Ash (Bruce Campbell) wields a 12 gauge Double Barreled shotgun that he refers to as his "Boomstick". He identifies it as a Remington, but it is not. The receiver and foregrip look similar to an IGA Stoeger Coach Gun with 20" barrel.
Ash displays his gun to a group of "primitive screwheads" in his famous "This is my Boomstick" scene. He uses it mostly in the beginning of the movie, then later to shoot Evil Ash in the face. He also uses it once during the final battle, but loses it when he crashes his 'Death Coaster' to avoid hitting the heroine, Sheila.
Despite only holding two shells, Ash fires this weapon a total of 3 times without reloading during the "This is my Boomstick" scene. He also fires it 4 times without reloading during the "She-Bitch" fight scene. (Every time he fires both shells the shot changes to something else and some soft clicking is heard. Apparently he's a very fast reloader, especially for a guy with only one hand.)
Ash is seen wielding a Winchester Model 1892 lever-action rifle with a "Trapper" loop handle when a Deadite appears and begins tearing up the S-Mart in the present day. Despite the fact that most lever-actions hold nine to 13 rounds, Ash fires 37 shots in quick succession without reloading.
Edit: It's actually shown that simply because he has a mechanical hand he can load and fire at the same time, and rather quickly.
Actually, this isn't necessarily a '94 model, as indicated by the chamber and the trigger-guard.
It is a Winchester 1892, as indicated by the screw pattern on the right-hand side of the receiver.
When the deadite hits Ash she send him flying right into the gun section of S-Mart. Bad news for her, as Ash obtains a Winchester Model 1892 from one of the cases to combat her. We can see various other arms in the gun section as well.
Error creating thumbnail: File missingThe gun case where Ash obtains his Winchester 1892. There are 3 other guns inside too, what appears to be Winchester 1866 Yellowboy and a sporterized straight bolt Military surplus rifle (type unknown unless we can see a better view of the receiver)Error creating thumbnail: File missingAnother look after he grabs the Winchester 1892, a clear look at the gun on the left can be seen, which looks like an over/under shotgun.Error creating thumbnail: File missingS-Mart's gun section. Multiple long arms and revolvers can be seen.
Winchester 1866 Yellowboy Carbine
On the far right, we can see a Winchester Model 1866 Yellowboy Carbine, or possibly the Non firing replica gun of the same design.
Winchester Model 1200 Shotgun
On the right case, left most gun is a Winchester Model 1200 shotgun - 12 gauge.
