Meplat equal to bore diameter?

[Obturation]

Hey all,
Looking for some wisdom on projectile design. Of course i'm familiar with wad cutters, my question is - why dont we see many projectiles that are cylindrical ? I've seen the 700 grain 500 magnum cartridges underwood makes, they appear to have a slight shoulder from the pictures but have never seen one in person. My question stems from the fact that i have a quantity of 1/2" copper rod and a friend with a proper lathe. Curious if its tabboo to turn some down for use as revolver projectiles or if thats something that has/can be done. I know copper projectiles are common now but something about this just seems wrong. I suspect theres a reason we dont see such pojectiles offered, just wondering why. I would think with a large meplat and sturdy construction they would be effective. Not that this project would be cost or time efficient, just wondering if i should tinker with it.
Appreciate any input, thanks.

 

[WrongHanded]

I seem to recall a number of somewhere around 85% being the preferred maximum meplat diameter, based off projectile diameter. I think it's regarding terminal stability, and how a bullet with a larger meplat than that doesn't create a consistent wound track (tumbling maybe?).

 

[LiveLife]

why dont we see many projectiles that are cylindrical?

We do, wad cutters.

Double end wad cutter - https://www.berrysmfg.com/item/bp-38-357-148gr-dewc#

Hollow base wad cutter - https://www.berrysmfg.com/item/bp-38-357-148gr-hbwc

 

[243winxb]

1/2" copper rod

The bearing surface greatly increases pressure. Barnes bullet history is proof. Grooves have lowered friction and fouling.

 

[Obturation]

We do, wad cutters

Yeah, i know - i meant where the projectile protrudes from the case .

The bearing surface greatly increases pressure. Barnes bullet history is proof. Grooves have lowered friction and fouling.

This makes sense, i would imagine with such a long bearing surface it would raise pressure very quickly. Hadn't considered that but i'm sure thats the reason this isn't done.

 

[Texas10mm]

Many wadcutters are seated so that a portion of the bullet protrudes from the case.

 

[Varminterror]

If you’re turning the bullets, go ahead and turn an ogive and a smaller diameter meplat. Even a crimp groove (or roll on a cannelure).

 

[Obturation]

If you’re turning the bullets, go ahead and turn an ogive and a smaller diameter meplat. Even a crimp groove (or roll on a cannelure).

I didnt want to spend a ton of time on each bullet, was going to cut to diameter, cut a crimp groove and part each off . I also didnt think consistancy would be perfect as its a manual lathe. Might still do it, depends on how busy my summer is.

 

[Varminterror]

Grandpa always said, “if something’s worth doing, then it’s worth doing right.”

 

[tightgroup tiger]

Do you know what kind of copper rod it is? Is it really hard, really soft? Electrolytic copper is really hard and not suitable for making bullets out of, neither is Beryllium copper, it just plain sucks. Some copper alloys aren't even machinable. I had some copper alloy plates out of a transformer that I could barely drill a hole through. Took three drill bits. Looked like normal copper or bronze plate.
If you rod is pure copper or is a softer alloy of copper you'd be fine machining bullets out of it.
Just remember if the alloy in your rod is to hard it won't engrave real well to the rifling in your barrel and could cause a serious problem.

 

[mdi]

My wild guesses about a cylinder of copper used as a bullet would be first what effect, if any would a straight sided copper cylinder have on the forcing cone of a revolver? Or the forcing cone have on a full caliber copper cylinder. The copper would have to be relatively soft. Lead is easily formed/swaged by a gun's cylinder throats, forcing cone and barrel, but solid copper may need a taper to get the bullet started straight and "gradually". I believe 243winxb had the right answer about pressure and adding grooves.

I think one of the reasons we haven't seen more development of bullet materials is lead is nearly perfect material for bullets. "No Lead" areas like CA have forced the development of solid copper bullets, but I believe so far, lead is still the ideal bullet material.

FWIW; wadcutters are like any other bullet, they are seated to any depth the reloader or gun deems proper. I have seated 38 wadcutters out long the barely fit inside the cylinder as an experiment, and many seated to about 3/16"-1/4" out of the case, which worked quite well for a particular revolver...

 

[reddog81]

but I believe so far, lead is still the ideal bullet material.

Dense, malleable, low melting point, and cheap. Makes it about perfect. Add in small amounts of tin and antimony to help with fill out and make slightly harder and you're good to go. Much easier to work with than anything else out there and better for most applications.

 

[Mizar]

...why dont we see many projectiles that are cylindrical ? I've seen the 700 grain 500 magnum cartridges underwood makes, they appear to have a slight shoulder...

