The Solid Bullet Debate

[edge]

The sabots are PVC type II.

It is a compromise material that is cheap, easily machined, impact strength, and shears cleanly.
Chlorides are released when shot at my velocities, over 3000 fps, and the barrel MUST be cleaned afterward or it will rust

edge.

 

[noel carlson]

Edge,

This question is directed specifically to you, but I would appreciate informed response from anyone with experience in this area.

The article which you linked, at the start of page 11 of this thread, had a section discussing the mechanics of cavitation. It's basic assertion is that a flat nose, of nominal bore diameter, will cause greater tissue disruption than a "mushroom" projectile deformation.

It has been bothering me since I read it, as it seems to take no account of mushroom diameter. What direct experience do you have with this claim, and are there any good gelatin studies on this subject?

Best,
Noel

P.S. ; That is a clean sabot design. Too bad we can not come up with something like that for breech loaders.

 

[Pdvdh]

Paul,

With that allowance, do you have any suggestions for a suitable case?

- Noel

In 30 caliber, I'd bet the majority of LRHs in the States interested in pursuing a preemo bullet are using one of the following three cartridges:
300 RUM
300 Win Mag
300 Win Short Mag

Of these three cartridges, the die-hard - dedicated to shooting at the very longest ranges - are probably shooting the 300 RUM to obtain the highest muzzle, and down-range, velocity. However owners of rifles chambered in any of these cartridges could be equally interested in a 190-200 grain high performance solid bullet. Some may need to re-barrel, and that would be an added expense. Some wear their barrels out every three years and re-barreling is just part of their standard operating procedure.

I mentioned RWS because RWS makes 300 Win Mag brass, however Lapua does not as of about 1 year ago, and I consider RWS and Lapua to be the best of the best.

I didn't understand the rationale on the brass issue, however I don't think brass will control who would - or who wouldn't - buy these bullets. The guys who have 30 calibers have already found a way to make do with the brass currently available for their cartridge. Many LRHs will be reloading their own ammo and they can make decent ammo from a variety of brands of brass cases. Some sort cases by tossing the losers and keeping and loading what they believe to be the winners. Others outside neck turn, primer pocket uniform, flash hole debur, etc..., taking measures to improve the quality and consistency of run-of-the-mill cases.

Best regards,

 

[MontanaRifleman]

MR,

If I gave you a reasonable assurance of a G1 BC of ~1, you could be certain to be disappointed .

Hmmm...

Realistically, the BC range would fall in the mid-to-upper .6's (but do not quote me on this because I do not rely on guesses). Now let me move up to a non-magazine compatible 6.5, or 7.0 caliber projectile, and I can guess a little higher (but still, don't hold me to a hard number ... same reason).

In all seriousness, I will commit to you that a ZA bullet out-classes anything of equivalent weight, in a given caliber.The rub is a higher twist-rate requirement.

A 190+ ZA bullet in the mid to upper .6's BC Would br running neck and neck with maybe a slight advantage over some existing 30 cal bullets (Berger 210, JLK 210, and SMK 240) If the ZA showed increased velocity with driving bands coupled with a lower expnding velocity, that would increase the advantage.

Low-velocity expansion I have no problem giving you an assurance on.

On the flipside, your 338 bullet has a 3100 fps upper limit. In the bigger 30 cal mags that will easily be exceeded. I would think a 190-200 30 cal ELRH bullet would need an upper limit of about 3500 or more. The GS 177 is currently being shot @ 3650 fps in a 30-338 LM Imp.

My reason reason for a Lapua, or Norma case preference (not necessity), is that I would prefer the end user not have to rework the brass to match grade, and like the idea of re-supply being well developed. It has an indirect bearing on the success of the projectile.

As Jon said, sounds like the 30 338 LM variations would be good test rifles, but as phorwath mentioned, I think other brass would be usable. The Rem 300 RUM brass seams to have a good rep.

-MR

 

[MontanaRifleman]

I was talking about the 177 GS HV that MR had brought up and the pic of it on their site, which is quite a bit different than the one shown on your bullet. I felt the difference between it and the VLD's to overall drag wasn't significant enough to bother mentioning, which is why I didn't and only brought up the nose length. Yours seem to have a couple features that I'd really hesitate to speculate about.

Jon

In the spirit of beating a dead horse a little more... I measured the noses of the 210 Berger (~.82, BC of .631) and the 180 HAT (~.84, reported BC of .7+) According the the GS site, the 177 HV has a nose length of .82 The over shapes of these three bullets "appears" to be very similar with the exception of a larger HP meplat on the 177. Now I have heard form someone who has some, that the HP is not all that large (wish I had some on hand) Sooo, IMHE A BC of ~.6 or more is not far fetched, but I am only a novice layman in this field. Anyway, this all speculative conversation (but it's fun). The proof, or lack of, will be in the shooting.

It would be really cool though if it were the magic bullet

-MR

 

[edge]

I certainly have no direct proof.

I do like the some of the information done by Veral Smith of LBT.

