

 

[GREATSCOTT!]

I was too. I ran short-batch speed tests on Superformance, Hybrid 100V, and RL16, and RL16 edged out the others for now. I'll revisit them once the barrel is finished speeding up.

 

[elkaholic]

I was too. I ran short-batch speed tests on Superformance, Hybrid 100V, and RL16, and RL16 edged out the others for now. I'll revisit them once the barrel is finished speeding up.

I think n550 and 555 would work very well!

 

[GREATSCOTT!]

Yep, I forgot to include those too Rich, I have a bunch of both 550 and 555 that I'll test after the barrel speeds up.

 

[Donelan47]

I know im basically resurrecting this thread but any updated info on this cartridge? I have a LA howa magnum bolt face and am trying to decide on the ss or the max

 

[Idaho Trecker]

Just had a second rifle built and will start shooting today hopefully to start breaking in. My original was a 28" barrel and this one is 22.75".

As far as building on a long action I think there are better options since you may run into feeding issues. The Mega would be better and would not be pushing your magazine capacity. I have a 338 mega built on a sako 85 long action and no feeding issues.

 

[Donelan47]

Okay I haven't done any research on the mega just the max I just notice that all of the ones posted on the sherman website's load data have short barrels. Side note that barrel is wicked man! very nice gun!

 

[Idaho Trecker]

Okay I haven't done any research on the mega just the max I just notice that all of the ones posted on the sherman website's load data have short barrels. Side note that barrel is wicked man! very nice gun!

They work well with short and long barrels alike. I know there is a reputable smith/company did a lot of testing on barrel length with the ss line and saw minimal loss/gain of fps/inch of barrel length down to 22" and below that the amount of loss increased more. That said I run a 19.5" 270ss and a 16.5" 6 Dasher and happy with both. The dasher only loses 180-200 fps over my 27" barreled dasher. There hasn't been much testing with the 300 mega other than with 215 Berger and h1000 so far but should have more data coming soon.

Don't get hung up on barrel length and just build what suits your purposes. I lugged my original 28" 13 pound 300ss around for 7-8 years as it was my favorite rifle and now it was time for a new build that was lighter and wouldn't be unwieldy now that I have a suppressor.