50 Allen Tactical, more work to report....

[Fiftydriver]

Dave,

You list a barrel shank diameter if 1.400 for stainless barrels, haven't you used 1.350" for alot of your 338 Sniper Tac rifles?

I have used these on several of the rifles I have built and will be using then on the 9 more that are currently on order for light weight rifles in my 338 Allen Magnum.

Just curious what your thoughts are on that. I thought I read you were using barrels of the same contour and barrel shank but I may have been mistaken.

Kirby Allen(50)

[James H]

Kirby
Looks like you have it pretty much figured on the machine work required. And your right for some reason I think I had it in my head that the cartridge dia. was around .68
I would not be afraid of the strength of the action handling the cartridge. The small barrel dia. allowed by the forearm hanger does concern me some though especially after drilling holes in the barrel for the scope base. I went with a CrMo barrel on my 338 LM because of the same concerns.
Also on my 338 LM I had to remove more from the top of the breach block than it would appear should be necessary to get reliable extraction because of ejector timing and a little slop in the breach block toggle.

Without a brake I totally agree that you will be way below dangerous pressures before you say OUCH #^*$##!.

As for the strength of the #1 Leonard Brownell the stock designer for the Ruger #1 tried very hard to blow one up and was never successful.
If you go foreward with this I will be very interested in how it works out.

[Black Diamond 408]

Kirby,
Yes i use 1.350 4140 bbls, 1.400 on stainless.
Stainless is not as strong as 4140. I only used one 1.350 stainless bbl, it is on the first proto type rifle i built in 2002, i use it as a test rifle only.
Being a custom rifle manufacturer i have to err on the side of caution. The size of the case vs the bbl shank, and total chamber pressures, a larger shank is more stable. I'm not saying a 1.350" stainless bbl is not safe. The added .050 material don't amount to too much extra weight. It adds chamber area stability. This is why you need larger bbl tennons as well. The 408C-T case is a whole new ballgame, special designed for high pressures and large bullets. There is a lot of thrust on the locking lugs and abutments, some of the early actions that were made for the 408 in testing were having problems with "lug set back" from the high chamber pressure and small dia lugs. 1 3/16" x 16 tpi threads seem to be the perfect size for the 408 based cases.

Dave

[Fiftydriver]

BD408,

Hopefully one of these days i will get around to designing and shooting one a wildcat based on a 408 case!! [img]/ubbthreads/images/graemlins/grin.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

Oh I forgot, I have two up and running and two more in the works!! Good points you make though I feel 1.350" of barrel shank is plenty. The tenon diameter is more critical in my opinion and of course the receiver bolt lug strenght and bolt lug recess integrity are very critical. In talking with several barrel makers offering 408 class barrels, they all said 1.350" was minimum with stainless barrel for high pressure 408 CT load. I guess there are alot of opinions out there.

Maybe someday I can get some experience with the 408 case. [img]/ubbthreads/images/graemlins/grin.gif[/img]

Kirby Allen(50)

Kirby Allen(50)

[B.Stanley]

Good looking gun Kirby. You should be abel to reach out and touch something, and in such a light package. Which bullet are you planning to shoot?

Ben

[Black Diamond 408]

I'm tring to remember who contacted me asking about the 408 wildcats and info on how to do them? [img]/ubbthreads/images/graemlins/grin.gif[/img]

[Fiftydriver]

B. Stanley,

I will be using the 750 gr A-Max and the 750 gr SBS ULD RBBT Wildcat Bullet for the long range 50 AT rifles.

Kirby Allen(50)