You may be able to find this book somewhere:
Order Page for Bullet Penetration: Modeling the Dynamics...  - by Duncan MacPherson

and for a reasonable fee these folks will shoot Ballistic Gel with your bullets:
Brass Fetcher Ballistic Testing

I must admit that I would prefer a bullet to penetrate deeply to guard against bone and poor hits ( big game ).
A bullet that makes monstrous wound channels must end up shorter on penetration.
I am not a believer in a bullet that passes through an animal has "wasted" energy in the dirt.
These are just my personal preferences.

Sorry that I don't have anything more concrete for you.

edge.

Edge,

This question is directed specifically to you, but I would appreciate informed response from anyone with experience in this area.

The article which you linked, at the start of page 11 of this thread, had a section discussing the mechanics of cavitation. It's basic assertion is that a flat nose, of nominal bore diameter, will cause greater tissue disruption than a "mushroom" projectile deformation.

It has been bothering me since I read it, as it seems to take no account of mushroom diameter. What direct experience do you have with this claim, and are there any good gelatin studies on this subject?

Best,
Noel

P.S. ; That is a clean sabot design. Too bad we can not come up with something like that for breech loaders.

 

[jmden]

"However owners of rifles chambered in any of these cartridges could be equally interested in a 190-200 grain high performance solid bullet."

For the 300 RUM or 30-338 Laps or 30-378 Weatherby my personal feeling for these large capacity cases is that 200g is the absolute minimum. With the slow powders available now and the desire for ELR application, you need some meat on that bullet for BC and downrange energy. Right now, for any of those three above, I would go right to the 240 SMK and US869 and not look back. I think if Noel could make a 220-230g expanding projectile in the .308 class, there'd potentially be a real winner. I hope Berger does the same sooner than later...

Cheers,

Jon

 

[MontanaRifleman]

...and learned a valuable lesson!!!! (THERE IS NO MAGIC BULLET FOR EVERY CAL AND USE).

JE,

Never fear.... The magic bullet IS somewhere and someday we SHALL find it

At the higher velocities they would shed the petals and the wound channels would vary shot to
shot.

Shedding of petals is really not a bad thing. The blunt frontal area will still cause cavitation and permanent wound channel and the shed material will cause collateral damage. The only draw back may be a smaller exit hole, but the extreme velocites at which this would occur would cause greater cavitation and permanent wound channel. The slower a bullet passes through, the more it "pushes" vs "tears" through flesh.

-MR

 

[MontanaRifleman]

Edge,

This question is directed specifically to you, but I would appreciate informed response from anyone with experience in this area.

The article which you linked, at the start of page 11 of this thread, had a section discussing the mechanics of cavitation. It's basic assertion is that a flat nose, of nominal bore diameter, will cause greater tissue disruption than a "mushroom" projectile deformation.

It has been bothering me since I read it, as it seems to take no account of mushroom diameter. What direct experience do you have with this claim, and are there any good gelatin studies on this subject?

Best,
Noel

Noel,

Here is some interesting reading form the GS site...

3. GS Custom HV Bullets
Expanding monometallic bullets have been found to be unreliable. Up to now, in many cases, hollow point monometallic bullets would act like solids on soft game with bad results. To eliminate this problem entirely, HV bullets are designed to expand reliably from as low as 1600 fps. We have driven HV bullets as high as 4700 fps and weight retention remains at a high 80%. This makes GS Custom HV bullets the most versatile premium expanding bullet on the market today.
The pictures below are of a .458" 450gr HV bullet fired into the water tank at the Ballistics/Forensic Laboratory in Port Elizabeth. Velocity was 2500fps.
Further, HV bullets are designed according to the findings of the latest research on terminal bullet performance. This is contrary to the traditional "perfect double caliber mushroom and 100% weight retention" theory. Research done by Duncan MacPherson and documented in his book "Bullet Penetration - Modelling the Dynamics and the Incapacitation Resulting from Wound Trauma", supports the observations we made during field testing of the HV concept.
It has been proven that a high velocity flat fronted cylinder shape will leave a larger primary wound channel than a slower, double caliber mushroom. HV bullets are therefore designed to start mushrooming reliably from much lower speeds than most other premium bullets, typically from around 1000fps. Two to four centimeters of penetration is all that is required to fully expand an HV bullet.
At higher speeds, HV bullets will lose the petals entirely, shedding 12% to 15% of weight and presenting a flat cylinder shape to the direction of movement. The HV concept thus offers, at worst, a good double caliber mushroom, with extremely high retention and, at best, a high speed cylinder shape for dramatic primary wound trauma.
Below left are photographs of a 95gr .264" HV bullet, fired into foam saturated with water. Muzzle velocity was 1900fps and resulted in complete expansion and 60cm (24") of penetration. On the right is a .284" 130gr HV bullet fired from a 7mm RM at a muzzle velocity of 3300fps. The bullet penetrated 120cm (47") on a kudu. ​

GS CUSTOM BULLETS - FAQ - Expansion and Weight Retention

Best,

-MR

 

[Jon A]

I measured the noses of the 210 Berger (~.82, BC of .631)

I'm sorry, I had pulled a number of .74" off the top of my head for the Berger. I must have misremembered--I should have double checked my measurement before throwing it out there.

