300 Blackout Cast Hunting Bullets - Calling all Expansion Experts!!

[wordsmith]

Sorry for the long post, but thought I’d share some successes and post some further questions of the experts out there. This post explores my quest for an affordable 300 BLK subsonic hunting bullet, that can be safely used with a non-serviceable suppressor. I’ve gained a lot of knowledge in this forum, and I wanted to give some back (hopefully).

First, some background. When I started looking for acceptable subsonic hunting bullets, I quickly ran into a wall. There are basically two choices, Lehigh or Outlaw State, both of which are $1.00+ per bullet. I preferred the Outlaw State design, but after multiple email attempts to place an order with no response, I grew frustrated and decided I’d develop my own. I also investigated swaging my own j-word bullets, but figured out that would require significant investment for what is essentially a personal hobby, so I abandoned that route as well. Plus, I’m a tightwad, which I think was one of the requirements for joining the Cast Boolits forum.

Pretty quickly, I ran into two primary issues. The first is finding a technology that will withstand the pressures of firing and reliably feeding in the AR platform, but still expand at subsonic velocities on soft targets. The second issue, which was even harder to solve, was finding options that were safe to fire through a non-serviceable AAC-SDN-6 suppressor.

I started like most others by loading up 208 AMax’es or 220 Sierra RN’s. After a decent amount of testing and tweaking, I was able to get sub-1” groups at 50 yards with both designs. They will shoot 5 rounds with all of them touching. 100 yard groups are a tad over 1”. Velocity SD’s are typically 15 fps +/- for 10 rounds using WC 680 (mil version of AA 1680) with 100% cycling and bolt lock-back. Two critical items I found – I apply a heavy crimp, and I lightly tumble lube the j-words with 45/45/10. Those two things dropped my SD’s by more than half and greatly increased accuracy.

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All is well, until it comes time to hunt with these rounds. To put it bluntly, they sucked. My style of shooting (mostly stalking) doesn’t always allow for pinpoint shot placement, so headshots on moving pigs with sometimes offhand shots isn’t feasible. I’ve gotten 100% run-offs on front shoulder shots (deadly with supers), and even raccoons run off more than half the time. Neither bullet is expanding (no surprise there) and doesn’t appear to be tumbling quickly enough to do the trick. In short, they’re not suitable or humane for anything but perfect headshots.

This pushed me to first consider modifying the j-word bullets to meet all of design goals. To date, I have finalized one design (j-words) and need help as I push forward on a cast boolit solution. My findings and questions are below.

300 BLK Subsonic J-Word Hunting Bullet Design – WARNING USE AT YOUR OWN RISK

My first fully successful design is using 220 gr Sierra RN j-words. After testing 3 different designs, I found the one that finally worked well.

To create it, I took a ¼” drill bit and carefully drilled off the exposed lead tip until just encountering the start of the jacket, leaving a shallow cup that I used to guide a #19 bit (0.166”) as I drilled out a 0.250” deep hollowpoint cavity. The #19 bit drills with only minor jacket removal and helps keep the HP centered (using the jacket as a guide) in my drill press. I drilled an undersized hole in a piece of 1”x4” with a split cut down the middle to allow me to squeeze the bullet and keep it from turning during drilling operations.

From there, I filled the cavity with flexible silicone caulk (Home Depot) and tapped a steel BB into the end of the cavity with a ball-peen hammer (several light taps). The #19 bit was chosen as it gave about a 0.005” interference fit between the jacket and BB and, together with the adhesion from the caulk as it dries, holds the BB is tightly in the cavity. Finally, I lightly skivved the outside of the jacket in four locations around the circumference of the bullet, and about as far down as the HP cavity. One note - leave the very tip of the bullet unskivved, as it will hold the BB more securely, a technique I figured out after taking the pictures in this thread.

To test the adhesion, I used a heavily crimped round in my inertial bullet puller, allowing rather aggressive hammering of the puller in an attempt to get the BB to come out of the cavity. I also used various other tools to attempt to pull the BB from the cavity, with zero success. I have fired about 100 rounds with zero issues. However, having the possibility of a loose BB in the barrel as it fires is going to be a problem, and you should thoroughly check your rounds before firing until you master the design.

CONSIDER YOURSELVES WARNED, USE OF THIS DESIGN IS ENTIRELY AT YOUR RISK AND CAN POSE SERIOUS HAZARDS IF NOT DONE PROPERLY. Hopefully enough said.

The point of the BB was to “recreate” the round nose of the bullet, which reduced fail to feed jams to zero in my guns, where a previous blunt open HP iteration was jamming every 2-3 rounds. Upon firing, the BB pushes against the column of flexible silicone caulk, causing very high pressures against the jacket walls, essentially exploding the HP cavity and leaving a 0.40-0.45” flat nose with about 180 grains of shank remaining.

