On average I would say the hole is about .062 less than the bullet. Wad cutters are different of course. I have noticed a new backer gives cleaner slightly larger holes. If you have a bullet pass through where the backer is ate up the hole is smaller & more ragged. I bet the humidity makes a difference - How wet the paper or backer is. I'm not going to get all "mythbusters" and test it. Paper does pick up moisture fairly easily.
JDGray - The black ring is what I use for the dia. It is pretty consistent in the groups. I did see a guy on the net that colored his bullets & got color coded rings for ladder testing. I think he used sharpies.
.308 around .257 ring
.22LR around .150 - don't always get the rings. Some stay white.
Honestly, for me @ 100 yds (prone) with a rifle there is 1 to .5 inch, .5 to .25, and the .25 or less. The numbers are nice but those are the ranges. Sub 1, Sub .5 and Sub .25. Sometimes it is just "gee that group looks better" If you have to measure groups to see which ones are better you are on the right track. I shot a rare sub 1/4" group next to a previous 1 I blew out @ 1.25". I decided to end my shooting after the good group. I find it is good to leave on a successful note, even though I'm not really into head games.
I have found that context is hard to capture by looking at a target with some holes in it. I have to make notes on the target fairly quickly after shooting. Making the notes before is better. I go though my targets later and throw most of them away. Load development targets are kept separate. I trim down any I want to keep and put them on a certain door. I only keep the best of the best or one from a range trip that was just a great day at the range with some friends. I am pretty hard on myself, but I don't construct monuments of my failures. Learn the hard lessons & move on. I only keep the rewards, not the punishments. Granted, my wall of fame is pretty sparse. It's only part of a door, not even a wall.:banghead:
JDGray - The black ring is what I use for the dia. It is pretty consistent in the groups. I did see a guy on the net that colored his bullets & got color coded rings for ladder testing. I think he used sharpies.
.308 around .257 ring
.22LR around .150 - don't always get the rings. Some stay white.
Honestly, for me @ 100 yds (prone) with a rifle there is 1 to .5 inch, .5 to .25, and the .25 or less. The numbers are nice but those are the ranges. Sub 1, Sub .5 and Sub .25. Sometimes it is just "gee that group looks better" If you have to measure groups to see which ones are better you are on the right track. I shot a rare sub 1/4" group next to a previous 1 I blew out @ 1.25". I decided to end my shooting after the good group. I find it is good to leave on a successful note, even though I'm not really into head games.
I have found that context is hard to capture by looking at a target with some holes in it. I have to make notes on the target fairly quickly after shooting. Making the notes before is better. I go though my targets later and throw most of them away. Load development targets are kept separate. I trim down any I want to keep and put them on a certain door. I only keep the best of the best or one from a range trip that was just a great day at the range with some friends. I am pretty hard on myself, but I don't construct monuments of my failures. Learn the hard lessons & move on. I only keep the rewards, not the punishments. Granted, my wall of fame is pretty sparse. It's only part of a door, not even a wall.:banghead: