Jacket skiving variations between different lots of Federal 9mm 147gr HST (P9HST2)

[David Pennington]

I recently purchased some additional Federal 9mm 147gr HST (P9HST2) to replace older lots of the same ammunition. I noticed that the later production lots have much shorter and shallower external jacket skiving. Does this effect terminal ballistics? When/why was the change made?

The older ammunition is pictured on the left and the current production ammunition is pictured on the right.

[ST911]

Just checked two batches I have and adding this for reference, using David's pic above. On the left, lot# q43j470 received early 2015. On the right, lot#u23g188 received early 2016.

[David Pennington]

These were shot into water from a Sig P239. The older projectiles are on the left and the newer projectiles are on the right in all pictures. These are all the same two projectiles.

[JBP55]

It appears as if the newer ammunition is designed to expand slightly less and penetrate slightly more.

[hufnagel]

To my layman's eye, the older/left ones look like they're on the verge of over-expansion and possibly coming apart.
If I get some time I'll go and gather some pictures of the various flavors of HST I have here.

I'd also agree with JBP there; it looks like a fine tuning of the overall performance.

[Luke]

To my layman's eye, the older/left ones look like they're on the verge of over-expansion and possibly coming apart.
If I get some time I'll go and gather some pictures of the various flavors of HST I have here.

I'd also agree with JBP there; it looks like a fine tuning of the overall performance.

He shot those into water though. I know water makes them expand more doesn't it?

[Tamara]

He shot those into water though. I know water makes them expand more doesn't it?

Generally. Water is how you get JHP glamour shots.

[David Pennington]

As an additional FYI, the older style projectile expanded to .795" at its widest area whereas the newer style projectile expanded to .725 at its widest. That's a 9-10% difference in diameter.

I wonder what the penetration gains are with the newer projectile?

[Wondering Beard]

Keep in mind that even with the same bullet, out of the same gun, into the same ballistic gel, you will get variations in expansion and penetration.

It may just be that they're tweaking the bullet for ease of production, having found out that there isn't enough difference in performance.

[Hauptmann]

I chronoed some of the old 147gr and the new 147gr, and the velocities of the new lots of HSTs have dropped from 30-40fps. I'm guessing Federal dropped the velocity to match Win RT and Speer G2 velocity and recoil levels. Personally I preferred the faster old lots of HSTs.