.40S&W bullet shape

[tacotime]

Probably answered before, but why do we see the usual bullet shape for the FMJ .40S&W being a flat point instead of round like the 9 and 45?

Thanks.

 

[Alk8944]

For a given weight the flat point will be shorter. Loaded to the same OAL it leaves more room in the case allowing better performance. The flat point is a significantly more effective shape than a round nose, particularly the typical sharply tapered round nose 9mm bullet.

 

[MK]

I had heard it was so the pistols could be
designed using a smaller 9mm sized frame.
But I don't know if that's really true or not.

 

[Gov]

Not 100% on this, maybe some others can comment on opinions they have heard about this, but I've read that the .40 S&W round was "sprung" (introduced to the market quickly) on many manufacturers by S&W. In an effort to keep up with S&W, they had to modify their existing 9mm frames to accept the .40 S&W.

I would suspect, but don't know for sure, that the .40 S&W ammo manufacturers found that a flatter bullet feeds more reliably.

Just speculation and a hunch on my part... anyone out there have better info?

 

[harry carey]

has to do with accuracy. truncated cone has greater bearing surface . bearing surface is EVERYTHING!!! accuracy ! a 122 tc in a 9mm is dramatically better in ACCURACY. bearing surface. this is why they are used in the forty.why is a wadcutter accurate ? bearing surface, thats about all a wadcutter is , is bearing surface.it is what it does in the gun , not what it does after it leaves the gun, stability.

 

[animalmother]

Never thought to consider it but now that you mention it, I have noticed that many 40 and 10mm Auto loads use FMJ bullets with flat points.

 

[tacotime]

Still not sure about it but it does help when identifying the 40's if they happen to be mixed in with 9's or 45's in the same place.

Are there any factory .40 rounds that are not flat point or hollow? I mean any FMJ's that are fully round or almost pointed like the 9 and 45 FMJ?

 

[MK]

Nope. Not that I know of. All .40 S&W rounds
I've seen have a blunt nose.
Myself, I still think the main reason for the
blunt nose is so the round can be the same
length as a 9mm round, and thus fit into 9mm
sized mag wells.
I think it came out of the FBI tests where they
were evaluating the 10mm. They found the 10mm
too stout for some users, and the large frame
10mm pistol hard for some to hold on to.
So.. They came out with the .40 S&W which is
basically the FBI "10mm lite" round.
It has less recoil than the 10mm, but still
managed to pass their performance aims.
With the blunt nose, it's the same length as
the 9mm round, and uses the small pistol primer
vs the large primer for the 10mm.
So it can be designed using the same size frame/
mag well as the 9mm pistol.
I tend to think that, more than anything else
is what led to the blunt nose of the .40 round.
Myself, I like the blunt nose. Punches a cleaner
hole which will bleed out faster than a sleek
pointy nose slug like the 9mm.
I use a .40 S&W as a "woods" pistol quite a bit.
With the blunt nose, I can use just plain jane
FMJ and know it's going to punch a pretty mean
hole, and will penetrate well. The blunt nose
lets it act as sort of a poor mans "woods" load
without the higher cost of say the cast "woods"
loads that double tap sells.
The FMJ is almost as effective, just has a
weaker charge than the high $$$ stuff.

 

[tacotime]

I like the .40 as a woods carry gun also. Seems to blow just a big a hole in the mud as the .45, but seems to get there faster. But so far, no encounters with wild hogs. Waiting to see what happens...

 

[harry carey]

it is called truncated cone, first seen in 45 bullets by Hornady. also available in 40 and 9. the increase in bearing surface is dramatic and accurate. these are available in cast bullets as well. this is not new. this is different than round nose flat point as rnfp has a rn ogive.