.40 cal, what weight?

euxx said:
Actually, if you remember, I started with the same powder as for 124gr and that is when I got exited about recoil feeling with 147gr bullets.
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Right. Certainly a softer FEEL, but unless you can take some accurate split-second measurements it is impossible to say truthfully if it was flipping more or less. What you think you see and what is actually occurring may be different things...or may not be. It's subjective without hard numbers.

The end result is that it is a better load for you and that's really all that matters.
 
relliott said:
Right. Certainly a softer FEEL, but unless you can take some accurate split-second measurements it is impossible to say truthfully if it was flipping more or less. What you think you see and what is actually occurring may be different things...or may not be. It's subjective without hard numbers.
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Actually I measured my split time between shots using shooting timer. Maybe a bit subjective, but I was watching the sight going up and down in both case. The difference was very significant to get excited and spend time on making that load work reliably.
 
euxx said:
Actually I measured my split time between shots using shooting timer. Maybe a bit subjective, but I was watching the sight going up and down in both case. The difference was very significant to get excited and spend time on making that load work reliably.
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Yes, it is subjective. Split times have nothing to do with muzzle lift. Reduced splits could occur for many reasons, chief among them the ability to track your sights better in recoil. Perhaps this load is merely returning to neutral whereas the other one may have been diving slightly when returning to battery. The point is that you can only surmise.

Your muzzle lift may indeed be less with that specific load combination, but the only way to know for certain (if it matters for any reason) is to measure the actual lift at the muzzle, preferably off a machine rest to take out the human variable.
 
relliott said:
Careful there Eugene; energy is energy.
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Actually, from academic point of view kinetic energy of the bullet is proportional to speed in the power of 2:
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Power factor in IPSC is calculated as weight times speed (m*v), so heavier bullet making same power factor will actually have less energy as lighter bullet.

This is academical and probably have little to do with perceived recoil.
 
iouri said:
Actually, from academic point of view kinetic energy of the bullet is proportional to speed in the power of 2:
4140f53f66a68e92afec2389ba289e25.png


Power factor in IPSC is calculated as weight times speed (m*v), so heavier bullet making same power factor will actually have less energy as lighter bullet.

This is academical and probably have little to do with perceived recoil.
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So if I'm doing the math correctly, Both the heavy bullet and a lighter bullet at the same power factor have the same momentum but the heavier bullet has less kinetic energy. Fair enough, the math actually backs up the argument that heavy bullets feel softer to shoot than lighter ones...because they actually are.

If I'm reading the wiki properly, the same amount of kinetic energy is transferred to the reciprocating mass in the opposite direction also, correct? So it would absolutely have something to do with perceived recoil. In fact that's why you would have to drop your spring weight when going to the heavier bullet; there's actually less kinetic energy available to move the slide.

I really should have paid less attention in drawing class and more in math!
 
According to my calculations to achieve 130 power factor 124 grain bullet needs speed of 1048 FPS, and 147 needs 884 FPS.
At these speeds 124 grain will have about 410 joules of energy, and 147 will have about 345 joules.

So from energy point of view heavier bullets should feel softer and produce less recoil at same power factor.
 
There is some great information here, really helps to understand what is happening between the bullet and the gun.:dancingbanana:

But, I never expected this to turn into a science/math course, (although I did find it interesting reading).

So with all this now understood, do you prefer to shoot a lighter or heavier .40 cal. bullet, and why?
 
Dan-O-Mite said:
There is some great information here, really helps to understand what is happening between the bullet and the gun.:dancingbanana:

But, I never expected this to turn into a science/math course, (although I did find it interesting reading).

So with all this now understood, do you prefer to shoot a lighter or heavier .40 cal. bullet, and why?
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Sorry about that. Boring...
But I prefer heavier bullets to light ones. I can track them easier.
Open Division is another matter though.
 
dinsdale said:
One of the things my GF and new shooters like about my 147 loads with Unique is the fact we are now sub-sonic and they "bark" less than my 124 grain loads.

You wouldn't get this benefit from a major load.
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What gun and what bullet you are using? I couldn't make AIM 9mm 147gr work with CZ, tried from 3.4 to 3.8gr of Unique.
 
dinsdale said:
Haven't done an AIM batch yet, that is next.
My Frontier load was:

3.8 grains Unique
1.085 C.O.L.
CCI Primers
134 PF

Ran on a 11# and 13# recoil spring in my CZ75b
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Thanks. I have couple thousands of Frontier stashed away and started from AIM first. They have completely different profiles. Please let me know how it will work with AIMs for you.
 
soooooo the general consensus is that heavier will have less felt recoil but will get back into battery slower...
thus a 200gr 45acp load will be softer than a 180gr .40sw load, and while the .40 will snap more, it will get back into battery splits of hairs faster
 
I wouldn't think comparing different calibers would be accurate, kind of the apples and oranges thing. But, different weights of the same caliber would be accurate.
 
i think it is on the contrary very appropriate to compare calibers

you will agree with me that 44mag has more kick than 25acp
 
The matter of bullet weight for .40 (or any other caliber for that matter) is a very complex situation as RElliot has pointed out.

Having shot WELL over 100,000 rounds of 40 in IPSC competition, I can tell you that there is no definitive answer. :confused:

It depends on the gun, powder, OAL, bullet type, shooter, etc. Each person will have a varied response to the muzzle rise and perceived energy of the bullet being fired. The only way to tell what you want, is to try it. You must load at least several hundred each of different weight, powder, OAL to check out what works for you.;)

The general concensus, and overall good choice is the 180 grain bullet (as Madness said ....Montana or Zero). I prefer Zero because they require less energy to make PF. Unless you are a very good shooter, you won't notice very much difference between a 165 grain and a 180 grain bullet. You still have to try to find out what is best for you if you want an answer.

Myself, I prefer the 165 grain bullet. That is me. I like the faster cycle time, and the quicker muzzle back to centre. Again, that is my preference. Doesn't make it right or wrong. :D
 
anyway I guess this comes down to preference as you pointed out

but why is 40cal the hands down favorite when it comes down to standard? Because it's the minimum requirement for major? Other than that, why not go with 45acp?
 
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