375/408 Banded Solids Test

[Black Diamond 408]

Edge,
I would have to run a test but if i remember right the total capacity is around 169gns of H2O.
With Retumbo, 140gns it is right at the top of the shoulder area.

Dave

 

[kellyzier]

Here is a comparison of some 375cal bullets that we have been talking about.

From Left to Right...

1. Sierra 350gn SMK "Jacketed"
2. Rocky Mountain 361gn Alum tipped "Jacketed" VLD
3. Predator 347gn Brass solid
4. GS Custom 355gn Copper solid
5. ZA 6.5cal length Copper solid 400gn
6. ZA 7.0cal length Copper solid 420gn

375 Snipetac shell casing

Dave

Dave, this foto is awesome, it really helps for comparison....If the 6.5 works in your barrel, I think I will order your barrel twist. I don't really need to go to 7, the 6.5 is a real missle...and compared to the smk, it's killer!!! Will the 6.5 open like a hallow point on game or will it bend at 90 degrees like others???

 

[kellyzier]

Dave, this foto is awesome, it really helps for comparison....If the 6.5 works in your barrel, I think I will order your barrel twist. I don't really need to go to 7, the 6.5 is a real missle...and compared to the smk, it's killer!!! Will the 6.5 open like a hallow point on game or will it bend at 90 degrees like others???

Based on what you guys are saying, it sounds like I can go up to a 6.0 cal with a stand twist like the 11.5 and if I wish to step up the 6.5 or longer, I will need a gain twist barrel like the 16 to 7.75......It would be killer if the 6.5 cal would stabilize in a standard twist barrel. If not, does anyone know how long you would have to wait for a "gain twist" barrel????

kz

 

[kellyzier]

Dave, this foto is awesome, it really helps for comparison....If the 6.5 works in your barrel, I think I will order your barrel twist. I don't really need to go to 7, the 6.5 is a real missle...and compared to the smk, it's killer!!! Will the 6.5 open like a hallow point on game or will it bend at 90 degrees like others???

Never mind, I see the 6.5 is a sold,,,do it will probably bend to a 90......Still would like to know the lead times on the gain twist barrels???

thanks
kz

 

[Augustus]

Kelly, I seriously doubt an 11 twist will stabilize the solid copper 6 cal ZA 375 at top velocities. You will not be happy with a 7.75 twist using the solid copper 6.5 cal ZA375. To be honest no one really knows how the bullet configurations and barrel twists are going to shake out in the end. The tungsten core bullets theoretically will stabilize in slower twist barrels than the solid copper when compared to configurations of the same demension. The CG and wt. can be manipulated in an almost unlimited fashion by changing the size and shape of the core. Also the tungsten core bullets should be frangible and if so will be devestating on game.

Franky, there are several people including myself who are trying to work all this out on their own dime. My advice to you and others is to be patient and see what shakes out in the next few months. There should be more to share about the whole line of Za copper solids and the Za tungsten core bullets within a few wks. It is for certian that you will need a switch barrel set-up to take advantage of the line of bullets Pictured in 408s post. If you really have the bug and cant wait any longer I would advise you to order two barrels. Get an 11ish for the SMK and similar bullets and a 10-6 gain twist for the various solids. Buy you an action wrench and barrel vise and you should be GTG. Anyway if you do this it will help us all when you post what you are seeing when you begin to fire some rds.

 

[kellyzier]

Kelly, I seriously doubt an 11 twist will stabilize the solid copper 6 cal ZA 375 at top velocities. You will not be happy with a 7.75 twist using the solid copper 6.5 cal ZA375. To be honest no one really knows how the bullet configurations and barrel twists are going to shake out in the end. The tungsten core bullets theoretically will stabilize in slower twist barrels than the solid copper when compared to configurations of the same demension. The CG and wt. can be manipulated in an almost unlimited fashion by changing the size and shape of the core. Also the tungsten core bullets should be frangible and if so will be devestating on game.

