We ? You got a mouse in yer pocket chief ? I suspect that mouse is a risk manager for your department who's really just a rat !
Real patrolmen, working the streets vs a desk can make do with a bolt patrol rifle, something that will punch the kevlar these bad guys wear these days as we observed at the BOA Hollyweird robbery a few years back....such as the FN Patrol rifle vs an M4 . But I'd think that the M4 carbine would fill the needs better for urban or rural LEO's needs across the board.
As a deputy working alone in the rural mountains where radio links were few and far and cell phones were still a toy vs a tool..... I carried an M1A in my cruiser along with my shotgun. Backup was too far away. I relied on me and my own abilities alone for the most part.
Were I the chief or sheriff of a department today I'd issue the semi-auto version of the M4 carbine to all my officers / deputies with the instruction that seems to be lost on most LEO's these days ....you are responsible for every round you fire. Your must be aware of where your rounds will impact and the range and penetration of that weapons projectiles. Be surgical with you application of deadly force at all times if at all possible.
The ONLY reason I select the M4 carbine is that is the US DOD primary weapon that most former servicemen and new LEO's have experience and training with and if the need for a national guard call out is needed to aid LEO's in preserving the peace they have a logistical common for spares and ammunition etc ........
Just my opinion based on what I know and did in the past.......
WE've carried Ruger mini14's since 1991 and disposed of the shot gun option shortly after that. M4 or AR's are authorized if you want to shell out the $$$. Only one thing came up where they've been used for deadly force in that time that I can think of at the patrol level. Not that there hasn't been events where they could have been used. The training lieutenant actually prefers if we sling 'em all the time in the spirit of your tagline.
I think more than two days of training would be preferrable. Something more intense, like a Thunder Ranch week long looks better on your training record for those wrongful death lawsuits that invariably come up