Subsonic expansion of cast bullets

[Eamonn]

Hi, Iv'e read articles and forum posts here on and off for some years now and I am now in the process of completing my hunters exam in Sweden (which icludes both theroretical and practical exams with range estimation etc.)

I am curious about the expansion of low power cast bullet performance. I'll start with a bit of background.

The reason for my question is the swedish regulation for hunting and game:
Class 1 loads allows for all game to be hunted and requires either a 9 gram bullet to have 2700J or a 10 gram bullet to have 2000J. -Energy levels to be met at 100m.
Class 2 loads are more or less up to roe deer and are at least a 3.2 gram bullet with 800J at 100m.
Class 3 loads are up to fox and hare sized animals and requires a 2.5 gram bullet with 200J at 100m.
Class 4 are up to animals like rabbits and magpies and require 150J at the muzzle

Class one and two require an expanding bullet and any load (not rifle or caliber) that achieve the energy requirements with an FMJ is considered a class three.
Common calibers and classes are .22lr for class 4, .22 wmr and hornet for class 3, .222 and .243 for class 2, 6,5x55 with a hot load and upwards for class 1.


With this background the question for the day is what rifle if any I should use for close encounters with roe deer and fox with sound supressed subsonic loads while still being able to achieve moose prestanda with supersonic loads.

Many roe deer in Sweden are shot persued by slow dogs using shotguns and 5-3 shot at less than 30 meters.
My thought is to have a rifle capable of normal class one performance and subsonic class two performance.
www.norma.cc (http://www.norma.cc) has a great ballistics table where you can type in your own data and they have an english version as well.

Using this data it seems that a subsonic 400gr bullet at .1-.15 BC at 1000fps from a .45-70 would perform to class two subsonic specs and it would have no problem what so ever to reach moose prestanda with normal/supersonic loads.

My issue is the expanding bullet requirement. While unlikely the police can require a test shot for the speed/energy of the load used and as subsonic- and lead bullets are very out of the norm a police officer having a bad day could probably press the issue with "expanding bullet" wich could result in me having my weapons licenses revoked and prohibited.

The effect of a .45 slug, expanded or otherwise on anything living is not in question btw.

So how can one expect to find the expansion of a soft lead bullet at subsonic speeds?
And should gas checks be used and/or would they ruin a sound suppressor?

Also the argument to just buy more guns is invalid as regulations here say you may only have four rifles/shotguns as standard and may have two more but must give good motivation for owning them to the police.
Pistols and revolvers btw are given with five year licenses and need active membership in a sporting club with enterance in competitions for licenses to be had/continued. If you have been an active member for half a year you are allowed to buy a .22 pistol and after one year you may buy a pistol of heavier caliber.

[Artful]

Soft lead Hollow pointed will expand just fine

https://www.shootersforum.com/attachments/marlin-1894-lever-guns/3187d1128098363-lyman-457122-m1894-sectioned-bullet.jpg

https://www.shootersforum.com/attachments/marlin-1894-lever-guns/3126d1127261176-lyman-457122-m1894-blt-bases.jpg

Shoot your loads without the suppressor and if the gas checks stay on the boolits and everything is stable (no tumbling / key holing etc)
then put your suppressor on.

[MT Chambers]

Not a lot of help here, not familiar with joules or grams, but pure lead needs about 800 fps for any expansion, the Gould hollowpoint shown is prolly the best expanding slug at the low speeds when cast of pure lead or say 30-1.
Not knowledgeable about suppressors and gas checks but you do not need a GC design bullet at those subsonic speeds.

[Blammer]

Here is my opinion, on what I would do.

Put a HP or shallow dish HP on any caliber you may need expansion on. If you use regular wheel wt alloy, say 96/2/2 and don't water quench it will expand.

If you are going top velocity, 2000fps and up, water quenched will still expand, due to increased velocity.

You could also look at paper patching to up velocity with soft lead.

For suppressors, I would look to plain base only. JUST in case the GC may give issues. Plus with suppressed velocity you won't/shouldn't need the GC.

