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Where’s the 12.7 Blackout?

It already exists, it’s the gigabased 510 whisper that I’m sure will get ripped off and rebranded by Q or Hornady when they need the reinvent the wheel
Ewwww…. Who wants to pull some MK211 projectiles and make some 510 Whisper Raufoss for me?

We’ll call it “Project Booming Whisper”
 
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510 wsm. Cheaper than a 510 whisper with all the fun. 650ish silver tip , 750 amax , 1004 ceb cast lead.

So… did you shoot the API? Did it do its “I” thing? What caliber brass?
 
Ewwww…. Who wants to pull some MK211 projectiles and make some 510 Whisper Raufoss for me?

We’ll call it “Project Booming Whisper”
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
 
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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
Fun sponge.

Assume API is similar?
 
Y’all need to stop pussyfootin’ around. 8.6 is barely more than 7.62. Time to get serious.

Seems natural. 750 AMAX in 12.7 BLK?

Hells yeah.

How does Raufoss work at subsonic?

1800s called and wants their 45-70 or 45 90 back...

Hand load up some 700 gr buffalo pills
 
12,7x55 AMOS. Developed as a sub-caliber trainer round for the 120mm Amos mortar turret. 338LM case cut below the shoulder and a .50 shoved in. Headspaces on the case mouth. The Vatniks copied it as their Sts-130.

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Feeding has never been an issue, but I did have to modify a .338LM mag to make it work. Not sure what the COAL is off the top of my head, but I think I just seat to the cannelure. I used N110 when I first started loading for it; now I use TAC. The only bullets I’ve used with it is pulled M33 Ball bullets and some Lehigh solids. I tried making a supersonic load but it got scary a little too quickly for my tastes. Those cast bullets @cas6969 poated look fun for supers.

@TheHorta the coolest thing when shooting non-exotic boolits in this thing is that it’s so big that sometimes you can see the bullet in flight on a bright day.
 
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I went with a 450 BM for my DTA subsonic thumper and shoot 500gr cast and 395 SubX. I use the SAC mid magazines and it feeds pretty good. I have a spare DTA mag bolt not doing anything so I might be tempted to do a 510 WSM in the future but I don’t have to time to make brass, which is why I originally went with the 450 BM - cheap Starline brass. 510 Whisper is still the OG.
 
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.510 brass making is annoying. No other downside I've seen. I don't have a lathe any more so no way to make more brass aside from the bit i have left. Have even considered getting out of it because of that, but it's so damn sick whomping steel with it lol.

Love it in the DT. Have considered doing a .458 socom before for the easy brass but haven't gone that route yet. There are some wild cast bullets available there too.

I guess cutting a 338 lapua case at the shoulder kinda sucks but totally worth it until you fuck it up lol.

Cbe in Australia makes a couple wicked cast bullet molds. Noe does now too I think.

I've seen the tracers light before. Can be iffy but can give a fun show if shooting out there a bit.
 
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APIT work at subsonic speeds, here, on light metal tube, also on plywood, and rock impacts.
Fun, ...small bang at the muzzle and a big pop down range, within 100yds of the muzzle in this experiment.
 

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I made a bunch of .510 Whisper brass, but yeah, it’s a pain. I’d take many times fired 338LM brass, use a pipe cutter to cut it below the shoulder
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then use a die to remove the taper.

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The trickiest part for me was cutting the shoulder with a neck turner, partially because it’s slow, but mostly because it’s not precise. A mini lathe is still the best way for this reason.

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In 2020 though, you could briefly get virgin .510 Whisper brass through SSK, but they weren’t cheap. It’s been a bit of a gimmick cartridge for me - not something I shoot very often.

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Brass is a pain to make up for the 510 Whisper but once made it lasts a long long time. In fact, I've never worn out or cracked a case.
I use a harbor freight micro chop saw to do a rough trim on length then run them through the expander die to remove the taper like Dogtown noted above. After that I trim them on a good trimmer with a pilot to final length before using a neck turner to finish them up. Always check the length after turning the neck. Sometimes it will grow a bit especially if your turner bit is getting dull. If needed trim length again and do a final cut with the turner. Shoulders will be precise if the length is right. I was doing batches of a couple hundred at a time this way though I did cheat and set up my neck turner in the lathe chuck with a clamp to hold the cases in the tool post. Lots of kerosene for coolant/cutting fluid will make the cutter last longer and prevent the brass from building up on the cutter.

The GI bullets are great and have been cheap but they're not very accurate. Most have been pulled with less than careful methods and none of them were particularly match grade to begin with. The API will pop if you hit hard targets when subsonic but soft dirt or wood won't set it off. Tracers light up just fine and are great for a display of long range trajectory. Shooting them at 1000yds demonstrates what a suborbital flight would look like. M1 Incendiery bullets will pop on cardboard but many of them will pop in the bore too which can be hard on your suppressor. They have not been made since about 1943 so all of them have aged and become more sensitive. APIT will light up if they're good though they have a much smaller base and are harder to light. They will pop when they hit hard targets too. I've never tried raufoss projos because they cost more than they're worth and are tough to find.

