I was reading again, this time about optimum velocity for various bullet performance and how more can really be less. This comment caught my eye(paraphrased): "The A2 monolithic solids are hard on guns, 500 rounds will shoot out a barrel" True?

Is this true? Would this be a general caution using any mono metal solids? If a concern; what would be the conventional wisdom, within practical limits, best solid metal - no jacket one alloy bullet? best in terms of game performance with minimal impact on barrel wear?

Would a stainless bbl be a much better choice?

good post. This is going to be an interesting topic. I would think that it all depends on the hardness of the alloy used for the bullet.

I wouldn't think that if the rifle was maintance
properly like all the copper was removed after 20 rounds I know that the barrel would last for
as long as it should.

I'm certainly not an expert but I believe that barrel wearing is mainly due to the very high temperatures and pressures caused by the powder combustion; in fact, most of the wearing/erosion appears just in front of the chamber. A correct cleaning is essential, of course.

I would estimate that a rifle barrel shooting A2(A Square) mono metal solids would out last the same barrel shooting steel encapsulated lead core solids by a large margin.

As far a velocity is concerned more velocity is always better if you want to maximize penetration on game.
The compromise is, you will cause increased wear which will shorten the life of the rifle barrel.

Rifle barrels are like brake pads, they are a wear item, If you drive fast and are hard on the brakes you are not going to maximize the life of the brake pads. Driving won't be as much fun either.

Rifle barrels are also a wear item.
Pushed hard and maintained poorly and it will have a short life span.
Slow the bullet down and it might not anchor game as surely.

Every time you shoot a box of cartridges the financial cost of those shots are spent in two places, the cost of the cartridges of course, but don't forget to factor in the wear on the rifle barrel.
For every shot fired set some coins a side to go towards barrel replacement.

quote:

Originally posted by greenjoy:

As far a velocity is concerned more velocity is always better if you want to maximize penetration on game.The compromise is, you will cause increased wear which will shorten the life of the rifle barrel.

quote:

As far a velocity is concerned more velocity is always better if you want to maximize penetration on game.

Especially in regards to solids...the above statement is untrue.

quote:

Originally posted by ledvm:

quote:

As far a velocity is concerned more velocity is always better if you want to maximize penetration on game.

Especially in regards to solids...the above statement is untrue.

When does less velocity improve penetration with non-deforming solids ...??

Macifej

I have to agree. I've talked to Larry at Superior ammo many times and he probably get more feedback than any AR member. He says all things equal that more velocity equals more penetration in all but very frangible bullets.

Mark

quote:

Originally posted by MARK H. YOUNG:
Macifej

I have to agree. I've talked to Larry at Superior ammo many times and he probably get more feedback than any AR member. He says all things equal that more velocity equals more penetration in all but very frangible bullets.

Mark

There's a Mt. Everest sized pile of data to support this and none contrary unless some alternate physical universe is considered. Guys who illuded to barrel wear being primarily a function of pressure and temperature are correct as well. Also a ton of data to support this. Material hardness has a minimal effect unless it approaches that of the barrel. IE - try not to shoot 4000 series alloy bullets in your 4000 series alloy barrel. Very few copper based alloys approach barrel steel hardness and they are mostly cast material unsuited to machining projectiles in volume. If you can think of it we or someone have tried it or at least looked at it in some detail.

quote:

Originally posted by Macifej:

quote:

Originally posted by ledvm:

quote:

As far a velocity is concerned more velocity is always better if you want to maximize penetration on game.

Especially in regards to solids...the above statement is untrue.

When does less velocity improve penetration with non-deforming solids ...??

There is no such thing as a non-deforming solid. Given enough velocity, they will all deform.

465H&H

quote:

Originally posted by 465H&H:

quote:

Originally posted by Macifej:

quote:

Originally posted by ledvm:

quote:

As far a velocity is concerned more velocity is always better if you want to maximize penetration on game.

Especially in regards to solids...the above statement is untrue.

When does less velocity improve penetration with non-deforming solids ...??

There is no such thing as a non-deforming solid. Given enough velocity, they will all deform.

465H&H

Thanks for the materials refresher. Did you want to lay that out with some analogous data or maybe an empirical observation of your own?? To reiterate the topic at hand - "minimally" deforming solids (you like that better?) do in fact penetrate in all known mediums (game, the LA Times, firewood, redi-mix, whatever) proportionally to their impact velocity. Faux solids of the multi-metal type come apart more readily therby reducing penetration potential with increased impact velocity amongst other variables.

