The Soviets had some AA variants of the BTR-152, but never came up with a self propelled artillery variant.
I'd imagine that the biggest issue there comes down to "why?" do this in the first place - the BTR-152 was a post WW2 vehicle, so the Soviets weren't exactly in a desperate rush to put guns on frames and could take their time making vehicles that were well suited for the task at hand, and practically every SPG in that era is tracked. The guns that'd be looked to for a self propelled gun are likely too heavy for a light frame (ie, the Soviet's first crack at a post war SPG was the SU-152G, which used, you guessed it, a 152mm cannon) and the direct fire role is equally troubled, because the heavy guns that people might want aren't going to be good to use on a small frame like that without a turret, and on the other side of the equation you've got lighter guns that are increasingly helpless in the face of advancing armor designs and will basically be the first things to end up on the chopping block when the first generation ATGMs arrive with vastly superior penetration power at a fraction of the weight, not that people know they're coming just yet, but the RPG-1 was just rejected for poor armor penetration at "only" 150mm; the RPG-2 is in development with a comfy 180mm of pen; a little glance at the Soviet's WW2 era penetration table for the ZiS-3 gives us the answer for how powerful it is in direct fire against armor...
...and the answer isn't exactly encouraging. You need a bigger gun, and a bigger gun probably means a bigger chassis. Wheeled SPGs are possible and
a thing, but they tend to use a more bulky kind of chassis than the BTR-152 usually in the heavy 6x6 or 8x8 range, like the
Tatra 815 which is used as a basis for a number of wheeled SPG designs, or perhaps more relevantly, the KrAZ-6322 truck, used as the basis of the
2S22 Bohdana. The original BTR-152 was based on the
ZIS-151 truck, later on its successor, which although a capable frame and certainly militarizable, is a fair bit smaller and lighter than those that tend to end up as SPGs proper - the Bohdana itself is on the lighter end, but works out fine as they basically slide the gun off the back to help brace it against the ground for firing; that works fine, but it means you wouldn't be able to get a turret of the kind that you want, and it wouldn't work in a direct fire position. A smaller gun like the 76mm helps, but then that just gets to the problem of the gun itself being anaemic and underpowered for what it might expect to face, and then we end up back at the beginning. All things considered, a purpose built design would work best - something that can carry a big enough gun to do proper artillery work and to bring some hurt to enemy armor if it must.
That kind of thinking process would eventually see the Soviets go for a full tracked self-propelled gun, which was the aforementioned SU-152G, aka, this thing:
This design was actually finalized for mass production, and on paper it seems like a pretty good design for the era - a capable 152mm gun that was identical to the D-1 howitzer and had a range of twelve and a half kilometers (a little short compared to its American counterpart, but not too bad considering the relative scarcity of Soviet guns of suitable calibre for an SPG without being too heavy - the other candidate that comes to mind is the
ML-20, which has superior range to its American counterpart and is also lighter; there's a catch in there somewhere, most likely to do with barrel length) but also capable of anti-tank work with direct fire HEAT, with mechanically assisted loading and enough armor to resist small arms fire...whilst also having a top speed of 63km/h? There's really not that much to complain about for an SPG this early into the cold war...
...but even still, the SU-152G never went into mass production - it was completely finalized and ready to go, but in what would be the biggest opponent for an SPG and for an upgunned truck, Khrushchev himself was (based on my readings) a staunch believer in the power of rocket artillery, not gun artillery, and ordered development to be halted = the Soviet Union wouldn't take another crack at the concept until the Brezhnev era, nearly twenty years later, with the Akatsiya and the Gvozdika following in
1971, and would instead go all in on various rocket designs - the BM-21 Grad and others
. With Khrushchev being a member of the rocket club, even a well designed and purpose built SPG like the SU-152G died; dire news for any attempt to modify an APC to serve that kind of role. If a full SPG can't get across the line, the conversion of a truck with a less powerful gun is going to be a nightmare to get through.
All in all, I don't see the BTR getting there - it can carry a gun, but the gun'd be too small for the usually artillery work in indirect fire, too weak for direct fire against tanks, complete overkill against something like an APC. You'd be much better off making the
ZIL-135 into an artillery platform; it's a few years ahead, but it also got combat work as the frame for rocket artillery, and that's a much bigger platform to work with for building a self propelled gun.
If you really want to make the BTR into a weapons carrier, then the best bet is to throw out the gun entirely, and take a peek at what happened with the M3 over in Israel, which Wikipedia gives to us in a neat little summary:
- M3 Mk. A (M3 Degem Alef) – M5 APC. Israeli Half-tracks were all designated M3, even M2/M9 variants and known as Zachlam זחל"ם in Hebrew. The Mk. An APCs were identified as IHC M5s by the use of RED-450 engines for the most part. While the M49 mount was retained, a variety of machine guns were used.
- M3 Mk. B (M3 Degem Bet) – M5 converted as a command carrier with extra radios and a front winch bumper. Mk. Bs featured M2HB machine guns.
- M3 Mk. C (M3 Degem Gimel) – Similar to M21 MMC, an M3 type (assumed from the common use of the White 160AX engine) Half-track with an M1 81 mm Mortar. Development began in 1950. A prototype underwent trials in December 1951. First vehicles were issued to units in September 1953.
- M3 Mk. D (M3 Degem Dalet) – Another M3 based mortar carrier, fitted with the 120 mm Soltam mortar. Development began in 1952.[39] Entered service in 1960.
- M3 Mk. E (M3 Degem He) - M3 fitted with Krupp 75 mm gun. A single prototype was built by may 1951, underwent trials in July 1951 and again in August 1953. By 1955 IDF Artillery Corps lost interest in the project.
- M3 Mk. F (M3 Degem Waw) - A proposed configuration of M3 with two 20 mm anti-aircraft cannons. The project was abandoned in 1952 after a preliminary check.
- M3 TCM-20 – M3/M5 Half-tracks fitted with the Israeli TCM-20 armament turret with two 20 mm Hispano-Suiza HS.404 cannon fitted to old Maxson turrets. The right hand vision port was often replaced with a ball mount for a machine gun. They proved to be very effective fighting anti-tank missile teams; their cannons proved effective in forcing the teams to take cover or suppress them so they could not use their missiles accurately
If you get rid of the gun, you could easily slap a hefty mortar into the back of the BTR, and that'd be a pretty decent weapon's carrier...but again, if it's the tank hunting part, you can get this:
Swap out the gun for a pack of fly by wire ATGMs, and even the humble BTR can eat MBTs for breakfast
