Terminal Velocity Effects

[Brent]

I found the paper that came with the GS bullets, they say they have a .540 BC. That's about .140 "higher" than the 400gr XLC and I should get 2950 fps out of it. I'm getting 2860 (68-69k psi) out of the 350 X bullet, been a while since I shot it but I had bought 2 boxes and was fixin to switch because of the low BC on the 400 XLC. Believe it or not, the 350 X bullet had a BC of .440 on the same day (only 1 test) I checked the 400 XLC at a .410 BC!!

If these GS bullets with less bearing surface by far, get a higher MV AND BC, this thing will be a better gun than I figured even before I bought it!! You have to figure, I was counting on 2600 fps and a BC of .545, so... 2950 and a BC of .540 would be waaaay too cool!!

The 330gr should have zero difficulty with anything in north america, and then some... Probably better than the 400, especially at LR.

Have you ever seen a pic of the GS bullet?

The 338WM seems to work almost like the fast 30's at 450yds. Beyond that I can't compare them yet. If I was hunting Brown Bear at 400 yards, which would only be in ideal conditions, if ever, I would rather use a 338 WM than my 300 Ultra. Even if I shot 180's, but I would go heavier than 180 if I had my choice.

I don't care what speed you shoot the bullet at, within reason, bullet diameter DOES have a significant effect on an animals reaction on Moose and Bear.

There's "quite" a bit more difference between the 338 and the 416 than there is the 30 and the 338. The same can be said for the 338 vs the 375 at almost identical energies, the nod goes to the 375 for effect, but the 338 producing the same muzzle energy shoots quite a bit flatter, so...

Other game, which I don't hunt up here, many guys say it's exactly the opposite, diameter don't mean squat and speed means lightning fast kills.

One interesting thing I recently learned, and had never really thought to ask, is that in general, Sheep and Mountain Goat die pretty easily. I'm still not sure how to quantify that, but it don't sound like they are real tough SOB's.

I'm interested in seeing what these 330gr 416's do, they'll get loaded up here shortly. Almost loaded them and took with us when we tested the 500 but my scope is off and I didn't have time.

[reed mosser]

Brent your right about the bullet diameter killing better. I think for my next barrel to make 338-416 rigbyimproved to shoot the 200 and 225 noslers. i figure with that combination i would speed,flat trajactory, and some knock down power. I have a 30 alumnium tensioned barrel on my 30 laupa that works very well. I have noticed with the alumnium tensioned barrel stays much cooler that my regular heavy barrels. I am going to use a alumnium tension barrel on a 338. I figure the cooler the barrels stays, the longer it will last. How long of a barrel do I need. Have you ever used tensioned barrels. How long of a barrel can you have before needing a bedding block. I never saw a picture the 330 GS bullet. It should be a real screamer in that 416. Thanks Reed

[ 01-13-2004: Message edited by: reed mosser ]

[a.JR]

Brent,I have very little experiance in bullet performance on animals as the only one's i have shot in the last 10 years have been rogue wild dogs and as such are not hard to get rid of if you can find them...Are you asking about the accuracy performance of a Meplat uniformed projectile or the effect a modified bullet on it's expansion??...I am currently doing accuracy tests on 4 lots of bullets,#1 187 BIB unmodified but classified to the Best of the Best,#2Meplat trimmed to 1.325 aol,#3 Melpat trimmed to 1.325 with the point dia cut to 55 thou dia,#4 Meplat trimmed to 1.325 with the point Re pointed to 40 thou dia..The tests are at 1K in my H/gun and will soon know which way to go for the '04 season..I can keep you posted as to the outcome with accuracy in mind but have no way of getting the info on game or pests..JR..Jeff Rogers

[Brent]

Reed,
I've seen a tensioned barrel one time, got a picture of it. Haven't heard anything about them though.

I doubt you'd need a barrel block on a tensioned barrel, the outer aluminum is removing a lot of stress on the receiver anyway isn't it?

Barrel length -
That cartridge would do well with a long barrel, depends ond what you want to do with it though. If you still want it fairly light, you might be wanting to sacifice some to keep it more portable, or is the tensioned barrel being used on yours for accuracy alone?

Here's a pic of the 330gr HV GS Custom. I wondered why the high BC rating, hadn't dawned on me the GS bullet's a boattail. Guess I been shootin boattails so long I never paid any attention it was different than the Barnes X, exsplains a lot!!







Jeff,
Have you ever used the GS Customs down there?

Anything I can learn about that meplat stuff is great, I'm all ears when you get the accuracy results.

It would be interesting to see how the various bullets perform on game with modified meplats, probably easiest to test expansion differences in water though, takes out the variables.

[ 01-14-2004: Message edited by: Brent ]

[a.JR]

Brent,As soon as i have proof of what works and what doesn't i will let you know....After 9.11 it has been very hard to get any bullets to AUST, so i'm going to make my own for a special 12 twist 7mm 1K set up..No i have not seen the bullet in the pic nor do i know anyone useing them...If you need info on "barrel Stretchers"(tensioned) ask away as i employ this principal on my current Heavy Gun... I did a lot of research and testing with conventional rifles before ending up with the present set up...One thing i can guarantee is if the stretcher comes loose as it did during the 1st shot string fired from the new gun the group changes dramatically(email me and i'll send a photo of that group)..JR..Jeff Rogers

[reed mosser]

Brent I will psot some pics asap. The reason I tensioned the barrel with alumnium was to make the barrel lighter and still shoot like a heavy barrel.My 30 laupa with 30 inch tensioned barrel weighs only 10 pounds with a barrel over 1 inch in diameter. I don't think the tensioned barrels shoot much better, but they do cool faster, especially with alumnium. I had a heavy stainless tensioned barrrel and it shot good but did not cool down nearly as fast as alumnium. I think the alumnium is a better material than the steel for that reason. I love big barrlels without all that weight for hunting rigs and it gives me that. The 330 gr GS bullet is pretty streamlined for a 416. Thanks Reed [img]images/icons/smile.gif[/img] [img]images/icons/smile.gif[/img]