Originally Posted by Autorotate
Interesting build...that sounds like an excellent rifle for future Alaska hunt
That is very consistent velocities...factory ammo nonetheless makes it that much more special.
Varminator 911-I would guess on 18-21 fps per inch with the slightly quicker powders/200-225 gr weight bullets, and 22-27 fps per inch with slightly slower powders/250-300 gr weight bullets.
JE Custom would know best on what improvements to case capacity might be seen with a different throat. My opinion would be the biggest benefit might not necessarily be a velocity gain from an increase in capacity, but better load density with the next slower/faster powder up or down the chart.
Example-338 Lapua Ackley Improved. It sees a 11 grain increase from virgin unfired brass, to fully formed brass with 2-3 firings. The virgin cases "cube out" before you "pressure out" with Retumbo....in otherwords you can't put enough Retumbo in the case with the 300 grainers to get yourself into pressure trouble....but with H1000 you can "pressure out" before you "cube out"...and definitely get yourself in pressure trouble. After firing, the formed cases now run into pressure/load density constraint at nearly the same time with Retumbo around 103.5 to 104 grains with 300 grain bullets.
The biggest benefit from lengthening the throat on this 338 RCM, may be the same as happens above...you might be able to move into a new class of powders, where as before load density kept you from doing so.
If this is insulting to your knowledge level, I definitely didn't mean it that way at all, just sharing my perspective/experience. I'm here to learn from all the smart fellas like JE Custom on here.
Very good comments ,and very true In my opinion. One of the first things I look at when trying
to decide on a cartrige after deciding use and distance,is case density.
I want the max velocity,(For energy and trajectory) with 100% case density using the optimum
bullet weight for the cartrige selected.
With the 338 RCM the 180 grain bullet produces=3647 ft/lbs of energy @ 2980 ft/sec velocity.
The 200 grain bullet produces = 3864 ft/lbs of energy @2950 ft/sec velocity.
And the 225 grain bullet produces=3778 ft/lbs of energy@2750 ft/sec vel.
These are 100% powder density,Max loads for each bullet and in a compact rifle a bigger/heavy
bullet would only increase BCs so the 200 grain was chosen for a max distance of 675 yards
for 1500 ft/lbs of energy at the POI for ELK.
If I were going bear Hunting I would probably choose the 225 grain bullet and limit distance to
under 400 yards.
There are so many great 338s that will shoot the 250 and 300 grain bullets for 1000+yards
I felt there was no need to increase case capacity or improve the case based on its use and
as is potential.
It is a special purpose rifle, just like most of the long range rifles that are intended to shoot
well beyond 1000 yards.
As said earlier it is a compact cartrige that is equal to a 338 Win Mag, and we all know what
it can do.
I would not hesitate to carry it in Alaska or any other place knowing what its capabilities are.
I appreciate all comments from all on this site and feel better about my choice after hearing
them,And best of all Its Fun to shoot.
J E CUSTOM