[kiwi]

155787This is a MP .308 hunting bullet 151 grain HP the recovered bullet was shot into a sheep at 40 metres at a velocity of 1040 fps
the lead mix is wheel weights and pure lead with 1% tin, as you can see in the picture the GC is still there I have sold thousands of these boolits
most have been fired through suppressors have not heard of a GC coming off, The GC is level with the base of the neck in a .308 when it is fired
the GC is crimped on harder by the rifling, the longest kill shot with this boolit I have heard of is 187 metres on a feral goat, on a deer it was a Fallow
deer at 100 metres both were subsonic, wether you could make the required joules with this boolits I don't know, but bigger diameter and real heavy
hollow points would work if the lead is soft enough,

[Artful]

So for Class 1
If I did the conversion correctly your 10 grams is only 154.324 grain bullets.

The Gould boolit I pictured is 330 grains so over 20 grams.
But that comes to 1.0951e+3 Joules at the muzzle at 1080
not 2000 Joules at 100 meters.

Even a 500 grain at 1080 fps is only 1.7554e+3 Joules.

To make 2000 Joules (at the muzzle) at 1080 fps you'd need
a boolit weighing 36.913 grams or 570 grains.

http://castboolits.gunloads.com/attachment.php?attachmentid=65955&d=1364705832
you can find .458 up to 720 grains - on the far right.
But you must have a twist that will stabilize that long a
boolit at 1080 fps.

http://www.castbulletengineering.com.au/bullet-moulds/rifle/458-calibre/458-730gc-single-cavity

If you are content to just quietly hunt Class 2, 3, and 4 I'd just
use the 330 HP Gould Boolit. Then boost the Velocity to 1800 fps to hunt Class 1 as that gives 3.2183e+3 Joules at the muzzle.

[runfiverun]

the core of jacketed bullets are lead, the copper jacket actually retards the leads expansion.
and more exposed lead at the tip [or an initiator like a plastic tip] makes the bullet expand faster.

convincing the police that a naked lead core expands should take all of one hammer blow.
or a slight explanation on the above.
putting it into terms like 'the jacket slows the lead from expanding' will convince them quick enough your cast bullet will work.

[white eagle]

Joules
I hate to be a d/a but what is this term?:shock:

[farmerjim]

Metric.
.74 foot pounds in the US.

[Artful]

Metric.
.74 foot pounds in the US.

More precisely
Joule
noun, Physics.
1.the standard unit of work or energy in the International System of Units (http://dictionary.reference.com/browse/International%20System%20of%20Units) (SI), equal to the work done by a force of one newton when its point of application moves through a distance of one meter in the direction of the force: equivalent to 10 7ergs, 0.2390 calories, or 0.738 foot-pound.

2. A unit of electrical energy equal to the work done when a current of 1 ampere is passed through a resistance of 1 ohm for 1 second or one watt-second.

Named after James Prescott Joule (1818–89, English physicist, who evaluated the mechanical equivalent of heat and contributed to the study of heat and electricity)

[xacex]

I thought Joules was a character in Pulp Fiction.

[nilz]

Another one reading the regulations wrong :) to be legal for class1 and 2 the bullit has to be CONSTRUCTED to expand
nowhere does it says at what speed.
This is a very common mistake here in Sweden
for j-word bullits just use any hunting bullit.. for Boolits use any hollowpoint.. of desired weight and diameter of course :)

Even if you seat a j-word huntingbullet backwords in the case its still a bullet CONSTRUCTED to expand and therfore legal..

[Smoke4320]

Another one reading the regulations wrong :) to be legal for class1 and 2 the bullit has to be CONSTRUCTED to expand
nowhere does it says at what speed.
This is a very common mistake here in Sweden
for j-word bullits just use any hunting bullit.. for Boolits use any hollowpoint.. of desired weight and diameter of course :)

Even if you seat a j-word huntingbullet backwords in the case its still a bullet CONSTRUCTED to expand and therfore legal..
So from above explaination
The 45/70 with 405 grain and up lead hp (is constructed to expand) would fit the subsonic role

[nilz]

So from above explaination
The 45/70 with 405 grain and up lead hp (is constructed to expand) would fit the subsonic role

yes! as long as the energy requirements are met!

[Swede 45]

Hello, Hej!
Well, the swedish hunting and weapon laws are a mess, and a bog to slowly sink in if you choose to walk the edges..

