I've got a Springfield Loaded M1A with a wood stock. Is it normal for magazines to rub on or contact the stock metal? More of an annoyance than a problem. Thanks.

I have one also but I've never noticed that happening. (I've gotten it where much all of my M1A magazines are same manufacturer).

It would seem that it would likely be the magazines vs. the well. I have seen some of the various made M1A mags (like CMI) that have rough welds that protrude unevenly or have dimensional problems. Some of these might also not be seating "straight" in the well relating to the tab/latch plate. I have heard some friends mention they had to file some of the CMI mags in the tab/latch plate area to fix seating issues. You can usually recognize the CMI mags by the horizontal line on the latch plate.
Supposedly ProMag industries M1A mags work well but the finish wears quickly in places. According to the M14 Forum (good info there also), you can identify M1A mags using this info:

USGI M14 magazine latch plate weld dimple patterns were consistently the same pattern according to manufacturer. The following latch plate dimple patterns have been consistent for genuine USGI magazines:

two dimples with a horizontal line immediately above the bottom pair - CMI
four dimples - W, bar W, HR-R
five dimples with the fifth centered - Atwood Vacuum Machine, UHC
five dimples with the fifth placed towards the top pair - BRW S-I, BRW B2
five dimples with the fifth placed towards the bottom pair - OM, OM over a dot
six dimples - KMT nine and thirteen front side weld versions
six dimples with a horizontal line immediately above the bottom pair - CMI

Magazine body (tube) wall thickness can vary from 0.028 " to 0.041 " as observed among USGI, Chinese, Taiwanese and U. S. commercial manufacture M14 magazines. The specification per USGI drawing 7790181 for the body (tube) thickness is 0.0310 " + or - 0.0015 ". If a magazine body is too thick, e.g., 0.041 ", it may fail to lock the bolt open after the last round is fired."

You may be able to match the friction point (by looking for loss of coating/finish) and match it to the magazine. (That's why dropping magazines in drills is always hard for me. I did one series of pistol drills where they had us drop magazines out onto hard gravel and it pained me greatly to let those mags hit)...
But shipping/handling can deform mags as well. If you have seen gunshow sellers have M1A magazines in brown wrappers and throw them around... Those are heavier mags and generate some inertia.

If you have a set of calipers around you can find out for sure by measuring the internal distances of the well all the way around, and the same for the mag outer edges.

The short answer is yes.

yes

Thanks, great info. Is this only present on wood stocks? How about GI fiberglass, sage chassis etc. Why does the wood stock even have this?

Your question doesn't make sense. Do you mean 'why does the magazine contact the stock'? A wood stock can swell, but a fiberglass or chasis system should be dimensionality correct.

Don't over-think it. If it inserts freely, without excessive resistance, then it's good to go. The stock liner is there to prolong the fitment of the action to the wood stock. It's not necessary on fiberglass.

Stick with CMI mags. Don't buy the ones with the SAI logo, they are more expensive and are made by CMI anyways. 44mag.com sells M14 CMI's for around $22. Avoid Pro-Mags. They are junk! For me, it's too much trouble to try and ID old GI mags, Israeli mags and Taiwan T-57 mags, so I just stick with CMI's.

Tony.

If it's more than 20 rounds, stay away. If it's blued, stay away. If it has no markings, stay away. If it's plastic, stay away. If it in some way implies USGI but satisfies any previous stay away, stay away.

During the AWB, it was worth identifying USGI mags, because they could be legally possessed. Now, just buy the new CMI mags as Tony says. If you really want to get some vintage mags, OK, learn the markings etc, but it is unnecessary.