I found a mossberg 500 in a pawn shop today. It is about 80%. The barrel is a 26" that has been cut to 18". It has the ribs on it. The barrel says 26"full choke 2/34 and 3"shells. He says he wants $170 for it. My questions are. Will this rifle shoot buckshot and slugs without a problem? Will the buckshot spreads be tight or really wide? Why? And , is the price good, if not, what should i offer him? Thanks.

Since the barrel has been cut down, there is NO choke.

This is now a Cylinder Bore barrel.  It will shoot all slugs and buckshot.
It will not shoot quite as tight a pattern with shot, or as tight of groups with slugs as an Improved Cylinder barrel, but the open Cylinder bore is what most short shotguns were until recently.

How tight it shoots depends on the gun and the ammo.  Some brands and types shoot tighter in some guns, looser in others.  You just have to shoot it to see.

For a 80% Mossberg Model 500, I think the price is too high.
Shop around and you can buy NEW Mossberg's for close to the same money, and for a few dollars more, you can buy a Remington Express model.

For an 80% Mossberg that's been altered, I would offer $100 to maybe $135.
First, 80% means it's been WELL used, if not abused.
Second, the barrel has been cut off, and who knows if whoever did it, did a good job and insured the muzzle was square with the bore and properly crowned.

What it is, is someone else's battered and beaten chop job, and quite possible someone's "it's got problems, so I'll dump it" gun.

thanks, for the reply.

Quoted: I found a mossberg 500 in a pawn shop today. It is about 80%. The barrel is a 26" that has been cut to 18". It has the ribs on it. The barrel says 26"full choke 2/34 and 3"shells. He says he wants $170 for it. My questions are. Will this rifle shoot buckshot and slugs without a problem? Will the buckshot spreads be tight or really wide? Why? And , is the price good, if not, what should i offer him? Thanks.

At that price you can get a new one rather than a hack job

I agree, $170 is just WAY too high for this thing. Assuming it's mechanically okay, $100 would be a very good price for it. MAYBE as much as $125.

I paid 200 for a new one at walmart

M4C

Just get a spankin' new one Smithy. I agree with all the above.
I make it a habit of not buying anything that someone else "modified" or worked on and dumped it on the market.

M4C