questions about ballistics

[Nsghunter]

Good morning,
I have yet again another question about ballistics. I was reading over ballistics charts at ballistics101.com . I love this site by the way. It all mostly made sense untili got to federal hs on .40 s&w and .45acp. The .40 shoots a hs jhp 135 gr At 432 lb and 1200 fps and the .45 shoots hydra shok 230 gr at 414 lb and 900 fps.
I know the bullet size is a little different .451/.452 for the acp and .40 for the 40 s&w but that's only 11.5% increase in the acp from.the .40.

Why do the acp rounds seem so much slower? And do these readings indicate the terminal performance of the .40 is greater than .45? I need some help, quite a bite of help I guess.

 

[DaveB]

This is physics in a real world application.

The larger mass of the 45 requires substantial more energy to get it moving. If we loaded the 45 brass with enough powder to achieve the FPS of the 40, we might blow the 45 apart (and bystanders also).

Look at it this way. You have to push a car that weighs 1,000 pounds. You find you can do so. Now, add 950 pounds. Your energy required to move the car goes way way up.

So you have to compare an apple to an apple. Compare a 40 to a 40 or a 135 and a 135. Bullet weight comparisons can vary by say roughly 10 or 15 grains. Calibers not at all, not really.

 

[Nsghunter]

Thanks and that makes sense but I always thought that even thought the heavier bullet travels slower but carries more energy. I guess this is true in that the acp is only a few less lbs of energy but moving almost 300 fps slower.

So then, is one to say the terminal performance is su substantially better out of the .40 with the hight ballistics readings? If the bullet construction is the same, or does the 11.5% increased diameter negate the lower energy/slower moving.

Only talking bullet performance, not shoot ability yet.

 

[ADR]

To quote Elmer Keith "bigger kills faster, faster kills farther". Good guy to read about when it comes to pistol performance.

Bullet performance has ALOT to do with how fast it's going when it encounters it's target and it's targets composition. Hope this helps answer your question. Reloading, especially bullet selection, is highly addictive.

 

[7mm08]

THAT kind of talk has started fights over the fact that the .40 is nearly equal to the .45 in the real world.

 

[Nsghunter]

Honestly I can't see much difference in the two. I shot a friend's Taurus 24/7 forty and I hit better with it but he shot better with my 1911. I have heard that the .45 has better sound reduction because it is lower speed. I don't know anything about that and the fellar speaking about it was notorious for using bro-science.

As for which is better, I ask a retired federal agent as a civilian what he carried once and he answered ".22 magnum snub nose." I was astounded and inquired deeper. He explained that as an agent his gun typically was a last resort anyways and situation awareness, level headedness and prevention training saved him more often than anything. A .22 mag would definitely do the job if it had to but it wasn't difficult to carry as a civilian. He concluded with" Oh sure, if I was going to shoot someone, I would carry my 12ga."

 

[infoman jr.]

Honestly I can't see much difference in the two. I shot a friend's Taurus 24/7 forty and I hit better with it but he shot better with my 1911. I have heard that the .45 has better sound reduction because it is lower speed. I don't know anything about that and the fellar speaking about it was notorious for using bro-science.

As for which is better, I ask a retired federal agent as a civilian what he carried once and he answered ".22 magnum snub nose." I was astounded and inquired deeper. He explained that as an agent his gun typically was a last resort anyways and situation awareness, level headedness and prevention training saved him more often than anything. A .22 mag would definitely do the job if it had to but it wasn't difficult to carry as a civilian. He concluded with" Oh sure, if I was going to shoot someone, I would carry my 12ga."

This goes to show that you have to take every bit of advice with a grain of salt.

 

[Nsghunter]

Honestly I can't see much difference in the two. I shot a friend's Taurus 24/7 forty and I hit better with it but he shot better with my 1911. I have heard that the .45 has better sound reduction because it is lower speed. I don't know anything about that and the fellar speaking about it was notorious for using bro-science.

As for which is better, I ask a retired federal agent as a civilian what he carried once and he answered ".22 magnum snub nose." I was astounded and inquired deeper. He explained that as an agent his gun typically was a last resort anyways and situation awareness, level headedness and prevention training saved him more often than anything. A .22 mag would definitely do the job if it had to but it wasn't difficult to carry as a civilian. He concluded with" Oh sure, if I was going to shoot someone, I would carry my 12ga."

This goes to show that you have to take every bit of advice with a grain of salt.

I'm trained to use evidence based practice on everything, because the proof is in the pudding.

 

[Deer Assassin]

if those number are accurate

there are a lot of variables in measuring a rounds fps

 

[MUP]

I've talked to a guy(now deceased) before that was shot multiple times with a .22, then subsequently a round from a .38, before he stopped his attack on another man. If I had to choose to be "supremely" armed for defense, and make the most of at least one shot, I'd opt for the .45 myself.

 

[Deer Assassin]

bullet mass is good

 

[7mminatree]

Ballistics are sometimes so contradictory it can be a little overwhelming at times. Bullet mass is good, but so is speed. A high ballistic coefficient is good but so is sectional density. Bonded core jacket or monolithic, Ballistic tip or hollow point. HMMMM! To much mass with speed and no expansion, to light a bullet and speed and overexpansion. HMMM. Reloading is a never-ending search for perfection. :tu:

 

[mr.big]

I tote a Glock 32 357 Sig 124 XTP with enough Blue Dot for 1410 fps,,if 14 of those dont stop him he is a tough sob and I am screwed,

 

[Nsghunter]

Whoa, I had heard in the past that .357 sig was a wicked round but I just looked at the ballistics and they are fast and hit hard. How is that possible?

 

[DaveB]

Mass and velocity.

Ballistics are really quite interesting. Ballistics do not necessarily address terminal performance of the bullet, although the retained energy is an indication. Its velocity, bullet design, drop over distance.

Its why some folks sight in at say 100 and then shoot at 25 to determine where the projectile is actually traveling on its path to the POI (point of impact). And then 50, then 200 and up (way way up) if they have room.

If you follow Mr. Bigs adventures you'll note he very carefully tracks velocity and projectile weight to determine vertical and horizontal clicks BEFORE he shoots. The Ballistics of a given load are repeatable if you hand load and are careful with what you do.

I wonder, does Mr. Big throw a charge? Turn neck on Brass? Full length size or neck size ? You know he favors higher quality brass, must be some reason, eh?