338 SHERMAN MAX

[DBoone]

Who's running 250 Elite Hunters? What's COAL?
Is H100v the best choice?
Running ladder ...... finally..... I know it's been a while and I'm not seeing speeds I was hoping.
Cheers

I just pressed some fireforming loads with the 250 Berger. COAL with 10 thou jump was 3.195". Rifle was throated long to eventually shoot some mono's.

For fun I'm going to try Berger's seating depth test, even though it's a fireforming load. After I finish barrel break-in and fireforming, I'll be moving to load development with 250 class bullets.

 

[Broncoguy]

Ok here we go......finally after some months (took that long to fire form 50rnds) did the start of a ladder.
Barrel fully cleaned and started w/ 3 FF loads to foul
Fully formed stamped brass
2k bump
FL sized w/ turning mandrel ran through after
CCI 250's
H100v
250 Berger Elite's
2.3050 ogive w/ Hornaday comparator
3.1550 COAL
63 - 2557
63.5 - 2566
64 - 2583
64.5 - 2612
65 - 2639
65.5 - 2665
66 - 2658
66.5 - 2621
67 - 2716
67.5 - 2728
Ran out of daylight and loads......guess I load 67.5 - ???
Hard hearing crunch, but I think 65g is the beginning of crunch??
Gurus?

 

[Broncoguy]

Pretty slow! You must not have ANY pressure yet at that velocity?
What barrel?

20" Hells Canyon wrapped Benchmark..... 0 pressure. If I handed anyone the spent 63g and 67.5g case you'd have a 50% chance of picking the case to charge.

 

[elkaholic]

Ok here we go......finally after some months (took that long to fire form 50rnds) did the start of a ladder.
Barrel fully cleaned and started w/ 3 FF loads to foul
Fully formed stamped brass
2k bump
FL sized w/ turning mandrel ran through after
CCI 250's
H100v
250 Berger Elite's
2.3050 ogive w/ Hornaday comparator
3.1550 COAL
63 - 2557
63.5 - 2566
64 - 2583
64.5 - 2612
65 - 2639
65.5 - 2665
66 - 2658
66.5 - 2621
67 - 2716
67.5 - 2728
Ran out of daylight and loads......guess I load 67.5 - ???
Hard hearing crunch, but I think 65g is the beginning of crunch??
Gurus?

Doc ran up to 71 grains but I dont know if he used a drop tube or what?
RL16 or 17 might be better?

 

[Broncoguy]

Doc ran up to 71 grains but I dont know if he used a drop tube or what?

I took a spent case from today with a 250 marked in pencil at the case mouth with modified case. Bullet bottoms out on 65g and just a smidge of pencil line above case mouth.

 

[Broncoguy]

All off of a Lab Radar..... lent my Magneto out but typically I would have both running as cross checks

 

[elkaholic]

I took a spent case from today with a 250 marked in pencil at the case mouth with modified case. Bullet bottoms out on 65g and just a smidge of pencil line above case mouth.

Id say he used a loooong drop tube

 

[elkaholic]

You might drop down to H414/W760 and give that a try as well.

 

[Broncoguy]

Wouldn't you know it...... don't have either. Do have a pound of CFE pistol!

 

[Broncoguy]

Got up to 69.5g of 17 loaded up with 250EH just touching. Plan on Friday afternoon session.

 

[elkaholic]

Got up to 69.5g of 17 loaded up with 250EH just touching. Plan on Friday afternoon session.

That should put a little more sizzle in it.
My guess is 2850+

 

[Broncoguy]

Fingers crossed

 

[Broncoguy]

Ok shot yesterday..... update RL17, CCI250, Berger 250EH AND a 20" tube!

67.0=2803
67.5=2820
68.0=2857
68.5=2859
69.0=2872
69.5=NoGo

all loads unfortunately were compressed..... felt like I may have made a diamond or 2.
69g showed ejector mark (AN on SHERMAN) and flattened the primer a bit. Still think other powers need explored - N540, 550, or 555??
Thoughts??
Cheers

 

[Broncoguy]

Still searching......
Scratch H4350
67-68g wielded a measly 2733-2744 w/ the 250EH
Who knows where 6.5 staball burn rate lands? I have a pound....