Water testing confirmed the validity of the design, and results on raccoon-sized game has been emphatic. Where I was seeing 50-75% escapes with coons using 208 Amax / 220 RN unmodified, the BB design has been 100% DRT. I won’t post pictures here, but suffice it to say expansion was confirmed. I haven’t shot a hog with this design yet, so that question remains. Some pics…

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EDIT 08/17/2014: Video of water testing above design. It's loud due to phone being right next to muzzle.


http://youtu.be/1X5d9ecp5HE

END EDIT.

The 220 gr Sierra RN j-word design is great and meets all of my criteria, but suffers from two issues. The first is the (lack of) availability of the 220 RN bullets. Recently, they’ve been very hard to get. The second is that, quite frankly, it’s a major PITA to make these bullets in any quantity. I have several friends that want them by the hundreds, and I just don’t have the time or patience for that. A third minor issue is that they’re still about $0.35 ea shipped, which isn’t bad, but the tightwad in me wants to do better. Which lead me down the road of Lead, so to speak…

300 BLK Subsonic Cast Hunting Bullet Design

I casted boolits as a kid under the close supervision of my Uncle, but hadn’t done it or had the equipment since then, some 35+ years later. It became apparent that maybe the best way to solve the problem was to go old tech and find a heavy cast boolit that would do the trick. So I broke out the CC and proceeded to spend a bunch of money on casting equipment, in order to save a bunch of money…?

Initially, I got discouraged due to the concerns of lead buildup in my suppressor and gas system from cast bullets. Gas checks might help, except they were problematic due to concerns of them coming off and remaining in the suppressor.

The technology that made it possible is the new PC’ing / Hi-Tek coatings. I’m currently using Gold Hi-Tek liquid coatings, and am having great success. During initial testing, I ran about 50 rounds through the gun, cleaned the barrel with my normal cleaning products, and was shocked at how little came out of the barrel (basically two powder residue patches and clean). I then examined the barrel and suppressor with my Hawkeye borescope. The barrel looked brand new, no deposits of any kind. Nice shiny barrel. The suppressor showed no difference before / after firing, with normal levels of residue deposits. The stuff works great.

I’m using this coating with the NOE 311247 PB mould, with and without hollowpointing. After two coats, I also lightly tumble lube with 45/45/10 to make sizing to 0.309 (from about 0.314 with Hi-Tek) very easy using a Lee push-thru sizer.

I have two problems that I believe are interrelated. I’m not getting the accuracy I’m looking for (1.5MOA or less) with a bullet hardness I expect will expand reliably. I recently tested various cast combinations for accuracy, and need some help from you guys interpreting the results. Here’s a picture of 50 yard groupings for four different cast designs:

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Group 1, Upper Left – 12.5 BHN, 75:25 COWW/Pb equivalent 247 gr monolithic.

Group 2, Upper Right – Two-part bullet, 12.5 BHN Base, Pure Pb Flat nose. Water testing showed excellent “expansion”, normally in the form of a very bent nose. Adjusted the scope to left from first group to better center.

Group 3, Lower Left – Two-part bullet, 12.5 BHN Base, 50:1 Pb/Sn HP Nose.

Group 4, Lower Right – this is two 5-shot groups, one left of center, one right of center - 9.5 BHN, 98Pb/1% Sb/1% Sn HP monolithic.


The group 4 boolit is the one I really want to get working better so I can move on to water testing, but at about 3.0 MOA, it’s twice the grouping that I want. It seems pretty clear that the 9.5 BHN boolit is too soft, and is either not tolerating the 1:8.5 twist rate or can’t take the 20,900 psi load (per Quickload). Here’s the bullet, with the HP enhanced with a gentle twist of the Lyman Flash Hole uniformer…

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Finally, to my question...

I really don’t want to have to cast softpoint bullets (groups 2 and 3 above) since they’re a major PITA and have a higher rejection rate than monolithic pours. Right now, however, it looks like I’m going to have to be closer to 12 BHN for accuracy and figure out a way to easily skive / weaken the HP of the cast bullet for reliable expansion.

Investigated so far: 1) Sizing down of the bullet when seated? Checked found 0.0005" diameter reduction (to .3085") with 9.5 BHN at base only (not driving bands), and no reduction on 12.5 bases using 0.001" neck tension with custom +0.002 oversize Expander 2) Leading? Nope, borescope shows clean as a whistle 3) Keyholing? I don't think so, as I don't really see evidence, and JBM Ballistics show a 2.65 Stability Factor.

Need to investigate: 1) Slug barrel to get true bore 2) hone out an extra Lee Sizer to 0.310" and see if increased diameter helps 3) 12.5 BHN HP Expanding? I'm thinking of water testing the 12.5 BHN HP's empty and with silicone caulk to see if I can get expansion and focus my efforts there.

I’m looking for some feedback to see if you guys have already been down this road and have some thoughts. If not, I’ll keep going and report back on my final solution. Thanks in advance for any input and enduring this booklet of a post.

