Flat nose vs round nose solids - What are the actual facts?

[One Day...]

There are 8 Absolute Known Factors for Solid Penetration and are as follows in Order of Importance.....


#1 Meplat Percentage of Caliber

Meplats that attain 65% Meplat of Caliber are terminally stable.... Above 70% Meplat bullets remain stable, however depth of penetration begins to decrease with every step up in meplat size. 70% Meplat or larger does increase trauma to, and destruction of tissue. 70% Meplats start to get difficult to feed, even in Winchester M70s...... From 65% Meplat to 68% Meplat is OPTIMUM for Stability, destruction of tissues, and feed and function in most quality rifles..........


#2 Nose Profile

There are many and varied Nose Profiles of solids on the market today, from the angled Nose Profiles of CEB and North Fork, to the straight nose profile of the older North Forks and GSC, the Barnes/Hornady Profiles (like a RN cut off at the top) to many more... Not all of these are created equal, and some are better performers than others. In recent tests in comparison between the old North Fork Profiles and the Newer North Fork Profiles I was getting 20% deeper penetration with the Newer North Forks than the older, with the same bullet, just difference in Nose Profile is all.... John at North Fork agrees, and in their work there they were getting more along the lines of 25% deeper penetration. One major thing that I noticed here, the stability at the end of penetration was 100% better. In most all tests here the last 2 inches of penetration of the old style North Forks would be unstable. Now this is and was of no consequence at the very end of penetration. The depth of penetration of these older nose profile bullets was always so deep that it had long accomplished its mission before loss of stability right at the very end. This new NOSE PROFILE of North Forks remains DEAD STRAIGHT to the very last of penetration, and always found NOSE FORWARD........


#3 Construction & Material

Construction of a solid is a major part of its ability to penetrate. To deny this is foolish to say the least. Some of our solids out there, lead core, are very very weak in construction and absolutely do not have the ability to bust through heavy bone and reach their intended targets. I have seen and have in hand failures of these bullets from the field..... A shame as well, as some of these bullets are promoted as Dangerous Game Solids, and some of them flatten out like pancakes when hitting heavy dense material. Some FMJ Have steel inserts, while this solves a problem in one area, it creates problems in other areas.... Brass is harder than Copper... No surprise there, but I have busted elephant heads with both copper and brass, and never had one distort, but, these solids were of a very STRONG NOSE PROFILE as well........ So you see, combinations of different factors work together to strengthen or weaken other factors..... A good strong Nose Profile, can overcome some material deficiencies and in the case of copper solids this is extremely important.

#4 Nose Projection

Nose Projection above the top bands was the last factor discovered. There may be more factors, but currently they remain undiscovered at this point in time.... We found that nose projection above the top of the bands of current CNC monolithic bullets is very important to depth of penetration. Some bullets designed to work through lever actin riflers require a SHORT NOSE PROJECTION in front of the bands so that they can be loaded deep enough to work through the actions of these guns... Nose Projection of these same bullets for bolt guns, single shots, and double rifles are longer, from .600 to .700 in front of the top band. The LONGER NOSE PROJECTION solids will penetrate on average 25% deeper than the shorter nose projection. Now, these bullets already have all the other required factors for stability, nose profile, construction and radius, so it is ONLY DEPTH Of penetration that is effected with properly designed bullets.



#5 Radius Edge of Meplat

We found that the radius edge of the meplat made a difference, small, but a difference none the less. A nicely radius edge penetrates about 5% deeper, and has more stability at the end than a sharp edged radius.... No more to go into here, thats it.......


All the Above Factors Deal with Bullet Design........


