BillyGoat Machine Mach V (375/50) Build

[LynnJr]

With all the hoopla about the King of Two Miles and our regular 2000 yard matches getting more and more shooters drilling the gong with more regularity I realized I needed a new gun to stay somewhat competitive with all these new Shooters.

I contacted CalGuns regular Skkeeter at BillyGoat Machine and got the wheels of progress turning.
He had an opening for Monday 7-1-18 so I drove up to his shop and we(Skkeeter) built me a 375/50 BMG or Mach V.
Again I don't take good pictures so bear with me on this project.
First thing was to remove the old barrel which meant he needed to saw off most of it so he could chuck it up in his lathe and cut off the shoulder. He used his band saw and in a couple minutes he was chucking it up in the lathe removing the shoulder. After that one good wack and the action spun right off.

Next he put the barrel in the lathe dialed her in and cut the tenon then the Cone for the bolts nose then the threads.
Once that was done he got out the big boy collet for the 3/4 inch reamer shank and started cutting the chamber. Making 0.050 passes on a chamber almost 4 inches long and constantly checking on his progress took quite alot of time.
Next he reversed the barrel redialed everything back in and cut threaded and timed the K-P Clamshell muzzlebrake.
Last thing to do was to mark the barrel and put the BillyGoat Machine logo on it pay him for his services and make the drive home.
The pictures are poor quality but they show the process.

[LynnJr]

More pictures.

[jconfus]

1st in line to shoot it for free .....

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[diver160651]

More pictures.

[sigstroker]

Any pics of a case? Is it short/fat with a long neck in the Creedmoor vein?

[MongooseV8]

You better start lifting weights right away. Thats the heaviest hunting rifle Ive ever seen.

[sigstroker]

[LynnJr]

Here are two cases before fireforming. One has a 350 grain Sierra MatchKing the other has a 400 grain Warner Flatline.

I will weigh it once it's bedded and has the scope installed but I have actually hunted with two guns that weigh more than this one.

[jconfus]

Here are two cases before fireforming. One has a 350 grain Sierra MatchKing the other has a 400 grain Warner Flatline.

I will weigh it once it's bedded and has the scope installed but I have actually hunted with two guns that weigh more than this one.

Holly mama

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[sigstroker]

Why isn't the .50 BMG used? Not accurate enough?

[LynnJr]

The 50 BMG is used but everyone is after a ballistic advantage if they can get one.
A typical 800 grain monolithic solid has a G1 Ballistic Coefficient of 1.18 and depending on the barrel and powder used will run 2650-2900fps.
The 375 Flatline bullet has about the same G1 BC number but in a case this big you can push it 3500+ FPS.
That is huge but the brass doesn't live long and neither do barrels.
Machining and the barrel blank run $1500 and I will get 5-6 matches out of the barrel.
Brass is $5 a piece primers run 50 cents each and bullets are $3 a shot. If you total up the cost involved and divide by the number of matches you get an idea of how expensive this sport gets and I haven't bought a new lathe or mill like some shooters.

[sigstroker]

Well, you guys can't have machine guns, so I guess you have to find a different way to spend ridiculous amounts of money on shooting.

[BillyGoatMachine]

I agree, this thread has the best quality pictures that Lynn has taken to date!!

Lynn, if you get your own lathe, I'll go out of business lol.

Always a pleasure having you in the shop.

[LynnJr]

Here is another picture that hopefully better shows the size of the Mach V or 375/50.

300 AAC Blackout or 300 Whisper.
338 Norma Ackley Improved.
375-50 or Mach V

SigStroker.
I am such a lousy shot I need all the ballistic help I can get.

Skkeeter
I fireformed some brass for the 338 Norma Ackley Improved and shot 5 rounds downrange in the backyard. Fireformed with cream of wheat and the first 5 shots I spent cleaning the barrel after each shot. Group was around 3/8 while cleaning between each shot.
I plan on getting to the range soon and will post some pictures of other shooters giving it a try.

[sigstroker]

Don't wildcats usually have a sharper shoulder?