Apart from the obvious problem with higher pressure, especially with hard materials like copper, you might not be able to fully seat the loaded cartridge into the cylinder depending on the diameter of the chamber throats - many revolvers have throats slightly smaller than barrel diameter. You can tweak your bullet design to a specific revolver, or ream the throats, but bullet/cartridge manufacturers don't have that as an option.

 

[forrest r]

Just make sure your copper is soft, people have been shooting steel core ammo for decades. Steel core ='s as the name implies a steel with either steel/tin/brass/copper jacket.

The real issue you'll face is accuracy. Several years back I bought a h&g #38 clone bullet mold to cast "ness" bullets for the 30cal's. The ness bullet is a bullet that is designed to dispatch vermin out of gardens at shorter ranges but implode upon impact, hence no ricocheting. The problem with the ness bullets is accuracy. They'd do 1" or better @ 50yds but the groups open up to +/- 3" @ 100yds. The ness bullet has a bore riding nose.


I have 308 swaging dies so I bought some jackets and started testing bullets. I started with flat nosed jacketed bullets (wc's) and ended up with the accuracy as the ness bullet. I made a nose forming die and started forming noses on the swaged bullets bring them out/longer a little at a time. It got to a point where the exposed lead nose was too long and nose slumping occurred and accuracy suffered. The end result was these bullets, they aren't pretty but the easily do moa @ 100yds .


That jacketed bullet pictured above hit extremely hard and the soft lead nose/core mushroomed out impressively. I did make a couple bullets shaped like those jacketed bullets above from brass rod and tested them. Accuracy wasn't quite as good as the swaged jacketed bullets (I'm thinking bullet base). I never did recover them, they went thru 4 bundles of wetpack that was setup @ 100yds. Bundle of wetpack ='s 12" of newspaper bundled together and soaked in water overnight.

Anyway just make sure the copper is soft/annealed and that you have a little taper on the shoulder/nose of the bullet. For some reason meplats of 80% or less of the bullets diameter is recommended for pistol bullets.

 

[Obturation]

Do you know what kind of copper rod it is? Is it really hard, really soft? Electrolytic copper is really hard and not suitable for making bullets out of, neither is Beryllium copper, it just plain sucks. Some copper alloys aren't even machinable. I had some copper alloy plates out of a transformer that I could barely drill a hole through. Took three drill bits. Looked like normal copper or bronze plate.
If you rod is pure copper or is a softer alloy of copper you'd be fine machining bullets out of it.
Just remember if the alloy in your rod is to hard it won't engrave real well to the rifling in your barrel and could cause a serious problem.

No, dont know the exact alloy or hardness. It was pretty clear why this design doesnt exist after a few responses to this thread. So yeah, im not going to try this project out. I really appreciate the knowledge and wisdom ive found on this forum. Its been such a valuable resource of information and i thank you all. I guess i should just get busy loading my standard stiff as i dont think ill be hitting the range for a couple months, we just had a new baby 2 weeks ago and my other daughter just turned 2 - ive got my hands full and the wife can use all the help i can muster.
Thanks all

 

[tightgroup tiger]

Well congradulations on the new baby.
You will have your hands full for a while.
Take care.

 

[Mowgli Terry]

There is an article by Glen Fryxell on lead wadcutters out there. At one time there was such a wadcutter(s). It was a special purpose bullet limited use and accuracy as I recall. This was the third sort of WC. The second type in common use now. It's worth a read if you have interest in this area. Yes, I forgot the name of the article or chapter.

Addendum: On memory. Don't get smart it may happen to you. What was it we were talking about?

 

[forrest r]

There is an article by Glen Fryxell on lead wadcutters out there. At one time there was such a wadcutter(s). It was a special purpose bullet limited use and accuracy as I recall. This was the third sort of WC. The second type in common use now. It's worth a read if you have interest in this area. Yes, I forgot the name of the article or chapter.

Addendum: On memory. Don't get smart it may happen to you. What was it we were talking about?

Yes but even the "type 3" wc's struggle much past 60yds. Owned/tested/shot a lot of cast and swaged wc's over the years. Thinned the herd but I still keep these 44cal wc/hbwc molds around.


Type 1: a wc/hbwc that is flat on both ends (top center & bottom right)
Type 2: button nosed wc (top left)
Type 3: a wc that has a tapered nose with a flat face (top right & bottom right)

 

[Texas10mm]

There is an article by Glen Fryxell on lead wadcutters out there. At one time there was such a wadcutter(s). It was a special purpose bullet limited use and accuracy as I recall. This was the third sort of WC. The second type in common use now. It's worth a read if you have interest in this area. Yes, I forgot the name of the article or chapter.

Addendum: On memory. Don't get smart it may happen to you. What was it we were talking about?

http://www.lasc.us/Fryxell_Book_Chapter_11_Wadcutter.htm