I have true story that might interest you.. Two swedish hunters was stopped on the Moose season opening at a police check on their way to their huntinggrounds. Normal, but unusual check.. Breathalyser for sobriety.. license for their guns, hunting permits and so on.. now, when checking their weaponlicenses and their guns (both shoot 45-70´s as they are both doghandlers and usually shoot at very short distances) they where asked to show their ammunition. Both shoots lead.. "no, these are not designed to expand, these are solids!" (both shoots wide flatnose boolits)

Argument ran hot at the scene, but the policemen confiscated their guns and reported them. After a long and complicated process with lawyers involved one of the hunters was convicted for breaking the huntinglaws of the "expanding bullet" requirement. Ammo was tested by the Swedish National Forensic Center. One hunters load expanded, homecast with a soft alloy, lighter boolit at higher vel.. guy went free..
The other hunters load, a hardcast commercial, heavier weight, lower velocity did not expand.. Both loads met the energy requirements.. so the case was built on the expansion of the boolits. Initial argument from the authorities stated that the boolits was solids (yep, cast boolis usually are made of lead only!)
and that they did not have any design that helped expansion (hollowpoint, softpoint as in jacketed SP´s or otherwise similar construction)
The hunter that casted his own counterstated that his boolits indeed was "designed to expand" by the careful selection of alloy he used and how he opted for a lower boolitweight and higher velocity to ensure expansion..
The hardcast commercial guy had no knowledge of the alloy, hardness of boolit, or the boolits expansionbehaviour in his load..

The NFC´s test medium was stated to "simulate the intended game". I don´t exactly know what media or how they calibrated that?
But as the law says, that the projectile has to be of an expanding design (for class 1 and 2 game) it´s probably ment so that the bullet/boolit has to expand in the game intended..
So I think, that with the "wrong" prosecutor you would be up the creek if you used a hard, but designed to expand bullet in the "wrong" application.
Lets say a Winchester failsafe that expands at warpspeed out of a 300win mag at a 500kg moose at 50yrds compared to the same boolit loaded soft in a 308win for a 25kg roedeer at 100yrds.. The 308 bullet would prolly act as a FMJ, even thou it is "designed" to expand..
A bog indeed!

[Smoke4320]

a pickle indeed

[Larry Gibson]

I've shot a lot of GC'd 311041HP sub sonic through a Sionics suppressor out of .308W rifles since 1980. The modern Crimp on pose no problem but loose fitting home made GCs may very well. PP'd bullets can cause a real problem. I shot a few of those and di not have any of the patch stay in the barrel but accuracy was very poor with known accurate loads in the same rifle w/o the suppressor. I suspected the PP was coming off the bullet and hitting the baffles upsetting the stability of the bullet. I didn't experiment that much as non PP'd achieved the same goal w/o the problem.

I've found that a GC'd subsonic 311041Hp cast of 30-1 or even 40-1 alloy can give excellent accuracy and will expand quite well at 700 or so fps depending on the medium.

Larry Gibson

[Eamonn]

Wow, thanks guys for all the great information. It seems the theory is valid and I will be keeping an eye out for a .45-70 lever rifle. It's between that and a .357 or .44 carbine for a dedicated class 2 rifle.


I have true story that might interest you..
A horror story indeed and the worst part is that it's all so arbitrary. Have they had their morning coffee yet or will they feel a need to mess up your day.

[Bigslug]

156000 To illustrate the hard vs. soft problem: 130 grain LBT flat noses shot into water-filled gallon milk jugs at about 1200 fps from a hybrid .32-20 / .310 Cadet. Bullet on the left is water-quenched wheelweight. Bullet on the right is cast of 20-1 lead/tin.

156001 The same 20-1 alloy in an NOE 180 grain flat nose from a .38-40 rifle at about 1350 fps.

Gas checks in a suppressor. . .hmmm. . .

They are certainly not necessary at the subsonic suppressor velocities you are planning for. HOWEVER, since you have that pesky "must be designed to expand" standard to adhere to, I would go with a gas check mold so that you can use a softer alloy and maintain accuracy with your higher velocity loads. I would suggest custom ordering from Veral Smith at LBT, and start by sending him a pound-cast of your chamber, a handful of the gas checks you plan to use, and in your instructions, specify the problems of Swedish regulation, the exact alloy that you plan to use, and that the gas checks must fit TIGHT due to your suppressor. His LFN design will give you a .32 caliber meplat that should feed in a Marlin just fine, and with 400 grains behind it, will hit like a bowling ball.

[Digital Dan]

A question arises as to what may work versus what is needed. I won't argue that a gas check can't be secured adequately for use in a suppressor. I ask however what happens if it does come off in the can?

