I bought a 243 just to mess with and probably rebarrel to a fast twist 6 or 25 Creed.
run down:
21.5" 1:10 twist barrel
.685" muzzle
mag inside length 2.880"
7lb 1 Oz w/mag, no scope
8lb 14oz w/rail & SWFA 3-15 G1
Scope base screws are Rem 700 Long action spacing
I tested 6 factory ammo in 5 shot groups for a basic accuracy test. I'm going to chop & thread the barrel and repeat these tests with a suppressor later.

Norma was the best with 5 inside 1"
100JSP 2953 advertised 2798 actual avg(5) ES 85

2960 Adv 2720 avg ES 52

sorry for the overlap on this one...
2960 adv 2770 avg Es 52

3150 adv 2947 avg Es60

3330 adv 3164 avg Es 65

3425 adv 3167 avg Es 47
-Hand Loads-
First, I checked OAL to lands on some popular bullets.
95TMK 2.875"
95NBT 2.733"
112MB 2.920"
108ELDM 2.840"
103ELDX 2.840"
87V-MAX 2.710"
105BTHP 2.795"
85TSXBT 2.740"

95TMK 2.80" oal
40.0 H4350
2907 avg
Es 42

87 V-Max 2.70 oal
35.0 H4895
2905 avg
Es 56

again, sorry for the overlap
95 NBT 2.70" oal
43.5 H4831SC
2864 avg
Es 34
I'll try the 103/105 and add to this.
Then I'll chop/thread to 18" and repeat.
I'll do a follow up post like this with the 18" info.