From the same question just asked:
Once again, here's the differences between an Express and a Police 870:
The Express is Remington's "budget" gun, made to compete with the cheaper to make Winchester and Mossberg guns.
The Police is Remington's top-of-the-line defense gun.
How Remington lowered the price of the Express was to reduce hand labor to a bare minimum, to eliminate much of the polishing and de-burring the better quality Wingmaster and Police guns get, and to use some plastic parts.
The Express is basically the same forged and milled steel receiver and heavy-duty internals gun the better 870's are, just without the smooth, no burrs, no machine marks finish.
The Express Home Defense Model has:
A plastic trigger group.
The dimples in the mag tube and the new style magazine retention system, EXCEPT on the extended magazine version, which does NOT have the dimples.
A rougher finish inside and outside, with machine marks and some burrs left.
A rougher blue job.
A less polished bore.
A two piece barrel. (not 100% sure about this)
Hardwood or synthetic stock, with a sporting-length fore end.
An 18", cylinder bore barrel, with a bead sight.
Some Metal Injection Molded (MIM) parts, like the extractor.
Has the locking safety button, although Remington MAY have discontinued it.
The 870 Police has:
An aluminum trigger group.
The old style magazine retention system.
A much smoother finish inside and out, no machine marks or burrs.
The Police gun receives a higher level of inspection and finishing.
A military-grade parkerized finish.
A polished bore.
A one piece barrel.
Walnut or synthetic stock, with a short police-length fore end.
Choices in different stocks, including Speed-feed, and others.
18" to 20" improved cylinder barrel, with a wide choice in sights, including rifle, ghost ring, and luminous.
Heavy-duty magazine spring.
Heavy-duty trigger-sear spring.
Sling swivel mounts.
No use of MIM parts, the extractor is milled.
No lockable safety.
The Express is a budget gun, the Police is the top-of-the-line in quality.
The Police is generally considered to be the finest quality defense
pump gun made.
Any one can buy a Remington Police gun.
The problem is, Remington only sells Police guns through Remington factory authorized Law Enforcement Distributors.
MOST factory authorized distributors only stock sporting guns, due to the licensing and paperwork required for some police guns like 14" barrel shotguns.
Since most dealers don't normally buy from the LE distributors, this means they have to make a special order, and some just don't want to go to the trouble.
Some dealers will blow you off by telling you that Remington won't sell Police guns to "civilians".
To get a police gun, simply find a dealer who either buys from a LE distributor, or who will special order one for you.
The Police 870 is well worth the added trouble and expense. It is the Cadillac of pump guns.
So I now have the Rem.870P Police shotgun and I am really money ahead over the 11/87 I used to have a Rem.870 pump but in a moment of brain failure I sold it.
That was really a bad move on my part.
I can't tell you how many times late at night I found myself really missing that shotgun.
This new 870P has this neat deal for keeping extra rounds in a spring loaded insert on each side of the stock they just feed into the slot just like loading. Really a nice improvment for having four extra rounds at you'r finger tips when needed.