From an older article in "American Hunter" referenced in the Winchester Owner's site. A little background on the 1300/SXP line:
Winchester likes to call the SXP “the pump that thinks it’s an autoloader” due to its fast, slick cycling. The first time I tried the gun at the SHOT Show, I loaded two shells to test that claim. I fired, then pulled on the slide. It wouldn’t budge. Puzzled, I looked at the gun. The slide wouldn’t move because it was already back, the empty already ejected and smoking on the ground. The gun is so smooth I had opened the action without knowing it. The same thing happened the next time I shot it. Once I figured out all I had to do was pull the trigger and flick the slide forward, I could shoot this gun very fast.
The Super X Pump is the latest version of Winchester’s Model 1300 “Speed Pump,” which hasn’t been made since 2005. Introduced in 1978, the 1300 was an improved Model 1200, which was the notorious low-cost 1964 replacement of the legendary Model 12. While both the 1200 and 1300 suffer in comparison to one of the greatest shotguns ever made, they were a good value, finding a niche competing with the Mossberg 500 and the Remington 870 Express. The 1200 and the 1300 both feature a rotary bolt that unlocks and opens very quickly and is the secret to the action’s speed.
The 1300 was made in the New Haven, Conn., Winchester plant until it closed in January 2006. At the time, Winchester management agreed with the union not to make the 1300 for three years. Winchester re-engineered the gun, renamed it, and found a Turkish vendor to produce it. Those guns are coming into the country now in 3-inch, 12-gauge, both as an 18-inch, cylinder-bored Defender model and a field gun with a 26- or 28-inch barrel. My test gun was a field model with a 28-inch barrel.
The SXP is not a Turkish-designed gun with an American brand. It’s a gun made to Winchester’s specifications in Turkey. The new gun combines the lines of the popular Super X3 semi-auto, the old fast-pumping action, and several significant improvements over the old model. Says Glenn Hatt, Winchester product manager: “This gun will function better than any 1300 ever made.”
Available in black synthetic, the 1300 takes styling cues from the Super X3. The stock has the X3’s semi-Cubist pattern of lines and planes. Red W’s here and there decorate the stock and receiver, and it even has replicas of the X3’s Quadra-Vent in the forearm. Of course, gas vents on a pump serve no purpose; they’re like the chromed, fake vent holes on the sides of 1950s cars.
More significantly, the SXP has the X3’s rib profile and stock dimensions, a near-parallel comb arrangement that fits many shooters. It also has the soft “Inflex” recoil pad with a hard insert on the heel found on the X3 and Browning Maxus semi-autos. The barrel is bored to Browning’s standard overbore of .742, and the gun takes Invector-Plus chokes.
Among the changes to improve the durability of the SXP is the elimination of the distinctive “fishtail,” V-shaped joint between the head of the stock and the rear of the receiver. The new straight-line joint is much stronger, while the receiver itself is made of aircraft-grade aluminum that is tougher than the impact-extruded aluminum of the old guns. Inside, the action bars and the plate upon which the bolt sits have been made from three pieces into one. Not only does that make the gun much easier to take apart—you can remove the action bars and bolt as one piece—it eliminates a source of wiggle and wear that was a weakness of the old design.