I agree with the previous that paper patch is not suitable for suppressors.

Given subsonic velocity and lead bullets, run soft alloys and don't look back. I've been working on my project of late with 30:1, so far up to around 970 fps with good accuracy and zero leading. 30:1 alloy approximates the hardness of virtually all .22 RF ammo. My experience with that suggests quite clearly that expansion in the 700 fps range is iffy with round nose bullets. Up around 1100 fps a hollow point will mostly disintegrate if it hits bone. I always shoot bone, your mileage may vary.

Thru a suppressor:

http://img.photobucket.com/albums/v298/muddler/Guns/Sneezer/Ducks_zpscqr0rx5a.jpg (http://smg.photobucket.com/user/muddler/media/Guns/Sneezer/Ducks_zpscqr0rx5a.jpg.html)

3 shots:

http://img.photobucket.com/albums/v298/muddler/Guns/Sneezer/800X-3_zpsbn9jap3b.jpg (http://smg.photobucket.com/user/muddler/media/Guns/Sneezer/800X-3_zpsbn9jap3b.jpg.html)

[Artful]

Swede 45 - Very interesting story and thanks for sharing
- wonder if the hunter had a hollow pointed bullet they would have assumed it would expand, because if you cast a hard alloy the hollow point will either not expand at all or will fracture off.

I would work very hard to find out what media they use for this ballistic test and would be testing my cast on it for proof of expansion and just maybe carry a picture in my phone of the expanded bullet (dated before start of hunting season) as proof that
I had done due diligence to be sure my home made bullet expended. Heck, I would probably have a fired/recovered boolit
in a pill bottle to show the local Eco posse.

[big bore 99]

Just take a good sized hollowpoint and fill it up with wheel bearing grease. Surprising how well they expand.

[nilz]

Hello, Hej!
Well, the swedish hunting and weapon laws are a mess, and a bog to slowly sink in if you choose to walk the edges..

I have true story that might interest you.. Two swedish hunters was stopped on the Moose season opening at a police check on their way to their huntinggrounds. Normal, but unusual check.. Breathalyser for sobriety.. license for their guns, hunting permits and so on.. now, when checking their weaponlicenses and their guns (both shoot 45-70´s as they are both doghandlers and usually shoot at very short distances) they where asked to show their ammunition. Both shoots lead.. "no, these are not designed to expand, these are solids!" (both shoots wide flatnose boolits)

Argument ran hot at the scene, but the policemen confiscated their guns and reported them. After a long and complicated process with lawyers involved one of the hunters was convicted for breaking the huntinglaws of the "expanding bullet" requirement. Ammo was tested by the Swedish National Forensic Center. One hunters load expanded, homecast with a soft alloy, lighter boolit at higher vel.. guy went free..
The other hunters load, a hardcast commercial, heavier weight, lower velocity did not expand.. Both loads met the energy requirements.. so the case was built on the expansion of the boolits. Initial argument from the authorities stated that the boolits was solids (yep, cast boolis usually are made of lead only!)
and that they did not have any design that helped expansion (hollowpoint, softpoint as in jacketed SP´s or otherwise similar construction)
The hunter that casted his own counterstated that his boolits indeed was "designed to expand" by the careful selection of alloy he used and how he opted for a lower boolitweight and higher velocity to ensure expansion..
The hardcast commercial guy had no knowledge of the alloy, hardness of boolit, or the boolits expansionbehaviour in his load..

The NFC´s test medium was stated to "simulate the intended game". I don´t exactly know what media or how they calibrated that?
But as the law says, that the projectile has to be of an expanding design (for class 1 and 2 game) it´s probably ment so that the bullet/boolit has to expand in the game intended..
So I think, that with the "wrong" prosecutor you would be up the creek if you used a hard, but designed to expand bullet in the "wrong" application.
Lets say a Winchester failsafe that expands at warpspeed out of a 300win mag at a 500kg moose at 50yrds compared to the same boolit loaded soft in a 308win for a 25kg roedeer at 100yrds.. The 308 bullet would prolly act as a FMJ, even thou it is "designed" to expand..
A bog indeed! Yes! use a hollowpoint when using homecast , and know what you put in your cases.. one guy in your story obviusly did not.
In cases regarding handloaded ammo its up to the loader to prove the ammo meets regulations,, a quick call to the mfg of the comercial boolits would confirm iif they are constructed to expand or not....

