338 snipe-tac project (338-408imp)

[Black Diamond 408]

Well its coming down to selecting a stock for the new long ranger. 338 snipe-tac (408c-t case necked to 338, 35 deg shoulder.) I call it the "338 Sniper~Tactical"
I designed a new action just for this project, 17-4 stainles, 1.600 dia, 1 1/8x16 threads, tennon 1 1/4" long to support the 35" Barney Lawton barrel. The bolt has three locking lugs, 30deg angle, hand lapped to 100% contact. I put in a Titanium firing pin and an aluminum bolt shroud. The barreled action weighs in at 11pounds 12ounces. The recoil lug is 3/8" thick hardened steel. It will have a IOR 6-24x50 35mm tube scope, on top of a 40moa picatinny rail base. The total weight with scope will be under 16#.
I had the chamber reamer made special for the 300MK bullet by Dave Manson. The bbl also has a special twist rate of 1x11.25" supose to stabilize the 300gr bullet at speeds around 3300fps.

I will post more pics when the project is done, and some targets. The cartrige in the pic has a 200gr nosler balistic tip, pretty bullet /ubbthreads/images/graemlins/grin.gif

 

[Shawn Carlock]

That must only leave you about 2 lbs or so for a stock? Hope it makes weight. In Idaho we have to be under 16.0 lbs to hunt with. It is an interesting project, I have a customer that wants me to build a heavy bench rifle in this caliber. What about a break? Keep us posted

 

[Black Diamond 408]

Shawn

Yes it will be just under 16# so its legal in the states with the weight law. The muzzel brake will be titanium, (what flavor i haven't decided). It also has a muzzel-thread protector for using it without the brake. (shown in the pic)
The picatinny rail will be Titanium also, all small parts are Ti or 7075 aluminum. Originally the reciever was going to be Titanium, but had to use the piece for another project, that would of shaved off another 2#.
The stock is Carbon fiber-Kevlar construction, light and strong.

 

[jb1000br]

16lb 338-408 with 300's at 3300fps+ NO THANKS! OUCH /ubbthreads/images/graemlins/shocked.gif

Ought to get there in a hurry though /ubbthreads/images/graemlins/grin.gif

nice action...why 3-lug? You make it?

JB

 

[Black Diamond 408]

JB

Yea its my action. When its locked up the bolt cant move up or down,or side to side, all three lugs are set back into a 30deg matching angle locking abutment. The bolt is cut to a very close tolerance .0015 - .002 clearance. bolt dia is .900

I built one several years ago for a friend, the 200gn nosler, no recoil...250MK light to moderate recoil...300MK tollerable recoil, dont recomend mega bench shooting with out the brake. With the brake, its a dream to shoot. /ubbthreads/images/graemlins/wink.gif

 

[Fiftydriver]

BD408,

Looks like a hell of a rifle. One question. Why did they stop the fluting so far up the barrel. I would think that with the size of those flutes that if they brought them back to the start of the contour increase that you could drop a significant amount of weight. Also extend them a bit forward toward the muzzle as well.

Just curious, as to the reasoning. Is it because of the high pressure of the round at the breech end that they started the flutes so far down the barrel?

Been nice talking with you about these monsters as well.

Have a good day,

Kirby Allen(50)

 

[Black Diamond 408]

Fifty

There was no rhyme or reason, that is just what specs i wanted. I left it short at the muzzel, i wasn't sure if i was going to keep it at 35" or shorten it(32" for powder burn) I have extra room at the breech end to set it back also. I thought about extending the flutes closer to the breech, maybe it would of got to busy. Weight wasnt a factor when i ordered the bbl.

Nice chattin with you also!

 

[Black Diamond 408]

Just a update on the project:

I got the stock in this week! Looks awesome, Bob at Lone Wolf stocks did a great job on my special order. The reamers came back from re-grinding also, i had them altered just a bit. In the mean time from when i posted this, i have taken an order for another one...Ti action, Carbon wrapped bbl, carbon/kevlar stock, magazine feed. Cutting Titanium will keep you busy for sure! I started with a 2" piece of Ti stock, it will be flat bottomed, with flats milled on sides and top (octagon based).

I will post some pics as the project progresses.

Kirby: I like the looks of your V-Block system on another thread. I may have to try that on a up coming project.

 

[1doug]

[ QUOTE ]
The reamers came back from re-grinding also, i had them altered just a bit

[/ QUOTE ]

What did you have changed?

d-a

 

[Black Diamond 408]

d-a

I put a bit more taper back into the case, the first test was with .012 case taper, i brought it up to .020, i wanted easier extraction for repeater type rifles. There is plenty of internal capacity so this change is nominal.

 

[Fiftydriver]

BD408,

Looks like your about ready to make alot of noise and send heavy bullets far far away!!!

Keep us posted as to your results. As you know, I have an great deal of personal interest in your results as we are building ballistic twins of each other.

By the way, final componant(receiver) arrived for my 338 AM project. Now just have to get some time to build it!!!

Keep on pushing, good stuff!!

Kirby Allen(50)

 

[Centre Punch]

Hi Black Diamond,
I have checked out your site and admire your workmanship eapecially your actions.
i have a question about bolt lug ways, do you utilize full length bolt lugways or do you use bolt lug recesses and a bolt where the lugs are the same diameter as the bolt body, also do you EDM the lugs ways.

Ian

 

[Black Diamond 408]

Centre Punch:

Thanks for looking at my site! I use both types of actions, but mostly i use the full bolt style that requires no EDM machining. I make them in two or three locking lug bolts. Some of my customers prefer the three lugs for a short bolt lift 65 deg vs the 90 deg of rem style actions.
Full bolt style actions are a bit longer than Cut raceway actions, 3/4" on average. My actions also have longer thread tennons and larger dia for bigger cartriges.

Dave

 

[Black Diamond 408]

Kirby,

Keep me posted on your 338AM as well. I hope to fire form some cases next week for the SnipeTac.