[rockrat]

I would first try the .310" boolits. Instead of steel BB's why not use airsoft BB's in the 220gr bullets, in case one falls off after feeding the round. Lastly, why not try water quenching your boolits, then putting them in water up to the nose of the boolit, and heating up the nose to take the hardening out of the nose and still have a harder shank. Then powder coating them.

[wordsmith]

Rockrat - great suggestions, I appreciate the input. I used steel BB's primarily because that's what I had on hand. I considered airsoft BB's, but IIRC, they were not available in a suitable size range.

In regards the HT/WQ/nose annealing technique, I've seen it mentioned a number of times, and it sounds like somewhat of a pain. I think it could work well, I'm just looking for the least effort required to get from mould to shooting, as I need to make hundreds of these for friends. If all else fails, I may give that a go.

Again, REALLY appreciate the input.

[runfiverun]

I'd add a gas check.
it protect's and squares the base of the boolit.
it's also great at gripping rifling.

my next go round with the 300 b.o. is gonna be with the LEE 240gr boolit plain base pushed slow.
I have been using the rcbs 165 silh boolit at 1300 + fps which I know will penetrate, but isn't an instant killer on chucks and squirrels.
one trick you can try with the noe boolit is to cut the alloy with a click more lead and water drop them from the mold, this will bring the bhn up and help grip the rifling better. [maintain your mold temp throughout the process this keeps the bhn in a window]
you'll also want to allow them to age for a month or so [14 day's minimum]
however it allows the alloy to do it's job and retain the malleability on impact.


if you want more violent expansion on the jaxketeds you could take a torch to the nose and slowly anneal the jacket. [keep the exposed lead]
be careful and go slow, sometimes they will try to bubble up an air pocket.

make sure you use the initiator you are using now if you want fast expansion, or just use the glue to slow things down a bit.
you don't want a blow-up on the pigs...

[Jupiter7]

Have you considered a slower twist barrel?
I know, not the answer you're looking for. I gave up on the sub-sonic 300blk in an AR as a viable option after some alloy testing with water jugs. Regardless of alloy most just penciled right through the first 5 water jugs. Expansion was minimal if any. Witnessed a few crazy bent bullets with quick course changes. This was all in 1/8 twist 10" lothar walther barreled AR pistol. I've seen others report better results with 1/10 twist barrels to impart tumbling quickly. I don't have a suppressor so subsonic really was of no concern to me, just wanted big and slow. I even pushed bullets of 250grs(accurate31-240e) up to 1400fps with no improvement. I will second that .310 seems to be more accurate regardless of speed, within reasonable range of alloy. My solution ended up being a 311-165 loaded long and running about 1800fps.

Best of luck, your patience has run longer than mine did.

[wordsmith]

Popper - first, thanks to all your contributions on this forum. I've learned a lot from you in various posts and appreciate you taking the time to respond.


With the HiTek, your BHN will be low. Annealing the noses after HT coated boolits may work, but HT'able alloy will regain some BHN over time after annealing. You will also burn off the HITek from the nose!

Not to turn this into a Hi-Tek thread, but I think I can get around the BHN issue with Heat Treated bullets. I read on one of the uber-Hi-Tek posts that some folks were using ultra short cooking times and getting good results. In addition, the instructions I received with my liquid Hi-Tek coating stated only 60-90 secs, max, are needed at 375F to cure the coating.

So I set to experimenting with my Gold Hi-Tek, and with a combination of a convection oven and a digital thermometer with thermocouple (intended for BBQ'ing), am able to get great smash / acetone wipe tests with 90 secs at a maximum of 375F. Recovered bullets show full retention of Hi-Tek, and I have no leading whatsoever. Point is, if I end up having to HT/anneal, I believe I can preserve the BHN's through the Hi-Tek process, as my total time in the oven is typically 5 minutes or under. Please don't flame me - just reporting what I've used successfully learning from all the good folks here.


Your 8 1/2 twist should be acceptable with your alloy, depending on the powder. 20K psi is nothing, think 45ACP?

I totally agree, which was why I thought a 9-10 BHN should work acceptably. AA 1680 is very slow in that application, which is necessary for AR gas port timing and reliable operation.


Shouldn't need the alox over HiTek for sizing.

Agree, just makes it a little smoother going through the sizing die, since I don't have the Extreme Catalyst. And I have a huge bottle of 45/45/10 to use up in this lifetime :-P


I think your biggest problem with the soft (<2% Sb doesn't HT) is nose bending from the ramp feeding. Read up on Cu enhanced alloy. I do think your pics show a lot of pits, dents in your cast so if they occur on the base, no accuracy. I'm sure there are some but I've not read about successes hunting with BO subs except at PB range. Hits, yes. Tracks, yes. DRT, no. I think the problem is the time to travel 100 yds or more, snap shots and moving target..

