338 wm loading questions

[vitaminado]

hello
I have a winchester xpr 338 win mag, 26" barrel
I'm loading with bullet hornady sst 225 gr, hornady brass, cci 250 primers and vihtavuori n160 powder.
3.376 OAL. 0.050" off the lands
I have measured speeds and these are the results:
71 gr: 2895 fps
71.5 gr: 2927 fps
72 gr: 2967 fps
there are no signs of overpressure

According to the hornady manual with 71.9 gr, 2800 fps are obtained with OAL 3.320
my loads get much more speed and I'm scared.
What is the cause?

 

[Scratch]

You may have a fast barrel. If there are no signs of high pressure, no injector marks or stiff bolt lift and your getting good accuracy you should be fine.
I have a 7 mag that shoots a 175 gr at 3060fps with no pressure sign.

I'm sure someone with more knowledge will give you more information as well.

Scratch

 

[waspocrew]

What was the length of the test barrel Hornady used? I'm too lazy to go digging around for my manual. It's possible they may have used a 24" barrel.

 

[MagnumManiac]

hello
I have a winchester xpr 338 win mag, 26" barrel
I'm loading with bullet hornady sst 225 gr, hornady brass, cci 250 primers and vihtavuori n160 powder.
3.376 OAL. 0.050" off the lands
I have measured speeds and these are the results:
71 gr: 2895 fps
71.5 gr: 2927 fps
72 gr: 2967 fps
there are no signs of overpressure

According to the hornady manual with 71.9 gr, 2800 fps are obtained with OAL 3.320
my loads get much more speed and I'm scared.
What is the cause?

I have a 26" barreled Model 70 in 338WM, with 225gr Accubonds I can easily reach the same speeds as you, but I am happy with the accuracy at 2890fps.

The most likely cause is the extra 2" of barrel length, as most velocity is taken in 24" barreled test guns.

Cheers.

 

[vitaminado]

Thanks everyone for your help
I have only measured speeds
this week I want to do grouping tests and keep the most exact load.
I'm going to put my limit in 71 gr.
from 71.5 gr the recoil is more unpleasant

 

[memtb]

We're running 225 TTSX's in my wife's .338 Win. (24" Barrel) at 2950 fps., though using a different powder (RL 22). Same results....no pressure signs - whatsoever! memtb

 

[jjmp]

enjoy your Great 338 , she's just showing you the merit of your reloads and her 26 inch bbl!!! regards , jjmp

 

[LoneTraveler]

I have Rem 700 SS 338 WM with a 24 " factory stainless steel barrel. With the Hornady 225 Gr. SST, Using IMR 4350 I get 100+ FPS more than what Hornady lists in their manual through my chronograph with no pressure signs.