Sig Sauer P320 Full Size 9mm vs Springfield Armory Echelon 9mm

These two full-size 9mms share the same 8.0" length and 5.5" grip height, but that's where the similarity ends. The Echelon is 4 oz lighter (24.3 oz vs 28.3 oz), runs a 1 lb lighter trigger (5.5 lbs vs 6.5 lbs), and ships with both a 17-round flush magazine and a 20-round extended magazine — three more rounds per reload than the P320 ever offers from a factory magazine. The P320 counters with the modular fire control unit, which is the registered firearm — the same serialized FCU drops into compact, carry, and subcompact grip modules without an FFL transfer, and no other striker-fired platform on the market offers that.

Pick the Sig P320 Full Size if:

• You want the modular FCU — one serialized chassis swaps between full-size, compact, carry, and subcompact grip modules, plus caliber conversions to .357 SIG and .40 S&W that no other striker-fired platform supports
• You want the M17/M18 military pedigree validated through extensive Army endurance testing, with parts and service through Sig's armorer network
• You want the extra 4 oz of slide mass to soak up recoil for snappier follow-ups, with a longer 4.7" barrel that adds roughly 25-30 fps over the Echelon's 4.5" tube

Pick the Springfield Echelon if:

• You want a 20-round magazine option in the box — three more rounds than the P320's standard 17-round magazines, with the flush 17-rounder still fitting the same grip height
• You want a 1 lb lighter trigger (5.5 lbs vs 6.5 lbs) without the Apex or Gray Guns aftermarket trigger work P320 owners typically schedule
• You want a 4 oz lighter gun for all-day carry — at 24.3 oz the Echelon weighs in the M&P/Glock G17 range rather than the P320's heavier 28.3 oz

Both ship with night sights out of the box (SIGLITE on the Sig, tritium/luminescent on the Echelon), both are optic-ready, and both carry the same 17+1 in standard magazines. The decision turns on the modular FCU and military pedigree against weight, trigger pull, and the 20-round magazine option.