Nose bending is possible. I cycled several through and examined them, and since I've optimized my feed ramps for the fat ogives on these bullets, I'm not seeing big issues. The fact that my 2-part softnose bullets with pure lead front halves shot better than my uniform 9.5 BHN bullets tends to reinforce my thoughts here.

I read up extensively on Cu and S HT, even purchasing 5 lbs of sulfur, only later seeing that Sulfur can cause adhesion issues with Hi-Tek, so I haven't used it. I have a lot of magnum shot I can use to get As to the necessary levels, so I haven't kept going on Cu, but I will keep in the toolbox for down the road.

I probably picked the worst bullet to have front and center for a picture, but you're correct. However, I examine each bullet before coating and cull religiously, especially with driving band or base defects. As you correctly pointed out, base defects have a major impact on accuracy. I also weighed all 50 rounds of 9.5 BHN HP's I casted, and they were within +/- 0.5 gr, so it seems like voids and other major hidden defects would be limited.

Finally, I agree that DRT with 300 BLK subs on medium game like feral hogs is just not likely. I've downed in excess of 100 hogs, and even with rounds as powerful as 300 WM / 300 WSM, I've had the occasional failure. With 308 Win supers, the DRT rate is about 75% with decent placement, while 223 is more like 33%. Considering the subsonic 300 BLK has a lot less energy to work with, shot placement (hence accuracy) is critical.

[wordsmith]

I'd add a gas check.
it protect's and squares the base of the boolit.
it's also great at gripping rifling.

my next go round with the 300 b.o. is gonna be with the LEE 240gr boolit plain base pushed slow.
I have been using the rcbs 165 silh boolit at 1300 + fps which I know will penetrate, but isn't an instant killer on chucks and squirrels.
one trick you can try with the noe boolit is to cut the alloy with a click more lead and water drop them from the mold, this will bring the bhn up and help grip the rifling better. [maintain your mold temp throughout the process this keeps the bhn in a window]
you'll also want to allow them to age for a month or so [14 day's minimum]
however it allows the alloy to do it's job and retain the malleability on impact.


if you want more violent expansion on the jaxketeds you could take a torch to the nose and slowly anneal the jacket. [keep the exposed lead]
be careful and go slow, sometimes they will try to bubble up an air pocket.

make sure you use the initiator you are using now if you want fast expansion, or just use the glue to slow things down a bit.
you don't want a blow-up on the pigs...

Runfiverun - thanks for the insights. Totally understand on the gas check, and I'd love to, but the risk of them coming off once they leave the barrel and lodge in the suppressor has kept me from going that route.

I have the Lee 240 PB mould as well, but I prefer the NOE PB, plus I have it with a HP cavity. Let me know how it goes with the Lee, as similar approaches should work with either.

Your experience with non-expanding slow 300 BLK bullets is identical to mine, in that even small prey (under 50 lbs) often makes it a good ways before expiring. Not satisfactory for me, which sent me down this path.

[runfiverun]

they don't blow off in my muzzle brake at 2400 fps, I doubt they'll come off at 900 fps.
get good gas checks that crimp on. 35 bucks is cheap insurance..

[wordsmith]

I realize that a slower twist could work, but between the difficulties in getting one made and the friends I load for that all have 1:7’s or 1:8’s, I’m still pushing to figure it out with the faster twists.

My wife says I’m the most patient, most hard-headed person she’s ever known, so hopefully I can outlast this challenge.
As a side note, here’s some pictures of softnosed 2-part 247 NOE’s shot into 3 gallons of water and stopped by 5 gallons of sand, which abraded off lead and Hi-Tek coating as shown in the pics. Interesting to note the “expansion” characteristics.

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[rockrat]

Don't forget to water quench/anneal noses before powder coating. You can set alot of them in a pan and cover the shank with water before annealing the noses. let cool, dry and powder coat. I would think you could do 100 at a time.

How would one of the NOE 247's do hollowpointed, using the soft alloy, and powder coated? Just a thought

[runfiverun]

hmm those are showing uneven mushrooming.
I am wondering if that is happening [or partially happening] before it gets to the target.

[Digital Dan]

It seems pretty clear that the 9.5 BHN boolit is too soft, and is either not tolerating the 1:8.5 twist rate or can’t take the 20,900 psi load (per Quickload).

Don't know I buy that or not, but here is something to ponder. I shoot a fair amount of paper patched pure lead from 1100-1600 fps, the latter at much higher pressures than you're dealing with. Accuracy is excellent.

Seems a fair number of folks have had success with CBs in fast twist guns from what I've read, so there's another reason I'm skeptical about the reason(s) for your results.

Couple of stray thoughts? Your cast bullet looks like a bore rider design. Maybe that's not the best approach. You're putting a significant crimp in the case neck, that may not be in your best interest either. Lastly, I think you're wasting a lot of time with the two piece bullet construction. I assume you are casting this in two steps? Only way I know to achieve good accuracy with two piece bullets involves swagging.

