Gentlemen.
I am not posting this to start a spitting contest but I am going to suggest that if you are shooting 14 - 15 lb rifles and you are not seeing your hits/misses then you need to work on your set-up/ follow through and gun-handling technique.
With the minimal recoil of the 223 and 40 gr bullets you should be seeing practically everything that occurs unless you are jerking the trigger, moving your head, closing your eyes or flinching. Yes it possible for people to flinch shooting a light caliber, heavy rifle - but more often it is poor gun-handling/technique. My favorite walking varminter only weighs 8 # and I see the hits/misses with it.
I have shot competition and literally thousands of PD's and Ground Squirrels over the decades and have observed many shooters, both competition and varmint shooters, I am always at amazed how few shooters do follow through correctly. In most cases they never realize what they are doing wrong unless someone points it out to them.
p.s. - I am sure that someone will eventually post that the 204 recoils less than the 223 and they can see there hits better - Ain't happening. The 204 with 40 gr bullets recoils virtually identically to the 223 with 40 gr bullets because the powder charges are near identical and the bullet weight is identical.
It is possible to have a slight reduction in recoil by going to the 32 gr bullets in the 204 but even then it is only about a half-ft lb less.
Here is the data for a 8# 223 with a 40 gr bullet
Recoil
Input Data
Charge Weight:
27.0 gr
Muzzle Velocity:
3750.0 ft/s
Firearm Weight:
8.0 lb
Bullet Weight:
40.0 gr
Output Data
Recoil Velocity:
4.9 ft/s
Recoil Energy:
3.0 ft•lbs
Recoil Impulse:
1.2 lb•s
09-Dec-18 15:34, JBM/jbmrecoil-5.1.cgi
Here is the data for a 14# 223 with a 40 gr bullet
recoil data - 14 # rifle
Recoil
Input Data
Charge Weight:
27.0 gr
Muzzle Velocity:
3750.0 ft/s
Firearm Weight:
14.0 lb
Bullet Weight:
40.0 gr
Output Data
Recoil Velocity:
2.8 ft/s
Recoil Energy:
1.7 ft•lbs
Recoil Impulse:
1.2 lb•s