Where’s the 12.7 Blackout?

[JoshPutman]

It would be sweet to see one of these rounds show up on Texas Plinking's 1000 yard challenge.

 

[cas6969]

I also bought yet another mold, 700gr flat nose to....

Ah, I thought I had a picture.

 

[MO Fugga]

Ah, I thought I had a picture.

View attachment 8424414

Makes me wanna dust off the ol 4-20

 

[dk17hmr]

This is what I did. Cut them at 2.100. That allowed seating a 690gr SA ball slug at the cannalure and plenty of room feeding through Rem 700 LA Mag after a few tweaks to the follower. Thought I was clever but just reinvented the wheel. As I remember Trailboss velocities were low so I went to Unique, 2400, VV340. All have a good sub spot but I do use a coffee filter "wad" to keep the powder against the primer. I see about a 200fps difference from Gordon's predictions. Will try VV110 next. Got sidetracked on a 250gr .338 slug in a 5.56 case feeding from a standard mag in an AR. Looks good so far. Attention span of a gnat.

Thank you,
MrSmith

My razorback is 2.375" I think. I use 50 Alaska dies. Sounds like your a little closer to 50 Alaskan.

I mostly shoot 500gr cast bullets from it. NOE has a 850gr mold I keep thinking about but for as much as I play with it the 500gr lee 50-70 bullet is good enough.

 

[45-90]

I don't think a Lapua-sized bolt face will work in an AR10.

If you have a lathe, they will absolutely work in an AR 10.
Just turn the case head to fit the standard .535" mag bolt face, and recut the extractor groove...done.
Rebated rim and it fits into an AR 10.

I machined some for AR 10 but saved the 510 whisper project for a bolt gun, and 3.7" long cartridges and turned this AR 10 .510 whisper project into a 338 Ruger Compact Magnum, and now have 18" AR 10 338 magnum.

 

[biffj]

Sorry Dogtown, I don't remember the company that made my trimmer. I got it from Sinclair and its gold anodized....I'll have a look tomorrow. I did make up a pilot for it so I can trim without resizing. It fits the case mouth after I run the expander into it. Works great with a battery powered drill.

I've built some AR10's in 338BR and they work great but I'm a little leery of opening up the bolt face for the larger case heads. I'm not that interested in the ARs anyway so haven't pushed it.

Frank

 

[45-90]

I use a Bridgeport mill, with lever collet closing fixture, set up with dead lenght collets, to trim to exact length.
Cut time, about one second to trim to length.

 

[45-90]

My 510 Whisper boltgun is done, in two days after... converting the AR 10 project to 338 RCM, and testing loads for it, it was a total sucess...running full power 338 RCM loads through a 18" barreled AR 10.
Barrel of the 510 Whisper is 25.75" to take full advantage of the light copper bullets available for supers.
I ain't gonna run a suppressor, the extra barrel weight will help with the recoil, and put the blast away from the shooter...kind of.
It was a bit more involved than a standard rifle build, of chambering, threading, etc. Bolt modifications, fitting the bolt, fitting the extractor, slight magazine mods to the 338 MDT Lapua mag 3.715" it feeds the long 750 Amax from the mag.
Gonna set up to make 100 or 200 cases. Made 10 cases just for fun, and a dummy cartridge to check feeding, and one modified for the Hornady case gauge.
Then on to load development.

 

[45-90]

Trim to exact length in the mill, with a dead length collet in a lever closing fixture.
Light ID deburr, in the lathe for neck turning.
trial and error working with the FL 510 Whisper die, to get it exact and Your rifles chamber.
Lube with Lee sizing lube, and run through die.
Check in homemade gauge with tbe reamer that made the rifles chamber
And you're done.

 

[45-90]

So I shot my 510 Whisper about 80 rds today.
Here's what I found, newer, 612 GR APIT pop on impact on every shot even with muzzle velocities down to 780 fps.
Totally fun to shoot, see the impact flash in the scope then the "pop" report.
Low velocity equals low recoil.
The all copper, Cutting Edge .510, 350 gr handgun bullet, was tried ...it was accurate and produced 2447 fps with 4700 ft/lbs of energy for a nice supersonic load.
Recoil was less than the supersonic 647/650 fmj bullet.
A fun day at the range.

 

[Rumlover]

If you want to go through all the aggravation to make 510 Whisper, go for it. If you want easy, get a 50 Alaskan. Starline makes brass.

