Purely Ballistics - What does it take for a .45 to be accurate @50yds

If the only constraints are accuracy at 50 yards and a .45 calibre, what determines the minimum ballistics for "acceptable" performance?

Would it be possible to determine the shape, minimum weight, minimum velocity and then design or modify a pistol to fire a cartridge designed to those specs?

Is there a defined definition of .45 calbre for bullseye competition? Wikipedia puts .45acp in a list that includes everything from 11-millimeter (0.43 in) to 12-millimeter (0.47 in).

There are several variables. Zero 185 JHP runs approximately 800 FPS. I see 1.25” groups regularly from this ammunition. My 200 gr LSWC with 3.8 gr BE gets 1.75”. Not sure of the velocity but considerably less recoil. I think it’s acceptable accuracy without wearing me out. So biggest variable to me is the shooter. A part time recreational shooter will do better with the lighter recoiling load because it is less fatiguing and more forgiving from hand. Zero load requires more practice time and conditioning.
Jon

Jon, From an academic point of view, I think I read that each bullet has a sweet spot, in terms of velocity, for smallest group. Then, I guess, you could compare the resulting group sizes, for different bullets, from the same barrel for the "most accurate".

But, back to your point; we're splitting hairs. What good is a marginally smaller group size with less "shootability"? The resulting scores would likely be lower.

Fun to think about but it's hard to argue the academic vs. the practical.

Slartybartfast wrote:
Is there a defined definition of .45 calbre for bullseye competition? Wikipedia puts .45acp in a list that includes everything from 11-millimeter (0.43 in) to 12-millimeter (0.47 in).

  The SAAMI dimensions for
45 AUTOMATIC / 45 AUTOMATIC +P / 45 GLOCK AUTOMATIC PISTOL / 45 WINCHESTER MAGNUM  bullet are -


Jacketed Bullet- 0.4520 +0/-0.0030"
Lead Bullet- 0.4530 +0/-0.0030"


45 COLT dimensions-

0.4560, +0/-0.0060"


See https://saami.org/wp-content/uploads/2019/01/SAAMI-Z299.3-Centerfire-Pistol-Revolver-Approved-12-14-2015.pdf for details.

I don't think the NRA Rule is any more detailed than "any .45 caliber."

I am a long range precision rifle reloader for many years but only recently started to do precision pistol and I will share with you one thing I learned and that is the bullet makes a big difference.

As a seasoned IDPA pistol shooter, I have shot Precision Delta 147 FMJ for more than 10 years.  To me, they are very accurate as I can hit reduced size IPSC steel targets out to 75 yards with no trouble.  However, I found out trying to shoot less than 2" groups with a PCC at 50 yards this was not real accuracy.

Apparently, FMJ by design cannot be as accurate as JHP since the opening of FMJ is at the back of the bullet.  With the opening at the front, JHPs can have a much more uniform tail.  And the tail is the last thing the barrel crown touches before it leaves the gun.  As you should know, a good quality crown is essential for precision.  The OTHER side of the fence is of course the bullet tail and a consistent one is also essential for precision.

So the long and short of it is, go straight to the JHP if you want precision.

"So the long and short of it is, go straight to the JHP if you want precision."

Or this bullet.  200gr Hornady JSWC.  Going pretty fast.  An excellent bullet

The two cut out targets were shot the 3 oclock first.   Then a left sight adjust.  And 5 more shots.  All offhand.  The 1955 model there has a fantastic single action trigger

Back when I was actively competing and living in a small remote town, I discovered the old Bullseye-L. As there were no other bullseye shooters in town, it was a blessing to me. Dave Salyer, who in partnership with Al Doorman developed the "Marine Corps Load" helped me out. I didn't have access to Vihtavuori powder. Dave said that during their tests, they found that Alliant Bullseye powder worked well. He gave me the load of 4.5 grains of Bullseye behind the Nosler 185 gr. JHP bullet in .45 ACP. Through the years, I never changed that long line load. Verified by the Ransom Rest, it shot very well through good pistols, even some very old builds. A shooting buddy bought a new Rock River wad gun and machine rest tested it right from the factory. He upped the load to 4.6 grains of Bullseye and got a 7/8" 10 shot group at 50 yards. I've heard that the Zero 185 gr. JHP is a good substitute for the Nosler, but have never verified it.

Seems a response I wrote was lost. Guess I forgot to hit send.

Anyways, lots of great info. But I was thinking about the feasibility of something outside the box.

Would it be possible to meet the .45 criteria with a cartridge that could fire from a Pardini/Matchguns type pistol.

Could a .45 bullet be shot at 32acp engeries and be accurate at 50yds?

Nope.

