338/408?

[Black Diamond 408]

JB

Yea i wasn't laughing at the time, Snap! And just try to find a 505 gibbs shell holder at the local sporting goods store! hahahahaha

 

[Black Diamond 408]

When i got a look at the first 408 case several years ago i said to myself.."hmmmm, this looks promising!" I did build several 408's but in the back of my mind i wanted to wildcat it. I cut one of the cases in half to see the internals, very thick webbing! My first choice was the 375 cal, but no long range bullets. I moved to the 338 cal because of the 300MK bullet. I think in my opinion it would be a better project with the 375cal bullets, dont get my wrong the 338 shoots rather well. The 408 shoots good too, just no real match bullets out there YET. When Richard gets his dies then we will see what the 408 will do.
He said 380gr up to possibly 450gn ULD's.
These cases will take a lot of abuse and pressures. we have loaded some of the cases over 10 times with none lost.

I think the case cap to bore ratio is better with the 375cal bullet. A 400grn bullet in 375 with bc's around .8-.900 would have to be outstanding for extreme long range shooting. Speeds around 2800-3000fps I wonder what twist rate will be needed for something like this????

 

[uncleB]

BD408 and Fiftydriver,
After reading your posts it makes me excited to try the 408 case with a 375 or a 408ct Imp. as far as a 338 NO THANKS the barrel will look like a dry lake bed after break-in and load developement.
My 338LapuaImp.(MOAG) needs to be set back 3" , and it has less than 1000rds down the pipe,I can hardly imagine what 50% more powder would do. I'm not saying dont do it but I'm just too **** old to set back a barrel every time I go hunting. once a year is my limit!!!!!!!!!
UB
ps for me I would rather do a few more clicks on my scope and get a few more shots from the tube.

 

[goodgrouper]

[ QUOTE ]
and it has less than 1000rds down the pipe,

[/ QUOTE ]

Yeah, waay less. I think we've only put about 450-500 rounds down it and she's already a set-backer. /ubbthreads/images/graemlins/frown.gif
50% more powder than that!? Me thinks me'd rather be havin me a 408 meeself! /ubbthreads/images/graemlins/ooo.gif

 

[jb1000br]

uncle and nephew b -- what is your powder charge on that beast anyway?

I saw 3300 with 128gns of h5010 with the 338-408 -- talk about muzzle blast /ubbthreads/images/graemlins/shocked.gif

 

[goodgrouper]

It burns 96 grains of RL25 behind the 300 grain MK. Velo is usually around 3050 to 3100 depending on the lot of powder.

To get another 200 fps they have to burn 32 grains more powder?! Muzzle blast is right, inefficient muzzle blast! /ubbthreads/images/graemlins/blush.gif

 

[Black Diamond 408]

UncleB

This is why i recomend the 375 or 408 to my customers, but first i ask, just how much are you going to shoot the gun?
Most of my customers only sight the guns in, make some ammo, get familiar, go hunting, put it away until next season, go hunting again. Maybe 20 rounds a year. But if they are going to be shooting a lot i inform them on bbl life. All high horse power rifles have this problem.

The 408imp has been done several different ways, still the bullets are the hold back. One guy was getting 3100 with the 419gn. Big heavy rig. I just dont care for the Monolithic bullets. Like you said its easy to add more clicks, if you have them.

 

[Black Diamond 408]

I used 140grns of H-BMG50 300MK 3283fps...went as high as 146grns, too HOT! 3590fps In these big cases, it takes two grains of powder to see any change.

Tried the Re-25, it just didn't like it. I cant rem the exact numbers but the pressures jumped up. Re-25 has been the staple for the 408c-t

I used it with the 250 MK's that was ok. 3500fps Groups were .5 moa

 

[Fiftydriver]

JB,

Thanks for the contact, TTI brass on the way for testing.

Kirby Allen(50)