 

[45-90]

I

If you want to go through all the aggravation to make 510 Whisper, go for it. If you want easy, get a 50 Alaskan. Starline makes brass.

Starline is always out of 50 Alaskan brass, made from 348 Win... that is rare too.
If one adds power accessories to the making of the .510 Whisper its easy..
Just made 100 of them a few days ago. Starting another one hundred today.
The rim of the 50 Alaskan is more for lever guns, which doesn't have the length in the action for long 650 gr plus bullets.
Mostly it's single shots proposition, with fast twist and throsted for 750 gr bullets. ...not boltguns with magazines.

For a single shot it would do the job with a fast twist and long throated barrel.
But the 50 Alaskan Starline brass is not readily available, I heard that Starline was 6 years behind in brass orders, filling the most common.
I got all the brass for making 510 Whisper for about 65 cents, for 600 Norma and $1 ea.for the 200 Lapua cheaper than Starline price for the 50 Alaskan.
But you can have your brass now, and if one adds some motor power to the process it's pretty easy. The box on the right was fired yesterday. A box of new brass started today, with a few minutes work.

 

[Dogtown]

You guys motivated me to try something besides pulled M33 Ball. Kind of surprising that it has that cavity in the base.

 

[biffj]

A few reasons for the cavity, first it moves the CG of the bullet forward which can help stability. It also can help the bullet expand into the rifling. I've heard some other reasons but many seem odd. My guess is you won't get any better engagement if you're loading for subsonics. Not enough pressure....
I found the turned solids worked much better in my 33XC. Accuracy was more consistent and I wasn't spinning the jackets off them.

Frank

 

[45-90]

So here is the 510 Whisper, and load data done today.
Photo of loads fired and recorded...
650 fmj resized pulls
Enlarge ...to see ..., for powder in grs, powder type, and velocity.
Needs adjusted for your barrel length and chamber....most were a bit high for subs.

The 750 Amax were all around 1200 fps with two surprises LilGun, and CFE BLK.
The Two loads off to the side are max for my rile chamber, H335 & W748....at 3.600" COAL do not load shorter, as pressure increases to dangerous levels.

APIT "pop" at the low velocities of 800 fps and probably around 600 fps.

They don't damage AR 500 plate at 900 fps
somewhere around 1100 it damages the armor at 1350 to 1450 the armor piercing start to work, penetrating the armor at 100 yds.

Have a place with nothing will burn and after a few hard rains before just going out shooting these. They are dangerous.

This 510 whisper is one of the most fun sub/ super calibers.

2000 ft/ lbs at 1000 yds with the 750 Amax at 1525 fps or the same energy with the 1002 gr copper bullet at 1100 fps .
350 gr copper are capable of 4700 ft/ lbs at the muzzle for hog or bear hunting.

The last is just a 50 yd 9 shot one ragged hole with imr 4227 and 650 gr resized pulled bullets ....two sighter on high, over adjust low, then shoot 10 ...the 10th was off to the right, the bullet or the shooter who knows.
Also, the barrel gets hot shooting these and the APITs ...you can not touch it, but for a fraction of a second.

 

[45-90]

Minimum impact velocity to detonate is 1500fps, used to put them in a handwarmer in winter to get a bang an longer ranges. Sorry, no joy at subsonic

Totally not true... I shoot a 510 Whisper. Never had an APIT fail to detonate at low velocities in the 800 to 850 fps muzzle velocity, when impacting at 100 yds down range....even really old resized pulls, go bang.
I believe they will detonate at 600 fps out of my 10 twist 510 Whisper.

Stay under 1000 fps, not to damage AR 500 steel plate, with 100 yd impacts.
It really starts to penetrate at muzzle velocity of 1350 to 1450 fps.
Total plinking fun at 850 to 900 fps, low recoil, with a bang at the muzzle, and a flash and pop come back.

 

[CoryT]

Totally not true... I shoot a 510 Whisper. Never had an APIT fail to detonate at low velocities in the 800 to 850 fps muzzle velocity, when impacting at 100 yds down range....even really old resized pulls, go bang.
I believe they will detonate at 600 fps out of my 10 twist 510 Whisper.

Stay under 1000 fps, not to damage AR 500 steel plate, with 100 yd impacts.
It really starts to penetrate at muzzle velocity of 1350 to 1450 fps.
Total plinking fun at 850 to 900 fps, low recoil, with a bang at the muzzle, and a flash and pop come back.

