the RP 180 grains hollow point bullet is .357 and my barrel slug out as .3565 so they work just fine.

one must distinguish the following terms:

System Mauser

Original System Mauser

Original Mauser

Mauser system means this is build how a Mauser system
Original system means an original Mauser system has been used in weapon of another manufacturer
Original Mauser means that the weapon was built entirely by Mauser

The question is whether the Commissions M 88 rifle is a mauser system or not.The army's rifle commission has not startet at that time from zero! They actually had the Mauser M 71 and M71/84 as a basis. the magazine with the en-block clip was a Mannlicher design but the Bolt and the receiver is based on the M 71. Let's look at these pictures:

Jägerrifle M 71

carbine M 88

M 93/ Romanian Mannlicher sporter

Mannlicher Schoenauer

You see that the rear end of the bolt with the bolt sleeve and the wing safety was never changed. the diffenece is how the bolt is looking. The M 71 action included only a bolt guide rib as its single locking lug. because of the black powder pressure its safe to locking only forward of the receiving bridge.
The technical leap for space age nitro powder called here a change.
The M 88 bolt have a seperate but rotating bolt head with two locking lugs to stand the higher pressure but if compare them you will see that its allways the old Mauser 71 bolt.

German repeating stalking rifle system Mauser, not realy wrong in my eye's

stalking rifle's system Mauser, like the other one's follow here copy's from M 71 action with different measurments for smaller cartridges

target rifle's system Mauser

but target rifle system Martini

and here target rifle system original Haenel Aydt - the rifle was build from another maker with an original C.G. Haenel action

cheap "Mauser" garden rifle's and gun's, not exact copys's

rimfire rifle system Mauser, "Mauserlein" means little Mauser

original mauser made rimfire rifle's