New GI bullets will normally shoot about 1.5-2" groups if you're careful with the loading. New AMAX bullets will shoot sub MOA. Powder weight consistency is critical as it is with all subsonics. Neck tension is too so while most guys don't anneal the necks often it does help maintain consistent neck tension. With that done a taper crimp will help maintain consistent bullet pull.

I've never been a big fan of JD Jones but the 510 whisper is really one of his, as far as I can tell anyway. It is a nice subsonic round and a lot of fun to shoot. There are other guys using other cases out there but so far I've been most impressed with the consistency of the 510 W for this one. I've made up a lot of barrels for the Desert Tactical rifles and even a couple Mausers in the cal. Three of those were CZ Safari Mag rifles I made barrels for and they were sweet. For the Desert tacticals I used the 308 magazines with the spacer removed because the 338 lapua mags have the front pinched to catch the shoulder under recoil. Great idea but it means the huge 50 cal bullet won't fit. The 308 mags have the shoulder part farther forward so the bullet clears. You do have to use the follower and spring from the 338 mag and trim the feed lips a bit. With all that done they feed well with the long BMG bullets.

I trimmed the cases to 1.79" to make them legal for deer hunting in Indiana. I loaded them with 300 and 450 gr Barnes soft flat points. The 300s will run about 2300 fps and the 450s will do about 2000. In the CZ rifles it was quite a smack to the shoulder and I found that I needed to use some rosin on the scope rings to keep the scopes from sliding in the rings. The rifles were about 12 lb with a scope. One customer got his first deer in 35 years with the rifle because the suppressor got him 3 shots at the deer. He was a bit old and not a great shot....first shot went over the deer, second went under and the third knocked it down. He was over joyed. For the much shorter Barnes bullets the regular 338 lapua mag will work in the Desert tactical rifles.

Hope something there helps and shows that the 12.7 has been in the running for a long time. I built my first in about 2008 and it had been around before that.

Frank
 
Brass is a pain to make up for the 510 Whisper but once made it lasts a long long time. In fact, I've never worn out or cracked a case.
I use a harbor freight micro chop saw to do a rough trim on length then run them through the expander die to remove the taper like Dogtown noted above. After that I trim them on a good trimmer with a pilot to final length before using a neck turner to finish them up. Always check the length after turning the neck. Sometimes it will grow a bit especially if your turner bit is getting dull. If needed trim length again and do a final cut with the turner. Shoulders will be precise if the length is right. I was doing batches of a couple hundred at a time this way though I did cheat and set up my neck turner in the lathe chuck with a clamp to hold the cases in the tool post. Lots of kerosene for coolant/cutting fluid will make the cutter last longer and prevent the brass from building up on the cutter.

The GI bullets are great and have been cheap but they're not very accurate. Most have been pulled with less than careful methods and none of them were particularly match grade to begin with. The API will pop if you hit hard targets when subsonic but soft dirt or wood won't set it off. Tracers light up just fine and are great for a display of long range trajectory. Shooting them at 1000yds demonstrates what a suborbital flight would look like. M1 Incendiery bullets will pop on cardboard but many of them will pop in the bore too which can be hard on your suppressor. They have not been made since about 1943 so all of them have aged and become more sensitive. APIT will light up if they're good though they have a much smaller base and are harder to light. They will pop when they hit hard targets too. I've never tried raufoss projos because they cost more than they're worth and are tough to find.

New GI bullets will normally shoot about 1.5-2" groups if you're careful with the loading. New AMAX bullets will shoot sub MOA. Powder weight consistency is critical as it is with all subsonics. Neck tension is too so while most guys don't anneal the necks often it does help maintain consistent neck tension. With that done a taper crimp will help maintain consistent bullet pull.

I've never been a big fan of JD Jones but the 510 whisper is really one of his, as far as I can tell anyway. It is a nice subsonic round and a lot of fun to shoot. There are other guys using other cases out there but so far I've been most impressed with the consistency of the 510 W for this one. I've made up a lot of barrels for the Desert Tactical rifles and even a couple Mausers in the cal. Three of those were CZ Safari Mag rifles I made barrels for and they were sweet. For the Desert tacticals I used the 308 magazines with the spacer removed because the 338 lapua mags have the front pinched to catch the shoulder under recoil. Great idea but it means the huge 50 cal bullet won't fit. The 308 mags have the shoulder part farther forward so the bullet clears. You do have to use the follower and spring from the 338 mag and trim the feed lips a bit. With all that done they feed well with the long BMG bullets.