1) Modern designed mono's such as Barnes banded cause less barrel expansion than Woodleighs of the same weight and same velocity.

Older barnes with a solid shank of Brass cause at least as much barrel expansion as woodleighs.

A square Bronz bullets cause nearly double the expansion of a woodleigh- about 90% more at the chamber and 70% more at the muzzle.

Anybody with one of the new Olehr Kit and strain gauge set up can easily verify these results.

Zim Parks used A square ammo for many years as its standard. They were great bullets. Even out of very high velocity rounds like the .378 I have never seen one deform. The down side was short barrel life. Our .30-06 Garands and Interarms .375's and .458's all lasted around 500 rounds when used with A square solids.

Our culling teams switched to Draganov's with AP ammo. Heavy rifles with better barrel steel like the F.N.'s lasted about a couple of thousand rounds.

465 is right. Given enough velocity all solids will deform. Bullet failures in .375 H&H are unforunately common. You almost never hear of one with .375 Flanged/.376 steyr using the same bullets. Sililarly, you almost never hear of bullet failure in a 9,3x62 or 74R but they are surprisingly common in 9,3x64....

The current 'solids' like Barnes Banded and Woodleigh are great up to impact velocities of arround 2400-2450fps. As you go above that velocity, the barnes begin to mushroom (rivet) and the woodleighs bend. Many Brass bullets that are made from regular comercial mix are too brittle and tend to break in half at any weak point (like the cannelure) at velocities over 2500fps...

The Speer tungsten cored bullets in .416 held together at impact velocities of up to 3000fps in tests (the .375's came apart at 2400fps).

If you drop the velocity to around 2200fps you can get away with using pure copper 'solids' or a thin steel jacket. At 2000fps you can get away with a guilding metal jacket like some of the old Kynock had.


Last though...penetration of a steel target is basically a simple case of velocity over coming resistance. In elephant, bullet stability is also a major consideration since the bullet has to penetrate up to 3' animal and all of varying hardness and density. As you go through a hard piece and into a softer section, there is a tendency for the bullet to try and turn over. For best accuracy and stability of the bullet from the muzzle you want 'the mass in the ass' of the bullet. To keep it point forward as it travels through an elephants head you actually want the mass forward.

Designing a great bullet takes more than just just a man with a CNC lathe, and an idea.

Did you do these experiments yourself Don? You have actually used a strain guage and developed a data set to compare various "expansion rates" amongst the bullets you've mentioned?

Takes more than equipment, training, software, and an idea. It requires discerning customers with enough engineering/math/science training to know what they're looking at, what to do with it, and how to properly analyze results. Just like any other product. Some of us will eat a Big Mac five days a week and some of us wouldn't feed one to a dog.

quote:

barrel expansion

I am not familar with this term. Could someone explain? is the bullet expanding to fill the grooves or is the barrel temporarily bulging? Does this relate to barrel wear?

Is this "expansion" a bad thing. I guess it must be bad ... I never hear of it.

hi
isen't that longer bearing surface on mono solids causing faster wearing of barrels? i have some 30 caliber 220 grain mono solids from Barnes and noticed these bullets are very much longer than wl steel jacket solids in same caliber and weight. does the newer design banded solids are wearing less ?
regards
yes

IMO,the greatest factors in barrel wear should be barrel steel and the hardness of the metal that is moving against, and is in contact with the rifling.When I say hardness,I mean hardness as a geology term-the way one mineral is harder than another.Another factor would have to be the ability for a bullet to give or to squeeze.A lead core bullet will give where a monometal will not.

Fellow shooters, it is real simple, shoot a hot barrel and you wear the barrel more. Keep that barrel cooler and the wear is minimal. Yes, the Mono Metal bullets are longer and unless the bullet maker considers that, as in the grooves by North Fork (bonded core front and solid rear) and Barnes, wear will be more. With Magnum chamberings I shoot three shots, then let the barrel cool while shooting another rifle. Do this and you can get several thousand rounds out of your barrels and maintain accuracy. Good shooting.

fourbore,

Don's post is referring to the momentary radial expansion of the barrel as the bullet passes through it and gas pressures rise and then fall. Steel is elastic, up to a point, just like the bullets (although in a rifle the bullets are plastically deformed ie rifling are engraved). The barrel expansions he refers to can be rather easily calculated in one knows the physical barrel dimension, the barrel alloy, barrel heat treat, barrel mechanical properties in it state, the bullet dimensions, the bullet material, and the mechanical properties of the bullet material. The calculation is simply the balancing of spring rates, although near the breech they become much more tricky due to the non-linear ie plastic deformation of the bullet, which therefore excludes the relatively easy spring rate balancing equations allowed by application of Hook's law (Hook's law is only applicable in the proportional or elastic region of the materials mechanical properties). Strain gaqes all work upon this physical property of materials and the stresses are calculated from the measured strains by utilization of Hook's law (the electrical side of the strain gage is a different story most work on the Wheatstone bridge principal (Kirchoff's law and I think I spelled it right), but you didn't ask about that and I don't feel like typing that much more )

Enough engineering ME305 ie Strength of Materials?

