Here's my experience with the Cheytac, not that anyone cares

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I looked into buying a 50 cal a few years back and was worried about the cost and availabilty of components at the time. I'm not sure what the situation is right now but I hear it's not much better.
I then looked into getting a 408 Cheytac built. The more I looked into it the more I wanted to go with a .338 Cheytac wildcat. After talking with several people who have them, the one concern is barrel life.
A gun builder in the states (Kirby Allen) recomended going with the .375 cal and he was working at the time with Jamison to resolve thier brass issues. I decided to go with his wildcat varient of the .375 cheytac called the .375 Allen Mag. It is an improved 408 (less body taper, sharper shoulder) necked down to .375.
I have not had much time to play with the gun yet but so far it shows promiss. With 350gr SMK's I am getting around 3100 fps. That is a light load, just breaking in the barrel and getting used to the gun. With the rocky mountain bullets I have on the way (375gr) I should be able to push them at around 3300fps or close to it. The new bullets have a B.C. of around 1, although George from RM bullets has not done enough testing to know the exact number, they are still very new. With this combo I should be getting about a 20% better tragectory than the average 50cal shooting an A-max, at least out to 2.5km or so.
As for cost I got the brass fire formed and stamped 375 AM right from Kirby for $4USD each so $5CND. The bullets come out to about $3.60CND each and the powder and primer come out to about 65 cents per round. The newer Jamison brass is good for at least 4 fireings (at least that is what I have been told) if it is not pushed to the max, so with the cost of brass factored in the cost per shot is around $5.50. Not sure what a 50cal A-max round is worth but I think it is a bit more, around $8 bucks depending on brass life.
The only downfall for the .375 AM that I can see is that it only delivers roughly 1/2 the energy that the 50 cal does. Not that it is really a downfall, I mean how much energy is needed for long range target shooting or hunting. At 2000m the .375 delivers roughly 1900ft/lbs of energy

. That's about as much as a .308 at 200m.
When I started out, I was looking for something to cut the wind as good as a 50cal and delivered a little more energy than the standard .338's like the Lapua and Rum. What I got is a flatter shooting gun that is as good if not better in the wind than a 50, and delivers more than enough energy out to 2000m to bring down any north american game (not that I'd try at that distance). It costs less to shoot than a 50cal and you don't need a special press to reload it, provided your using a RCBS Rock chucker or something that size.
The Cheytac may be a niche cartrige right now but it has been around for a quite a few years now and is still growing in popularity, at least the wilcats are.
Dave