[swaghauler]

I have been playing with the Penetration ratings and have decided that Penetration is primarily a function of Velocity with both bullet diameter and a bullet's Sectional Density a distant second. I have tentatively arrived at the following Penetration Ratings for both pistols and rifles based on the maxim "Velocity Defeats Armor," which has been proven time and again by such Youtubers as The Military Arms Channel, ShootingtheBull410 and The Wound Channel (which has several good barrier and armor tests). Here are my Penetration Levels/Ratings by Velocity:

Pistol Velocity Thresholds:
1801ft/sec + = PEN 1/2
1501ft/sec to 1800ft/sec = PEN 1
1101ft/sec to 1500ft/sec = PEN 2
701ft/sec to 1100ft/sec = PEN 3
699ft/sec or less = PEN 4

Rifle Velocity Thresholds:
3001ft/sec + = PEN 1/2
2001ft/sec to 3000ft/sec = PEN 1
1501ft/sec to 2000ft/sec = PEN 2
1000ft/sec to 1500ft/sec = PEN 3
999ft/sec or less = PEN 4

The PEN can be increased by 1 step for any pistol caliber of less than .30 caliber that is within 10% of the Velocity Threshold. Any pistol caliber that is .25 caliber or less may be bumped up 1 PEN Level if it is within 20% of the Velocity Threshold of the next step and 2 PEN Levels if it is within 10% of the next PEN level's Velocity Threshold due to its bullet's generally higher cross-sectional density.
For Example: The 7.62 Tokarev cartridge has a velocity of 1420ft/sec in the standard Pact loading. This would normally result in a PEN of 2 at short thru long range, and a Pen of 3 at extreme and max range. However, it has a .30 caliber diameter and is within 10% of the 1501ft/sec Velocity Threshold. Therefore, when you compare its velocity by range band, its PEN Values become 1(short), 1(medium), 2(long), 2(extreme) and 3 (maximum)
The PEN of any rifle round which is LESS THAN .30 caliber may be increased by 1 PEN Level if it is within 10% of the next PEN Level's Velocity Threshold. Any rifle round that is LESS THAN .25 Caliber may increase its PEN Level by 1 if it is within 20% of the next Velocity Threshold or by 2 if it is within 10% of the next Velocity Threshold.

It should be noted that I have adjusted Armor Values in my game to reflect the NIJ Standards. The AV for my body armors are:

NIJ Level 1 = AV 1/2S
NIJ Level 2 & 2A = AV 1S
NIJ Level 3A = AV 2S
NIJ Level 3(rifle)/SAPI Plates = AV 4
NIJ Level 4 (rifle)/ESAPI Plates = AV 5
PASGT Helmet = AV 2S
Steel Helmet = AV 1

The "S" designator indicates a soft armor designed to defeat ONLY pistols and fragmentation. In game, you HALVE the AV of soft armor when determining the base AV for resisting Rifle rounds (before multiplying it by PEN). This is the reason pistols even have a PEN in my game (instead of nil). Armor values without the "S" designator are treated normally when opposing Rifle rounds.

Also note that I use 1D10 for Rifle Rounds and 1D6 for pistol rounds (designating pistol damage with a P to differentiate the damage). I have also increased the Damage Dice for my pistols. The damage for a 9mmP is 2d6/2d6/2d6/2d6/1d6 (by range band) while a .45 does 3d6/2d6/2d6/2d6/1d6 (by range band) and a .44 Magnum does 4d6/4d6/3d6/3d6/2d6 (by range band). By comparison, a 5.56N does 2d10/2d10/2d10/2d10/1d10 (by range band) while a 7.62X39mm does 3d10/3d10/2d10/2d10/1d10 (by range band) and a .308 does 4d10/4d10/3d10/3d10/2d10 (by range band) I figure my damage by using the round's energy at a given range. A round's energy can drop significantly by range band, hence the reducing damage.