338 SHERMAN MAX

[DBoone]

Another round of shooting today. Worked on some groups with the 250 Berger's, Fed215's, and H100v. Early signs of accuracy appears to be around 68.5-68.8. Groups opened up as charge weights increased from there. Went up to 69.5.

On a different note...
Did a bit of testing with some 250 grain Cutting Edge Lazer's also. Two shots each. Speeds were a little faster then the Berger's...

H100V - FPS
68.6 - 2821, 2837
68.9 - 2847, 2830
69.2 - 2868, 2855
69.5 - 2865, 2866

Last two charge weights grouped together nicely, even with the Magento on. I'll be exploring that area more for sure.

 

[DBoone]

Has anyone played with RL26 yet?

Would 65 grains of RL26 be an ok starting point for the 250 and 300 gr Berger's?

I tested my case capacity last night and got 72 squished grains behind a 300 seated just off lands. Don't know if I'll get there in a pressure ladder, but I'll try.

 

[elkaholic]

Has anyone played with RL26 yet?

Would 65 grains of RL26 be an ok starting point for the 250 and 300 gr Berger's?

I tested my case capacity last night and got 72 squished grains behind a 300 seated just off lands. Don't know if I'll get there in a pressure ladder, but I'll try.

You cant put too much. behind a 250.
It wont pressure up.
You need about a 285 to utilize RL26

 

[Broncoguy]

Another round of shooting today. Worked on some groups with the 250 Berger's, Fed215's, and H100v. Early signs of accuracy appears to be around 68.5-68.8. Groups opened up as charge weights increased from there. Went up to 69.5.

On a different note...
Did a bit of testing with some 250 grain Cutting Edge Lazer's also. Two shots each. Speeds were a little faster then the Berger's...

H100V - FPS
68.6 - 2821, 2837
68.9 - 2847, 2830
69.2 - 2868, 2855
69.5 - 2865, 2866

Last two charge weights grouped together nicely, even with the Magento on. I'll be exploring that area more for sure.

So what's you OAL with the 250 Berger and how far you figure you are off lans?

 

[DBoone]

So what's you OAL with the 250 Berger and how far you figure you are off lans?

My COAL is ~3.200" and that's 0.010" jump.

 

[Broncoguy]

Giving good accuracy? Any more numbers to share? SD's?

 

[DBoone]

Well I'm getting close to sending Idaho Trecker some final numbers with the Berger 250. My load of 68.6gr H100V was below .8moa (0.010" jump) and with a change to seating depth got it down below .5moa (0.130" jump). Now that the paper is telling me I've got some accuracy, I'll throw the magneto back on and get some numbers. I think it will be around 2800fps. I'll try longer distances too, everything to date has been at 100 yards.

Now for the 300 grain Berger info. These without a doubt hit the shoulder harder.

COAL ~3.190"
BTO 2.339" (0.010" jump)
Reloder 26 - FPS
66.0 - 2508
66.5 - 2521
67.0 - 2529
67.5 - 2541
68.0 - 2559
68.5 - 2600
69.0 - 2602
69.5 - 2628
70.0 - 2640
70.5 - 2672 (minor bolt lift and stopped)

I'll have to run the ballistic numbers and see if this is worth continuing with. It looked like 2520ish might have accuracy potential and 2630ish, though I'd feel more comfortable at the 2600 range.

No real progress with the Lazer's today, tried one group with a load at 69.3 of H110v and it's going to need more work.

Hope my info helps others and I'll throw out the usual disclaimer to start low with your own rifle and work up.

Dan

 

[jmden]

Have components heading to Shawn Carlock for a 338 Max. Want a 'temp-stable' powder. VV550/555? Or?

Anyone have idea of where to get said magic powder? Pretty sparse for everything it seems at the moment...

 

[elkaholic]

Have components heading to Shawn Carlock for a 338 Max. Want a 'temp-stable' powder. VV550/555? Or?

Anyone have idea of where to get said magic powder? Pretty sparse for everything it seems at the moment...

We found that 555 wont quite pressure up with a 250.
550 works though as well as RL17 and H100V

 

[jmden]

Thanks, Rich.
How temp sensitive in this chambering have folks found these three powders to be? Which is most temp stable? VV550, H100V, RL17.

 

[elkaholic]

Thanks, Rich.
How temp sensitive in this chambering have folks found these three powders to be? Which is most temp stable? VV550, H100V, RL17.

Probably 550, H100, and 17 in that order

 

[ihuntak]

I received my 338 Max barrel (Blaser R93), however, the bolt won't close using a non-fired brass Sherman head-stamped case. The neck was sized up to .338 but that's it. Do I need to form a false shoulder first before the bolt will close? Or might there be a headspace problem? I'm clueless about this gunsmith and chamber demension/wildcat stuff so any help is appreciated!
Thanks.

 

[elkaholic]

I received my 338 Max barrel (Blaser R93), however, the bolt won't close using a non-fired brass Sherman head-stamped case. The neck was sized up to .338 but that's it. Do I need to form a false shoulder first before the bolt will close? Or might there be a headspace problem? I'm clueless about this gunsmith and chamber demension/wildcat stuff so any help is appreciated!
Thanks.

Probably just need to bump the shoulder a couple thou. Let me know if you need help.

 

[peaceje]

Probably just need to bump the shoulder a couple thou. Let me know if you need help.

Thanks Rich. I'll give it a shot tonight.