Franky, there are several people including myself who are trying to work all this out on their own dime. My advice to you and others is to be patient and see what shakes out in the next few months. There should be more to share about the whole line of Za copper solids and the Za tungsten core bullets within a few wks. It is for certian that you will need a switch barrel set-up to take advantage of the line of bullets Pictured in 408s post. If you really have the bug and cant wait any longer I would advise you to order two barrels. Get an 11ish for the SMK and similar bullets and a 10-6 gain twist for the various solids. Buy you an action wrench and barrel vise and you should be GTG. Anyway if you do this it will help us all when you post what you are seeing when you begin to fire some rds.

Augustus.......Good advice, Thanks....I will use your suggestion and use two barrels and swap them out....It's a heck of a lot cheaper than two guns!!

Do you think I can use the rkm rbtat 370 gr, RKM rbtat 370 gr, Lehigh 350 gr in a standard twist around the 10 to 11 ish range? Also, someone mentioned the Hooker for standard twists, but I can't find any data on their web site on the bullet, no bc no weight etc??

And yes, I will post my findings this spring as I shoot,,,,

thanks
KZ

 

[kellyzier]

Sorry, I typed RKM twice, I ment to type Preditor 350 gr instead.........

 

[Augustus]

I havent had any experience with the bullets you mentioned except the Rocky Mtns. They were fired out of an 8 twist and SPLODED. Others here should be able to answer your question better than I.

 

[Black Diamond 408]

I tested the first generation of the 370gn Rockymtns and they came apart in my gain twist. Geo said that the jackets were to thin so he increased the thickness. I have a box of the new ones to test, with the thicker jackets they now weigh 359 gns. This weekend i will be running these through the barrel (weather permitting)

Dave

 

[kellyzier]

Dave, please let us know the results of your test...For now, this seems like a bullet that I can use.....thanks

 

[kellyzier]

KZ, I have fired several of the bullets mentioned in this thread, I have done almost all of the testing on the various ZA 375, I have also shot the SMK and the Rocky MTN bullets. Here is what I have found:
An 8 twist will explode the Rocky Mtn hollow point and alum. tip
The SMK shot OK in the 8 twist, nothing spectacular
The 6 cal ZA works nice in the 8 twist
The 6.5 ZA is going to need at least a 6.5 twist
The 7 cal will most likely need a 5.5 twist to stabilize at 2900
The gain twist barrels should have entrance and exit twist with less deviation
than my 13-6.5
A 375 Chey w/o a break is not fun to shoot.

Augustus,,,,You mentioned here the 8 twist will explode the rocky mtn in 375 cal.....Please clairify for me....is that a 1 in 8 twist only....or is that the gain twist also 16--8 that will explode the rky mtn bullets?????

If I can get 1/2 moa in accuracy with the 350 smk with the 16--8 twist, and it wont explode the rky mtns, ths may be the configuration I need. I can have good accuracy with the smk and still play around with lengths up to 6 cal ????????????????

 

[kellyzier]

Dave, I know you are testing the newer rky mtn this weekend, but I can't keep up with all your rifles...What twist will you be using in 375 cal????????????


KZ

 

[Black Diamond 408]

Kelly,
I only have one test rifle, gain twist barrel. 16 to 7.75"

Dave

 

[kellyzier]

Upon striking a median these bullets have a very predictable habit of the first 1/2 inch of the long thin nose folding to one side. It dont seem to take a lot of impact for the nose to bend ninety degrees to the body. When I fired it into the clay the nose completely folded back and the body also bent causing the recovered projectile to look like a doughnut with a little tiny whole in the center. Right now I cant tell you how fast this will happen when striking a game animal; however it dont seem to take much to get at least the first 1/2 inch of the nose to go ninety degrees. These bullets are copper and after they have been perfected there may be a oxygen free copper version that will deform more quickly. Just as it is I think on Mule deer and Elk this thing would be devastating. The hunting applications of this projectile is still a big question mark. We will see. I dont know if it would be legal in some states.

Augustus,,,On a big game animal, do you suppose this bullet would doughnut up and pass through the body on a straight course or would it alter its course significantly. I know you have not tried this, but what is your educated guess?

I try to recover most bullets on our big game, especially the ones we kill over 900 yards. Most have been SMK''s and they ball up real well. Not sure what a doughnut would do, but it sounds devestating if it did'nt alter its course????