.458 big bore mule test bed project (video added)

[lloyd-ss]

Amazing, the things coming out of "Lloyd's Laboratory"   

Glad to hear your still having fun.
Thanks for sharing with us.

Bill,
You bet.  The obsession is still a LOT of fun, especially when everything is working and forward progress is being made.
I hope you are doing well these days.
Lloyd

[lloyd-ss]

Marvin,
Sure thing.  That's what the GTA is all about.    

The spin of the bullet is definitely another factor that I really haven't done much with but I imagine it is more important in the "external ballistics".  Another thing that is hard to visualize (at least for me it is hard to visualize ) is that the instant the bullet leaves the muzzle, the acceleration drops from a few thousand 'Gs to a MINUS number (only a couple of -g's deceleration)as the speed starts to get scrubbed off.   Amazing what that bullet goes through!

Lloyd

[lloyd-ss]

I finally got back on this and made a video of it shooting a shot string.  Right now it has a .458 barrel, about 31" long, with a 380 cc air tank.   
Control of the valve dwell is all electronic.
Starting PSI  approx 3,200 psi.  ending PSI after 7 shots 1,133 psi.
405 grain bullets.
Average Velocity for shots 1 thru 7,   743 fps            
Average energy for shots 1 thru 7,   497 FPE   
         

[uncle paulie]

Great post Lloyd, Way beyond my thought processes for sure, but I'm sure to want one once the bugs are worked out. If you need a tester for the first production run, I'd pay a couple of hundred bucks for the privilege... as long as long as I could keep the gun, of course! 

pv

[jetmangd]

LLoyd-SS,

       Wow,  Super impressive Big Bore .458 you are developing there LLoyd. The Test figures are just Awesome with some
       Amazing Performance. Wow, 500+ FPE with a 404 Grain Projectile at 700 Plus FPS. Very Impressive LLoyd , No Doubt
       you are quite the Engineer and Designer. It is also Cool to be able to follow your Progression on this thread. Wow, What
       A Cool GTA Thread. And please Keep up the astonishing work and developments.


                                                                              Jetman

[melloroadman]

Impressive . Keep up the good work. Marvin

[lloyd-ss]

Thanks for the comments guys.  The controls and power plant I have in it now really like the .458 barrel with heavy bullets.  The 36" barrel was doing even better, but I wanted to put the shroud on it, so I dropped down to the 31" barrel and kept the same overall length. This setup actually likes to shoot a lot faster at the higher pressures, but the controller was able to flatten the curve out fairly well.  Even flatter would be nicer, but considering everything was made in my garage (including the electronics), I am ok with the results.
Marvin, getting the Lee sizing press has helped.
Lloyd