Thread: Jacket thickness

I have been wondering for a while now about jacket thickness & how it effects bullet performance.
I have noticed & heard of a few "failures" or what I would consider poor performance from .338 300 OTMs.
These have been shot at 2800-3050 fps & expanded little.
I have put them straight through 12mm mild steel hanging at 800 yards at 3050 fps

Also a 338 300 SMK at 2700fps that expanded little on a Red Deer at 800 ish yards.

I got some of the new Berger .338 300 Elite Hunters a few weeks ago now & decided to section them to see if they were the same as the old Gen Is.
I really like the Gen Is terminal performance but they generally don't cope well when launched over 2900.
Hopefully the Elite Hunters will stand up to being launched at 3000-3100, time will tell.

I decided today to cut up some other popular bullets to see what they were like.

The weights etc seem to add up reasonably well considering they were cut with a hack saw very unscientifically

Bullet. Jacket Base Lead Jacket Total
. Thou Grains
162 A-Max. 15 20 98.1 35.2 133.3
180 Hybrid. 18 28 101 45.6 146.6
208 A-Max. 19 30 126.3 46.7 173
230 OTM. 21 24 131 58.9 189.9
230 Hybrid. 21 25 130.5 61 191.5
300 Gen I. 22 28 179.2 73.6 252.8
300 E.H. 25 28 165.9 83.9 248.9
300 OTM. 29 29 164.7 86.7 251.4
300 SMK. 23 57 179.7 73.3 253
350 SMK. 31 80 190 111.2 301.2

It is difficult to draw conclusions on a bullets performance from shooting a few animals, but I think it helps a bit more if you can find out about bullet construction.

Obviously, twist rate, rifling construction, throat condition & velocity have a bearing on bullet performance as well.

I have seen from numerous recovered bullets shot into media that the rifling engraving seems to initiate the jacket splits & resulting deformation.

Disclaimer, these are the measurements I got using digital calipers & several measurements, "your milage may vary" a thou is a fairly small measurement using this gear.

Thanks for that info, and for the hours its cost you.

Finally done and proved what we been talking about for over a year

This kind of information is exactly what alot of new reloaders would find very interesting and helpful when picking a long range bullet.

Originally Posted by Terminator

This kind of information is exactly what alot of new reloaders would find very interesting and helpful when picking a long range bullet.

Yep, top value in the 7mm/30 cal a-max or 300g 338 cal Elite Hunter projectile