I trimmed the cases to 1.79" to make them legal for deer hunting in Indiana. I loaded them with 300 and 450 gr Barnes soft flat points. The 300s will run about 2300 fps and the 450s will do about 2000. In the CZ rifles it was quite a smack to the shoulder and I found that I needed to use some rosin on the scope rings to keep the scopes from sliding in the rings. The rifles were about 12 lb with a scope. One customer got his first deer in 35 years with the rifle because the suppressor got him 3 shots at the deer. He was a bit old and not a great shot....first shot went over the deer, second went under and the third knocked it down. He was over joyed. For the much shorter Barnes bullets the regular 338 lapua mag will work in the Desert tactical rifles.

Hope something there helps and shows that the 12.7 has been in the running for a long time. I built my first in about 2008 and it had been around before that.

Frank
So… I wanna do this with AMAX, APIT, and MK263, along with some ball. I have a bunch of Barrett factory headstamp M33, which is about the cleanest I’ve seen.

Any way/chance to get this into an AR? .50 Beowulf is in a small frame, but I assume anything that takes a legit .50BMG projectile would have to be at least AR10/Large Frame.

Making this into a gas gun would be flippin’ awesome.
 
"New GI bullets will normally shoot about 1.5-2" groups if you're careful with the loading. New AMAX bullets will shoot sub MOA" - biffj

This is what I have found as well. 1000gr cast is showing promise at 2" 100yds . I think it can be better. Quite a hit on steel plates.
 
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Any way/chance to get this into an AR? .50 Beowulf is in a small frame, but I assume anything that takes a legit .50BMG projectile would have to be at least AR10/Large Frame.
I don't think a Lapua-sized bolt face will work in an AR10.
 
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510 wsm uses the magnum bolt face instead of the lapua bolt face. I think Olympic made some bolts at some point?

Could always turn the lapua rim down to a related rim. Then throw all your carefully prepped brass all over creation with the semi auto.
 
Man, now this thread has me wanting to go back and revisit mine with some quality bullets. I totally agree that the pulled M33 bullets aren't consistent or particularly accurate; it's just that I've still got about 30 lbs of them sitting in a box in the back of my bullet rack.

.510W guys, give me some load options.
 
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Man, now this thread has me wanting to go back and revisit mine with some quality bullets. I totally agree that the pulled M33 bullets aren't consistent or particularly accurate; it's just that I've still got about 30 lbs of them sitting in a box in the back of my bullet rack.

.510W guys, give me some load options.
30 lb of bullets ain't much for a 50. I've got a few cans of 500 API and they weigh about 50lb ea.

I did try running some of the spotter tracer bullets but the barrel has to be throated for them to work safely. If you don't seat them out far enough they compress the powder way too much and then the spotter charge goes off in the bore. Once again a bad thing for suppressors. Good thing I know the guy who makes all mine.

For the 650gr GI bullets I'm running about 28gr AA1680 or Alliant 2400. Adjust your load for your rifle as there are a lot of variables in individual rifles. Both powders are reliable and consistent though many complain they're dirty. I never had any issues with buildup or function using those powders in bolt or semi autos with all the subs in any cal I've run. There are other powders out there but H110 is not a good choice for subs. I know guys who run compressed loads of H110 in their Leinbaugh wheel guns and love it but partial loads get really inconsistent and sometimes spike pressures. I've also run IMR 4227 and a couple others in that burn rate range but I've pretty much settled on AA1680 for the most part.

I can't recall what the load was for the 750gr AMAX but I think it was around 26gr of either powder noted above. I've been making and running 17" barrels because I needed that length on the Desert Tactical rifles to clear the handguard with the can.

Yes, the 510 W or 12.7 X 48 as some call it uses the .585" dia rim so making an AR to run it will be tough. Yes, you could probably rebate the rim but keep in mind the energy the cartridge has. You may be flinging subsonics but even so its a heavy bullet and a large diameter case so bolt thrust is still up there. Recoil is up there even shooting subs too. I'm not sure the AR is a good choice for the heavies and mag length is an issue as well.

Frank
 
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Really wanna see what a subsonic APIT does to AR500 at 100y.

Suppose the easiest way is to download some actual rounds and just run them out of a regular Fiddy.
 
30 lb of bullets ain't much for a 50. I've got a few cans of 500 API and they weigh about 50lb ea.
650g would get you about 10.75 rounds per pound!!

Even scarier is the 33 rounds per pound of powder to load 650s for just plinking 😱
 
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What's the case capacity of the 510 WSM ?
QL is showing 87gr h2o for 510 whisper
 
I have a 50 razorback in the safe. It's a 300 RUM cut off at the shoulder and a .510 shoved in. Trail boss is an easy solution for subs. H322 for super. Here it is next to a 6.5SS
View attachment 8424226


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
 
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I also bought yet another mold, 700gr flat nose to put the smack down on Bambi. About a year and a half now, still haven’t cast any.

I still want to buy these.

But only if I can work up an accurate load in a couple shots. 😏

Said it many times before, the great irony is I hunted for many many years with shotguns and handguns, wishing it were legal for me to hunt with a rifle. Now that it’s legal for me to hunt with a rifle, I hunt with stupid shit like this. 🤣