Kirby, I was reading an artical by CheyTac Associates and they will be relasing the 375x408 CheyTac soon. What do you know about this, and are you thinking about adding the 375x408 Cheytac to the Allen Mag family. I am thinking you probably already thought about this, but due to poor bullet selection you decided to go with the 338 Allen Mag. I think I remeber you saying Sierra might be making a 350grn Match King, or that somebody was making a bigger bullet with better BC for the 338 caliber.
I was just curious. By the way, I am ready to send some MONEY [img]/ubbthreads/images/graemlins/shocked.gif[/img] for my 338 Allen Mag project to get underway. I am just waiting for the e-mail, so we can get this project finally started.
Not Kirby, but I started promoting that cartridge. Others had made it first, such as Barney Lawton, Bill Shehane, etc. Cheytac only responded to the potential of that cartridge when I posted on my website and information about it. I was a former owner in the cheytac group, but walked when bad management took it over and is still driving it into the ground. Cheytac may be releaseing it in their line, but it is NOT their idea. Lately, they seem to be mastering the idea of idea stealing, then releasing a press release as if it's their own idea. I've built 3 of these 375 rifles, will release brass with a headstamp indicting credit in a different direction than Cheytac.
3 years ago, a couple of us in the company proposed the idea of 408 based cartridges and was laughed off. Now, someone wants to grab headlines by making it some novel idea. Not true. It is a great cartridge, destroys the .408 and yes, the 338/408 based guns. Supersonic range of the 375 is around 3000 yards, 2800 better than the .408.
Driving the 338 300 gr. matchking at 3300 fps still only yields 2200 yards of supersonic range. The 375 is 800 yards superior.
On the M310. It's a fine rifle in .408 CT. The only fault i find with it is the bipod mechanism that is supplied with the gun. They use the harris short BR version. It's too near the center of the gun, with too much gun weight on top of it, makes it floppy and tough to manage.
It's a very accurate rifle, barrel and action by Barney Lawton in Dillon, Montana, CT puts it together in idaho. They use a 29" barrel, and get a speed of about 2900 fps, with a supersonic range of 2200 yards. Good setup, bad bipod.
[/ QUOTE ] why would you load down the 338 -408 to what is abtainable with a 338-416 imp? the 338-408 will easily hit 3500 with the 300 grain mk
d-a... The supersonic range is not much gained by adding velocity, it's more BC value based. The faster you drive a bullet, the faster it also slows down, and the SHAPE of the trajectory is what changes the most. Flatten out the rising branch of the trajectory, you get a steeper fall angle on the falling branch end of it. For long range work, in unknown distance conditions, you want a more even shape to the curve, hence speeds NOT exceeding 3050 fps or so. BUT, if you only intend to "work" in the front end of the trajectory to get maximum use of the "flat" trajectory, push up the speeds, and don't shoot past maximum ordinate range, which is about 65% of the range of the shot.
On the 338 Lapua using a 300 gr. SMK, at 3300 fps, you get a supersonic range of 2200 yards at sea level standard conditions. Drop the velocity down to 2900 fps, you get a supersonic range of 1970 yards under standard conditions. By hammering up the speed to 3300 fps of barrel eating speed, you only gain 130 yards of supersonic range.
Worse yet, your falling branch is steeper, making range determination much more demanding. High speed only means two things in reality:
1. Faster barrel burnout
2. Long range unknown distance shooting much more difficult past the maximum ordinate range of the shot.
As for your speed of 3500 fps, you are past the point of diminishing return. With that speed, your supersonic range is actually 50 yards LESS than at 3300 fps. The faster you push it, the faster it will slow down.