375 Remington Ultra Magnum necked up to 50 caliber (.510)

Wow Bravo 4, that looks great. What ballistics are you getting out of this cartridge ? If it's within the fps range I'm looking for I will have to talk to you about your wildcat . And just wow with that short of C.O.A.L. I wouldn't have to use a long action either.
 
It isn't my original idea, Google .50 Razorback. The guys that originally made them weren't around long and only made a few rifles. I tracked the company owner down and he didn't care if I made my own. After going a few rounds with PTG and a couple different gun builders, I finally got it all together. My chamber is just a little different in case length.
I run this one subsonic/suppressed for the most part with 725 grain Lehigh subsonic fracturing projectiles...very nasty terminal performance!
However, I have pushed the 750 Amax to 1750 fps with no pressure signs in a 16" barreled Savage long action. May have went higher, but didn't push it. Unsuppressed and unbraked made recoil pretty fierce in such a small rifle. With longer bullets it has to be ran single shot and with the Amax the bolt has to be pulled slightly for a round loaded out (had it throated for the longer bullets). With these lighter-short hunting bullets it will feed from the factory magazine.
 

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Thanks again Bravo 4, I wonder if a longer action could be used so that it would feed and eject out of a magazine without any problems. I forgot just how long those Amaxes are, even if the case was 2.1 C.O.A.L. exactly it might still have feeding and ejecting issues. The main reasons that I went with the 750gr Hornady Amax was 1. The incredible B.C. of the bullet, and 2. They are expanding bullets so they could be used for hunting.
 
My project for this will be on a long action Weatherby Vanguard. The only thing I don't have is the reamer and barrel.

Oh and time....
 
375rifleman,

Basically I'm wanting to send a 750gr Hornady A-Max to 1800fps-2000fps range, out of the shortest possible barrel length without getting into SBR's so 16"-20" barrel length as cost efficienct (using as common components as possible) as possible.

Here is just about exactly what you're looking for:

B & M Rifles and Cartridges - 50 B&M

This .50 B&M is set up for .500" diameter bullets, not the .510 but that's a simple change if desired.

The other that I've built is the .50 Battleship. You can contact Josh at Copper Creek:

Copper Creek Cartridge Co.

I have built several on the .460 Weatherby case which has been called the .510 Wells Express. This uses the full length case and has the 750 grain AMAX seated out for the most powder space at 4.750" approximately. Re-17 will net you about 2000 fps. with a nearly full case on a 20" barrel.

Regards.
 
Thanks sable tireur, I'm wondering wether or not a modified .50 B&M would have a 1800fps-2000fps velocity with a 750gr Hornady Amax ? What rifle action are you using with the .510 Wells Express ? I'm want to use a detachable magazine fed bolt action, possibly in a Tube Gun configuration with an integral suppressor.

375rifleman
 
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Thanks sable tireur, I'm wondering wether or not a modified .50 B&M would have a 1800fps-2000fps velocity with a 750gr Hornady Amax ? What rifle action are you using with the .510 Wells Express ? I'm want to use a detachable magazine fed bolt action, possibly in a Tube Gun configuration with an integral suppressor.

375rifleman

I highly doubt that it'll get the velocity you want, especially in a shorter barrel. The 50 B&M case is based on the RUM but cut shorter than what I use.
 
375rifleman,

I highly doubt that it'll get the velocity you want, especially in a shorter barrel. The 50 B&M case is based on the RUM but cut shorter than what I use.


Here is the .pdf that they supply for load data for the 50 B&M:

http://www.b-mriflesandcartridges.com/upload/Gen Load Data 50 BM 1302013.pdf

You can judge for yourself.

As for the .510 Wells Express, we were using the case full length with the bullet seated out quite a distance. In reality, this combination will not fit in any standard magazine. However, if you are looking to use this for hunting, several of the best bullets outside of the 750 will fit in one of the extended magazine available for chassis.

Accurate Mag makes magazines to accept 3.850" OAL cartridges. Using a 600 grain Woodleigh seated to 3.750", you can load VVN-133 (cool burning powder) to a full case and achieve just a pinch less than 2,200 FPS. You can load slower powders to get less velocity but you may not achieve a complete burn in 20" barrels.

Regards.
 
The reason that I wanted to use the 750gr Hornady Amax was its incredible ballistic coefficient so that reduced velocity while still keeping a flatter trajectory and it's heavy enough at 750gr for increased down range energy.
 
Sable,
I gotcha about the B&M chamberings. I did my homework before I made my choice, with months of research and calls to several builders before I made my choice. I spoke with Delta Company Arms, SSK, B&M and several other builders. B&M was not interested in making me a .510 version of the B&M or MDM. If I had to do it all over again (and stayed with my Savage long action) I would have made the case 2.25" like the .50 B&M. I run it subsonic for the most part. However, if speed is what you want then the longer case is obviously gonna get more. More case for more powder and less intrusion of those long freaking Amax boattails.
 
I bet that a Bat Machine action would work considering that they have actions ranging in size from 223 or PPC to 408 cheytac or 50 BMG. I just don't know if there would be any detachable box magazines compatible with the .510 Wells Express. Because if the 510 Wells Express can send a 750gr Amax 2000fps it would be ideal for me. What does everyone think ?

375rifleman
 
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