.40 loaded to same as .45 acp = same power?

HighValleyRanch

New member
If one loaded a 200 grain .245 acp to 800 fps, and then loaded a 200 grain .40 sw to the same speed, would both rounds be similar in penetration and muzzle energy?

Would the recoil pulse be similar, i.e. push rather than snappy .40ish.
 

JohnKSa

Administrator
Assuming the guns are similar then the recoil should be similar since recoil is directly related to momentum and momentum is the product of projectile mass and projectile velocity.

Muzzle energy would be identical.

Penetration would likely be lower in the larger projectile. Larger frontal area means more resistance as it pushes through the target medium.
 

Jim Watson

New member
Same mass, same velocity, same energy, same momentum.

Newton's recoil would be the same; FELT recoil might be noticeably different to the Princess and the Pea types due to the different loads used.

Penetration depends not only on bullet size but on shape and construction.
 

HighValleyRanch

New member
So I assume that the .40 would have more penetration because of sectional density mass?

So if FMJ .45 hardball is considered such a man stopper, why wouldn't 200 grain FN FMJ .40 at subsonic be viable as well considering that in all actuality, .05" of a hole is really not that much different?
 

RickB

New member
I'd expect the .40 to have greater penetration.
Comparing a lightly-loaded .45 to a hot .40 would make for interesting comparison of perceived felt recoil.
 

JohnKSa

Administrator
So I assume that the .40 would have more penetration because of sectional density mass?
In non-deforming projectiles of similar design, the .40S&W is definitely going to penetrate more.

Without specifying the bullets, all you can say for sure is that the .40S&W would likely penetrate more than the .45ACP. If the bullets are very different, then all bets are off. For example, an FMJ .45ACP is almost certainly going to penetrate more than an aggressively expanding .40S&W, even with identical energy/momentum.
So if FMJ .45 hardball is considered such a man stopper, why wouldn't 200 grain FN FMJ .40 at subsonic be viable as well considering that in all actuality, .05" of a hole is really not that much different?
Who is saying otherwise?
 

bamaranger

New member
.40/200

Can one drive a 200 gr projectile from a .40 case and not get seriously high pressures? The 200 gr slug will occupy a lot of case space to boot, not leaving a lot of space for a powder charge. None of my manuals show the .40 SW and a 200 gr bullet, loads stop at 180. I suppose a lead slug will give less pressure and no doubt somebody has done it. But, the .40 operates at serious high pressure already.
 

HighValleyRanch

New member
Yes, of course, BB, Underwood and Doubletap all sell 200 grain .40 cal ammo, and if you investigate, there is a lot of data on reloaders loading 200 grain bullets into .40 cases at lower velocities.
The above are all jacketed bullets, hard cast, FMJ
 

44 AMP

Staff
Can one drive a 200 gr projectile from a .40 case and not get seriously high pressures?

Absolutely.

The OP is asking about driving a 200gr .45 and a 200gr .40 at the speed of 800fps.

If you think about it, it should be obvious that is actually a fairly low speed (and a low pressure) for either round.

800fps is near the top end range for .45 acp 200gr lead swc target loads. And, that's because of a desire for a target load, not the gun's capacity for pressure.

.45acp 200gr JHP loads top out in the 900-1000fps fps range, at standard pressure. (from a 5" Govt model).

Certainly the .40 can be loaded to a 200gr at 800fps.

None of my manuals show the .40 SW and a 200 gr bullet, loads stop at 180.

The Hornady 7th edition (2007) lists 200gr bullet .40 S&W loads. Three different jacketed bullets and eight different powders. The data exists, you just need to find a more recent manual that lists it.

Remember, reloading manuals do not list every possible bullet or powder, most list what is expected to be most popular or loads with the bullets they make. And the most focus is on full power loadings.

Generally speaking, when two objects of different sizes are pushed into soft medium with the same force the one with less surface area will penetrate more.

Tip shape is a factor as well. An extreme example would be "its easier to poke a hole with a knitting needle than a baseball bat". ;)
 

Jim Watson

New member
Published data, sure.
There was some USPSA Limited Major shooting done with heavy bullets and fast burning powder. Felt recoil and less muzzle rise were the justification. Pressures were no doubt high but the sturdy race guns held it.
 

bamaranger

New member
stuff ya' don't know

OK, duly noted. I'll admit that some of my manuals are a bit dated, and I certainly don't have any of them completely memorized. The .40/200 combo is new to me and now I have been enlightened. Stuff you think you know and don't.

Even more enlightening is the chamber pressure bit. For reasons unknown, I thought that the .40 operated at a noteably higher pressure than other auto pistol ctgs, the fact that the 9mm and the .40 are similar was another eye opener. In following up on my ignorance, I note that the .45 acp operates, even at +P pressures, considerably lower than all of them, a fact of which I was certain. So...

Would not the lower operating pressures of the .45 acp create a softer shooting combo than a high pressure .40, ie, perhaps a felt recoil v. actual recoil sort of thing? I'd think certainly easier on the gun?
 

MarkCO

New member
If one loaded a 200 grain 45 acp to 800 fps, and then loaded a 200 grain .40 sw to the same speed, would both rounds be similar in penetration and muzzle energy?

Would the recoil pulse be similar, i.e. push rather than snappy .40ish.

Not exactly. IF both were TMJs, then the .40 would penetrate further than the .45. The .45 would slow (in the atmosphere and in the body) faster due to the frontal area and it would also have less sectional density which would diminish penetration as well.

Also, the .40, when fired, acts on a smaller case head which means more rearward thrust. so the recoil would be snappier than the .45 even if the slides were the same mass. If you could feel it, different question.
 

Recycled bullet

New member
How about comparing terminal ballistics against a 200 grain 357 or 309 bullet at 800 ft per second?

I am loading both of those, the first loaded into 38 special brass shot out of 357 chamber guns and the second is my current ongoing 300 blackout experimentation.

I only shoot a paper targets but I'm getting round holes so no key holing...yet.

Sent from my moto g power (2022) using Tapatalk
 

bamaranger

New member
stuff ya' learn

Disclaimer-I load little .40 S&W, like 100 rds my whole life and that from maybe a decade ago when I bought (and still have) a Browning HP so chambered. So after my faux pas above, I went and looked in the most recent manual I possess, a Sierra. Yup, there in the .40 section were loads driving their 190 gr FPJ bullet to 1000 fps! :eek:. A max load for sure,and likely very barrel length dependent, but there it was, in print. So getting a 200 to 800 fps would be no big deal. Stuff ya" learn
 

RickB

New member
Published data, sure.
There was some USPSA Limited Major shooting done with heavy bullets and fast burning powder. Felt recoil and less muzzle rise were the justification. Pressures were no doubt high but the sturdy race guns held it.

If they were sturdy, the power factor for major wouldn't have been reduced from 175 to 165?
Though I doubt there was ever a public announcement to the effect, there was an "understanding" among the membership that major was reduced to 165 because 175 was too hard on .40 guns.
 
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