Alec Chambers is the recipient of multi-disciplinary military training from the U.S. Marine Corps. While a S.H.I.E.L.D. Special Ops Agent, he also received training from the U.S. Army and Navy.
In addition, since beginning his work as the Punisher, Chambers has used his military discipline and training techniques to update and expand his skills in areas that aid in his mission (disguise, acting, use of non-military weapons, etc.). From this training, Alec is proficient in not only basic infantry skills, but in special operations, which includes the use and maintenance of specialized firearms and explosive ordnance. He is highly trained in infiltration into heavily-guarded enemy territories and structures for the purpose of assassination, capture, and military intelligence.
Also, he is trained in various forms of camouflage and stealth. He is also highly adept at Hand-to-hand_combat, and has been trained in multiple forms of Martial Arts. From his Airborne training, Alec is able to pack and maintain his own parachute rigs, as well as professionally control his landings, in daylight and at night.
From his Navy UDT training, Alec is well-skilled in extended underwater operations, including demolitions. He is skilled with a great many types of explosives, ranging from simple dynamite to plastique to improvised explosives.
His hand-to-hand combat skills are more then sufficient to allow him to incapacitate and kill men much stronger than he is, as well as to deal with groups of armed and unarmed enemies, killing them all without weapons if he deems it necessary. He is also extremely deadly in knife training, preferring the knife he learned to fight with in the USMC: the ka-bar.
Additionally, he is a preternaturally-precise marksman. He is thoroughly trained and experienced in unconventional ("guerilla") warfare. He is an armorer, a gunsmith, and an expert in field medicine.
Nick_Fury has commented on how extraordinarily high Chambers pain tolerance is. He does not take even over-the-counter painkillers, as he feels that their benefit of dulling pain is not worth the side effects of drowsiness and slowed reflexes
He maintains multiple safehouses and vehicles around the greater Manhattan area as well as multiple forged identities and bank accounts (most of the funds and equipment aiding him in his work being taken from the criminals he hunts).
Alec has a SHIELD Developed Kevlar uniform which protects him from most gunfire, though he can still suffer concussive injury or penetration from sufficient or repeated impacts. The bright crimson skull in his chest is used both to intimidate his enemies and to lure their fire to the more heavily protected area of his armor.
Alec has been using technology derived from super-villains and other costumed characters that have either been captured, or work with S.H.I.E.L.D..
Alec's ever-changing arsenal of weaponry includes various automatic and semi-automatic rifles, and an array of handguns, fragmentation and tear gas grenades, other explosives, and combat knives. A personal favorite is his ballistic knife, which can launch its blade with lethal force. He commonly uses M16 .223 caliber automatic rifles, Sterling Mark 6 9mm, semi-automatic rifles, 9mm Browning Llama automatic pistols, .45 caliber automatic frame rechambered for 9mm. ammunition, .223 caliber Derringers, and Gerber Mark II combat knives.