Great discussion about the PSR rifles in this thread in the vintage section:
https://www.snipershide.com/shooting/threads/remington-psr-need-help.7013757/
A few of us own these rifles, I've got one of the prototypes. Here's my response to someone asking about the chassis footprint:
The MSR receiver has a completely different footprint than the 700, which makes me wonder why so many people bid on the MSR RACS chassis when they come up for sale on gunbroker. In the last 2 months, CDNN has sold 5 of the MSR chassis for $900 to $1,300. Brownells also has them listed on their site for $1,400:
https://www.brownells.com/rifle-par...er-rifle-msr-psr-short-action-prod105917.aspx
Since they don’t fit the 700 receiver, these are as useful as a boat anchor in your gun safe. Loose MSR receivers are nonexistent, so it's nearly impossible to build one (I was able to build my prototype MSR from loose parts and I only know of one other loose receiver). Within the past year I've had 2 people contact me about the chassis after they purchased them from Brownells, even though they make it clear in the description that it won't fit a 700 receiver. Thankfully, for those two people, Brownells has a great return policy!
If anyone here is thinking of buying an MSR chassis for a build, don't do it unless you have an MSR receiver with bolt in hand (and the barrel nut, barrel nut torque wrench and magazines in the same caliber as the bolt head).