Best Bullet Type for Knocking Down Steel?

[Religious Shooter]

I'm developing a 9MM load specifically for knocking the s___ out of steel.

I'm going to get the heaviest bullet I can afford in bulk.

But there are FMJ's, hollowpoints, truncated cone, CMJ RN, etc. Which bullet type is more effective when it comes to moving steel?

Thanks.

[Religious Shooter]

Also is there a .355 bullet out there that's heavier than 147 grain?

I know Ranier has a .356 151 grain. But other than that all I'm seeing is a max of 147 grain.

[Sarge]

I have heard 160's mentioned. See what a search gives you on those.

[herky]

Flex used to say that hollow points had "more dwell time on steel". I'm not sure of the science behind this statement, maybe he will chime in with his reasoning.

[M ammo]

I have been working on a 9mm load with a 160Grain lead rn. sized in .356.

3Gr of TG is pretty good I'll probably get that down to 2.7 and give it a try.

Jim M ammo

[Joe4d]

assuming you could get a heavier bullet to stablize, I had problems with 147's in some guns, I know there are 150 gr SWC sized .356. I tried for bowling pins with a 9mm, In thinking about it since there is no grab potential or penetration like there is on bowling pins, I dont see how bullet design could have much effect,

[JThompson]

Simple terms

How heavy the bullet is x how fast is it going / how long it acts on an object

F=mxa

Screw the Physics, check this out!!

For those that just have to know why??? Se below.

Kinetic Pulse

a study in bullet impact

by james n. hall copyright © 2000

revised January 1,2002

copyright © 2002

www.kineticpulse.us/math/kp.html

The debate goes on as to whether MOMENTUM or KINETIC ENERGY is the best measuring rod for determining the effective striking power of a bullet.

Of course the obvious answer has somehow been obscured or avoided.

What is the answer? It is to merge somehow these two parameters of bodies in motion . What is that merge and what empirical observation could lead to a mathematical formula to represent this OTHER measuring rod? The easiest start to dealing with the unknown is to name it and the author takes this easy route and coins KINETIC PULSE as the name of the new measuring rod.

Now we have Kinetic Pulse as our quick reference to a new method of measuring a body in motion such as a bullet or a meteor. We will confine our study to the ballistics of the bullet.

The formula for kinetic energy for a bullet in motion is:

ENERGY (in ft-lbs) = .5 times (mass in grains) times velocity squared all divided by a number to represent slugs in mass or 225218 or symbolically:

KINETIC ENERGY = ( .5 * m * v ^ 2 ) / 225218 in units of ft-lbs.

1 grain which is 1/7000 th of a pound is equal to 1/ 225218 th of a slug.

Thus an 180 grain bullet = 180 / 225218 slug = .0007992 slug in decimals.

In order to get the correct ft-lbs of energy all measurments will converted to slug units of mass. Thus 1 grain unit in mass is equal to 1 / 225218 slug or in decimals is equal to .0000044 slug or 1 gr = .0000044 slug.

NOTE! what a grain weighs will be different at higher altitudes than at sea level. A slug was intended to be the amount of mass that represented the acceleration of mass at sea level. This may be different at 4000 feet or 10000 feet in the mountains of Utah. The mass is the same even in outer space but the acceleration of 1 slug of mass at 100 miles high will not be 32.17xxxx ft/s^2. It is difficult to find the exact number for a slug except at sea level it is the same weight in pounds as the acceleration of gravity at that altitude. Hopefully the calculations here are accurate enough for practical purposes. I would appreciate an email with the acceleration of gravity at sea level in feet / sec^2 to 10 places. As of September 9,2002 settled on 225218 as it seems to matter very little significantly.

The formula for MOMENTUM of a bullet in motion is momentum is equal to mass times velocity and it's unit of measure is the (slug ft/sec) or symbolically:

MOMENTUM = ( m * v ) / 225218 slug ft/sec.

225218 resolves mass in terms of grains which is the common unit of mass for a

bullet. There are 7000 grains in a pound. Or 7000 grains = 1 lb of mass or .0310815 slug.

