My bullets have flashing....

[SierraHunter]

I know Khornet did this in the past. I have never tried it but heck, why not?

I've often wondered about an HP just large enough and deep enough for a small pistol primer......

Way back in the day, my dad used to swage primers into the noses of rifle bullets. I tried putting some in 357 hollow points once, but never shot anything with them.

I have some older bullets that at .357" that appear to be pulls and aluminum jacket that have primers swagged into the nose.

 

[SierraHunter]

I read the Handloader article, seems like ten or more years ago, and I've seen the split tip thing pop up quite a few place so for sure it's nothing new, but the idea of placing the foil behind the tip of a spitzer-type nose was what I wanted to explore. The AR-15 chambered in 300 Blackout has special needs which are contrary to every normal thing we'd do to try to get good, low-velocity expansion, hopefully this is a solution. Will report as soon as I can, might coat one in BLL and shoot it through my .308 just to see what happens.

Still open to ideas for a test medium. The primary purpose for me is pigs and maybe deer, though with deer and sub-sonic .30 caliber I maintain the best thing is to blow their minds for DRT, but still it would be nice to have the boiler-room option.

One thing I can report for sure is even 12.5 bhn ACE 235 bullets poke pencil holes right through the skull of Mr. Piggy with no expansion, tried that one from several angles on a "volunteer". Even one shot through the spine at the base of the neck just went right on through with 30-caliber exit hole in the hide on opposite side after shattering vertebrae. Miss by an inch and piggy runs away.

I personally use a 5gal bucket filled with moon dust (very fine sand). Works very well. If you get it wet, it will actually hold the shape of the wound channel. Dry, it can be run through a strainer to get the bullets out.

 

[SierraHunter]

So tomorrow couldn't wait. When you have a silencer and a flashlight the test range is always open.

What I did is place a powder-coated, split nose bullet in a vee-block and drill a 1/8" hole through the bullet nose right at the end of the foil at the end closest to the base. That puts it about 1/4" from the front band. That's SIDEWAYS, Freebullet, not through the point in the usual, lengthwise fashion.

This seemed to start expanding in the carpet, and blew a very satisfying hole through the stack of cardboard. Examining each layer closely, it appears that the bullet grew two "wings" as it went through, and after 3-4" the cavity damage in the cardboard pack was starting to grow considerably The exit hole was about .45 caliber but the cardboard was shredded fiber mush radiating nearly an inch all around, indicating what I think is shock energy dump. The bullet did not come apart. I used the long end of a power pole as a backstop and the bullet base is at least three inches inside the pole, with shredded cardboard fragments and shredded wood all around the hole.

So I think this will work, combining the foil strip for an almost-split nose with intact tip, and drilling a hole through the side of the nose right through the parting lines at the back end of the strip. Believe me, it made me a little nervous putting one of these abortions through my silencer, but no harm done this one time anyway, and the hole wasn't perfectly centered. These may not group well if I can't keep the bit from walking.

The Lee mould's alignment pin locations prevent me from cross-drilling the mould for a sideways "hollow point" pin, but I wonder if it wouldn't be possible to drill through the sides of the mould and install slightly tapered half-pins in each side to cast the crush zone in place. Maybe even a crush zone that's more effective than a drilled hole if the tip of the half-pins were filed to a teardrop shape....

Hole in the side....I wonder if they will whistle.

 

[SierraHunter]

Now, it may have already been tried, but I am fairly new to the blackout. In 45 ACP, I fill the nose of a HP with bullet lube which helps to expand using hydraulic pressure.

So. Let's cast the bullets from a almost pure lead with a bit of tin, with a 5 point HPX and water quench them to get the bullet to the 12 BHN you want.

Now let's set them in water up past the front driving band, and anneal the noses to get them back down to the the 8 or so BHN.

Now fill the cavity with bullet lube.

Might be a dumb idea.

 

[358156 hp]

I know Khornet did this in the past. I have never tried it but heck, why not?

