Re#33 250gr .338

[Ironworker]

Re#33 behind a 250gr Sierra 338-378 WBY Mag . Is this powder to slow for this combination ?

 

[ELR Researcher]

"Specifically designed for the .338 Lapua" - http://www.alliantpowder.com/products/powder/reloder33.aspx

338-378 Wby is the same cartridge class as the 338 LM and 338 NM.

 

[shortthroat]

Not too slow, but H1000 works better for 250gr SMK in my 338LM rifle. RL-33 works best with 300gr bullets.

 

[Zero333]

RL-33 is about perfect for the 338-378 weatherby with 250 grainers.
Ever RL-50 will work with 250 gr bullets in the 338-378.

I even use RL-33 in a 300winmag with 240 gr SMK.

RL-33 settles in the case densely.

 

[Zero333]

Here is some food for thought. Hope you find it helpful.

========================================

Cartridge : .338-378 Weath. Mag.
Bullet : .338, 250, Nosler AccuBond 57287
Useable Case Capaci: 120.847 grain H2O = 7.846 cm³
Cartridge O.A.L. L6: 3.750 inch = 95.25 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-33

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 79 96.80 2382 3149 29484 11846 88.4 1.835
-18.0 81 99.22 2449 3331 31684 12280 90.0 1.787
-16.0 83 101.64 2518 3519 34064 12700 91.6 1.737
-14.0 85 104.06 2586 3714 36643 13101 93.0 1.690
-12.0 87 106.48 2656 3915 39442 13481 94.4 1.633
-10.0 89 108.90 2725 4122 42475 13837 95.6 1.577
-08.0 91 111.32 2794 4335 45762 14167 96.6 1.522
-06.0 93 113.74 2864 4553 49284 14467 97.6 1.470
-04.0 95 116.16 2933 4777 53075 14737 98.3 1.420
-02.0 97 118.58 3003 5005 57168 14973 99.0 1.371 ! Near Maximum !
+00.0 99 121.00 3072 5239 61593 15173 99.5 1.325 ! Near Maximum !
+02.0 101 123.42 3141 5476 66381 15335 99.8 1.280 !DANGEROUS LOAD-DO NOT USE!
===========================================

So according to Quickload prediction with 250 Accubond...

121 gr of RL-33 = 99% case fill = 3,072 fps = 5,239 ft-lbs = 61,593 PSI = 99.5% powder burnt.

But I would start load work up no higher than 110 gr. The Lot of RL-33 I have is much faster burning than QL suggests. I wouldn't be surprised if you start seeing pressure signs between around 116 gr... Only one way to find out now !

Curious lurkers might wanna know the 338-378 Weatherby Magnum has roughly 29 grains more capacity than the 338 Lapua.

If you do decide to give RL-33 a shot, please give us a update in the future.

 

[Preacher]

RL-33 is all I use in my 338 Ultra Mag with 250's and it shoots really well with it..

 

[Ironworker]

I shot the Re#33 yesterday 114.5 grs behind the 250 SMK . No pressure signs of any kind,but had a scope mount failure. Recoil shook the standard leupold rings lose.Ordered and waiting on Farrell industries WBY G force Steel rail .