Unfortunately, this is only more bad news for the 177. That means its nose (easily the biggest portion of form factor) is likely no better than the Berger, maybe even worse if it has a larger HP. And it's down 19% in mass. This puts it in the low-mid .5's as I don't see the boattail or any of the rest of it making up for that in a significant way. But like I said, that's not all that bad, it's still usable and a huge improvement over the 173. It's just not really any better than the 180 class Scirocco, Interbond, A-Max, etc, not to mention the 185 Berger.

 

[MontanaRifleman]

I'm sorry, I had pulled a number of .74" off the top of my head for the Berger. I must have misremembered--I should have double checked my measurement before throwing it out there.

Unfortunately, this is only more bad news for the 177. That means its nose (easily the biggest portion of form factor) is likely no better than the Berger, maybe even worse if it has a larger HP. And it's down 19% in mass. This puts it in the low-mid .5's as I don't see the boattail or any of the rest of it making up for that in a significant way. But like I said, that's not all that bad, it's still usable and a huge improvement over the 173. It's just not really any better than the 180 class Scirocco, Interbond, A-Max, etc, not to mention the 185 Berger.

Well... let's look at this some more...

At first, I thought the same as you about the difference in mass between the Berger and the 177. But then I looked at and measured the 180 HAT (BC of .7+) The 177 is .005 longer overall and the HAT has a EDIT .002 longer nose (and very pointy) I also measured a 180 E-Tip with BC of .523. It has a nose length of ~.7 and a short boat tail. The measurements of these two bullets would suggest to me that the 177 is somewhere between .523 and .7+ in BC. And that the difference in mass between the Berger and the 177 have minimal impact on the BC. Also, I suspect the Berger BC (which was recently lowered) is conservative. It is almost identical JLK which lists a BC of .665 and one of the guys in here (I believe either Michael or phorwath) tested the Bergers out to almost 1K anf found them in the .66-.68 range. Sooo... I am still clinging to my faith in the BC of the 177 (despite our new President) And if it proves wrong then I may take a few weeks off the forum until all this blows over

 

[Michael Eichele]

I would be willing to bet the 177 despite its all copper construction would very very easily be well over the .550 mark.

Some years ago, I tested the old Barnes 180 grain XBT and all be darned I came up with exactly what was published. That was .550 for a BC. Now that was before the grooves AND the nose was more streamlined. This being the case, I could see where the 177 being much more streamlined than even the older sleeker XBT, could have a higher BC. I would be willing to bet that the 177 would come in higher than .550, he!! the 180 E-tip is .523 and is really really close to that. If that short boat tail and tangent ogive can yield .523, surely the the 177 can be much higher. I am guessing .575 to .590.

My next barrel WILL be a 9x 26" 30 cal. I will dinking around with the 177's and 180 HAT's.

It wasnt me that tested the 210 Bergers but I have tested the 208 AMAX and came up with .671 which is higher than published. This was also concluded by double chronies.

 

[noel carlson]

jmden,

230 grains is just about where the ZA30/7.0 will fall. This would require a dedicated 5.6" exit-twist, in a gain geometry. Bartlein has no problem manufacturing 416R barrels in a LGT rifling function if you are interested.

If I was looking for a quantum leap in 30 caliber performance, this is the projectile which I would focus on. Everything else is unnecessary compromise, including the 6.0... but we are talking about a ground-up, custom-build proposition.


Edge,

You have really got my mind working on this terminal ballistics problem. I can make the nose fragment, expand, or any combination thereof at varying velocities. The question really seems to be, what is the most flexible compromise? I believe I have made some progress in understanding the requirements, and you have contributed significantly to that understanding... Thanks.

MR,

You are making an error which is understandable. Do not use manufacturer supplied BC specifications for your estimates. Two of the companies you mentioned are good on this kind of reporting, the other is not... you are relying too heavily on the one that is not.

To all,

I realize that there are not many 50 cal shooters here, but I think some of you might be interested in hearing a piece of range news. My ZA50/6.0-M (930 grains) flew stabily out to 1,000 yards today from a 1: 15" (30 calibers) constant-twist barrel. It appears that the ZA tail design is out-performing my expectations.

There will be more information available on this next week.

Best,
Noel

 

[edge]

SNIP


Edge,

You have really got my mind working on this terminal ballistics problem. I can make the nose fragment, expand, or any combination thereof at varying velocities. The question really seems to be, what is the most flexible compromise? I believe I have made some progress in understanding the requirements, and you have contributed significantly to that understanding... Thanks.

SNIP

IMO, the nose which is normally hollow and low in mass is expendable. The worst thing a bullet can do is to "pencil" through the game. So losing the nose ( shape ) asap and retaining the bulk of the bullet mass at the lowest velocity should be your goal for long range hunting bullets.

I envision a steel shank with a foam rubber ogive as the "magic bullet"!
High BC ogive that will instantly disintegrate when it encounters hide, and a shank that will hold up to the highest impact velocities

edge.