As soon as I received my new 18" T/C barrel chambered in 5.7x28FN, I went to the range to sight it in. I purchased one box of 50 rounds of the only factory load I could find in the LGS. The load I use for sighting the rifle was the S195LF (27 gr Lead Free) which it cost me $32+ out the door (ouch).
At the range, I was totally disapointed: the smallest group I cuold get with this load was 4 inches at 25 yards (bench rested and scoped). I also noticed the impact were semi-key-holes in most of the cases. I have no clue of what happened but the only thing I can think to try to make sense was the following:
a) The 27 gr bullet was too light for a 1 in 12" rifling?
b) The 27 gr bullet was not quite .224 caliber? I use my caliper and I measure the bullet diameter and I got a .219" readings; but that could be because of the factory crimp or simply too much ogive taper of the bullet where I could measure it.
c) Can the barrel be the culprit? I don't want to think so but it could be possible.
I can't wait to get my reloading dies to start experimenting my own 5.7x28FN brewings. Any one of you experience the same thing with the factory loads? Please, share your experiences so I can learn. Thank you.
Camba
Camba