I don't know that paper patch is doable with a suppressor either, but am of the opinion that your objective can be had with a different bullet form/design.

[wordsmith]

No GC boolit I've pushed to 1800 with accuracy from a 1:7 carbine, 2R nose.

What was your alloy and / or hardness?

[303Guy]

I don't know that paper patch is doable with a suppressor either, It's doable but maybe in some suppressors only - like mine.

Just thought I'd share this one showing extreme expansion. [smilie=s:

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Weight retention was astoundingly high like nearly all of it. And that boolit is all in one piece! Not any good for hunting though I'd think. I have other boolits that turned inside out which y'all might remember.

[heathydee]

A couple of years ago I devoted a thread on a now defunct site to the whole problem of getting reliable expansion at subsonic velocity with 30 caliber boolets . The main boolit used was the Lee 200gn RN and the expansion medium was a 2 litre bottle of water. I have the advantage of having a lathe in the garage and this proved very useful in my experimentation . Boolits could be flat-pointed or hollow pointed by placing them in a 5/16" collet which ensured accurate centering and repeatabily .
I began by casting a heap of boolits with soft lead - around BH 9 - and drilling eighth inch diameter hollow points almost the length of the boolits . Accuracy was good but disruption to the water jug was little better than an unmodified boolit . Flat noses were not much different .
I experimented with placing aluminium foil between the mould blocks to split the boolit over about half its length . Sometimes they flew apart on the way to the target .
The best results were achieved with a boolit split by aluminium foil but with a short sections of the nose and base left solid . A small hollowpoint was then drilled in the nose section to initiate expansion . I tried this boolit on both water jugs and ballistic gel .
A boolit modified in this way tears into three sections almost at once in ballistic gel . The nose splits and the two "wings" break off, traveling away from the impact point at an angle , leaving the base to penetrate in a staight line. It disrupts a water jug in a very satisfying manner .
Here is a link to a water jug hit .
https://www.youtube.com/watch?v=buprWD66MTQ&list=UUdza0w1OiFq1ByUehsRXzdA
The Lee 240gn boolit behaves in a similar manner when treated this way although to have it stabilize in my 1 in 10 twist about 200 thousandths have to be removed from the tip before the hollow point is drilled .

[r6487]

I know in your original post you mentioned afforadable. the outlaw bullets are comparably expensive. I use them and we have had good expansion in the 1050 ft/sec range with 1:10" 308 with TB and 1:8" 308 x 1.5" with sr4759. have you looked at www.hawkbullets.com (http://www.hawkbullets.com)? not cheap there either but they expand at slow speeds(made very soft). I am slowly following your trek with the NOE 247 and just acquired a lee 230 also. jus got a little hi-tek and starting the PCing . keep up work and keep posting your progress.

[wordsmith]

A couple of years ago I devoted a thread on a now defunct site to the whole problem of getting reliable expansion at subsonic velocity with 30 caliber boolets . The main boolit used was the Lee 200gn RN and the expansion medium was a 2 litre bottle of water. I have the advantage of having a lathe in the garage and this proved very useful in my experimentation . Boolits could be flat-pointed or hollow pointed by placing them in a 5/16" collet which ensured accurate centering and repeatabily .
I began by casting a heap of boolits with soft lead - around BH 9 - and drilling eighth inch diameter hollow points almost the length of the boolits . Accuracy was good but disruption to the water jug was little better than an unmodified boolit . Flat noses were not much different .
I experimented with placing aluminium foil between the mould blocks to split the boolit over about half its length . Sometimes they flew apart on the way to the target .
The best results were achieved with a boolit split by aluminium foil but with a short sections of the nose and base left solid . A small hollowpoint was then drilled in the nose section to initiate expansion . I tried this boolit on both water jugs and ballistic gel .
A boolit modified in this way tears into three sections almost at once in ballistic gel . The nose splits and the two "wings" break off, traveling away from the impact point at an angle , leaving the base to penetrate in a staight line. It disrupts a water jug in a very satisfying manner .
Here is a link to a water jug hit .
https://www.youtube.com/watch?v=buprWD66MTQ&list=UUdza0w1OiFq1ByUehsRXzdA
The Lee 240gn boolit behaves in a similar manner when treated this way although to have it stabilize in my 1 in 10 twist about 200 thousandths have to be removed from the tip before the hollow point is drilled .

Very creative solution, and just the sort of information I figured was out there from those that had come before me. Did you find it to be a pretty slow process with getting the aluminium foil placed in the mold?

