Guys,

Any ideas on loads to try in my 375 WBY with the 250 TTSX? It shoots the 300 TSX or NF's very well and the NF's zip right along at 2765 FPS with 86 gr of H-4350. I'm guessing the 250 TTSX if accurate would clock at 2900-3000 fps. Any ideas or comments?

Mark

78 grains RL-15 in my Brno rechamber gets 2825 fps. +3" at 100 and -3" at 300 yards.

Mark, this is my data with my 375 AI (2 grs more H20 case capacity than the 375 Weatherby - I can shoot both 375 H&H and 375 Weatherby in my gun, but I don't think the Ackley will go into the 375 Weatherby chamber - but bottom-line, they are essentially the same cartridge). You're welcome to the data - I know you reload and know what you're doing; but, as always start low and work-up. My gun has a 26" barrel and very little free-bore. I'm currently using URP. Regards, AIU


250 Sierra BT
W760 – Norma Cases
85 -3100
86 -3117
87 -3159
88 -3189 Very Accurate, 3104 Rem. Cases (Oehler)
89 -3115 Rem Cases

250 Sierra BT
N204 Remington Cases
82 -2895
85 -3032
87 -3108
89 -3187 EXTREMELY ACCURATE/THE LOAD!!
90 -3228(70oF) /3210 (60oF) MAX. EXTREMELY ACCURATE THE LOAD!!

250 Sierra BT (Brand new barrel – Lilja)
Ram Hunter Remington Cases
84 -2896
86 -2956
88 -3024
90 -3070 ACCURATE
92 -3151 Too hot.

250 TTSX
Ramshot Hunter
95 – 3080 Lilja
96 – Kreiger 3137/3182// Lilja 3198/3157/3154/3135/3100
97 – 3182/3183 HOT

250 TTSX
N204
90 – 3052/3057 Kreiger//3110/3124 Lilja

250 TTSX
Lever evolution – FAST BURNING - Caution
84 - 3204 blown primer

250 TTSX
N204 EXTREMELY Accurate
78 - 2743
80 - 2830
82 - 2865
84 - 2931
85 - 2970
86 - 3093
87 – 3115/3129/3108 [66oF] /2962-new mix
88 – 3158/3130/ Accurate 3.63”=OAL (55oF), 3167 [66oF]old N204/3073-new mix
89 – 3084/3088 new N204
90 - 3150 85oFAccurate Lilja barrel new N204 [94oF, Krieger,3156,accurate]
90 – 3090/3091/3075/3105/3085/3083/3082/3100=newmix

250 TTSX 2nd Lilja barrel
N204 EXTREMELY Accurate
80 - 2855
82 - 2925
84 – 2971/2957
86 - 3027
87 – 3068 VERY ACCUATE!!
87 – 3081 - brand new barrel
88 – 3105 Very early ejector port marks

250 TTSX 2nd Lilja
MRP Accurate
85 - 2778
89 - 2844
93 - 2917
95 - 2976
96 - 2996
97 - 3062
98 – 3063 accurate

250 TTSX 1st Lilja and Krieger barrels, which are very similar
Ramshot Hunter SUPER EXTREMELY Accurate
87 - 2780
91 - 2911
93 – 2994
94 - 3050
95 – 3080
96 - 3124
97 – 3118 accurate

250 TTSX Brand new Lilja
Ramshot Hunter EXTREMELY Accurate
84 - 2835
88 - 2915
90 - 2980
91 - 2987
92 – 3016 accurate
93 – 3051
94 – 3074 - brand new barrel Very Accurate!!

