I know this isn’t necessarily the forum for cheap deer rifles but my experience yesterday verifying my zero for my Ruger American has me wondering about group sizes and barrel heat generally.

Modern gun season opens Saturday so I was rushed for time on my lunch hour yesterday (and hunting ammo is still really scarce locally) so I decide to shoot 3-shot groups rather than 5. I’m just trying to verify my 100 yard zero from last season.

Holy cow! I shoot one group of Federal Power-Shok and one group of Herter’s soft point (Cabela’s house brand) and the groups measure .604” and .665” respectively. BTW, I was in such a hurry that I forgot to burn a fouling round so that Herter’s group includes the first round of the day for that rifle. But the barrel was not cleaned after last shooting session, so it was cold but not clean.

I shot each group fairly quickly. No more time in between shots than it takes to carefully get back on target and ensure good eye alignment and trigger pull … certainly less than 45 seconds between trigger pull #1 and #3. The time in between the 2 groups was MAYBE five minutes because I was in a hurry. Just long enough to switch to a different rifle and shoot a group before switching back.

Now, I absolutely agree that sample size is meaningful, so 5 shots tell a truer story than do 3 shots. But how much is barrel heat potentially influencing my group sizes in a rifle with a sporter contour? I’d mark up one group so small as a fluke. But 2 groups of 3 that close together in time seems to be more meaningful.

When shooting groups, I do tend to shoot the shot string relatively quickly, but then allow someone time in-between groups for barrel cooling. But I’m starting to wonder how much I should let the barrel cool in between shots within a group to more accurately judge the precision potential of the rifle.

I know that barrel heat must be part of the criteria when judging a barrel which will be used within competition or performance parameters which require higher shot frequency. But how much attention do you guys pay to it when doing some initial evaluation of a barrel’s potential?

Would you ever go so far as to use a laser thermometer, for instance, to track shots in a shot string relative to the exterior barrel surface temps?

This just has my wheels turning about how to isolate barrel heat as variable but yet still be practical. I mean, if I am going to use this rifle at 500 yards for one or two shots from a stone cold barrel, does it even make sense to zero it for a 5 shot group or should I be adjusting zero for the net group which results from five 1-shot groups where the barrel has returned to ambient temperature between groups?

5 shots of deliberately aimed pace shouldn't open up or walk a significant amount with a well made barrel.

If this is a deer rifle it is the first and maybe the second shot that counts. I always tell people my hunting rifles shoot perfect one shot groups. If you hunting rifle shoots a good 3 shot group call it good. If you want to do a prairie dog shoot then heat should come into the equation.

I have a Ruger American in 6.5c. It’ll shoot good 5 shot groups but does heat up fast. If they are spread out and the barrel is allowed to cool it’ll hold its own.