I recently purchased a new Marlin 1894 SS and when I inspected the bore I noticed small hash marks going down 2 riflings. They run perpendicular to the bore and can be felt when you run plastic or something across them. It looks like ||||||||||||. Is this a defect that will affect the accuracy or is it suppose to be like that?

Welcome to the forum.

What you see are reamer marks. First the barrel blank is drilled, then the reamer is run into it while it is spinning to widen it to its final size. That's why the marks it leaves have the direction they do. Unless a commercial barrel is made by the hammer forging process, After reaming it has the grooves of the rifling formed in by a hydraulically pressed button, or else they are cut into it using a multiple-toothed broach cutter. Custom barrels are cut-rifled, which also leaves the reamer marks intact.

If the reamer got some shavings caught in it or if it was getting dull or if the lubrication wasn't adequate during the reaming of the bore, you can get exaggerated reamer marks. They tend to grab at bullet jackets and accumulate jacket metal fouling. Whether they will affect the accuracy of the bore or not, I can't say? I have fired barrels pitted by rust that shot beautifully. All you can do is try it and see? If the fouling becomes bad, you can usually shoot the marks out by firelapping. I can't see how deep they are, so I can't tell from here whether they are really extreme or not? You might drop by your local gunsmith and ask him if they appear out of line?

bsbean, I have the same tooling marks on my new 1894 Cowboy .45 colt, on just 2 of the riflings as you have described. Mine came with a badly cracked stock, I figured that if I had to send it back to get the stock replaced I might as well see if they would replace the barrel as well. I have not heard back from them yet, but I'm really looking forward to getting it back. It's a fun rifle, I'm missing it badly.