#6 Velocity

Velocity is a factor, but it also goes hand in hand with Nose Profile and Construction/Material. If we assume that the Meplat is optimum, the nose projection is optimum, and the bullet has a nice radius then velocity becomes a factor in combination with nose profile and construction/materials. Different Nose Profiles react differently with velocity. Some nose profiles at very low velocity cannot maintain stability, but this would be in the extreme, and other factors may come into play with some of this. In essence with some Nose Profiles, added velocity will equate to added depth of penetration, and of course trauma and destruction of tissue. Some nose profiles react better than others, but if properly designed, then all will get some gain from added velocity, UNTIL you reach the point that you get distortion of the meplat by TOO MUCH VELOCITY. Once you begin to distort that meplat, then all sorts of strange things begin to occur. One is depth of penetration will decrease, stability will decrease as well....... Normally you will only get this at extreme velocities at 2700-2800 fps or more, which in our big bore rifles is somewhat extreme.......... Lead core bullets will be effected in a serious manner at extreme velocities, followed by copper, and then brass........ Nose Profile and Construction & Material are very important for Factor #6.........





#7 Barrel Twist Rate

Barrel twist rate really only becomes a factor when Factor #1 is DEFICIENT....... If the meplat of caliber is undersized, less than 65%, then faster twist rates WILL INCREASE the depth of penetration by increasing the stability of terminal penetration. A 65% Meplat of Caliber can stabilize in slower twist rates of 1:18, or even slower...... I have seen 65% Meplat of Caliber stabilize with ZERO TWIST....... I have seen 50% Meplat of Caliber stability increase with faster twist rates, and have documentation to prove it, several times...... If you are using a properly designed Solid, then twist rate becomes less important, and more important if you are not using a proper designed solid. Fast Twist Rates can also increase stability of even RN Solids of decent design, hardly anything can increase stability of a more pointy RN FMJ.......



#8 Sectional Density

Sectional Density will ONLY BE A FACTOR with two bullets that are exactly the same in every other Factor or aspect. Factors #1 and #2 far outweigh Sectional Density in the terminal performance of Solids. We can take a properly designed 458 caliber 325 gr Solid and far out penetrate in depth and stability a poorly designed 550 gr 458 caliber bullet....... My son recently shot a medium sized elephant at 10 yards, perfectly executed side brain shot, with a 350 gr .474 caliber properly designed solid at 2200 fps. This bullet exited the head on the far side and still may be going for all I know. A 350 gr .474 caliber bullet has a sectional density of .223, and I personally would choose this little 350 gr bullet over the Woodleigh 500 gr RN FMJ at .4725 (ones I have here) any and every day for any mission............




These are undeniable facts, and can be proven over and over and over again in all test work, and these factors have been exercised in the field and have proven themselves in the field, many many times over...... These are the 8 Known Factors of Terminal Penetration of Solid Bullets.................

This is a great post, Thank You.

There is an additional set of considerations...

Since the thread title is "flat-nose-vs-round-nose-solids-what-are-the-actual-facts" this does not limit the discussion to only the terminal effects of the solid.

The additional considerations relate to how the given solid feeds in the given rifle. Depending on magazine length, feeding rails profiling and width of the magazine as related to case diameter and taper (a proper fit is becoming nowadays a rarity in the age of one action size fits all - remember, Mauser was selling 20 (twenty) different actions tailored to various groups of cartridges); length and slope of the feeding ramp, etc. some truncated cone solids may or may not feed well in some individual rifles.

Hence one additional step in the selection of the ideal solid: does it feed in your rifle? If the answer is no, well... a lot of other considerations become less important, and that trip to the gunsmith better take place before the hunt rather than after...

 

[Forrest Halley]

Yes, and you can use either 450 gr CEB Solids or the 450 North Forks (new design) and you will never need anymore than that. You can easy run those to 2400 fps and they are a hammer. I shot broadside elephant with one in 458 B&M at 2200 fps and it passed completely through. Also used on buffalo and hippo. I would not be overly concerned about flatter shooting for what these are designed for.



The CEB is a FAR FAR FAR better bullet. Designed from the ground up and tested at each step in the process to get it right. It is 100% stable to the dead end of penetration ,the Nosler is not. Nosler is not bad, better than a RN, but it don't compare to the CEB or North Forks.

