I just bought a box of winchester 30-30 150grain silvertips. As always when I got home I checked them and found that two of them have a darker primer than the other 18. Are they different primers that will mess with preformance or is it just a colour differenc?

Sounds like a manufacturer error. They all should look marginally the same. As in color difference are we talking a change from brass color to silver color or more like a fade?

last year i got a box of plain jane .270s and the lead was set back 3/4" to far i sent them back the next day.
assumeing no man eating bears come and try to get you today i would send them back do you want to find out?

Winchester recently switched their large rifle primer finishes from shiney steel to brass. I handload and noticed a more currently purchased box of primers was a different finish. I wouldn't worry about it. If you don't trust them though, use them for practice.

Thanks I will just shoot them and find out if there is much of a problem.

When you buy a box of shells one year, they may be loaded completely different than a box you buy a year later. the performance will be roughly the same but manufacturers simply use whatever is available or cheapest at the time including powders and primers. You could have two different types of primers but everything else in the cartridge (powder type and charge) should be correct to make them perform relatively close to eachother in performance. I'm just suprised that they would be in the same lot and in the same box.

I wouldn't think that it would make much difference, but like wingbone said, shoot them for practice. When I buy factory ammo (not often anymore) I always check to make sure that the lot #'s are the same. Just one of those funny habits that probably doesn't make that much difference in reality.

Not a problem.

More than a few years ago, when CCI began to manufacture rifle primers for reloading, I bought a thousand to try. They were natural brass--as opposed to Rem and Win who used plated brass. The CCI's were several different shades. I was curious about any differences in accuracy, but could find none. Apparently when the cups are stamped from brass sheet, there is some discoloration which is noticeable in the finished product.

Today, both Rem and Win are using unplated brass for their primers (plating adds to the materials cost) and it is not unusual to find several different shades of primers in a box.