Meplat and metal type for solid slug

[hkr]

I'm revisiting a project from a year or two ago, making custom 12 gauge slugs, due to the dearth of brenneke style slugs in Canada. Back then I tried turning brass and copper to just under bore diameter and swapped them into a 3" foster slug shell of equal slug weight. They worked ok but I didn't do very extensive testing because they were too much work to make. Now I am trying gluing a piece of 5/8" round bar in a shot cup.

I have been reading all I can find on the affect meplat size has on ballistic and terminal performance. From what I have gathered, the larger the meplat, the greater the permanent wound cavity will be. The bullet will be less prone to deflection and will track straighter within the target due to more forward mass (although this is less relevant with longer bullets). It will also be less likely to deflect off a shallowly angled hard target such as a bowling pin or bear skull. The ballistic drawback is that velocity decreases more quickly the larger the meplat, and the bullet can become unstable at longer distances (eg. ~75 yards for a full wadcutter).

Given the intended target is a larger predator at less than 50 yards, I think as close to full bore meplat as possible would provide the best performance. Am I on track? Most of the info seems to be on meplat of 70-80% max.

Secondly, when I fired the solid copper and brass slugs into solid wood, deformation was negligible. Because of this I'm considering using steel because it's cheaper (also the metal store was closed on the weekend when I made the first batch). Is there any benefit I'm missing to using a denser, softer metal like copper or brass? Length doesn't appear to be an issue in the first batch I made, and the slug is in a shot cup so it won't touch the bore.

I'm trying a few different shells and swapping the bird shot for a slug of the same weight, secured in place with hot glue while in a mold to ensure it isn't oversized. Trying a few different variations for fun while I'm at it but the two primary ones are spec'd at 1 1/8 ounce at 1635 fps and 1 3/4 ounce at 1330 fps, although velocity will be less as the barrel is only 8.5" Would either of these stand out as the better choice for this application, given that they have simlar ft lbs energy? I read once that momentum was more important for penetration in large game, but I think a 5/8" rod is already going to penetrate very well on the lighter end, so perhaps the velocity would be more beneficial in this case to create a wider wound channel.

Thanks in advance for any advice. I will be sure to post pictures when I have a chance to visit my 'test facility'

 

[antiqueguy]

id stay away from steel and id would most likely do the same for copper and brass especially in a load where yor subing slug for shot

i'll stick with lead slugs and round balls a hard cast round ball is not something to take lightly

 

[hkr]

Do you mind elaborating why you wouldn't use those metals?

I wasn't happy with the lead foster slug performance on anything solid, they just pancake and then disintegrate. I'm sure a solid lead slug would perform much better. From the pictures of recovered solid lead slugs I have seen, expansion is minimal; however the edge of the meplat tends to get smeared off, which means it is effectively reduced as it moves through the target. A harder metal would keep this sharp shoulder and presumably continue to produce the associated wider wound channel as it moved deeper into the target. That's my interpretation anyway, happy to discuss.

Yes, I certainly wouldn't want to be on the receiving end of a .73 round ball! But wouldn't comparing a 100% meplat cylindrical slug to a round ball be similar to comparing a round nose bullet and a wide meplat bullet? From the reading I have done, the wide meplat bullet has superior terminal performance, so I would think the same would apply in this situation.

 

[trevj]

With a cylinder bored barrel, you can pretty much stick what you want in there.

If it has to go through a choke, you want some compressibility. That is what all the ridges and 'rifling' on the commercial slugs is about.

I'd suggest that worrying about the smearing of the metplat, is worry time poorly spent. Once you punch a 3/4 inch-ish hole in anything, the terminal effects are pretty much established.

Now, YOUR mileage may vary, but I'd look at something like a wrap of cereal box cardboard around a harder than lead slug, maybe in two pieces, inside the shot cup, if you were going to go that way (brass, leaded free machining steel, etc.) just on the off chance that someone got it into their head to try your slugs out in their choked gun.
Other than that, have fun and be safe!

Cheers
Trev

 

[willisjake]

Oh wow...where to start......

Go get a slug mould from Budget Shooter. They are cheap and produce a great slug. I use the 7/8 slug. It is very tip heavy and they fly very well.

It took a while to get the load figured out, but now that I have it dialed in I can produce far better groups that any factory slug load.

As far as stopping power......If I hit it at 50 yards, it wont be getting back up. They will punch holes in steel fry-pans no problem.

While I have never fired one at a bear, I am confidant it would do the job.

I would not waste too much time coming up with a MacGyver load. You can get the Mould for 30$ and you are off to the races.

Then if you are casting your own slugs there are a number of things you can do to harden the slug, such as quenching the hot slug or adding tin to the mix, or both....

You mention you want to shoot large predators, but are unhappy with the slugs performance against solid targets. Apples and oranges.

That is my two bits.

Cheers

 

[hkr]

With a cylinder bored barrel, you can pretty much stick what you want in there.

If it has to go through a choke, you want some compressibility. That is what all the ridges and 'rifling' on the commercial slugs is about.