I've often wondered about an HP just large enough and deep enough for a small pistol primer......

It does work. I used reversed 38 HB wadcutters and managed to press a small primer into the nose cavity. They made me nervous to have around. I ended up storing them in a plastic ammo box turned upside down so the protruding primer has at least some protection. I took them out to the creek and shot at frogs with them. They would detonate on impact, and leave a huge crater and no frog.

Ideal used to offer a 458 mould and a 50 cal mould that had cavities large enough to insert a .22 blank into. I think they were discontinued in the 1930s at about the same time they invented lawyers. I'm still looking for one, and I will find it, and I will buy it. Regardless of caliber.

 

[SierraHunter]

It does work. I used reversed 38 HB wadcutters and managed to press a small primer into the nose cavity. They made me nervous to have around. I ended up storing them in a plastic ammo box turned upside down so the protruding primer has at least some protection. I took them out to the creek and shot at frogs with them. They would detonate on impact, and leave a huge crater and no frog.

Ideal used to offer a 458 mould and a 50 cal mould that had cavities large enough to insert a .22 blank into. I think they were discontinued in the 1930s at about the same time they invented lawyers. I'm still looking for one, and I will find it, and I will buy it. Regardless of caliber.

Some of those new 22 blacks for concrete guns are HOT. This sounds like a real fun idea.

 

[358156 hp]

Cast hollowpoint tips from the Beagle himself, I've always loved Johns writing.

http://www.castpics.net/subsite2/ByCaliber/The 457122.pdf

 

[Tom]

Since the bo is supposed to tumble upon impact ( in theory), I wonder if filing an angle onto the top would help initiate tumbling? I've seen several videos of gelatin testing where the bullets didn't tumble. Also, since they're powder coated, a mould with smooth sides might help get the center of gravity back to the rear a little.
I figure the angled meplat would hurt accuracy, but it might be worth a try.

 

[Ian]

Something usually referred to as "silencer shift" or simply "POI shift" is caused by a little phenomena that I have chosen to name "baffle yaw", which is what happens as the bow wave from a sub-sonic bullet encounters asymmetrical silencer baffle apertures (such as notch or step "clips") used to create cross-bore turbulence and increase the dwell time of gas pressure within the silencer. The asymmetrical pressure on the nose can deflect, or "steer" the nose toward the are of lower pressure as the point of the bullet penetrates the baffle aperture, causing a yaw. If the bullet nose has been dinged, as often they are on the M4 feed ramps of an AR-variant rifle, this can cause some interesting spiral flight patterns similar to a bad imbalance (but with slightly different behavior at longer range) and group POI shift which disappears when the cartridges are single-loaded by hand in to the chamber without damage to the nose.

So no, I don't think slanting the nose is a good idea if you shoot through a silencer.

 

[Tom]

Well, it was a thought. I have too much time to think, and too little to think with.
Edit to add. I have no experiences with suppressors, but I'm surprised to learn that a change in nose shape would have an effect on bullet stability that soon after it exits the muzzle. Learn something new every day.

 

[Ian]

Well, it was a thought. I have too much time to think, and too little to think with.

It's a good idea which won't affect accuracy much if you don't use a suppressor. It doesn't take much to make a long, skinny, marginally-stabilized .30-caliber bullet tumble when it hits something more solid than air, and a nose imperfection can certainly cause this. I see all sorts of banana-shaped bullets in my sand traps. The troublesome yawing only occurs as the bullet nose passes a tight hole in a baffle which is otherwise surrounded by some free air space. In the wide-open atmosphere, nose imperfections have some effect on bullet flight, but not a whole lot at subsonic speeds.

 

[Tom]

I had some ideas on an easy form 1 build, but am waiting on the hearing protection act to make my own. Given what you described, it looks like I would have to make the holes a little bigger or not go with the clipped cone design.