[wordsmith]

I know in your original post you mentioned afforadable. the outlaw bullets are comparably expensive. I use them and we have had good expansion in the 1050 ft/sec range with 1:10" 308 with TB and 1:8" 308 x 1.5" with sr4759. have you looked at www.hawkbullets.com (http://www.hawkbullets.com)? not cheap there either but they expand at slow speeds(made very soft). I am slowly following your trek with the NOE 247 and just acquired a lee 230 also. jus got a little hi-tek and starting the PCing . keep up work and keep posting your progress.

I haven't looked at the Hawk Bullets, good to see another option. I'm gonna keep pushing on this cast bullet front until I solve it. My current research is following the research of others and annealing the noses of heat treated boolits to get the 12-14 BHN bases I believe I need for the 1:7 twists, and keeping the BHN 9'ish on the HP noses. The final trick is keeping the heat treatment in place and still getting Hi-Tek to work, which I believe I've already solved based on early testing. I'll post an update here when I get new data.

[crawfobj]

Glad to hear the Hi-trek coating works. I'm working with PC for clean suppressor use. I wonder if a larger HP on the NOE boolit might help.

Nice work on the modified J-words.

[heathydee]

Very creative solution, and just the sort of information I figured was out there from those that had come before me. Did you find it to be a pretty slow process with getting the aluminium foil placed in the mold?

I used strips of foil about 3/8" wide and about three inches long . A heap were pre-cut and placed in a handy position . After a little practice I found it easy to place the length of foil accurately between the mold halves.
Closing the mold holds the foil in position with some hanging out each side . Pour as normal . The boolits fall from the mold as normal and the foil can easily be torn off . A section of foil remains in the boolit .

[wordsmith]

I used strips of foil about 3/8" wide and about three inches long . A heap were pre-cut and placed in a handy position . After a little practice I found it easy to place the length of foil accurately between the mold halves.
Closing the mold holds the foil in position with some hanging out each side . Pour as normal . The boolits fall from the mold as normal and the foil can easily be torn off . A section of foil remains in the boolit .

This is intriguing, until I remembered you are post-pour drilling your HP's, where I'm casting with a single cavity HP mold (actually 5-cavity, 4 non-HP and 1-HP). I think it might still be worth trying and just letting the HP pin move / tear foil as needed when inserted into the mold. I expect it will not completely cut it and it'll still be in place to weaken the boolit walls adequately.

[Pink_Vapor]

Thanks for your extensive post.
I'm wanting exactly what you're chasing down. AR-15 300BLK 1/7 10" pistol length gas, TBAC suppressed for reliably hunting hog & deer.
Keep it up & I want what the final verdict is.

[Pink_Vapor]

it seems a poly tip would solve a couple problems, reliable expansion and feeding. I didn't see anyone selling just the tips, but I did find different sized poly balls for this purpose. I don't know i the outcome would be the same as the silicone.
http://www.swage.com/ftp/bballpg1.pdf
http://www.swage.com/

[Dinny]

Can I be added as your "friend"? :bigsmyl2: With much luck us Hoosiers will be able to use CF rifles for deer hunting next year. I gave my mother a H&R Handi rifle in 300 BLK that she thoroughly enjoys shooting subs from. I don't have the budget, experience, nor time to test like you have. I'll watch this for more news.

Thanks, Dinny

[wordsmith]

Final update... At the suggestion of Heathydee, I spent some time experimenting with split noses using aluminum foil on non-hollowpointed bullets. This was done with the theory that the nice (relatively) wide meplat on the NOE 247 bullet would help provide sufficient force to push against the split ogive and cause mushrooming, or at least splitting. Based on water testing, this turns out to work very well.

The key was to have the split start no farther than approximately 1/16" from the tip of the bullet, or splitting / expansion was not reliable. You could certainly split the boolit all the way through the meplat, but I was concerned about bullets coming apart in my suppressor as a result of 1/7 twists, so I wanted to leave a little unsplit section at the very tip for insurance.

I also solved my accuracy issues with a combination of steps. Firstly, I had to up the BHN for the plain boolits to take the 1/7 twist rates. I'm using a 50% COWW / 50% SOWW + 2% tin mixture, for a BHN of about 11-12. The second step was to modify my Lee push-through sizer diameter from 0.309" to 0.310". Finally, and most importantly, I purchased a modified expander / decapper stem from Lee for my full length resizing die that was 0.002" larger than standard to provide 0.001-0.002" of bullet neck tension for the 0.310" boolits. These steps eliminated bullet distortion and tightened up my groups considerably.

I'll post up some pictures for discussion in the next few days, but I'm considering the experiment complete. I'm actually using both the j-word and split nose boolit designs for different setups. I'd like to thank Heathydee for his help, both on this forum and in PM's.

[pls1911]

I'm just starting into 300 BO with about the same NOE bullet/barrel set up.
I will be using MUCH harder (heat treated), gas checked, pc'd bullets, sized .310, so I expect fewer issues than you have experienced.
Regarding expansion, don't over think it...
I expect no expansion, and have never found any advantage on pigs, yotes or deer when the bullet punches through both shoulders and the spine... the normal situation with my 30-30 cast bullets at 1900 fps.
Bang flop, DRT.
I never find a bullet and critters drop.
Same for 45/70.