Velocity is another important factor,IMO.

Barrel wear is greatest during the Winter Solstice, less in the Southern Hemisphere, and extraspecially on Thursdays if you're using a LH twist of 3 or more grooves ...

quote:

Originally posted by Macifej:
Barrel wear is greatest during the Winter Solstice, less in the Southern Hemisphere, and extraspecially on Thursdays if you're using a LH twist of 3 or more grooves ...

With this I agree, but only if you consider picking the white stuff out of the CHICKEN SHIT first !!

BS!- Monometal Bullets dont wear out barrels, CLEANING RODS in the hands of MORONS wear Barrels!-Rob

ScottS...Ir was much simpler just to load 60 rnds and fire them with a guge at each end of the barrel!

Macifej- Yes, I tried it personally. A maker of double rifles was concerned that the monometal bullets we use in some of our loads would 'harm' his rifles. Since Barrel expansion with the mono's in question was (approx) half that of woodleighs, he was happy enough for us to send him 1000 rnds and test fire them to ensure that the barrels wouldn't "spring".

Don,

With your comment I agree IF one has the appropriate equipment.

Rob,
You should stop using those hard carbon fiber rods (seriously they are MUCH harder than aluminum)!

Is the barrel expanding more because the bullets are sealing the gases? How about the GRINDER effect a hard bullet has on rifling? I don't think it has to expand the barrel to grind away at the rifling and increase the effective bore diameter.Someone once told me a barrel acts in the same way a snake swallows an egg.Expansion might not neccesarily mean damage.

shootaway,
There is NO "grinder effect" unless one is coating their bullets with sand, dirt, or lapping compound(personal favorite being silicone carbide followed by aluminum oxide)! Macifej is incorrect in is comment about the hardness of the bullet also, it is very important. Although, if the hardness variation of the various bullet alloys used for the monolothic solids is small it will have a small effect relatively speaking among the various MONOLITHIC solids.

quote:

Originally posted by ScottS:
shootaway,
There is NO "grinder effect" unless one is coating their bullets with sand, dirt, or lapping compound(personal favorite being silicone carbide followed by aluminum oxide)! Macifej is incorrect in is comment about the hardness of the bullet also, it is very important. Although, if the hardness variation of the various bullet alloys used for the monolothic solids is small it will have a small effect relatively speaking among the various MONOLITHIC solids.

maybe SCRAPER would be more suited

quote:

When does less velocity improve penetration with non-deforming solids ...??

Ok, lets first define what a "solid" needs to do: 1) achieve adequate penetration...ie: penetrate the desired organ or fully penetrate the whole body mass. 2) pentratrate in a straight line so that an aiming sight might be picked in such a way that a targeted organ (ele brain) may be intersected with the bullet path.

I think we can all agree here.

Ok...Once a "solid" has exited the body or even the back of an ele's brain, any residual energy from velocity is wasted because the solid just punches a straight bullet diameter hole. We are NOT looking to enhance the terminal performance of a "solid" projectile.

As velocities increase...the percent chance of bullet deformation likewise increases. Bullet deformation decreases the chance of achieving "straight-line penetration" which is the "name-of-the-game" in the one instnace where a "solid" is the only option...the brain shot on an ele...esp the frontal where NON-straight-line penetration often means NO dead ele.

So in my opinion...when shooting a "solid" projectile..."just enough velocity" to ensure adequate penetration should be your goal.

To increase from adequate at the very minimum will NOT help but possibly could hurt. Why??? By causing bullet deformation which might cause an errtic bullet path which might cause the target organ to be missed.

quote:

Originally posted by ledvm:

quote:

When does less velocity improve penetration with non-deforming solids ...??

Ok, lets first define what a "solid" needs to do: 1) achieve adequate penetration...ie: penetrate the desired organ or fully penetrate the whole body mass. 2) pentratrate in a straight line so that an aiming sight might be picked in such a way that a targeted organ (ele brain) may be intersected with the bullet path.

I think we can all agree here.

