.408 CheyTac Initial Test Results

Len Backus

Staff member
May 2, 2001
This is just a FYI, but I thought you guys might be interested.
We just completed a week long trial series with THEIS's new .408 CheyTac in a cutdown EDM Windrunner. Here are some of the numbers.

Cartridge: .408 CheyTac, 419 gr. projectile
True BC. .903
Ave. MZ Vel. 2890 fps.
Accuracy <1 MOA to 1900 yds.
1.5 MOA 1900-2400 yds.(errors were wind induced horizontal. Max ordinate at 2400 yds. is 52 ft.)
First shots at each range to 1900 were within 60" high by 20"wide box. The rifle was disassemble the scope taken off, the barrel cleaned, the scope base was remilled to 76 min.( to center the optic field). Then the rifle was reassembled, zeroed at 200 yds., and then immediately shot for a 3-shot, 39" group at 2300 yds., on target and 9" left of center. I don't believe I have to emphasize to you guys how amazing that feat was. The shooter was Dean Michaelis of S.O.E.

Supersonic Limit: Greater than 3000 yds.(3000 was the range limitation)

[email protected] http://www.lostriverballistic.com

posted April 21, 2001 10:29 AM

Len Backus

From: Oshkosh, WI
Registered: April 10, 2001
Posts: 19
Simply amazing!
I know this "projectile" is your own Lost River Ballistic bullet developed in a new caliber just for this special project.

Trivia question: During the new bullet's development, how many bullets did you make, test and discard before you were satisfied with the result?

posted April 21, 2001 09:12 PM

Warren Jensen

From: Arco, ID US
Registered: April 12, 2001
Posts: 7
.408 Chey Tac
In today's world of computers we are able to simulate manufacturing, loading, and firing to a very close degree of accuracy. In the computer simulations we worked through "hundreds" of possiblities searching for the optimum combination of velocity, trajectory, and accuracy. We did a pretest with a prototype last fall that eliminated a number of questions that we had. When we got the first production rifle, XM01, we got it with three different barrels with different twists and bore and groove diameters. The questions during this week long test were which barrel would produce the optimum results. We learned that very quickly in the week, and then we put that barrel through it's paces.

I think one thing that we have finally put to rest is the old concept that long, pointed bullets, with meplates down to .02" cannot be shot accurately, especially at long range. What we have shown is that if the bullet, load, and twist combination is tuned correctly you can get unprecedented performance at long range. That .903 BC at the muzzle is actually increasing at 2400 yds. with the .408 projectile.

The rifle was in a tactical, day/night, combat configuration. Many of the finer points of competition accuracy, such as finer set triggers, finer scope reticles, and a tighter chamber would reduced the group sizes measurably. Improved methods of measuring winds a mile down range and fifty feet in the air will help the accuracy beyond 2000 yds. A discrepancy of 1 mph. in wind correction moves the group off the target. There were a number of recommendations we will make in the support equipment area that will improve the ultralong range accuracy.

After working at beyond 2000 yds. we came back to some material tests at "short range". We termed shortrange to be anything under 1000 yds. We did some masonry tests at 400 yds. in which we asked Dean to place the bullet in certain parts of a cinderblock. He was able to do this without any difficulty. Longrange became relative. By the way, he never used a bench. All of his shooting was off the ground with a glove as his butt bag.

[email protected] http://www.lostriverballistic.com

[This message was edited by Warren Jensen on April 22, 2001 at 11:50 AM.]

[This message was edited by Warren Jensen on April 22, 2001 at 11:51 AM.]

posted April 22, 2001 11:42 AM

David P. Herne
New Member

From: Houston, Texas (USA)
Registered: April 11, 2001
Posts: 2
.408 Cheyenne Tactical
What a splendid accomplishment!!! When I asked Dean how this rifle would compare to the .338 Lapua Magnum and .50 BMG, respectively, he said; "It's gonna blow'em all off the face of the earth!" Would have paid just to have been able to watch the tests. I commend you and the whole project team.
Hope you and Dean will put a little bug in Mr. Ritchie's ear about us left-handed shooters. I know their looking at doing a run of Windrunners in left-handed configurations, but I'm not too interested in a .50 BMG next to this little monster. Unfortunately, Keary at EDM Arms said they aren't even considering this for Intervention.

Dave Herne


posted April 24, 2001 05:49 PM
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