JHP opening greater with larger bullets?

[TheProf]

I realize that the major handgun calibers (9mm, . 40, and .45) all pretty much function ballistically the same... roughly the same penetration and expansion...given that a person is using premium defense rounds.

So.. if the rounds expands... its pretty much a wash because .1 inch extra expansion will most probably not make any difference. It's about shot placement anyways.

But looking at .40 vs. 9mm Gold Dot Hollow points... I cannot help but feel that the .40 round is more likely to expand due to the bigger HP cavity.

So... I'm not asking which one will expand to a greater size... but which of the two is more likely to fail to expand.. given that we are comparing the same brand of HPs.

From the same manufacturer/brand, would a 9mm HP have more likelihood of failure to expand than say .40?

It's kinda like seeing .22 JHPs. I don't think that they would reliably expand. The HP is too small to "catch" enough flesh to cause it to expand.

Anyone else feels the same?

 

[Skribs]

A .40 will expand to a greater degree than a 9, and penetrate slightly more. The reason most people say they're roughly the same as far as effectiveness is that both penetrate "enough" and the difference isn't going to be much in the grand scheme of the human body.

Velocity plays a part in expansion, so that's a pro to the 9, but you are right - bigger is easier to design.

 

[rcmodel]

It's kinda like seeing .22 JHPs. I don't think that they would reliably expand

Oh, they reliably expand all right.

Shoot a rabbit or squirrel with one and you will believe it expanded way more then a solid bullet I betcha.

As for caliber?
Modern JHP bullets are designed caliber specfic to expand reliably.

The .40 may have a bigger hole, but it may have a thicker jacket or harder core and need a bigger hole.
Also, the .40 S&W was designed from the getgo to use truncated cone or flat point bullets.

9mm and .45 ACP were designed to use RN-FMJ bullets.

As such, there is only so much a bullet designer can do to the HP opening and still get them to feed in most guns.

Bullet shape, core hardness, jacket thickness, scored or unscored jacket, and velocity all play into the cavity design.

rc

 

[TheProf]

Hmmm... the only reason I carry a .40 is the belief (which I could be very well be mistaken) that the .40 is more likely to expand than the 9mm...due to the bigger cavity.

Interesting points... RCmodel.

 

[BADUNAME37]

I shot several woodchucks lately with high velocity HP's .22 Rimfire, made in Germany. I was quite surprised that the bullet went through the thing and made like a quarter- size hole coming out!

 

[Skribs]

I think modern techniques bridged that gap, Prof. Not that the .40 is bad, but I'm going to make the swtich from .40 to 9.

 

[Deus Machina]

I figure it's probably more likely to expand, but it's also more likely to pick up a good plug of clothing.
So maybe it evens out.

 

[StrawHat]

9mm is considered a major caliber now?

 

[mljdeckard]

Do you consider 9mm to be a minor caliber?

I echo exactly what RC said. It's not like bullet designers would give the .40 some innate advantage over .45 or 9mm bullets, look at their charts, and say; "Well, that's exactly where we wanted them to be, with one working better than the others."

And I think the likelihood of cloth clogging a hollowpoint and decresing its chance of expansion is so low as to be called a marketing gimmick by one brand that has invented a 'solution' to the problem. I intend to test this shortly.

 

[TheProf]

When I listed the "major calibers"... I was referring to handguns and "major" referring to what is most popular in law enforcement...hence, 9mm, .40, and .45


My question was not to which round is ballistically superior, but rather, which round is more likely to function the way that it was designed to function (that is , hollow points expanding).

Would a bigger caliber (say a .45 Gold Dot ) have a greater probability of expanding than a smaller caliber (say a 9mm Gold Dot). Would the larger starting cavity have a greater chance of "catching more flesh" thus making the bullet expand with greater reliability.

I realize that the 9mm is traveling usually at a higher velocity...and velocity affects expansion. But if the velocity is about the same (say like a .40 and a 9mm), would the larger starting cavity play a role.

From what I am reading here... it sounds like the likelihood of each respective caliber, coming from the same manufacturer, and of the same brand...would be expected to expand with the same frequency...regardless of each starting cavity size.

 

[Skribs]

.40 and 9 aren't going the same velocity. Your average 9mm is going to be 150-200 FPS greater than your average .40. If anything, the .40 is closer to the .45.

I know you didn't want to bring velocity into it, but it's not a vacuum. The 9mm is smaller, which makes it harder to engineer controlled expansion, but it moves faster, which makes it easier. I guess you'd really have to test it to see.