[Good Cheer]

Heh, like the Deforest Kelly line in one of the trek movies, the bureaucratic mindset is a universal constant.

No doubt about it:
heavy boolit
soften the alloy
shallow hollow point
gas check
expanded boolit in a pill bottle for show and tell.


Oh yeah, and get a contract from the state to write an official bulletin (a little English pun that one) on how home casters may successfully meet the regulations!
:drinks:

[Crawdaddy]

An interesting read. I have crossed deer hunting in Sweden off my bucket list. A shame you guys have to put up with that.

[RogerDat]

And to think Ted Nugent was upset at the Canadian hunting laws. I agree best defense is an affirmative one. Especially one that convinces the officer on the scene that there is no need to proceed with further action. "You can go now, have a safe hunt" right at the check point is the least trouble. Carry examples in the pill bottle suggested that show expansion, maybe any print outs or work sheets that show the muzzle and down range energy of the load given the powder and projectile weight.

Probably work better than shooting the officious prick in the butt sideways and ask him "does that 400 grain soup can feel like it expanded? Or just went right through?"

One thing I believe (I could be wrong however) is much of the reason for expansion being designed into bullets was to allow/compensate for the smaller caliber at higher velocity designs that came out later. Early hunting rifles at the advent of black powder brass cartridges were lethal due to size, weight and velocity yielding a significant wound. Not expanding soft point jacketed or hollow point rounds.

[Don Fischer]

OTE=Bigslug;3474696]156000 To illustrate the hard vs. soft problem: 130 grain LBT flat noses shot into water-filled gallon milk jugs at about 1200 fps from a hybrid .32-20 / .310 Cadet. Bullet on the left is water-quenched wheelweight. Bullet on the right is cast of 20-1 lead/tin.

156001 The same 20-1 alloy in an NOE 180 grain flat nose from a .38-40 rifle at about 1350 fps.

Gas checks in a suppressor. . .hmmm. . .

They are certainly not necessary at the subsonic suppressor velocities you are planning for. HOWEVER, since you have that pesky "must be designed to expand" standard to adhere to, I would go with a gas check mold so that you can use a softer alloy and maintain accuracy with your higher velocity loads. I would suggest custom ordering from Veral Smith at LBT, and start by sending him a pound-cast of your chamber, a handful of the gas checks you plan to use, and in your instructions, specify the problems of Swedish regulation, the exact alloy that you plan to use, and that the gas checks must fit TIGHT due to your suppressor. His LFN design will give you a .32 caliber meplat that should feed in a Marlin just fine, and with 400 grains behind it, will hit like a bowling ball.[/QUOTE]

Like that photo. I made up a lot of 20-1 ingot's several years ago thinking I might try hunting with cast in rifle. Well gonna do it in 2016 but had never seem a photo of what the bullet might do. I like that! But some time this spring I will get out and shoot into either milk jugs of water or soaked phone book's just to see if I come close to that. My bullet will be a 180gr Lee but I've got a HP tool for them and will try them as hollow point's. Waiting for the tool to get here I tried doing a few by hand. The 1/16" point doesn't look exciting to me so I followed the 1/16" with a 1/8" hole. Still didn't look all that great so I took a reamer I made to get inside flash holes and dit a couple quick twist with it and lot better looking. I noticed in the photo of the bullet cut in half, the HP goes very deep, mine don't. Goes in about 1/4" and tapers back to the nose. People claim a flat nose will mushroom well so I figured I'd give it a running start with the wider HP and tapered inside. I'll try them out when the weather get's better. oh, the bullet's I'm using came out to 14 BH

[Brett Ross]

I hollow point my handgun hunting rounds as we have a expanding bullet clause here in Iowa for handguns. I spoke to the DNR and explained a soft cast boolet WILL expand but got no-where. I decided to just give in and hollow point my boolits to make them happy.

[TXGunNut]

I'm pretty sure I'd have to ask how may 6.5mm bullets expanded to .458 but I'm pretty sure logic wasn't welcome in this courtroom. A 45 caliber boolit doesn't need to expand to kill, mine are designed to make big, deep holes and they seldom fail.

[Bangbangman]

To paraphrase Dicken's Mr Bumble:

"If the law supposes that... the law is an ***!"

Here in UK we, too, must use bullets "designed to expand" for hunting deer. The specific m/e and velocity requirements vary for species and are different in Scotland, too.

