Generally, the heavier the bullet, the deeper the penetration.
“Is there much difference, performance wise between the 124-127 bullets and the 147?”
As previously posted, let’s compare apples to apples—below is factory test data comparing a couple of Winchester 9 mm loads. How does the 127 gr +P+ compare with the 147 gr?
FBI Test Protocols:
Bare Gelatin at 10ft
Denim, 4 Layers at 10ft
Heavy Clothing at 10ft
Steel, 2 pieces of 20 gauge at 10ft
Wallboard, 2 pieces of 1/2" gypsum board at 10ft
Plywood, 1 piece of 3/4" AA fir plywood at 10ft
Automobile Glass, 1 piece 1/4" laminated safety glass set at a 45 degree angle with an offset of 15 degrees at 10ft
9mm 127gr +P+ RA9TA at 1250fps:
Bare Gel: 12.3”/.64”
Denim: 12.2”/.68”
Heavy Cloth: 12.2”/.68”
Wallboard: 12.1”/.66”
Plywood: 12”/.68”
Steel: 20.5”/.40”
Auto Glass: 9.4”/.48”
9mm 147gr RA9T at 990fps:
Bare Gel: 13.9”/.65”
Through Denim: 14.5”/.66”
Through Heavy Cloth: 14”/.66”
Through Wallboard: 15”/.67”
Through Plywood: 14.8”/.62”
Through Steel: 17”/.45”
Through Auto Glass: 10.8”/.52”
I think you may find typically higher velocities in the lighter weight bullets. I think you will also find many of the heavier bullets expand to a bit larger diameter. In the Winchester Ranger ‘T’ line, it seemed like the heavier bullets typically gave more consistent performance across different barrier material penetrations.
BTW… I didn’t see DocGKR’s answer above until after I posted mine. It seems to back-up what I am saying here. I ‘edited in’ this second paragraph…