I'd suggest that worrying about the smearing of the metplat, is worry time poorly spent. Once you punch a 3/4 inch-ish hole in anything, the terminal effects are pretty much established.

Now, YOUR mileage may vary, but I'd look at something like a wrap of cereal box cardboard around a harder than lead slug, maybe in two pieces, inside the shot cup, if you were going to go that way (brass, leaded free machining steel, etc.) just on the off chance that someone got it into their head to try your slugs out in their choked gun.
Other than that, have fun and be safe!

Cheers
Trev

They will only be fired through cylinder bore. I can't envision a situation where someone would try the slugs without me handing them over, so I think labeling should suffice. Also if I'm wrapping them with cardboard I won't be able to permanently attach the shot cup to them, so they won't be stabilized any more. Regarding the meplat, are you saying it's basically diminishing returns once your projectile gets up to this size, whereas with smaller bullets like 45-70, there is more of a need to maximize the effects of the round?

Oh wow...where to start......

Go get a slug mould from Budget Shooter. They are cheap and produce a great slug. I use the 7/8 slug. It is very tip heavy and they fly very well.

It took a while to get the load figured out, but now that I have it dialed in I can produce far better groups that any factory slug load.

As far as stopping power......If I hit it at 50 yards, it wont be getting back up. They will punch holes in steel fry-pans no problem.

While I have never fired one at a bear, I am confidant it would do the job.

I would not waste too much time coming up with a MacGyver load. You can get the Mould for 30$ and you are off to the races.

Then if you are casting your own slugs there are a number of things you can do to harden the slug, such as quenching the hot slug or adding tin to the mix, or both....

You mention you want to shoot large predators, but are unhappy with the slugs performance against solid targets. Apples and oranges.

That is my two bits.

Cheers

MacGyver? Come on, I haven't even broken out the duct tape yet! Point taken, but I do enjoy the process of creating something different and testing it, even if it means I am sometimes reinventing an inferior wheel.

Thanks for the tip on the mould, that is a very reasonable price, I will look into that. Have you recovered any of these slugs to see how they stand up?

It's true, bears haven't wised up and started donning armor yet, but nor are they a uniform blob of ballistics gel. It seems reasonable to test on a medium that includes hard elements. To be fair, perhaps the end grain of a 6x6 I used last time was not the best medium. This time I plan on layering wet newspaper and wood, with sandbags to capture the slugs. It's the most realistic I could think of without spending a lot, and will be relatively consistent for each slug, so that I can make a valid comparison.

 

[antiqueguy]

Do you mind elaborating why you wouldn't use those metals?

I wasn't happy with the lead foster slug performance on anything solid, they just pancake and then disintegrate. I'm sure a solid lead slug would perform much better. From the pictures of recovered solid lead slugs I have seen, expansion is minimal; however the edge of the meplat tends to get smeared off, which means it is effectively reduced as it moves through the target. A harder metal would keep this sharp shoulder and presumably continue to produce the associated wider wound channel as it moved deeper into the target. That's my interpretation anyway, happy to discuss.

Yes, I certainly wouldn't want to be on the receiving end of a .73 round ball! But wouldn't comparing a 100% meplat cylindrical slug to a round ball be similar to comparing a round nose bullet and a wide meplat bullet? From the reading I have done, the wide meplat bullet has superior terminal performance, so I would think the same would apply in this situation.

well one little issue could happen the slug could turn in the barrel not a good thing the fact your using factory loads and subing this way is even worse

a hard cast .69 round ball with drill through a 4x4 no problem its around 1 1/8oz the reason the foster slugs from factory dont hold together is they driving them too fast a pure lead hollow based slug can only take so much

a round ball will punch and leave a big hole so will a round nose slug smaller calls really depend on meplat a shotgun slug will leave a nice hole

 

[willisjake]

Get yourself a Lee or Lyman Shotshell reloading book. Or google the Data. As you read up on reloading the one thing that you will not is how big of a change in chamber pressure you get with just little changes on projectile weight. Be careful, you are now on the path that leads to blowing up a gun.
As for cheap ballistics gel, try 4l milk jugs filled with water. Don't worry they are very solid when the Slug hits them at 1400 feet per second or 950 mph. Four in a row should do it. If you look around you can find the ballistic conversion for water
We shot gongs on Friday with the more accurate 7/8 oz Lee slugs. At 50m they were punching holes in mild steel. I recovered a few that we mostly intact and badly deformed.
I took a few shots at a stump and had very good penetration. Too deep for me to take the time and dig them out.

And Finally, Never shoot "wax" slugs. While cheap to make they are very dangerous. Drop one in a warm barrel and they can fall out of the end of the hull. The resulting bore obstruction could remove your hand.

They will only be fired through cylinder bore. I can't envision a situation where someone would try the slugs without me handing them over, so I think labeling should suffice. Also if I'm wrapping them with cardboard I won't be able to permanently attach the shot cup to them, so they won't be stabilized any more. Regarding the meplat, are you saying it's basically diminishing returns once your projectile gets up to this size, whereas with smaller bullets like 45-70, there is more of a need to maximize the effects of the round?