250 TTSX
SuperFormance EXTREMELY Accurate
81 – 2832 brand new barrel
83 – 2933 brand new barrel
84 - 2896
86 – 2885 // 2980 - brand new barrel
87 – 2952 // 3014 - brand new barrel
88 – 3010 // 3054 - brand new barrel
89 – 3052 // 3090 - brand new barrel
90 - 3107/3150 85oFAccurate!!!!! [94oF, Krieger,3086,accurate]
90 - 3040 Good pockets
90 – 3134 - brand new barrel

250 TTSX
URP - EXTREMELY Accurate
79 – 2800 brand new barrel
81 – 2905
83 – 2932 brand new barrel
85 – 2975
87 – 3048- brand new barrel
88 – 3081/3091/3070 [72oF]- brand new barrel – OK pockets
88.5 – 3105 [86 oF] //3072 [65oF]//3086[72oF] THE LOAD!! Very Accurate
89 – 3126[72oF] THE LOAD!! Very Accurate

Mark,
My .375 Weatherby work was done before the days of the TTSX.
But I tried it in the .375/404JS.
You are on the right track with H4350 and the .375/250gr TTSX, I am sure.

My version of the .375/404 Jeffery Saeed of 2012 has the same throat as the .375 Weatherby of 2001 (CIP 2002).

My rifle has a Rigby box, so I can seat this long:



Here is my maximum load from workup trial at 50 yards:



Here is the QuickLOAD prediction, incredibly close to real life results:



I settled on an accuracy load at about 3000 fps.

Here is a drop table for use when you get to 3005 fps with your .375 Weatherby, which will be no problem:

BC = .424


Roughly 2.5" high at 100 yds,
3.0" high at 150 yards, max ordinate,
DEAD ON at 254.5 yards
and -3.20" at 300 yards, etc.

Mark,

With my excellent results in QuickLOAD with this bullet and H4350 for the .375/404JS,
I could do a QL for your .375 Wby that would also be "incredibly close to real life," if you have the same throat as standard CIP/standard .375Wby of 2001 (CIP 2002).
To do this, I need your cartridge overall length and the brass water capacity.
If you are using standard Norma-made, properly headstamped .375 Wby brass, I know that case capacity.
That will be the top performer.

RIP,

I'm using the factory brass but the rifle is built on a standard M70 action so the OCL can't exceed 3.57"-3.58" to feed reliably. I'm thinking I'll run out of case capacity way before I hit max load with H4350 so perhaps a different powder will work better.

Mark

I would not want any more velocity, but I bow to your experience.
Brice

quote:

Originally posted by MARK H. YOUNG:
RIP,

I'm using the factory brass but the rifle is built on a standard M70 action so the OCL can't exceed 3.57"-3.58" to feed reliably. I'm thinking I'll run out of case capacity way before I hit max load with H4350 so perhaps a different powder will work better.

Mark

Yep,
This is a good exercise for the next time I load the .375 Wby, with the 250-grain TTSX.

Top 3 powders in QL are:
1. RL-17
2. W760
3. H4350

My Norma-made brass has a once-fired, not re-sized, gross water capacity of 111.5 grains.
That is what I use.
The brass gets even bigger while it is being fired, then shrinks down to 111.5 grains.
Loaded COaL used was 3.580".
The max brass length is 2.860" for the .375 Wby, 0.010" longer than the H&H.
Barrel lengths of 26" and 24" were compared.
I really like RL-17, compact and high energy extruded powder.
Winchester 760, I do not like as much, because I am prejudiced against ball powders, which are more temperature sensitive,
as well as possibly harder to ignite uniformly, and not good as compressed loads.
H4350 is about as temperature insensitive as powders get, and takes well to mild compression like 105%.
Use whatever works best in your rifle, with your particular powder lot.

MAXIMUM .375 Wby QuickLOAD PREDICTIONS with 250-grain TTSX

Alliant ReLoder-17: 86.4 grains (97%)
24" barrel: 3001 fps
26" barrel: 3052 fps

Winchester 760: 89.3 grains (100%)
24" barrel: 2996 fps
26" barrel: 3049 fps

Hodgdon H4350 Extreme: 88.3 grains (105%)
24" barrel: 2995 fps
26" barrel: 3048 fps

This is all hypothetical until you start low and work up with a chronograph.
I will try RL-17 vs. H4350 in my Winchester M70 .375 Wby with a 24" barrel when I load the 250-grain TTSX in it.

RL-17:



H4350:



W760: