I had a older Mini 14 stock that was really nice , so I took my stainless tactical with fact G/B type flash and put it into the older fact stock , put a M1 Grand style sling that was made for this gun on , every thing seemed to fit very well, seems a little tighter than the black fiber glass stock that came on it . I just have to check how it shoots , did change out the rear sight for the one that looks like the M14 rear sight . we`ll see how she shoots .

I did this with my 580, think I got the stock at Midway.
P1000025  

The plastic stock doesn't have the metal frame that the wood ones have and therefore have a shittier lockup.  The only thing the plastic reallyhas going for it is the reduced weight.

Just beware if considering this:
I had a blue Tactical with the poly stock.
Ordered a wood one from Midway.
It wouldn’t fit.

I called Ruger and they said it should fit.
Ordered another one.
Wouldn’t fit.

I gave up.

Ruger would probably have fixed it for free but I was over it at that point.

Syn stocks don't (usually) have the metal stock reinforcement bracket seen on the wood stocks because they don't need it; the plastic of the stock in that area being stronger than thin wood.

Vertical Lockup of the barreled receiver is done by clamping action of the trigger guard to the receiver.  The stock itself (and the metal stock reinforcement) comes into play if the fit of the stock to the barreled action is "loose" (causing horizontal movement of the barreled receiver) and this can happen on both wood and syn stocks; with/without metal stock reinforcements.  In my experience, the wooden stocks are much more likely to have "loose" fit--and that fit can change due to moisture, even atmospheric moisture.

Syn stocks are not subject to dimensional changes due to any kind of moisture, and so preferred by folks using the firearms in all types of weather.  Syn stocks are not subject to long-term compression of the wood near the trigger guard, which progressively reduces vertical clamping action.

A "loose" fitting stock, whether wood or syn can be greatly improved by using a little bedding compound in the right places.

Lastly, the fit of the gas block to the fore-end of the receiver is important.  A "tight", but sliding fit is necessary, requiring installation of thin, narrow stainless-steel shims.

It would be interesting to know why the stock didn't fit.  If you want some help, please describe the problem, and be prepared to supply pix.

Mini-14 wooden stocks have a different thickness metal stock reinforcement than the Mini-30 stocks.  Wondering if they sent you the wrong stock.

Looks good OP. Ruger also sold a Hogue camo over molded stock for that rifle. Long time discontinued. I preferred it over the wood stock.