MacGyver? Come on, I haven't even broken out the duct tape yet! Point taken, but I do enjoy the process of creating something different and testing it, even if it means I am sometimes reinventing an inferior wheel.

Thanks for the tip on the mould, that is a very reasonable price, I will look into that. Have you recovered any of these slugs to see how they stand up?

It's true, bears haven't wised up and started donning armor yet, but nor are they a uniform blob of ballistics gel. It seems reasonable to test on a medium that includes hard elements. To be fair, perhaps the end grain of a 6x6 I used last time was not the best medium. This time I plan on layering wet newspaper and wood, with sandbags to capture the slugs. It's the most realistic I could think of without spending a lot, and will be relatively consistent for each slug, so that I can make a valid comparison.

 

[SandRoad]

In response to your question about bullet/slug frontal area, at shotgun velocities it's not going to make much difference. Just like a 22 hollowpoint doesn't expand very well. As for shooting them at a "solid object", well, you aren't going to get everything you want out of a shotgun slug. It's either going to be expansion OR penetration. Not both.

At rifle velocities, there is definitely a shock force transmitted, but again, it depends on velocity, higher the better. Take a look at Woodleigh Bullets, they have an example of what you are looking at. Tradeex carries them

http://www.woodleighbullets.com.au/products/hydrostatically-stabilised


However keep in mind, that if you go with a longer slug, it's going to need much quicker rifling to stabilize the projectile. I believe most rifled slug barrels are around 1:28 to 1:34 twist. So, short projectiles only or they won't stabilize.

http://kwk.us/twist.html

If your barrel isn't rifled, use round ball.

 

[hkr]

I ordered a chronograph so I'll wait until that arrives to shoot these, so I have a better handle on their performance and can do it a bit more safely. Found some DGS-12 slugs made by Ballistic Products at the gun show on the weekend, so I picked up 50. Hopefully it was a good move, we'll see how they do.

For now here is a quick shot of what I will start with and then go from there based on the results. Hopefully the DGS do well and I can just load them up and be done. For this year anyways

From left to right, weight includes shot cup/wad as they will be attached to slug in flight, except for #5:

1. 825 grains - 1/2" copper cap and pipe partially filled with melted birdshot.
2. 825 grains - 5/8" steel round bar.
3. 570 grains - 1/2" copper cap and pipe partially filled with melted birdshot.
4. 570 grains - 5/8" steel round bar.
5. 548 grains - 1 1/4 oz Federal 3" foster slug.
6. 502 grains - DGS-12 slug.

Get yourself a Lee or Lyman Shotshell reloading book. Or google the Data. As you read up on reloading the one thing that you will not is how big of a change in chamber pressure you get with just little changes on projectile weight. Be careful, you are now on the path that leads to blowing up a gun.
As for cheap ballistics gel, try 4l milk jugs filled with water. Don't worry they are very solid when the Slug hits them at 1400 feet per second or 950 mph. Four in a row should do it. If you look around you can find the ballistic conversion for water
We shot gongs on Friday with the more accurate 7/8 oz Lee slugs. At 50m they were punching holes in mild steel. I recovered a few that we mostly intact and badly deformed.
I took a few shots at a stump and had very good penetration. Too deep for me to take the time and dig them out.

And Finally, Never shoot "wax" slugs. While cheap to make they are very dangerous. Drop one in a warm barrel and they can fall out of the end of the hull. The resulting bore obstruction could remove your hand.

Thanks for the safety tips. I will do some further reading before proceeding. And not interested in wax slugs at this point, not going for a home defense or breaching round here, but that is good to know for future reference.

I'll look in to just testing on water, or at least using that for the 'soft' portion, would be more convenient. But I suppose it wouldn't show permanent cavity like wet paper would, would be nice to know both how deep it will go and what it will do on the way.

In response to your question about bullet/slug frontal area, at shotgun velocities it's not going to make much difference. Just like a 22 hollowpoint doesn't expand very well. As for shooting them at a "solid object", well, you aren't going to get everything you want out of a shotgun slug. It's either going to be expansion OR penetration. Not both.

At rifle velocities, there is definitely a shock force transmitted, but again, it depends on velocity, higher the better. Take a look at Woodleigh Bullets, they have an example of what you are looking at. Tradeex carries them

http://www.woodleighbullets.com.au/p...lly-stabilised


However keep in mind, that if you go with a longer slug, it's going to need much quicker rifling to stabilize the projectile. I believe most rifled slug barrels are around 1:28 to 1:34 twist. So, short projectiles only or they won't stabilize.

http://kwk.us/twist.html

If your barrel isn't rifled, use round ball.

Thanks for the Woodleigh link, some interesting pictures there on gel tests between expanding, flat nosed, and fmj. At this point I'm going to go with a wider diameter slug than those bullets. Sounds like a second vote for round ball, is there a source for these in Canada, or have to cast yourself?