Velocity issues with Barnes Triple X handloads

[higunner]

I've been working on hand load development for my Tikka T3 chambered in .338 WM for my September moose hunt in Alaska. Using Barnes volume 4 manual and using the data provided for their 250 grain triple X FB bullet, I started at the minimum, using H4831SC powder.  My C.O.L. was 3.288 and I was able to shoot a .486 group @ 100 yards using 64.5 grains of powder.  I was thrilled until I chronographed the load and learned it was only at 2250 f.p.s at the muzzle.  The manual shows the low end load @ 59.5 grains 2350 f.p.s. and the high end @65.0 grains 2517 f.p.s. I'm not into super high velocities or anything but I knew this was low, but an excellent group for .338 WM.  I called Barnes and spoke to a really nice guy who agreed the velocity was to low.  We reviewed my used components and without coming out at actually saying it, I gathered he recommended bumping up the charge either 1/2 or a whole grain at a time until I achieved between 2400 and 2500 f.p.s. He recommended these velocities for the best bullet performance out to 500 yards.  He did however remind me to check for pressure signs as I proceeded. 

Today I conducted some additional testing, Finally at 71.5 grains of powder I was able to get 2492 f.p.s without any signs if excessive pressure.  I did increase my c.o.l. out to 3.335 to allow for the additional powder.  Now I need to go to the range and she how she groups.

I don't know how to tell what I'm at for load density or if it matters.  I've never experienced this issue.

Any input would be appreciated.   Thanks

[bobcat]

I think I would try a lighter bullet. A 250 grain is on the heavy side for a 338 Win. Mag. and in a Barnes bullet you can afford to go lighter because of the nearly 100% weight retention. Also, the Barnes bullets expand more reliably at higher velocities, so normally when using Barnes bullets (or any 100% copper bullet) I think it's a good idea to step down to a lighter weight.

[Jolten]

What was Barnes testing barrel length? And what's yours?? If they're testing out of a 26" barrel and you're shooting a 24" that could possibly account for some if the fps missing

[higunner]

Thanks Bobcat, I might try the 225 grainer.   Good point

[higunner]

Thanks Jolten, both are 24" barrels

[Jolten]

No problem. I shoot a savage axis .243 in a 20" barrel. Imagine my surprise when it didn't add up. Now I just buy them factory loaded

[higunner]

If the 250's group well, I'll stick with them.  There are no signs of pressure issues.

[bearpaw]

I think I would try a lighter bullet. A 250 grain is on the heavy side for a 338 Win. Mag. and in a Barnes bullet you can afford to go lighter because of the nearly 100% weight retention. Also, the Barnes bullets expand more reliably at higher velocities, so normally when using Barnes bullets (or any 100% copper bullet) I think it's a good idea to step down to a lighter weight.

I've been loading some .338 160gr Barness TTSX and have seen one bear killed in his tracks thus far. I plan to try them on another animal soon. Amazing velocity, less recoil, and flat shooting. I also have some 185's to try too.

A friend and his dad shot two elk with 250's at around 400 yards and recovered the bullets which barely mushroomed. I would recommend a lighter weight ttsx to get more speed. 

[higunner]

Thanks Bearpaw

[higunner]

I'm 6 1/2 grains over Barnes recommended max and still shooting less f.p.s?,,,

[higunner]

Thanks cboom

[bearpaw]

You might take some photos of the brass and post them for others to look at! 

[bobcat]

Velocity is your best indicator of pressure. If you're getting the same or nearly the same velocity as Barnes with their max load, then your load should be perfectly safe.

[bobcat]

I guess another thought is how do you know your chronograph is giving accurate readings?

[higunner]

Thanks guys.   I'm gonna try a different chronograph tomorrow