Slartybartfast wrote:Seems a response I wrote was lost. Guess I forgot to hit send.

Anyways, lots of great info. But I was thinking about the feasibility of something outside the box.

Would it be possible to meet the .45 criteria with a cartridge that could fire from a Pardini/Matchguns type pistol.

Could a .45 bullet be shot at 32acp engeries and be accurate at 50yds?

Maybe, but it would require lots of development.

One area that might prove fruitful is the 45 GAP cartridge.  Could a pistol be made and ammo be made for it to shoot well at 50 with a 155 grain bullet?  At 800 fps this would have recoil like a 38 Special.  Very likely it would still require a locked breech with all that entails.  Maybe even shorted than the GAP.  Dunno.

Is anyone winning the CF/45 matches with 150 gr 45 cal bullets?

Slartybartfast wrote:Could a .45 bullet be shot at 32acp engeries and be accurate at 50yds?

Energy NO, speed yes.  Ideal for the speed for a .32acp is 850-900fps (108ft/lbs) which is even a little fast for some .45acp bullseye loads, I'm running 750-800fps with a 185gr LSWCHP (263ft/lbs).

Shooting the 45 bullet at the same energy as the .32 would be = to shooting a 185gr @ 515fps.  If you sighted in at 25yds you would have a 6 1/2" drop at 50yds.  #1) Would it function the gun #2) would it be stable

- Dave

Blsi2600 wrote:Is anyone winning the CF/45 matches with 150 gr 45 cal bullets?

So? Based on that, all discussion would be pointless, and no equipment would ever advance.

Has anyone tried?

I've come across 125g 45cal bullets and Aquila once made 45acp cartridges with 117gr alloy bullets.

A Pardini that could shoot 22lr and 45cal could give an advantage.

dronning wrote:

Energy NO, speed yes.  Ideal for the speed for a .32acp is 850-900fps (108ft/lbs) which is even a little fast for some .45acp bullseye loads, I'm running 750-800fps with a 185gr LSWCHP (263ft/lbs).

Shooting the 45 bullet at the same energy as the .32 would be = to shooting a 185gr @ 515fps.  If you sighted in at 25yds you would have a 6 1/2" drop at 50yds.  #1) Would it function the gun #2) would it be stable

- Dave

Not really understanding your statement "Energy NO, speed yes." 
A given bullet with a given drag and ballistics coefficient needs a given energy to get to target and do so accurately and repeatably. (In bringing up ballistics cooefficient I may answer my own questions)

But how about a .45cal 73 gr @ 850-900fps (108ft/lbs)? Same bullet weight and speed as a .32acp, same energy.

Just found Aguila once made 45acp cartridges with 117 grain bullets. Liberty Ammo currently makes 45acp cartridges with 78 grain bullets. These are shot at 1900fps/625ft/lbs energy to get energy for penetration and damage. Could they be reliable and accurate at half that speed?

A 78gr bullet at 850fps would be 125ft/lbs energy.

Back to whether anyone is winning CF/45 with 150gr bullets: What determines best bullet weight choice in the first place?

Greetings,

A interesting read, thus far.

My friend, who does not cast, purchased some X-Treme 200 grain SWC and I barrel tested some loads for him.

"Normal" velocities (700-800 FPS) were all over the paper.

I tried some with even less powder.

Finally got some reasonable groups at 50 yards via the barrel tester.

Please note the Average Velocities on the chronograph tape. Interesting...

We settled on 4.45 grains of Winchester 231.

By the way, X-Treme has filed for Bankruptcy.

Cheers,

Dave

Greetings,

Remaining two images...

Cheers,

Dave

Very well done data fc.

I think you were hoping that one of us is an exterior ballistician.  If you talked to a guy from one of the major bullet manufacturers and asked him/her this question, he/she would probably say yes, it is certainly possible; a XXX grain bullet made from some lighter combination of alloys (copper plated aluminum...???) can be designed to be very stable at XX rotational speed and YY linear speed.  But nobody will want to pay for it.  Not sure why such an academic question would be asked but I suspect your answer is "certainly."  Now what?

inthebeech wrote:Not sure why such an academic question would be asked but I suspect your answer is "certainly."  Now what?

Just figure there's some knowledge on here that could provide ideas/limitations.

Why ask? Why not? Just to learn the limitation of various calibres and cartridges for one.

For two, the idea of a Pardini that could be used for .22, .32, and .45. One gun for all Bullseye stages.

Although if not a Pardini, I'm hoping the Laugo Arms Alien is a success and they create a .45 version.

But regardless of the firearm, wouldn't the lowest energy/lowest recoil requirement projectile that meets the .45 requirement lead to an advantage?