230 grain vs 165 gr in .45acp

Discussion in 'Centerfire Pistols & Revolvers' started by RedHawk, Jun 27, 2011.

  1. RedHawk

    RedHawk Former Guest

    Joined:
    Jun 26, 2011
    Messages:
    177
    Ive never even thought about this before because Ive never shot 165 gr , anyone want to tell me the differences regarding these 2 ,Im thinking the stopping of the 230 is probably alot higher ,but I dont know anything about rounds , other than the rounds my gun "likes" or "dislikes" .

    Please educate me!!
  2. Alpo

    Alpo Well-Known Member

    Joined:
    Feb 3, 2007
    Messages:
    11,194
    Location:
    NW Florida
    Accuracy would probably suck. Bullets are, generally, much longer than they are wide. This cylindrical shape allows them to have more of their surface area in contact with the rifling. This is called the bearing surface. When you lighten a bullet, they weight much come from somewhere. You can remove it from the inside, like a hollow point, and keep the same length, but still be lighter. Many match rifle bullets are hollow-point especially for that reason. They can be longer for their weight, and have a longer bearing surface. The more of the bullet that is in contact with the rifling, the stabler and more accurate the bullet is likely to be.

    But, usually, when you want to lighten a bullet, you just shorten the base, which causes you to lose bearing surface, and potentially means bad accuracy. See attached ABSOLUTELY NOT TO SCALE drawing of regular bullet and light bullet. :)

    Then you have the rifling twist. This controls how fast the bullet spins. Normally, a "faster twist" is used for a heavier bullet, while a "slower twist" is used for a lighter one. If a twist of "one in twelve" is used, that means that the bullet makes one complete spin in twelve inches of travel. If you have another barrel with a "one in six" twist, if bullets were fired are the same velocity from both guns, one bullet would be spinning twice as fast at the other one. The speed of the bullet also impacts the speed of the spin. If you take two bullets, fired from the same twist barrel, but one is going 500 fps and the other is 1000 fps, the second bullet is also spinning twice as fast as the first bullet.

    The rifling rate for any specific barrel is decided upon based on the weight of the bullet, the speed of the bullet and the bearing surface of the bullet. If you change any of them drastically, you might need to go to a faster or slower twist barrel, to keep your accuracy.

    A 70 grain weight change in a 600-grain elephant gun bullet isn't that much. A 70 grain change in a 110-grain 30 carbine bullet is HUGE. A 70 grain change in a 230-grain bullet isn't that bad, but it's still a 30% weight loss. I doubt that a bullet set up for a 230-grain bullet would provide good accuracy with one that small.

    Attached Files:

  3. RunningOnMT

    RunningOnMT New Member

    Joined:
    Nov 19, 2008
    Messages:
    4,720
    Location:
    Akron, Ohio
    Alpo, are there charts which provide the gr.wt. bullet providing optimum performace for barrels of various lengths and twist ratios in a given caliber?
  4. Alpo

    Alpo Well-Known Member

    Joined:
    Feb 3, 2007
    Messages:
    11,194
    Location:
    NW Florida
    I'm sure there are, but I don't know where they'd be.

    I got interested in this, from reading about the M16. When it was first issued, the Black Rifle was deadly as hell. 55 grain .22 bullet at 3000 fps and a 1-in-14 twist was just barely stable, and when it hit a soft target it yawed, and did massive tissue damage. But they changed the powder from IMR rod to WW ball, and the speed went up to 3200. Now it was stable, and drilled nice little 22 caliber holes through Charlie. That won't work. Increase the bullet weight. There we go. Now it's slightly unstable again, and does massive tissue damage. But if it's just barely stable at 3200, when it drops to 2500 - out there around 300 yards or so - it's so unstable that the accuracy is gone. We must make it accurate. Go to a faster twist, to stabilize the bullet. That worked. 1-in-12? 1-in-11? Anyway. Now they are accurate. But they don't kill worth a damn. Heavier bullet makes it slightly unstable, so it does damage. But now it's not accurate, so increase the twist, that makes it stable, so it does not damage, so increase the weight to make it unstable, so it isn't accurate, so increase the twist to make it stable, etc., etc, etc. What is it now - something like a 72 grain bullet and a 1-in-9 twist?

    Then I found out that Pennsylvania long rifles had like a 1-in-40 twist, to stabilize a round ball. Lightweight with very little bearing surface. My T/C Renegade has, I believe, a 1-in-28 twist. Fast enough to still stabilize a round ball, but also slow enough to stabilize a Maxi-ball, which is both much heavier and has a long bearing surface.