Hence I have cast this gas-checked HP Mihec 305gr boolit which is clearly "designed to expand":

http://i68.photobucket.com/albums/i10/xavierdoc/more%20pics/7BDB9876-677A-4DBF-A6D5-0FF07DAB8B72.jpg (http://s68.photobucket.com/user/xavierdoc/media/more%20pics/7BDB9876-677A-4DBF-A6D5-0FF07DAB8B72.jpg.html)

http://i68.photobucket.com/albums/i10/xavierdoc/more%20pics/104D6F8F-610C-4A34-930C-4861E48E25AB.jpg (http://s68.photobucket.com/user/xavierdoc/media/more%20pics/104D6F8F-610C-4A34-930C-4861E48E25AB.jpg.html)


I am sure they would expand at subsonic velocity but the muzzle energy is 1013J at 1050fps, so wouldn't meet your Swedish 100m threshold. The mold comes with shallower HP pins, which would increase the weight and thus energy, but I doubt it would get you to 1000j at 100m (can't recall your velocity limit- might also be a problem.)

Here in the UK, I'd prefer to hunt with my Mjöllnir (excuse my spelling)- a 460gr, large meplat, GC design made to fit my Marlin 1895 45-70 (tel:1895 45-70):

http://i68.photobucket.com/albums/i10/xavierdoc/more%20pics/2D3BB5E4-AAD9-4EF5-AEAE-B99E2BF812D4.jpg (http://s68.photobucket.com/user/xavierdoc/media/more%20pics/2D3BB5E4-AAD9-4EF5-AEAE-B99E2BF812D4.jpg.html)

...but until I fire some into a "deer simulator" (lots and lots of wet newspaper) to demonstrate they do expand, I think it's safer (legally) for me to use the HP design. (When I do hunt with Mjöllnir, velocity will be sub 1700fps.)

In reality, the chance of being challenged by Police would be very low.

This bullet would probably work subsonically but you'd have to make sure your alloy was sufficiently ductile to deform. Perhaps carrying a recovered, expanded boolit from testing would be useful to show your Police in the event of being challenged.

[Bangbangman]

Ha- I can't believe Charles Dickens triggered the swear filter! The censored word is a synonym for "donkey"; nothing anatomical.

[richhodg66]

This is a very interesting thread, and I'm happy to see that at least some of our brothers across the pond are able to enjoy some of the things we do here and take for granted. Seems all you hear in the states is how "the USA is the ONLY country where (fill in the blank) takes place". You'd think gun ownership was non-existent outside our biorders.

[Digital Dan]

Couple or three images on the topic, first being a .22 short bullet retrieved from the neck of a hog after penetrating the skull front to rear. MV was in the mid 700 fps range. CCI advertises 710 fps MV but they travel a bit quicker from my rifle.

http://img.photobucket.com/albums/v298/muddler/Guns/DSCN0520_zps7db471ca.jpg (http://smg.photobucket.com/user/muddler/media/Guns/DSCN0520_zps7db471ca.jpg.html)

The path:

http://img.photobucket.com/albums/v298/muddler/pig%20pen/DSCN2968_zps85ccff04.jpg (http://smg.photobucket.com/user/muddler/media/pig%20pen/DSCN2968_zps85ccff04.jpg.html)

http://img.photobucket.com/albums/v298/muddler/pig%20pen/DSCN0550_zps4461c968.jpg (http://smg.photobucket.com/user/muddler/media/pig%20pen/DSCN0550_zps4461c968.jpg.html)

The 180 grain bullet used in the Sneezer, 30:1 alloy, retrieved from a sand berm, velocity in the 900 fps range:

http://img.photobucket.com/albums/v298/muddler/Guns/Sneezer/Bullet%20meet%20dirt_zpsvy42l3co.jpg (http://smg.photobucket.com/user/muddler/media/Guns/Sneezer/Bullet%20meet%20dirt_zpsvy42l3co.jpg.html)

[missionary5155]

Greetings
Without reading all the previous posts Near pure lead will expand at sub-sonic velocities. 3F BP pistol loads in 45 colt which come close to the desired velocity will expand... at least my 40-1 mix does.
If you desire more expansion then use a flat nose type (smash it flat or file) or with a razor knife slice a groove across the round nose lengthwise. Scructural imperfections tend to lend to cast expansion.
Mike in Peru