 

[Ian]

The mechanisms that cause yaw are finally being understood and have been conquered by following three very specific yet universal rules with your build. Four, actually, but the fourth is a non-issue if you are diligent in your bore alignment duties. Feel free to contact me for an explanation of these build guidelines if you decide to file a 5320.1 or if the HPA passes, which it won't unless someone finally remembers that stand-alone bills like that almost never make it out of committee and decides to tack it onto a larger bill going through late on a Friday.

 

[Tom]

Thanks, Ian. My idea, refined a bit from a post at silencer talk, is to use freeze plugs shaped into m baffles using a 45 to 60 degree die in a hydraulic press. I'm no engineer, so I would pretty much need to utilize designs that others have had success with.

 

[John]

Rumor has it these blow up coming out of the muzzle. Not good for suppressors.

I think drilling a hole through the nose right at the bottom of the foil strip might help. May have to go try that and smack one with a hammer...back in a minute.

I have somewhere in storage a copy of the Sept? 1967 issue of American Rifleman where someone writes of a split nose using check tear off paper, which I interpret as being the stub left behind on a commercial check thickness common in '67. Since few of use checks nowadays and mine are as thin as newspaper so much for that. Writer mentioned that 1 in 10 come apart at the muzzle, when inserting the 1/4" or 3/8" paper stub in the mold end.
If I were going to try an expansion for 300 BO through a can I would look at a soft nose using a gas check with a hole drilled in it. Pour soft allow with a case for a ladle through the check leaving a slight tail, then follow up with hard alloy.
Of course, consider this thoughts from a dinosaur who prefers wood and bluing to an AR.

 

[Ian]

The whole problem here is bullets that will feed and not get damaged so badly that accuracy is ruined....in an AR-15. Tall order. Also, to fit the Magpul magazines that work so well with the BLK, the bullets need pointy noses due to the vertical rib on the front magazine wall. If the nose profile is too torpedo-shaped, or has a FN with too large of a meplat (.100 is about as big as will work), the noses tend to jam in the channel and bind in the magazine under recoil and feeding issues ensue. The Lee, ACE and NOE copy of the ACE bullets have the correct tip shape to work, but it's pointy and needs at least 12.5 bhn alloy on the point to survive.

 

[SierraHunter]

I have somewhere in storage a copy of the Sept? 1967 issue of American Rifleman where someone writes of a split nose using check tear off paper, which I interpret as being the stub left behind on a commercial check thickness common in '67. Since few of use checks nowadays and mine are as thin as newspaper so much for that. Writer mentioned that 1 in 10 come apart at the muzzle, when inserting the 1/4" or 3/8" paper stub in the mold end.
If I were going to try an expansion for 300 BO through a can I would look at a soft nose using a gas check with a hole drilled in it. Pour soft allow with a case for a ladle through the check leaving a slight tail, then follow up with hard alloy.
Of course, consider this thoughts from a dinosaur who prefers wood and bluing to an AR.

Hey, I'm only 23 and I prefer wood and steel.

 

[RBHarter]

This bullet feeds fine in the M4 style extension with little to no bullet damage . Just nose scuffs and if I had taken the time to polish the edges that wouldn't happen either .

 

[Ian]

That is one superb looking bullet design.

Left-feed 6.8 SPC magazine I presume? My BLK ARs will actually feed .180" meplat bullets pretty well, with just a ding on the edge of the meplat, it's more of a magazine problem with Pmags. Lancer and GI mags don't have the rib in the front that binds bullet noses, but the GI mags don't play well with subsonic blackout loads due to the side guides being too proud to the inside. Problem with hollow pointing anything is it weakens the nose enough, with a soft enough alloy to perform at 1K fps, that it will get much more of a ding when feeding. Also, small hollow point cavities, or narrow, parallel ones, don't expand very well when the ogive is long and sweeping, they tend to crush inward rather than open up like a flower. The cup needs to be more shallow of an angle than the ogive. All of these factors create problems for the BLK.

 

[fiver]

that design looks real familiar to me.