[wordsmith]

As promised, here's a picture of the expansion of 50/50+2% mixture with aluminum foil split noses, no hollowpointing. They were shot into water jugs and backstopped with sand, hence the rough finish and removal of Hi-Tek coating.

134846

[wordsmith]

I'm just starting into 300 BO with about the same NOE bullet/barrel set up.
I will be using MUCH harder (heat treated), gas checked, pc'd bullets, sized .310, so I expect fewer issues than you have experienced.
Regarding expansion, don't over think it...
I expect no expansion, and have never found any advantage on pigs, yotes or deer when the bullet punches through both shoulders and the spine... the normal situation with my 30-30 cast bullets at 1900 fps.
Bang flop, DRT.
I never find a bullet and critters drop.
Same for 45/70.

We may be talking apples and oranges here. I've been referring to subsonic ammo going around 1030 fps, and from my numerous tests on pigs and coons, non-expanding .30 caliber boolits that function reliably in an AR are downright horrible on game. Even with the 0.150" meplat (about as big as will work in an AR), everything but a CNS shot allowed animals to run off, including coons. With the much wider meplat on 30-30 / 45-70 rounds and higher velocities, performance should be great as you've mentioned. Zero expansion with subsonic 300 BLK = zero performance, from my field testing on about two dozen test subjects. YMMV.

[Harter66]

I'm way late here in this thread. I'm probably throwing oranges in with your apples.

I have a home boolit a nice pointy 1 like the pointed boat tailed 250s. I need 1910fps out of the 200 gr boolit to make my required 1000ftlb @ 100 yd legal big game needs. It is dismal in 308,06 and even the 7.7 but it worked in a x39. Granted it has a 24" bbl but with a full load of 4350 it would cycle an sks. It will only clock about 1400 at mag length but continue to cycle. With 50/50 WW -1-20 I had .700+ mushrooms in several mediums. On the few that I HP'd I lost the nose but retained a 150 gr wad cutter . As low as 1200 fps .450 mushrooms weren't un common. The alloy was water dropped.

[trw1051]

Hello,
Thanks for all the great info. How do you skive the bullet nose? Thanks


+8

[runfiverun]

if you mean split he used foil in the tip of the mold to make them open easier.
you can use paper to do the same thing.

skiving is used to thin a shot shell hull into a taper and prepare it to crimp easier.

[xacex]

if you mean split he used foil in the tip of the mold to make them open easier.
you can use paper to do the same thing.

skiving is used to thin a shot shell hull into a taper and prepare it to crimp easier.
Now this might be something to try with the new Mihec blackout boolit Bill designed. You could put the foil strip right behind the hollow point by just marking the block with a sharpie. With the wasp waist, hollow point, and foil to initiate fragmentation I am sure you could get some satisfying results without to much work.

[Bigslug]

Sorry that I merely skimmed your post, but the gist I get is that you need a subsonic option that expands:

141349141350

130 grain LBT flat nose from a Martini Cadet shooting a somewhat blown out 32-20 Winchester - very similar to the Blackout in size. The mushroomed bullet is 20-1 lead/tin and was moving in the ballpark of 1200 fps. It took three gallon milk jugs of water to stop it. The non-expanded one next to it is water-quenched wheel weight using the same powder charge. That one took nine jugs to stop.

141351
The same 20-1 alloy in an NOE 180 grain .40 cal fired from a '73 Winchester in 38-.40 at about 1350fps. If I remember correctly, that one took four jugs to stop.

Personally, I'd cut noses back on pointy bullets to see how large a meplat your upper will feed reliably, find or order a mold that matches that, cast harder (which should help your accuracy) and not sweat expansion.

[JDNC]

Wordsmith, Thanks, for this thread! Exactly what I'm trying to do.
I have PC'd an Accurate Mold #31-235P sized .309-.310" and have consistent groups under 2" at 100yds with some around an inch. But this is useless if they won't expand. I can't wait to try heathdee's idea. I also want to shoot these through closed silencer and am very interested to any future information you might have to your bore and can since you have a bore scope.

I have not at this time shot any (cast) through my can (scared to) but will this week. I'm an old fart that has shot many rounds gas checked and I have seen GC's stuck into my start screens! I know how to seat them, crimp on etc., and I for one don't want to use them through my new silencer either as I know sometimes they come off at the exit of the muzzle.

Please keep this thread alive! The only thing the BLK needs is a bullet that performs on game at subsonic velocities!

JD

[LongRangeAir]

I'm Way late to this thread, but may-be this can help. I'm shooting a .257 cal. at 1020-1030 with a good suppressor. Accuracy is under an inch at 100 yards, and expansion is excellent.