The force a bullet exerts on impact is a ratio to the time it takes to stop the bullet divided into the momentum or symbolically:

Force = momentum / (time to stop) or F = mv/t

If a bullet hits an object and it stops in 1/10000 of a second the force is for a bullet traveling a 2000 ft/s and weighing 180 gr is for example

Force = ( ( 180 gr * 2000 ft/s ) / 225218 ) / .0001 = 15984.6 lbs .

That is if it stops in 2.4 inches of medium 15984.6 lbs is applied.

If a bullet hits an object and it stops in 1/1000 of a second the force is for a bullet traveling a 2000 ft/s and weighing 180 gr is for example

Force = ( ( 180 gr * 2000 ft/s ) / 225218 ) / .001 = 1598.46 lbs .

That is if it stops in 24 inches of medium 1598.476 lbs of force is applied.

If a bullet hits an object and it stops in 1/100 of a second the force is for a bullet traveling a 2000 ft/s and weighing 180 gr is for example

Force = ( ( 180 gr * 2000 ft/s ) / 225218 ) / .01 = 159.846 lbs .

That is if it stops in 20 feet of medium 159.8476 lbs is applied.

In all this slowing down in a medium the same energy is expended which is:

Energy = ( .5 * 180 gr 2000 * 2000 ) / 225218 ) = 1598.46 ft-lbs .

Now two bullets of the same momentum can have different energy content. for example: a 360 gr bullet with a velocity of 1000 ft/s has the same momentum of the 180 gr bullet with a velocity of 2000 ft/s which is

• momentum of 180 gr bullet = ( 180 gr * 2000 ) / 225218 = 1.59846 slug ft/s

• momentum of 360 gr bullet = ( 360 gr * 1000 ) / 225218 = 1.59846 slug ft/s

• energy of 180 gr bullet = ( .5 * 180 * 2000 * 2000 ) / 225218 = 1598.476 ft-lbs

• energy of 360 gr bullet = ( .5 * 360 * 1000 * 1000 ) / 225218 = 799.238 ft-lbs

The lighter 180 gr bullet has twice the energy of the 360 gr bullet. This means that the penetration of bullets will be the same due to the same force on the medium; but, twice as much energy will be expended on the medium at a right angle to the direction of penetration. This will cause a greater cavity of impact; never the less, the same depth of penetration. This is assuming the bullets are geometrically the same dimensions but only differ in weight. This is done as in a comparison, so some factors can be canceled. If you were to predict the behavior of an object of a given geometry and a given medium to impact all factors must be determined. But we are here only building a comparison and these can be ignored because they will be assumed the same in both bullets.

"Here endeth the lesson."

Edited December 31, 2009 by JThompson

[DougCarden]

My data is as follows as I did a little research over the last 7yrs....Take it or leave it.

If you are pushing it, you are going to get less than desireable hits at times, so you will have edge hits, period. Since I know realistically I will have some edge hits, I want as much bullet weight hitting the steel. A edge hit with a 147grain bullet will more likely take down the target versus a 115-124gr bullet with an edge hit, period.

I like the heavy bullet/fast powder theory.

If I need really accurate ammo, I use the Zero 150 JRN .356 for my Short Colts and Big matches with small targets like the PSA Shootout.

For everything else Bulk 147gr FMJ will be just fine. I use Montana Gold 147s and am very happy with them.

For practice and local matches I cast up a bunch of 160gr LRN, and am very happy with them as well.

Find whatever works for you

Hope this helps,

DougC

[Tom Freeman]

As on old Silhouette shooter, I have a little experience with this.

A heavy JHP or FP with lead exposed at the tip will "dwell/stick" longer on the steel.

I had the best luck with the Sierra 41 caliber 220 gn FP. Not one ringer, ever.

[Flexmoney]

Flex used to say that hollow points had "more dwell time on steel". I'm not sure of the science behind this statement, maybe he will chime in with his reasoning.

Sierra calls their dwell time bullet a Full Profile Jacket (FPJ). They emphasize not having the bullet be too soft (not enough dwell time to generate adequate momentum).

