Let's get the "variants" out of the way first. This goes for USP/C handguns with and without LEM as well as the HK45/C The P30 Trigger Variants: P30 (V0):
Innovative safety trigger with concealed cocking piece in the spurred hammer. Centrally located de-cocking button, with a constant enhanced double action only Law Enforcement Modification (LEM)* trigger pull of approximately 4.5 pounds (20 Newtons) without operation of the de-cocking latch, and defined let-off point. P30 V1:
Innovative safety trigger with concealed cocking piece in the spurrless hammer, without de-cocking button. Constant LEM trigger pull of approximately 4.5 pounds (20 Newtons) and defined let-off point. P30 V2:
Like P30 V1 but with LEM trigger pull of approximately 7.3 pounds (32.5N). P30 V3:
Conventional single action/double action (SA/DA) trigger without cocking piece in the hammer with spur and centrally located decocking button. P30 V4:
Like P30 V1, however LEM trigger pull approximately 6.2 pounds (27.5N). P30 V6:
Conventional double action only (DAO) trigger without cocking piece in the spurrless hammer. Constant DAO trigger pull of approximately 8.8 pounds (39N). Don't for get to add the safety lever for the S models. The P2000 Trigger Variants: P2000 V1:
Innovative safety trigger with concealed cocking piece in the hammer, with a constant trigger pull (Combat Defense Action/LEM trigger of 20 Newtons) from the first shot to the last, without decocking. P2000 V2:
Like P2000 V1, however LEM/CDA trigger pull 7.3 pounds (32.5 Newtons). P2000 V3:
Conventional DA/SA trigger and hammer, with decocking. P2000 V4:
Like P2000 V1, however CDA/LEM trigger pull 6.18 pounds (27.5 Newtons). P2000 V5:
Double Action only (DAO), trigger pull approximately 7.87 pounds (35 Newtons).
Best accessory for an HK??? Magazines. Yeah, I know they are expensive but you knew what you were getting yourself into. Best night sights? Trijicon of course. Miscellaneous: 9mm/40/357sig magazines all have the same follower so if you have a 9mm USP and buy a 40 mag by mistake the mag will still hold 15 rounds of 9mm. Of course the hole counters in the mag won't line up right. The same works the other way. If you have a 40 cal USP and get 9mm mags you will still only be able to put 13 rounds of 40 in it. But, I have been able to fit 15 rounds of 9mm in a 40 cal USPC magazine for all you 9mm USPC/P2000/SK owners out there as opposed to only 13 rounds in a standard 9mm USPC magazine. USPC/P2000/SK mags are interchangeable except for 45's of course. Best rail adapter for USP/C is GG&G's Best light is Streamlight TLR-1 or Insight Tech's M2 for those who don't want a rail adapter. Trigger HK's are designed to be "duty"/"combat" handguns. If you want a "crisp" light trigger then get a high end 1911. If you can't pick up ANY handgun and fire it effectively for the first DA pull then you need more training/practice. Please remember to use "quality" ammo when shooting HK's. Stovepipes are not jams!!!! Use your trigger finger or middle finger to release the magazine. Almost forgot: HK's use the dead on/cover up hold.