So I am looking for a used Winchester with iron sites, my question is, are there certain years I should stay away from?
Also can the older winchester handle the heavier loads like 200-220gr?

I am guessing you are talking about a model 70 in .30-06?   I didn’t catch a caliber.  

Pretty simple guns.  Only chamber from the magazine if a controlled round feed type.  But look at the claw extractor for damage from operation where people dropped a round in and forced it closed.  

Look at bore condition and the crown.  

They are really a pretty simple device.   I have one 90’s vintage M70 classic with the pre64 style CRF and two customs built on FN SPR controlled round feeds.  (A near straight M70 clone)

If rebarreled look it over really well.   It is more work to rebarrel the cone breach and extractor clearance cut than your remington screw in and screw out set up.

Yes in 30-06. But I’m looking for one that can handle heavy loads like 200gr for when I go bear hunting.

So I found a gun shop near me that had a model 70 he thought was from the 80s. He was asking $450, I went to the shop it has a smooth black fiberglass stock that I guess was added on. And it came with a old weaver 3x6 scope. I looked up the serial number and it says between 1969-1970.

From that time period, I personally would be a little leery for the following reason.
Post 64 when the bean counters took over and changes were made. Mostly cosmetic, but nonetheless some corners were cut. Still a basic Win Model 70 though.

Sometime in the early/mid 1980's the company was bought back by employees and upper management (IIRC) and the guns were sold under the US Repeating Arms Co./Winchester moniker on the boxes. I have a 1986 vintage M70 Featherweight in 7x57 Mauser the is an outstanding rifle in all regards. Controlled feed is preferred, but the push feed models have never given me any trouble either.

From what I've been told, and remember from those days things were pretty much back to normal up until they closed their doors several years ago.

So, go online and check the date of manufacture and see where it falls.

Inherited my Gramp’s 5-digit (1942) M70.

He hunted it hard with irons, but the barrel and crown were still in excellent shape. Yes, mine likes the Remmy 220grn Corelokt ammo (2405fps, IIRC) as well as a handloaded equivalent using the Hornady 220grn RN bullets over Varget.

If you’ve got the coin and can find a decent-condition pre-‘64 CRF model in 30-06,  those are the cat’s ass of M70s. The heavy 200-220grn loads will be fine for black bear.

Are you completely set on a used one?  I only ask because you can buy a new Model 70 Alaskan in 30-06 which has irons and will handle heavier loads with no problem.

Huh, I wonder if that is an older McMillan stock.  

Not the charm or warmth of wood but a no nonsense stock.  If it was a McM and the bore and metal condition is good I would say it’s a buy.  

I’d check the bedding if he was willing to pop it out of the stock.  

I would scuff and paint the stock a camo pattern.

not an issue at all! Even 220gr. is satisfactory, but keep in mind those heavier bullets do drop faster and adjustments for elevation must be factored.

Respectable Rifle at a reasonable price point.
I had one in .300 Win Mag and the first two shots (rapid succession) would touch and the third one would fly up and left due to heat torquing the barrel..."G" prefix serial number from the 70's~80's  each horse has its own personality; rifles are no different.