First off, thank you for the multifaceted reply. I appreciate the time you took to do so.
With respect to flatter shooting, I am just looking at my options and one fellow said something about the 325 grain solid and it got me thinking about 350 soft points and cheaper practice while still having the sights set up for a viable full power load. My .458 Lott is a Ruger No. 1 and I am looking to maximize my utility with fixed express sights. I am all ears to suggestions.
The reason I asked about the Nosler is that it was cheap ammunition during the great repackaging sale so I have a decent amount of it and it looks similar to the CEB solids at a glance.

 

[PaulT]

Well, there goes this thread

Ruined with facts and knowledge

What is there left to do now

 

[BenKK]

CEB Safari Solids have copped a mention here. This baby buffalo collected a few 180 grain CEB Safari Solids on Saturday. Making me feel hungry as he rests in the fridge!

 

[michael458]

@michael458 at what speed does the difference between copper and brass start to make a difference, provided the design is the same?
And in a 375 what weight of bullet would you choose.

Good Morning Wyatt. Not 100% sure exactly what you are asking, but since you distinguish between copper and brass, I assume "Construction & Material" factor. In soft medium and or tissue brass will start to flow at 2900-3000 fps impacts, and copper just a bit less than that 2500-2600 fps. By "Flow" I mean that the Flat Meplat will start to distort some. And of course that really depends on the metallurgy of the particular brass or copper as well, which is a bit out of my area. There are different versions of each.

Both will and can distort heavily when contacting large dense bone at any velocity impact. Ball joints on shoulders are hell on any bullet. Copper is softer than brass. Brass will fair a little better, but is not immune to getting mauled by heavy bone.

You can see this #13 Solid hit some heavy bone on a buffalo distorting the nose a good bit. Regardless it still managed to complete the mission.

Same bullet used on a hippo, one of these contacted some heavy bone, the other two did not..........................

I have shot buffalo with various different copper solids and had those bullets distort as much or more in most cases, but can't find a photo of those right now. Either way, Copper or Brass, both are superior to FMJ in this area.

 

[michael458]

Do any of the members here have experience with Dzombo solids?

Good morning Dewald.

I thought I had tested some of these back in the days, but can't find anything on them. Tested Rhino and Peregrine here, and I was sure Dzombo, but can't find photos of them, and I may have had some and never got around to them. I will continue to look for that.

The measure of any solid and how it may perform, go to Factors #1 and #2 and review. For a Flat Nose Solid to be terminally stable it needs to have a 65% Meplat of Caliber. Meaning you can shoot a 65% Meplat in a smooth bore, and it will be terminally stable for 90% of its terminal penetration. Less meplat, and it will not, you will require other factors to come into play to keep the bullet stable enough once it starts terminal penetration to accomplish the mission required of it. Nose Profile #2 is very important as well.

Dzumbos appear to be basically a Round Nose that is flattened off on the top. This is not a bad nose profile, and very much like many of the first FN Solids, Barnes followed this as basically did Hornady. The Dzumbo looks to be a little shy on meplat size for optimum stability. However, keep in mind that under most circumstances even less than perfect bullets can remain stable long enough to accomplish the job required of it. In all the test medium we are working with a solid consistent mass, always aqueous. Taking bone out of the equation for now, and considering only comparison from aqueous test medium to animal tissue, one will get 35% more penetration with Animal Tissue than the test medium. This is a basic rule of thumb, and can be slightly more, or slightly less depending on variables involved in the particular path of any given solid. This penetration rule of thumb is different with expanding or trauma inflicting bullets, but basically count 35% more for solids.

I have no doubt that the Dzumbo would do well in the field. In my opinion it could be better with a larger meplat. The RN Cut off to a Flat Nose is a good design, it is a strong nose profile, possibly stronger than most others. But it is not the optimum nose profile for depth of penetration. Other nose profiles are better in that Factor. Again, not kicking this bullet. I used a lot of the Barnes FN when they came out and found them superb. Barnes were at 65% meplat.

This Rhino seems to be close in design........ But mind you, small tweaks in these solids, ones that require measurement to be known can make a big difference.. So appearances can mean nothing with a solid. And keep in mind, 58" of straight line penetration is more than enough to accomplish any mission asked of a solid in 90% of all cases.

