338 cal bullet "proto type"

[Black Diamond 408]

338 cal bullet \"proto type\"

I have been working on a new bullet for the big case 338 magnums, (It will be offered with my 338 Snipe-Tac loaded ammo). A specialty bullet for long range shooting, target version and a hunting (expanding) type. In no way am i tring to compete with the Sierra Match King, just am fiddling around with something different. The first prototype off the lathe for testing is a turned brass bullet, 1.995" long, driving bands, boat tailed. The weight ended up at 289 grains. I will experiment with a lighter bullet, in the 250-275grn range. With the driving bands the bearing surface has been reduced for less friction = increased speed. The bullet ogive is similar to the match king, only with a more slender tip. I will be testing different materials later on. This is a winter project with a friend who has purchased a Precision Hardinge Chucker Lathe, If all works out there might be other cal. bullets avalible.

Testing will start soon, groups and velocity.

Here are a few pics...
[image]http://[/image]

On top is the prototype 289grn bullet, bottom is a 300MK

[image][/image]

Loaded 338 Snipe-Tac (338-408Imp) with the 289grn bullet.

 

[jb1000br]

Re: 338 cal bullet \"proto type\"

Dave, beautiful bullet, hope this works out /ubbthreads/images/graemlins/wink.gif

JB

 

[remingtonman_25_06]

Re: 338 cal bullet \"proto type\"

Looks like it should fly a hell of a lot better then that 300g SMK. Im interested to see what it does when you get to shooting those bullets downrange. Pretty cool to be able to make your own bullets!

 

[screech]

Re: 338 cal bullet \"proto type\"

after flinging a few rounds down field you'll have to tell us the results. Accuracy, bc, the hole nine yards. /ubbthreads/images/graemlins/wink.gif Make sure you test them at more than nine yards though.

 

[Mountainsheep]

Re: 338 cal bullet \"proto type\"

Great looking bullet. Good luck with the project.

 

[Wild_Bill]

Re: 338 cal bullet \"proto type\"

Hi Awsome looking bullet what twist do you think it will require and do you think it will work in true 338 bores or will it have to go in a barrel designed for the Lost River bullets?

I would love it if i could get one sent to me to have a look at and how well would you think they would go in a 338BR

Cheers Bill
Australia

 

[Black Diamond 408]

Re: 338 cal bullet \"proto type\"

Wild Bill,

With the proper design of the driving bands they should work in any std bore. I will be testing them in a Lawton 11.25" twist and a Mike Rock 10" twist. looks like 10"-12" twist rates will be the spectrum. Lost river bores are only .0002 oversized .3382 is the 338 LRB bore size. I'm sure there will be changes along the way. When i get some extras in stock i can send you one to ponder over.

Dave

 

[James H]

Re: 338 cal bullet \"proto type\"

The grooves look rather narrow to me, a wider groove would do more to reduce bearing surface. Also while you are experimenting, if you're familiar with the Barnes 50 cal solids (with the front and rear driving bands) there's something to think about too. It looks to me like they would cause less drag (higher B.C.?) than the multiple grooves in the prototype you show and the TSX.
Just throwing out something else to experiment with since you have the equipment available.
Good Luck, looking foreward to results.

 

[Black Diamond 408]

Re: 338 cal bullet \"proto type\"

James,
Yes the groves are a little narrow, i wasn't in the shop when he did the programing. He just used one tool setup for the first test. We wanted to see what kind of tolerance the machine can hold throughout the process. I will be testing bullets with wider grooves and more of the same. I have been visting with a professor at a university here, kinda brain storming, his mostly. This is what i have been thinking and tring to bring into the mix. In relation to a golf ball, the dimples is what make the ball perform, with out them it goes no where. With the radial grooves around the bullet this will impart(in theory)a drag reducing factor. The riflings will cut grooves length wise through the radial grooves making little rectangle dimples. While the bullet is spining these dimples help hold the bullet airborn. This is all theory at this point. If it don't work at least the testing will be fun. The Doc said he wants to write a paper on the tests and results.

Dave

 

[jmden]

Re: 338 cal bullet \"proto type\"

+1

 

[Wild_Bill]

Re: 338 cal bullet \"proto type\"

Hi Dave that would be awsome.

If other calibres are in the works down the track i would be very interested in 100gr 6mm's as they would likely have an equivelent or higher BC than a 107gr 6mm and be able to be pushed faster in small cases like BR's and realy fast in the bigger cases. It could even go down to around 95gr.

The other would be a heavy 7mm between 180 and 200gr what ever the maximum weight would be to be able to stabalise in an 8 twist barrel they would be awsome at 3000fps+

I am sure you will also work on 30 cals and also the 375's as their would be a market on the 375/408 straight away and the 375 Ultra and 378 WBY for long range shooting i wonder if you could get them up to 350 to 400gr in 375"

Cheers Bill
Australia

 

[Black Diamond 408]

Re: 338 cal bullet \"proto type\"

WildBill,
I dont know how many bullet dia's we will be making, lots of testing will be needed just to produce one caliber bullet. The 375cal will be one that will be looked at later on due to the 375-408 wildcat. The problem with solid bullets is weight, for example: Take a 350grn 338cal bullet in jacketed lead core, the same basic size or length bullet will be 60 grains lighter in turned material. The only way to get more weight is making the bullet longer, then you run into problems of seating depths and fitting magazines. A monolithic bullet with the same profiles of its counter part, jacketed bullet, will be lighter, travel faster and have a higher BC. There are some Draw backs to lathe turned bullets, if not designed properly they dont work good in std barrels, Cost of manufacture (making jacketed bullets is very cost effective). No matter how you stack it up, lathe turned bullets will be expensive. They should be looked at as if they are only used for specialty purposes, not plinking.

There is a lot that goes into designing and building bullets, i had some 10,3mm bullets made several years ago to my specs by a small bullet company, they worked very well, cut about half the group size from my 408 rifle, sadly he went out of business.

I'm not looking to go into the bullet business, just have some that guys can test and maybe use if they like. Offer them for my custom rifles, ect.

Dave

 

[sniper2]

Re: 338 cal bullet \"proto type\"

good looking bullet keep working with the grooves sounds like you are going right... /ubbthreads/images/graemlins/wink.gif

 

[su37]

Re: 338 cal bullet \"proto type\"

Those grooves may help you with muzzle velocity but they are
BC parachutes. Counter productive.