If I felt the need to drive the steel with 9mm, and wanted to use 147's...I'd just up the power factor. (rather than chase around for heavier bullets that aren't easy to find)

[M ammo]

My data is as follows as I did a little research over the last 7yrs....Take it or leave it.

If you are pushing it, you are going to get less than desireable hits at times, so you will have edge hits, period. Since I know realistically I will have some edge hits, I want as much bullet weight hitting the steel. A edge hit with a 147grain bullet will more likely take down the target versus a 115-124gr bullet with an edge hit, period.

I like the heavy bullet/fast powder theory.

If I need really accurate ammo, I use the Zero 150 JRN .356 for my Short Colts and Big matches with small targets like the PSA Shootout.

For everything else Bulk 147gr FMJ will be just fine. I use Montana Gold 147s and am very happy with them.

For practice and local matches I cast up a bunch of 160gr LRN, and am very happy with them as well.

Find whatever works for you

Hope this helps,

DougC

What powder and how much????? on the 160 LRN's

Jim M ammo

[bigbrowndog]

A tough bullet that will not MELT or break up, on impact will cause energy to transfer to the target better. having said that, pretty much any bullet we shoot will melt or break up on impact, so the best we can do is slow the process, FMJ does this best, the profile of the bullet will have negligible effects, because shortly after impact they are ALL flat point bullets.

too many people get hung up on external ballistics to figure out what they want the bullet to do to the target, its terminal ballistics that determine effect on target. Velocity does not help as much as some think, compared to weight/mass when dealing with terminal ballistics.

Trapr

[ManNamedJed]

I've loaded up some MG 147s and used them on steel heavy stages, and at pin matches. I absolutely feel they made a difference. I've loaded the 147s with 3.6 and 3.8gr of TG with great results (warning, these are max loads, work up appropriately) and even tested 4.gr, but was certainly seeing pressure signs there. Sorry I can't remember my chrono or OAL numbers right now, I can look them up if anyone is interested.

Recoil was more than when I shoot 124s at 130pf, but still less than shooting a factory .40 load.

One issue is that the longer 9mm rounds can do some weird things to the cases. You can get weird bulges where the brass buckles at the base of the bullet. I think some brass just wasn't designed for that long of a bullet.

Edited December 31, 2009 by ManNamedJed

[Chris Christian]

+1 to heavier bullet weights, and profile (IMHO) makes little difference. I've yet to have a popper not drop with ANY hit from a 9mm/147/880fps load. My 230 .45 ACP (740 fps) take them down faster. As a IDPA SO I've watched a lot of shooters shoot steel. The 115 grain 9mm loads can be comical, at times. Ding.. ding... ding... then someone yells " Shoot for the head"... ding, ding, and finally down. Heavy bullets drop steel better than lighter ones. If all you have to do is hear a "ding" and see a black mark on the steel target ( Steel Challenge) bullet weight makes no difference.

Chris Christian

[Boats]

Weight knocks steel down. Velocity can do it but to increase knockdown weight has the most effect. In a 9mm I would go for 147's and a load that shoots well in your gun. You have to hit them first.

Boats

[tightloop]

the one that hits the plate....LOL

[steel1212]

the one that hits the plate....LOL

That is what I was going to say. If its above minor and you call your shot a hit, move on!

[Religious Shooter]

My primary reason for the load is to spin an MGM spinner.

At :40 and :53 (etc.) of this vid:

Just hitting it isn't going to do.

[sargenv]

You know, if it's weight you want and lead or moly coated lead is ok to use and your 9mm will feed a semi wadcutter or truncated cone, why not get a Lee swaging die and size down .358" bullets to .356"? I have a 627-4 in 38 Super that likes .357" diam bullets. I am sizing down Bear creek .358 158 RN's to .357" and they are proving to be very accurate. The Push through sizers are meant for single stage presses like the Rock Chucker or their own challenger press. I can size down 1000 of these in an evening.. The bear creeks don't need lube as they already have the moly coating. I am getting no leading even after sizing them down through the sizer.