 

[michael458]

The additional considerations relate to how the given solid feeds in the given rifle. Depending on magazine length, feeding rails profiling and width of the magazine as related to case diameter and taper (a proper fit is becoming nowadays a rarity in the age of one action size fits all - remember, Mauser was selling 20 (twenty) different actions tailored to various groups of cartridges); length and slope of the feeding ramp, etc. some truncated cone solids may or may not feed well in some individual rifles.

Hence one additional step in the selection of the ideal solid: does it feed in your rifle? If the answer is no, well... a lot of other considerations become less important, and that trip to the gunsmith better take place before the hunt rather than after...

Good Morning One Day. HOW CORRECT YOU ARE. You hit the nail on the head my friend and what has caused many issues with Solids for the last 15 + years.

Let me start by saying I use Winchester M70 Control Feed guns. Since most feeding issues will be with Bolt Guns, that is where we will start. When designing the modern Cutting Edge #13 and working with North Fork during the same period we determined that while 65% meplat was required for self stabilization, what happens when you have a larger meplat? Well, at 70% meplat we got very much close to the same depth of penetration, bullet of course was stable, maybe a bit more destruction of medium, but they would not feed and function in a Winchester M70 100%. In the end we settled at 67% Meplat in the CEB Solids and John at North Fork went up to 68% Meplat in the newer designed NF Solid. Both of these feed and function in Winchester M70 guns 100%.

Now, I have some Ruger bolt guns, and 65% Meplat will not feed in them PERIOD. It has to be much less, down around 50%-55% meplat. We know this is not optimum for stability. Other rifles will not feed the 65% meplat either.

So the owner of said rifles will have to make a choice.

#1 Take the gun to a proper gunsmith and get it up to speed to feed properly designed Solids. This is what I would advise. Listen, you are going on a very expensive hunt, in most likely hood it can be dangerous. Personally I am NOT willing to compromise Bullet Performance, because I don't get my rifle tuned properly. I think it is very important to put a lot of effort into going with the very best bullet one can get, it can make or break a hunt, it can determine the success of a hunt, and in some cases it might even save your life, or life's of those near you. I am not willing to compromise that because I was too cheap to get my rifle worked on and feeding proper designed bullets.

#2 Use a less than desirable bullet and go with that POS rifle and hope you have a good PH that can shoot straight, and hope he is not using crap bullets as well............

SOME manufacturers of SOME solid bullets have decreased the size of the meplat, so that it feeds in POS rifles. More interested in selling bullets than Performance. I will not mention names.

As One Day states;

that trip to the gunsmith better take place before the hunt rather than after...

I CONCUR 100% with that statement..................

 

[michael458]

Well, there goes this thread

Ruined with facts and knowledge

What is there left to do now

Good Morning Pauly! I know how this stuff drives you crazy...... Sorry! HEH..... Hey, they let me in, what do you expect?.................. I hope you don't run out of drink!

Paul and I did a lot of bullet testing together.................and we had one hell of a good time doing it too..........

 

[michael458]

This baby buffalo collected a few 180 grain CEB Safari Solids on Saturday. Making me feel hungry as he rests in the fridge!

Good Morning Ben, it has been awhile since we had a chat, good to see you out there and continuing to do some shooting....... Assuming .308 caliber, how is the penetration on that bullet? I tested a few .308s a few years ago, but never been to the field with any.

Good to hear of you!

 

[michael458]

If I missed anything or anyone, don't hesitate to let me know and ask again please.

 

[BenKK]

Good Morning Ben, it has been awhile since we had a chat, good to see you out there and continuing to do some shooting....... Assuming .308 caliber, how is the penetration on that bullet? I tested a few .308s a few years ago, but never been to the field with any.

Good to hear of you!