    Oh, here we go. Stole this off Wiki.

    Twist rate and bullet stability

    In 1879, George Greenhill, a professor of mathematics at the Royal Military Academy (RMA) at Woolwich, London, UK[10] developed a rule of thumb for calculating the optimal twist rate for lead-core bullets. This shortcut uses the bullet's length, needing no allowances for weight or nose shape.[11] The eponymous Greenhill Formula, still used today, is:
    [​IMG]

    where:

    * C = 150 (use 180 for muzzle velocities higher than 2,800 f/s)
    * D = bullet's diameter in inches
    * L = bullet's length in inches
    * SG = bullet's specific gravity (10.9 for lead-core bullets, which cancels out the second half of the equation)
  5. Alpo

    Alpo Well-Known Member

    Joined:
    Feb 3, 2007
    Messages:
    11,194
    Location:
    NW Florida
    So, lemme see here.

    150 x .452 = 67.8, squared = 4596.84, /.660 = 6965

    hmmm. That seems wrong.

    Lets try C x (D squared) instead of (C x D) squared.

    150 x .204 = 30.65 / .66 = 46.4. 1 in 46. That seems more likely.

    Been a while since I been in math class. :p
  6. Alpo

    Alpo Well-Known Member

    Joined:
    Feb 3, 2007
    Messages:
    11,194
    Location:
    NW Florida
    Back figuring.

    Colt 1911 is 1-in-16, according to the chart in the back of my Sierra manual #1.

    We are figuring for L - the bullet's length, not its weight.

    C x (D squared), /L = 16

    (150 x .204)/L = 16

    30.65 / L = 16

    30.65 = 16L

    1.92 = L

    The optimum bullet length, for a 45 bullet and a 1-in-16 twist, is 1.92 inches.

    Somebody want to check my math? Like I said, Algebra class was 40 years ago.

    40 years? :eek: God I got old!
  7. RunningOnMT

    RunningOnMT New Member

    Joined:
    Nov 19, 2008
    Messages:
    4,720
    Location:
    Akron, Ohio
    Thanks Alpo. The thing is it doesn't suggest barrel length or the best round for a given barrel length. For example 230 gr. .45 typically has a muzzle velocity of approx 830 fps out of a 5" barrel. Now that's pretty slow but would imagine even slower out of a 3.5" barrel. So would it be better to use 165 or 185 gr bullet to bring the mv back up a bit? That's why I wondered if given the barrel length and twist rate in a given caliber, if you can determine the optimum gr wt bullet to use.
  8. Old Grump

    Old Grump New Member

    Joined:
    Feb 21, 2010
    Messages:
    2,320
    Location:
    Little hut in the woods near Blue River Wisconsin
    According to this it is a high velocity load that will give you better penetration for a short (3") barrel than can be achieved with standard 185, 200 and 230 gr loads from that small a gun. Looks to me from looking at the bullet that the weight was taken from the hollow point and not so much from the base so accuracy shouldn't be that much affected, at least for up close and personal self defense ranges.

    I think I will stay with my 230 gr bullets when plinking at 2 liter water jugs at 200 yards. It may take awhile for the bullet to get there but get there it does and in a nice group if I am paying attention and do what I should be doing.

    On the other hand if I want a small compact gun in 45 ACP then this bullet may very well be the way to go.


    Only 40 years ago? :confused: Dadburn young whippersnappers. I still have my slide rule from calculus class. I can't remember how to use it anymore but big deal, I don't remember where I put my 7.5x55 box of ammo I wanted to shoot today and that's more important.
  9. RunningOnMT

    RunningOnMT New Member

    Joined:
    Nov 19, 2008
    Messages:
    4,720
    Location:
    Akron, Ohio
    I'd sure love to see that. Hard to believe one can hit anything at 200 ft. let alone yds. with a .45 cal handgun. Makes me embarrassed to admit I only practice at 7 and 15 yds.:eek:
  10. RedHawk

