Originally Posted by Trickymissfit
another major problem with driving most of the 7mm bullets that fast is that they'll probably explode after a couple inches of impact on something like a deer. Just not made for those kind of velocities
Years ago I built a rifle in 7 STW for velocity. It had a 31" barrel with a 1 in 10 twist.
I used the 140 grain bullets because at the time A Squair had a load that was advertised at 3550
ft/sec.(They later cooled it down to 3500 ft/sec).
I reached 3800 ft/sec but accuracy went to hell with anything over 3650 ft/sec. I did some very
close test on paper (10 yrds) because I suspected bullet problems, and found out that the bullets
were coming apart at somewhere around 3650 ft/sec (Shedding the jackets).
I tried the monolithic bullets and they gave problems at these velocities also so I decided to back
off and settled for 3600 ft/sec and was very pleased with accuracy and performance with the two
bullets I used (140gr partitions at 4 to 500 yards and in and the ballistic tip for shots over 500 yards).
I had to use a drop tub for the powder I used to keep from breaking the grains due to compressed
charges of very slow powder. (H 5010).
With less twist you might reach 3800 ft/sec with the right setup but it is doubtful. I recommend a
1 in 9 twist for the STW and it works well with any bullet up to 3550 ft/sec.
Velocity is like gas mileage, some like to exaggerate.
J E CUSTOM