I just finished my 870 build, then again will it really ever be finished.
I have a question though
i see most factory remingtons 870Ps etc with the 18 inch barrel and mag extensions.
the barrel is shorter than the extension. on my build the barrel is the same length...
so now it kinda looks like an over under.
its a factory barrel and extension... the barrel is a police express , thats what the box says
any ideas
also waht choke might it be, less its just a cylinder bore
any ideas?
this is the rifle a two weeks ago
now it has a few changes

www.ar15.com/forums/topic.html?b=8&f=9&t=223786

My all factory 870 is even too.

Your gun is either a Police Magnum or an Express Magnum.  There's no such thing as a "Police Express".
From the pictures, you have a genuine 870P Police Magnum gun.

For some years now the Police guns have had the Improved Cylinder choke.
This year, Remington appears to have gone to the Improved for all their Express 18" guns too.
The slightly tighter choke gives better performance with buckshot and slugs.
Look on the left rear of the barrel, and you'll see the stamp IMP CYL, which means Improved Cylinder.

I recommend measuring your barrel.
Close the bolt and insert a rod down the bore until it touches the front of the bolt.
Mark the rod at the muzzle, remove and measure.

For many years, Remington has used either a true 18" or 20" barrel on the Police and Express guns.

It appears that they've recently gone to a 18 1/2" barrel, which makes it the same length as the extension.

the receiver is from a 870 Police not sure about the magnum but it came with a 20" IC rifle sight barrel...I bought a new one 18" Police express , bead sight,I have to look at the box again
this is the barrel
cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73955&item=7217899913
and the extension was apparently remington judging by the bayonet recess

looks like the norm 18" express barrel(fixed cylinder, smooth bore). The Police barrels are Imp. cylinder.

hmmm
it says express police barrel
i dunno anymore

Does it have Imp. Cyl stamped on it?

I just took a look at the Remington parts section and that barrel, Number 24620 is listed as an 18" blued Express cylinder bore barrel NOT a Police barrel. Price $121.00.

Possibly Remington is labeling these as for Express OR Police.

Take a look at the front of the barrel support ring.
Is there a spring loaded plunger in the front face of the ring?

If there is, it's good for both.  If there is NO ring, it's not really suitable for the Police gun since the lack of the plunger won't lock the extension collar in place and it may unscrew under recoil.

In any event, MEASURE THE BARREL.  I know it SAYS 18", but lately Remington seems to be shipping 18 1/2" barrel but still labeled as 18".

ok so it is a police magnum
the barrel says cyl so its a cylinder bore
as for the plunger im not sure what you are talking about
im new to shotguns and i have to measure just to find out still

so i guess this is a cheesy barrel per se?
it looks parkerized as it pretty much matches everytrhing else
which of those barrels in remingtonle site
fall under 18" bead sight parkerized? and improved cylinder?
I would still buy it and sell thins one as its still unfired just mounted on the receiver