Ok...Once a "solid" has exited the body or even the back of an ele's brain, any residual energy from velocity is wasted because the solid just punches a straight bullet diameter hole. We are NOT looking to enhance the terminal performance of a "solid" projectile.

As velocities increase...the percent chance of bullet deformation likewise increases. Bullet deformation decreases the chance of achieving "straight-line penetration" which is the "name-of-the-game" in the one instnace where a "solid" is the only option...the brain shot on an ele...esp the frontal where NON-straight-line penetration often means NO dead ele.

So in my opinion...when shooting a "solid" projectile..."just enough velocity" to ensure adequate penetration should be your goal.

To increase from adequate at the very minimum will NOT help but possibly could hurt. Why??? By causing bullet deformation which might cause an errtic bullet path which might cause the target organ to be missed.

You have assumed that to increase penetration you must increase velocity. Another and in my opinion a better way is to increase bullet weight at a somewhat lower velocity.

465H&H

Another potentially useful thread headed south! Going back to my "All in the Family" re-runs ...

quote:

Another potentially useful thread headed south!

Macifej,

Do you disagree with something I said in my above post about the purpose of a solid projectile in regards to it use in hunting?

phurley5 is on to something. Letting barrel cool betweeen shots will extend life, irrespective of other factors.

At what point in the bullet's travel down the barrel is it fully engraved (to full depth) by the rifling? I assume that this happens by the time it has gone its own length down the barrel. After this point, the rifling no longer has to deform the bullet, but simply guide its rotation. It's not like you are trying to pound a golf ball through a garden hose, where the bullet does not deform and the barrel has to stretch like a snake's belly to allow it to pass through. The barrel does have some radial expansion as the bullet passes down it, but this should be no different for various bullet types once the bullet is engraved by the rifling. The bullet makes a 'moving dam' for all the pressure built up behind it, and this pressure is what expands the barrel, not the diameter of the bullet. The bullet has already been squeezed down to fit.

I would agree that the solid shank monometal bullets are probably initially harder to deform with the rifling, but this is only a factor in the first section immediately after the throat (and serves only to increase chamber pressure which means you have to watch this when developing loads). Grooved shanks will likely ease much of this increase in effort by minimizing the amount of material that has to be removed as well as providing it a place to go. I doubt either variety of these will wear the barrel faster than other bullet types, as barrel steel is much harder than the bullet. The wear comes from heat and pressure, as has been stated already. In fact, I'd wager there are several 'monometal' alloys with a high lubricity that might even be easier to push down the barrel than your typical gilding metal cup and core bullet (once fully engraved).

quote:

Originally posted by Mikelravy:
phurley5 is on to something. Letting barrel cool betweeen shots will extend life, irrespective of other factors.

I am not so sure about that.Ever tried to shave,right after coming in from the cold,with cold water and a cold razor-tear your skin apart.Ever tried to start a diesel engine in the cold-not smooth.IMO,barrels may last longer when they get hot.

quote:

Originally posted by shootaway:

quote:

Originally posted by Mikelravy:
phurley5 is on to something. Letting barrel cool betweeen shots will extend life, irrespective of other factors.

I am not so sure about that.Ever tried to shave,right after coming in from the cold,with cold water and a cold razor-tear your skin apart.Ever tried to start a diesel engine in the cold-not smooth.IMO,barrels may last longer when they get hot.

Fact, steel gets softer and weaker the hotter it gets. A barrel can and will get much hotter than will an engine if one fires enough rounds continuiuisly, even to the point of turn red


I find it hard to believe that a Monometal bullet with groves or driving bands can be as hard on a barrel as a steel jacketed solid with it's greater bearing surface

When a rifle barrel heats up the outside diameter increases. What happens to the bore diameter? Does in increase or decrease?

465H&H

Steel expands when heated, inside, outside, lenght, all direction

quote:

Originally posted by jwp475:
Steel expands when heated, inside, outside, lenght, all direction

If that is the case, wouldn't we expect a very hot barrel to have more room between the bullet and the bottom of the groves? That would allow more hot gases to pass around the bullet base increasing barrel erosion. That is one of the reasons why machine gunners are taught to fire in short bursts rather than long bursts.

465H&H

IMO,a warm or hot barrel will cause less friction between the bullet and rifling.As for the rifling becoming soft,I don't think we need to worry about that.We are shooting a bunch of rds with it not heating it up with an oxygene torch.Did you ever see a barrel turn red,so that you couldn't touch it?IMO,the most damage to the rifling occurs from the first shots fired before it gets hot.