I have a 53 SA special M1. Reparked and a new walnut stock. Who
does The CMP use to make these stocks? Also how close are they
to the originals as to dimensions?

The CMP stocks are Boyd's/Dupage Trading Co.  IIRC, Dupage has Boyd's make them to their (Dupage's) specifications.  I don't know how/if the CMPs are stained/oiled differently than what you can get directly from Dupage.

The most recent Dupage walnut stocks I've seen most closely "resemble" later-production SA stocks, but as far as actual dimensions?  Well, they fit the rifles well enough... certainly better than some of the "fatties" of years past.

ETA pulled a 5.87 SA out of the safe with a fairly recent Dupage walnut stock, and I'm comparing it now to pics of a 5.87 SA unissued the CMP is auctioning.  Compared to an actual 3/8 DAS HRA stock I've got here too... yeah, they were definitely using the SA as a pattern... but it's not perfect by any means.  The wrist on the Dupage seems a little "long" as compared to the correct pics, and the comb seems to be set back a bit further.  But overall size, shape, profile around the receiver heel... yeah, the Dupage is much closer to the SA.  You can spot the HRA's differences a mile away.

Thanks for the info ABM41!!

They are much better than the regular Boyds but they all still need some tweaking on the interior for accuracy and function. I have worked on 6 of them and they all needed work, some more than others. Still a very nice stock

M1G, by tweaking do you mean sanding and reshaping the stock?

Mostly work to the interior of the stock for fit. The outside is still not completely accurate but pretty darn close so most dont even notice

Ok, thanks.

It's really remarkable how much effect the stock has on accuracy (and reliability, I suppose) with M1s.  Handguards too, to some extent.  A well-fitted/adjusted stock can really "wake up" a rifle.  Conversely even seemingly minor fit issues can make an otherwise good rifle unpredictable, inconsistent, etc...  Many USGI stocks seem to have had some of these "tweaks" from the factory... the original builders of these rifles understood the importance of the stock.

The 5.87 SA with a new Dupage wood is one I've put a lot of effort into.  It's a fun learning experience, making small changes and seeing the rifle's performance come up a notch.  There's a ton of info out there on what to do (esp. on the CMP forums... wealth of info), though it's helped to experiment on several new stocks, and make careful comparisons to actual USGI stocks, in addition to all the research/reading.