50cal WSM

[375rifleman]

Increasing the muzzle velocity to 1850 fps completely defeats the purpose of the questions and of the cartridge itself. Which is Large Bore Long Range SUBSONIC. If one was to have it at1850 fps it would be supersonic and that person could just use conventional methods of scope mounts and conventional scopes.

 

[RockyMtnMT]

In my conversation with a gentleman that has spent a lot of time shooting for accuracy with the 300 blackout. His opinion is that bullets starting close to the supersonic mark at in a disruptive state when they leave the muzzle. He said he could get better accuracy if he started about 900fps. This makes sense as the sound barrier is not a finite line. It is an area of speed that causes disruption going into or out of. Thinking about all the aircraft testing trying to break the sound barrier. The stresses on the aircraft got bigger the closer they got to the mark.

I think for a projectile to be accurate under the sound barrier it must have enough weight forward in order for the orientation to stay put. Like an arrow. The heavier portion of the projectile is always going to try and lead the way. The spinning is the equalizer, but the struggle is still there.

So my opinion is good accuracy is going to be very difficult with a normal projectile. Load them backward and you may see better accuracy.

All theory on my part as I have not tried any of it.

Steve

 

[TXAoudadKlr]

I had a long conversation with a fellow using the 300 Blackout. He was talking about a group of guys that were competing with each other long range. They were able to keep some fair accuracy to 200y. That was their threshold. My thought on this is it will take a different bullet design to get better accuracy down range.

Steve

For a supersonic application could you scale up the 300BLK bullet you offer to .510? Be pretty sweet in my opinion sling a 400ish grain bullet 22-2400FPS of that diameter. 510 black out...sounds cool to me

 

[Bravo 4]

I believe that a cartridge designed for subsonic velocity will be better for longer range accuracy than one that can simply be loaded down to sub velocities. It's hard to get consistent velocity with a lot of unused case or lots of trailboss powder. I have been using lil'gun and a filler. I wish I would have made my case shorter but wanted to also run supersonic, in case I ever wanted to hunt a pachyderm. Accuracy at 100-200 is acceptable but goes to crap past that. I think at the ranges you are wanting that minute of house should be expected. As much as you have researched this you could have already built your rifle and thoroughly tested everything. Sometimes I don't mind being proven wrong.

My barrel is a really fast one for a .510 caliber. I have also (as RockyMT stated) loaded spritzer boattails backwards and had better accuracy.

 

[RockyMtnMT]

For a supersonic application could you scale up the 300BLK bullet you offer to .510? Be pretty sweet in my opinion sling a 400ish grain bullet 22-2400FPS of that diameter. 510 black out...sounds cool to me

Yes we could make that bullet. I simply do not have a way to test it. Would certainly make a heavy hitter out to 200y or so.

Steve

 

[Bravo 4]

Yes we could make that bullet. I simply do not have a way to test it. Would certainly make a heavy hitter out to 200y or so.

Steve

I'd be happy to test some subsonic .510's for ya.

For practice I use either pulled API or ball, for hunting I've been using the Lehigh subsonic fracturing projectiles. Originally I was gonna use the 750 grain Amax but for the price I get waaaay better terminal performance with the Lehighs. The Amax has got a gigantic BC advantage for longer ranges.

 

[Deleted member 46119]

I'd be happy to test some subsonic .510's for ya.

For practice I use either pulled API or ball, for hunting I've been using the Lehigh subsonic fracturing projectiles. Originally I was gonna use the 750 grain Amax but for the price I get waaaay better terminal performance with the Lehighs. The Amax has got a gigantic BC advantage for longer ranges.

What twist rate do you use?

 

[Bravo 4]

What twist rate do you use?

Mine is a 1-8" twist. When ordering the barrel this is what John Krieger recommended and made for me. Not gonna argue with him about barrels or twists.

 

[ohnomrbillk]

I'm more interested in a 458WSM

A friend of mine did this with efforts to maximize 458 in a short action. He held a 458 Socom die 0.5" above the shellholder for case forming. It worked well. Necking the cases up to bigger than 458 first allowed for a shoulder for the minimal fire form.

If you were going for subsonic, plain 458 Socom is easier. You can also size down WSM brass the the 458 Socom die in conventional relationship with the shellholder. It essentially results in 458 Socom with a magnum boltface instead of a 308 rebated head.

 

[ohnomrbillk]

I had a long conversation with a fellow using the 300 Blackout. He was talking about a group of guys that were competing with each other long range. They were able to keep some fair accuracy to 200y. That was their threshold. My thought on this is it will take a different bullet design to get better accuracy down range.

Steve

I've found Mr. Corbin to be correct in his statements here on subsonic projectiles

Corbin Bullet Swage Dies

 

[RockyMtnMT]

I've found Mr. Corbin to be correct in his statements here on subsonic projectiles

Corbin Bullet Swage Dies

Interesting that he liked the rebated bt for subsonic. I know in our testing with supersonic bullets the rbbt did not work well.

I'll say again that I claim no expertise in sub sonic drag. But my mind says better accuracy would come from a projectile similar to a pellet from a pellet gun. Seems to go along with Corbin with the large front and tapered back end.

Steve

 

[Deleted member 46119]

As far as I can determine and I'm no expert: For sub-sonic, the consensus is CG (Center of Gravity) forward. Supersonic is CG rearward.

I do know that this is consistent with aircraft flight. As the speed increases the center of pressure moves rearward. CG and CP have a significant relationship in stability.

I make the supposition then that the rebated boat tail pushes the CG forward making sub-sonic stability more likely. Our VLD type bullets intended for multiple mach numbers are CG rearward. We know that they experience instability slowing to close or below mach 1.

I do a bit of playing with sub-sonic loads. 30-30, 30-06, 45-70, 7.62x54R, 8mm Mauser. The bullets for all these are neutral CG. Accuracy is from great to acceptable for plinking.

Time and money will get me a 50 WSM (or similar) setup. Maybe a 458 WSM using the SoCom dies is the way to go.

 

[Deleted member 46119]

I can't find 458 projectiles that match the 50s.

 

[ohnomrbillk]

I can't find 458 projectiles that match the 50s.

.458 SUBSONIC - Outlaw State Bullets LLC

https://www.lehighbullets.com/product/458-510-458-subsonic-controlled-fracturing/

https://www.makerbullets.com/proddetail.php?prod=458500S