APIT is not the same as Mk211

 

[Dogtown]

Mmmm…Whisper Raufoss would be neato.

 

[45-90]

APIT is not the same as Mk211

Send me a few Raufoss bullets and we'll find out, at the lowest speed they detonate on the armor plate.
Detonation occurs 100%, even with APITS bullets that are really old resized pulls from wars gone by, not to mention the new bullets, available.
I don't see why the Raufoss round at their ridiculous high price would be any different. But it'd be a fun and expensive experiment...haven't tried a supersonic sabot either.

But even if it takes 1500 fps, its covered in the longer barreled 510 Whisper as I shot the 750 Atip over 1500 fps, for a short range super load

APITs are cheap, available, and fun to shoot, and detonated easily at very low speeds, on a variety of surfaces.
A hoot to shoot, for plinking.

 

[biffj]

I've had API and APIT pop at 800 yds when fired subsonic to start with. The key is hitting a hard target. They won't pop when they hit the ground unless they hit a rock at those speeds....

Raufoss is a completely different animal. Never shot any of them as the live rounds were worth too much to disassemble for a bullet.

Frank

 

[Dogtown]

@biffj what’s your take on using .338 NM cases to form .510 Whisper brass? I was asked this earlier and didn’t have a good answer. Part of me thinks “yes” because same bolt face and similar case length to shoulder, but it does have more taper than .338LM and might be more work to remove?

 

[biffj]

I hadn't thought about the Norma Mag but it might work fine. The taper should come out when you run it into the expander die for the neck. Any body taper should fireform. I guess the only question is the wall thickness of the cases. I don't know if they're any different than the 338 Lapua. If you've got some cases give it a try. I'll bug a buddy for a couple scruffy cases to test too.

Frank

 

[Dogtown]

^^ @Thunderkok

 

[45-90]

The 300 NM is the perfect case for the .510 Whisper....I have used 338 Lapua, and even 416 Rigby.
But as you can see the 300 NM made perfect for the .510 whisper.
Just cut the neck and shoulder off, still partially annealed...works great just did 200 pcs.
I trim to exact length in the Bridgeport mill and collet fixture, very fast and accurate with Hardinge dead length collets installed.
Then off to the lathe neck turn, I use a carbide tool with a 41.5° angle.
Lube and size in FL sizing die, then I check in my go gauge, made with the reamer that cut the chamber.
Works great.
For those who do not have machine tools it will take more effort by hand, but the 300 NM case, for me, is the perfect case for making .510 whisper.

 

[45-90]

The 300 NM is larger in dia than the 338 Lapua mag, at the shoulder, a perfect fit, the Lapua is .010" smaller. So no mandrel up is needed,...its like it's already fire formed.
Here is Fired. 510 Whisper case .565" at the shoulder, new 300 NM .565" aprox where the .510s new shoulder will be...maybe even sizes it a bit with the FL die, for a perfect fireformed fit the first time.
So that's why it's my favorite, plus ease of making with machine tools.

 

[45-90]

As far as APITs go, I've had 100% detonation at subsonic speeds, on everything from plywood, very light sheet metal, gravel pile, dirt...but there is always a rock in the dirt around here.
This sheet metal pipe is .020" thick they would detonate on this, blowing out the back side... I have been surprised at how little it takes. It just has to have enough hardness. A tin can?
Wondering about bone ?

 

[biffj]

The feds spent a bunch of your tax money testing the raufoss bullets on pigs to insure it wouldn't go off on hitting bone. I'm guessing the API and APIT won't pop either.

Frank

 

[Emerson0311]

View attachment 8423935View attachment 8423936View attachment 8423937

Reminds me of 43 Egyptian.

 

[45-90]

The feds spent a bunch of your tax money testing the raufoss bullets on pigs to insure it wouldn't go off on hitting bone. I'm guessing the API and APIT won't pop either.

Frank

It would be interesting, if we had any "varmint" pigs to test on around here, or a big bone from a cow, would be a more practical test, and hunting anything but varmints would likely be illegal.
But the government probably doesn't want them to detonate on humans because of excess destruction, making for "war crimes" charges....maybe,... but they use other weapons that other countries have signed off on not using, like cluster bombs.
One never knows unless one tests...
Could the tips be altered? Thin the tips?
Seat the bullets and they detonate, one could get carried away...
Probably no practical purpose for that, as they are fun for plinking just as they are.