    RedHawk Former Guest

    Joined:
    Jun 26, 2011
    Messages:
    177
    yep I was wondering because a site I was looking at touted the +P ammo @ 165 gr!!So for a Government model the 230 would be preferable and a Commander it would be the 165? Or is the 165 +P strictly a duty carry round?
  11. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,269
    Location:
    Heart Of Texas
    P.E.M.D.A.S. Alpo, mathematical order of operations. Apply it before trying to figure compound equations such as the greenhill formula. It makes life easier..:)
  12. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,269
    Location:
    Heart Of Texas
    Its all irrelevant ROMT. Concerning the .45ACP with bullet S/D bullet weights from 185-230 grains, any velocity over 600 FPS is gonna penetrate well into or completely thru a 'soft target'.. A standard ball load in a 5 incher, 230 grain bullet at 830 FPS, will run about 750 from a 3.5" barrel. Still plenty fast enough to get the point across.. So to answer your question.. Optimum is what your weapon shoots best.
  13. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,269
    Location:
    Heart Of Texas
    I wish you were closer ROMT. At my range we do stuff like this all the time. I like to shoot at water balloons with my 1911s. It does take a good while for the bullets to get there and if the sun is at your back you can see them arc to the target. Its really cool..:)
  14. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,269
    Location:
    Heart Of Texas
    Oh yeah.. I almost forgot.. I have a link here that calculates optimal twist for any bullet at any concievable velocity. All you have to do is plug in the variables of your particular bullet and load..

    http://kwk.us/twist.html

    It sure beats long form mathematics like the stuff Alpo so painstakingly posted for us;)
  15. Alpo

    Alpo Well-Known Member

    Joined:
    Feb 3, 2007
    Messages:
    11,194
    Location:
    NW Florida
    Had to google that, to find out what you was sayin'. Yeah, I remember "order". You do what's in the brackets first. If there are no brackets, you do it in order.

    That's why I did CxD, and then squared the product. If it had said C(D squared), I'd have squared D first, but it didn't so I didn't. Apparently you are supposed to do exponents first.

    Like I said, high school math was 40 years ago.
  16. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,269
    Location:
    Heart Of Texas
    Parentheis, Exponents, Multiplication, Division, Addition, Subtraction..

    Parenthesis does include brackets, but in an equation that includes both brackets and parenthesis, you would do the parenthesis first then the brackets.
  17. RunningOnMT

    RunningOnMT New Member

    Joined:
    Nov 19, 2008
    Messages:
    4,720
    Location:
    Akron, Ohio
    Thank you sir. I guess I can use the same .230 gr Golden Sabers I use in my 1911's in my M&P compact and Kahr CW45 as well. That's great. I hate to have to stock very many different varieties of ammo.
  18. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,269
    Location:
    Heart Of Texas
    No need. I promise the squids will look the same.. I have tested expansion on goldensabers in everything from 3 inch barrel BUGs to a 6 inch barrel S&W 625. they all made 3/4" diameter squids and penetrated between 10-14 inches in wet phonebooks. The average human torso is only about 10 inches thick sternum to spine. Just so you know.. ;)
  19. carver

    carver Moderator

    Joined:
    Jul 28, 2008
    Messages:
    15,986
    Location:
    DAV, Deep in the Pineywoods of East Texas, just we
    Personally, I don't like the lighter bullets. Let's face facts, handguns balistics are at best just barely acceptable for SD. I don't trust the lighter bullets to give me the penitration that is needed to stop the BG. As Josh stated the 230gr Golden Sabers gave him up to 14" of penatration in wet phone books, that would probably jump to 18" if shooting at lined up gallon milk jugs of water. These lighter bullets travel faster, and have more of an incident of coming apart. We all know that there are two ways to get a sudden stop on a living target, one is a hit to the brain, or spinal cord. The other is a sudden loss of blood pressure. A .22 bullet to the brain, or spinal cord will drop you where you stand, but a hit to the body will most probably not give you the loss of blood presure needed to make a quick stop. To assure the quick loss of blood pressure you need to make big holes (2 or three hists) that leave large, deep, wound channels. Wound channels deep enough to reach the spinal cord. And only the heavy bullets can be relied on to get to the vitals, and sometimes they won't make the trip! Shot placement is everything in handgun SD. Will your bullet of choice pass thru the arm of an assaliant, and then enter the body, through clothing, creating a large, deep, wound channel, that will reach the vital organs?
  20. hogger129

    hogger129 Active Member

    Joined:
    Nov 29, 2009
    Messages:
    4,152
    I stick with 230gr loads. The 185's are okay, but my gun doesn't like to feed them as reliably because of the bullet shape.
Similar Threads
Forum Title Date
Centerfire Pistols & Revolvers Range Report: 240 Grain Buffalo Bore 44 Magnum +P Deer Grenades Oct 15, 2012
Centerfire Pistols & Revolvers Large Frame 45acp Best Choice? Apr 13, 2014
Centerfire Pistols & Revolvers Compact 45ACP Feb 17, 2014
Centerfire Pistols & Revolvers kriss vector 45acp pistol Oct 26, 2013
Centerfire Pistols & Revolvers I am looking for a Colt .45acp cylinder for a 3rd gen Colt SAA. Sep 24, 2013

Share This Page