Bushing vs, Collet sizing

[Pahoghunter]

Several weeks ago I picked up a Savage 112 FVSS-S in .223. The gun is super accurate when I control the trigger. The rifle came with Wilson dies and loaded ammo. After I fired the loaded rounds I sized half using the Wilson die with bushing, the other half with a collet die. Loading the brass with the same bullet, powder and primers. I went to the range and shot 4, 5 shot groups. Two using collet sized brass and 2 using bushing sized brass. At 200 yds. the collet sized rounds POI was 6 inches lower than the rounds using the bushing sized brass. Different bullet tension must really make a difference?

[Dean2]

Very neat test. Which of the two has the greater tension, I am guessing it is the bushing die doe one. Did you measure run out on them after you loaded them just out of curiosity? Was there any difference in group size?

[Bill K]

How much different were the grouping, between the two ? Bill K

[Chickenthief]

And if you anneal the difference will be zero.
The harder the brass the less the collet die will size the brass and initial pressure will drop of = lower speed = more drop.

[Pahoghunter]

I did not measure run out, with the Wilson seater I could not tell if one was more difficult to seat the other, since this is pre-accutrigger controlling the trigger pull was difficult, but I did get excellent groups with both at 200 yards 5 shot groups in the 6's were not uncommon.