It really staggers them. It’s in a .300H&H. I am often under the pump doing all the chores so haven’t yet done great autopsies. I’ve only killed three bulls with this bullet. I got a pass-through on a double lung hit, but somehow a heart shot captured the bullet (couldn’t find it in the quick search but it didn’t make the offside shoulder - and it didn’t break the onside leg; I am kind-of suspicious at what I think I saw, as it isn’t adding-up, and I suspect there’s a story I missed). I’m only pushing them a little over 2800fps, so not real fast. It’s hitting them hard and putting them down fast, though, like, not making it more than ten metres (the initial double lung bull went sixty metres before being clear for a second shot that dropped him).

I wish CEB would make a Safari Solid for .303 now that Woodleigh won’t do Hydros in this calibre! But not much demand, I guess.

Another wish is for a Safari Solid designed for lever-action .30/30. I’m over-cautious so won’t load a tube of Hydros because the lip sits on the primer in front. It’s still brilliant, but only a two-shooter.

 

[Nhoro]

If I missed anything or anyone, don't hesitate to let me know and ask again please.

You mention the Peregrine bullets- how does their penetration compare ? I see they are less rounded than dzombo solids but more rounded than North fork for example and. I think they are 67 % or so Meplat.

 

[michael458]

but somehow a heart shot captured the bullet (couldn’t find it in the quick search but it didn’t make the offside shoulder - and it didn’t break the onside leg; I am kind-of suspicious at what I think I saw, as it isn’t adding-up, and I suspect there’s a story I missed)

Yes, Ben, that is very odd. But I have seen some wild things in the field as well. I would think at those velocities and that bullet it would go end to end on buffalo unless it hit bone. I also suspect that smaller calibers may not be as stable as larger caliber bullets as well. Plenty good, but not as good as larger caliber.

It is good to hear about it putting them down in short order. Meplat size and velocity working for you on that.

Another wish is for a Safari Solid designed for lever-action .30/30.

I am also a lever fan, and I like that 130 gr ESP Bullet, and particular using the solid side. ESP... Enhanced System Projectile, for those not familiar. These are rather odd bullets, but they do work. One end is a #13 Solid and the other end is a Hollow Point Raptor. You can load them either way. There is a 130 gr .308 caliber ESP. It works rather well in the 30/30. It does not get the incredible depth of penetration that you might get with a standard solid, but it does well enough.

 

[BenKK]

That is awesome, Sir! I hope I can get some from Meplat in South Australia!

 

[michael458]

You mention the Peregrine bullets- how does their penetration compare ? I see they are less rounded than dzombo solids but more rounded than North fork for example and. I think they are 67 % or so Meplat.

I was asked in 2015 to test some of the Peregrine bullets by Peregrine. They sent .458 and .416 caliber. At that time I measured the meplat size and it was a bit shy, which I told them at the time. The ones I had came in at 52%, which is not as good as I would have liked to see. But none the less, it is a good nose profile and I believe that made up for it, because they tested very good actually, somewhat to my surprise.

In 458 caliber they sent 480 gr Solids and expanding, and in 416 they sent 340 gr Solids and expanding. I tested in two different 458 rifles, 458 B&M EX and standard 458 B&M. And in 416 I used one of my 416 B&Ms.

I tested 4 bullets in each rifle. In the 458 B&M EX all 4 were stable and straight to 65-66 inches. This is very good, and a lot of penetration in .458 caliber. More than enough to do any mission asked. After this they lost stability and were unpredictable as to what they would do.

In the 458 B&M I only had one box set up, and actually lost some of the bullets in the berm after exits. The only one I recovered lost stability or I would not have recovered it either. Again, straight penetration to 65".

Honestly I was surprised at how good they did, and attribute most of that to a very good nose profile. We had tested a similar bullet with a similar nose profile some years before adopting the #13 Degree angle in the CEB and the slightly less angle in the North Fork.



The 416 Peregrine was not as successful as the 458 version.

After the tests I sent back a complete report and told them they could increase straight line performance by increasing the Meplat Size to 65% or better. I never heard back from them and I have not looked or seen any since.

 

[michael458]

That is awesome, Sir! I hope I can get some from Meplat in South Australia!

