FMJ vs AP vs JHP

If you are unsure of the difference the three ammo types makes, this guide should help you. This guide will go over how many bullets/magazines it takes to defeat SCPs and humans with body armor. Even if SCPs receive health changes in the future, which will happen, this guide should still apply. Same goes for body armor.

VERSUS SCPs

OVERVIEW
This section will let you know how many bullets & magazines it would take to defeat SCPs with all the ammo types. Even if there are health changes to SCPs in the future, these results should still apply.
I used the MTF-E11-SR for testing.
All results were collected in version 13.5.0

AMMO (CAP)	SCP-049	SCP-096	SCP-106	SCP-173	SCP-939	SCP-3114	RESULT
JHP (30)	~80 bullets (~3 mags)	~91 bullets (~4 mags)	~82 bullets (~3 mags)	~311 bullets (~11 mags)	~94 bullets (~4 mags)	~50 bullets (~2 mags)	~708 bullets (~27 mags)
AP (30)	~104 bullets (~4 mags)	~118 bullets (~4 mags)	~106 bullets (~4 mags)	~236 bullets (~8 mags)	~122 bullets (~5 mags)	~64 bullets (~3 mags)	~750 bullets (~28 mags)
FMJ (40)	~104 bullets (~3 mags)	~118 bullets (~3 mags)	~106 bullets (~3 mags)	~266 bullets (~7 mags)	~122 bullets (~4 mags)	~64 bullets (~2 mags)	~780 bullets (~22 mags)

JHP Conclusion

Positives
• Most bullet efficient

Negatives
• The worst for fighting SCP-173
  
• You will be reloading quite a bit

AP Conclusion

Positives
• Best at fighting SCP-173

Negatives
• Least magazine efficient (by only 1)
  
• The worst for fighting SCPs in general. FMJ gives you more bullets per mag for the same performance

FMJ Conclusion

Positives
• Most magazine efficient. You will be spending the least amount of time reloading
  
• Performs the same as AP (besides SCP-173) but you have more bullets in each magazine

Negatives
• Least bullet efficient

Conclusion
If there is no SCP-173, bring FMJ or JHP. If there is an SCP-173, maybe bring AP. The only SCPs that take headshot damage are the zombies (049-2).
SCP-173s damage resistance does not apply to its Hume Shield. It took ~23 bullets to break SCP-173s Hume Shield with JHP. It took ~30 bullets for AP and FMJ.

VERSUS BODY ARMOR

OVERVIEW
This section will show how many bullets it takes to defeat all armor types. This is more straightforward than the SCPs and I doubt changes will happen to armor.

	NO ARMOR (Head)	NO ARMOR (Body)	LIGHT ARMOR (Head)	LIGHT ARMOR (Body)	COMBAT ARMOR (Head)	COMBAT ARMOR (Body)	HEAVY ARMOR (Head)	HEAVY ARMOR (Body)
AP	2 bullets	4 bullets	2 bullets	5 bullets	3 bullets	5 bullets	3 bullets	5 bullets
FMJ	2 bullets	4 bullets	2 bullets	5 bullets	3 bullets	5 bullets	3 bullets	6 bullets
JHP	2 bullets	4 bullets	2 bullets	5 bullets	4 bullets	6 bullets	4 bullets	7 bullets

Conclusion
JHP performed the worst while AP and FMJ performed better at tougher armor. AP performed better than FMJ, but by only one bullet on heavy armor. Most people will be running around with combat armor so FMJ is probably the best choice.

OVERALL CONCLUSION

FMJ having a higher magazine capacity and still having good penetration makes it better overall. The weight that's added because of the higher mag cap is not that big of a deal. AP and JHP are very situational ammo types. You're sacrificing magazine capacity to hopefully defeat something faster. For guns like the AK or Crossvec where your only two ammo types are AP and JHP, choose whatever you feel will help you survive.