I recovered a bullet last week what went .501". Everything that I have shot has been DRT! Instant kills.

I saw where you hp'd the J-word bullets, and how you did it, but not how you were doing the Cast bullets.

In talks with Eric at HP Mold Service, Eric pointed out a HUGE mistake many make in trying to HP their bullets on a lathe, or drill press. Its' all in the angle of the HP cavity. Eric pointed out that the HP cavity walls need to be at a steeper angle than the ogive of the bullet it's self. If this is not done, the taper of the ogive will try to push the bullet nose towards it's center. In other words, collapsing the bullet nose, or bending it. Exactly as your pic's show.

I have done a LOT of testing in this regards, and I have found this to be Exactly Accurate advice.

Here's a little trick I picked up. If you have a screw bit set with some star drives in it, select one that is just smaller than the opening of your HP. Press it in by hand. Firmly, but don't ham fist it. It will cause the HP to open a 6 petal flower. Sorta like the old Talon was Supposed to work, but never really die.

I have also used square drive bits, and they open beautifully, but hit at a different poi. About 2" high, and 2" Right in my gun at 100 yd's.

One other thing, when you simply drill the HP, you leave a sharp shoulder at the bottom of the HP, causing the (what would otherwise be called the mushroom) to be sheared off). This is Bullet failure., and not what your looking for at all.

I cast at pure lead, 2% tin, and have a touch of antimony in the mix at the moment.



I live aprox. 10 mi north of you near Killeen, (Fort Hood). Send me a PM and I will give you my number if you like.

KnifeMaker

Pic of the boolits, along with two shots from cold barrel. One solid, one HP. Note the very small difference in poi . These were at 76 or 80 yards. Don't remember which. LOL

149625
149624

[wordsmith]

LongRangeAir - thanks for the input. Lots of interesting information there. Very clever on the star bit to serrate the inside of the hollowpoint. I've put this experiment on hold, waiting for the new Mihec boolit to continue this research.

http://castboolits.gunloads.com/showthread.php?236225-MiHec-300-ACC-Blackout-2-or-4-Cavity-Brass-Cramer-HP-GC-or-PB

[LongRangeAir]

We've been plagued with possums and squirrels lately. So far, these modded bullets are opening fast. With instant kills. Beautiful full mushroom's from the .257 in the .50+ area of expansion. I'm really pleased with the results.

Barrel is 1/14" twist at 1020 fps. 81 grain bullet Noe, RanchDog, HP'd by Eric for varmint at my velocity. The star marks in the HP really caused a more violent expansion, yet, no blow up. The HP's have a 6 petal mushroom that follows the marks left in the cavity from the bit.

Lead is Pure+2% lead/tin, with traces of antimony in it.

Knife

[ka30270]

tag for later reading

[pls1911]

I'm way late to this conversation, but gentlemen, you're overthinking expansion.
Yes, it's beneficial, but how many men died in wars to non expanding bullets... many instantaneously.
Penetration has its profound benefits as well when recognized and utilized.

I've never had a raccoon, armadillo, or coyote run away from a properly placed (non expanding solid) .22 shot either, or other edible "tough" targets several times their size...
If the .22 can do it, then the non expanding hard cast 30 blackout slug at the same velocity can certainly perform as well.
We're not at war stateside (except perhaps with pigs), so there's no excuse for broadside butt shots or other poorly placed slugs.

The good element of a 247 grain NOE Blackout bullet is the you can put it between the eyes of an average pig... even when properly aligned through the bung hole bulls eye.

A 160 grain alternative is the SAECO #316... a sweet slug in most any .30 cal.

Be realistic about your round, your range, your ability, and your gun. You will do fine.

[Boolit_Head]

I've never had a raccoon, armadillo, or coyote run away from a properly placed (non expanding solid) .22 shot either, or other edible "tough" targets several times their size...




Uhhh I have, took a raccoon one night at a feeder that sat through 5 hits with a 22 before he had enough and ran away. One was right through the boiler room and he made it 200 foot after the 5th round. Tough old coon didn't know he was supposed to fall over I guess.

[KVO]

[QUOTE=LongRangeAir;3385247]
"Here's a little trick I picked up. If you have a screw bit set with some star drives in it, select one that is just smaller than the opening of your HP. Press it in by hand. Firmly, but don't ham fist it. It will cause the HP to open a 6 petal flower. Sorta like the old Talon was Supposed to work, but never really die..."

^
The Torx bit swaging into the cast HP cavity can make a dramatic difference in expansion. I'm having lots of fun lately playing with various scewdriver bits. These were a T20 and the NOE 358156 clone @ 825fps, 20:1, Clear Ballistics gel.
210583
210584

Left two boolits had the torx treatment, right two as cast HP. Middle unfired for reference.

[MT Chambers]

I'd use a 160grain or lighter cast bullet(hollowpoint) at much higher speeds, this will flatten trajectory and cause bullet to expand.