Absolutely, give them a go and see what comes up. I think they will accomplish what you need in 30/30.

 

[michael458]

I’m over-cautious so won’t load a tube of Hydros because the lip sits on the primer in front.

You might take a Hydro in the chamber, and follow up with the 130 Solid ESP? That would be a good combo I think........

 

[Nhoro]

Michael458 I am not sure if you have read Charles Hayley article in African Hunter some time back. He tested round nose solids- conventional and monolithics finding that they all penetrated the same distance if given the same energy. Fairly understandable- same shape same energy. 32 inches total- 3 inches elephant leg bone- 24 inches wet phone books and 5 inches pine plank. All penetration was straight. Now considering that was bone + pine boards + wet phonebooks, I am thinking it is less but not that far less than the 60-70 inches of wet phone book of flat nose solids. Maybe the leg bone + pine planks would reduce that to 40-45 inches. So is it fair to say that flat nose are an incremental improvement of say 20-30 % in straight line buffalo and elephant penetration ?

 

[michael458]

Nhoro
No, never heard of Charles Hayley. The difference in these tests is the bone and the planks. If one tested the bullets in total wood, say 1 inch boards. Then the RN and FN would all be basically the same, the RN would not veer off course. While in some cases, the bone and planks are a good test, but only a test that would supplement a true aqueous test. Animal tissue has bones in of course, and can be and are a factor, however animal tissue has far more tissue that a bullet may have to travel through than pure bone. We tested in a wet print mix, 10 inches of wet print and 1.5-2 inches of wet magazine/catalog print. It is amazing how the texture of the catalog/magazine print made the medium far tougher than just straight wet print. It is tough on bullets. This medium is extremely good, in fact damn near perfect, in comparing "Bullet Behavior", to animal tissue. Obviously since animal tissue is far less dense, one will get deeper penetration in animal tissue than the test medium, but behavior of the bullet is the same.

When a Solid starts terminal penetration in any aqueous medium it becomes "Front End Drive". Round nose and pointy fmj or solids are not stable at all in any aqueous material, medium or animal tissue. Should the round nose profile come in contact with any variables along the way, it can very easily veer off course to the area of least resistance. I have personally seen and witnessed RN Solids veer 90 degrees off course and exit before getting to the vitals from rear shots on large animals such as buffalo. In other words, shoot up the rear, watch it exit the sides. There are numerous cases of this happening in such shots taken. We have all heard about the round nose solids or FMJ turning in elephant heads, and I have known people that this happened to. Not all the time of course, and many a RN has killed many a critter, I am not trying to argue that point. But it happens often enough that I personally did not want to experience it again, and is one of the reasons I went in search of better.

A Flat Nose solid of proper meplat size and Nose profile is far less likely to veer off course unless it becomes mangled in some way on heavy bone or something such as.

As for the tests, I don't believe that test is 100% conclusive. I believe it would be a good supplemental test to go along with other tests. We conducted similar tests here. We called it a "T'Rex" test, in which I would take 5 inches of wet print up front, place a 1 inch Cinder Block slab behind that. Then 20 inches of wet print behind the first block and add a second 1" Cinder Block, and then of course wet print behind the second block. This sort of test is excellent to test Construction and Material Factors. This sort of test is not the end all of end all, but damn good to test a bullets construction and material to understand if it can hold up under the worst of circumstances, much the same as I would place the Charles Hayley tests in the same sort of category. That is my opinion anyway.

After enough time I actually quit testing Round Nose bullets, they were just doing way too much damage to the range and the bullet boxes. But that was after testing 100s if not 1000s. I have many a mark on my indoor range from RN Solids! LOL.......... Below are some samples of some of the RN Solids tested...........

 

[Brian]

I use CEB Solids on cape buffalo and they work perfectly as advertised. Generally my velocities in .500 cal are lower that what Michael likes to use and the result is the same, excellent.
Not to change the topic but I want to mention that I have also used the CEB Talon on three cape buffalo and all were dead right there. Brian