Barrel Cooling During Load/Group Development

[UIBassWrangler]

Here is a question I have been wondering about and would like some of your guys advice...

When someone talks about having their rifle shoot sub minute groups, are most guys shooting 3-4 shot groups one shot after the other, or are they allowing for barrel cooling between shots? Seems like I can usually put the first two shots right where they need to be, then about the third shot I will get a flier. To clarify a little more, I'm not talking about the flier being 6 inches out of the group, but pushing out to 2 inches or so at 100 yards. If I take time between shots to allow the barrel to cool, I get much better groups, sub MOA.

I have a good experience with reloading and have played with different powders, powder charges, seating depth, etc. But I am no master by any means...

Any opinions welcomed, what do you guys think?

 

[steeles1]

absolutely. even bull barrels get hot in heavier calibre's shooting 5 shots straight.this accelerates barrel wear and fouling.i pull the bolt back immediately after the shot,eject brass,blow into chamber to remove hot air/smoke,inspect brass for pressure signs,make notes in book,look how group is going then get ready for next shot. as the barrel gets lighter/thinner it heats up that much quicker but cools down quicker too.take your time and think of what your doing.

 

[Deleted member 46119]

You betchya.

Like steeles1 said, eject the brass, maybe give a puff down the breech, find something to do for a couple minutes.

Even read a book like applied ballistics between shots. LOL.

 

[HARPERC]

If those first two are on top of each other, and reliably on your aiming point, I would not worry too much provided it's hunting rifle.

If you're going to play some of the other games such as bench rest, or tactical shoots where a higher round count, at a faster rate is necessary you'll need to make some changes.

 

[AZShooter]

I have encountered barrel walking from time to time. If the chambering isn't some big magnum it would be interesting to shoot 5 to 8 in a row to see what happens. My 1000 yd bench rest friends will shoot up to 6 shots THEN go for their record group. The idea besides verifying the POI is if there is any barrel movement due to heat it will have moved to the final location.

I helped a friend get his 6.5-284 shooting last year.(the barrel was cryogenically frozen) It would shoot fantastic three shot groups then the group would walk. One time I shot 8 in a row and the last five were in a cluster under 1/4" just 3/8" away from original POI.

I know a well known rifle maker here in Tucson who only shoots the first shot then lets it cool to ambient and repeats. Takes a long time but he will know if the first shot is reliable.

My favorite test of a hunting rifle is to shoot one shot then let totally cool and shoot one more. Do this for several DIFFERENT range sessions then superimpose all targets to see the real group size. If a rifle keeps putting them into a small area it can be trusted.

Like HarperC says if it is a hunting rifle don't worry.

 

[UIBassWrangler]

Thanks guys that's exactly what I was after

 

[SteveBurton]

It's already been said but I let my barrel cool between shots also. I typically wait about 3 minutes. I will look at my group, write in my log book and maybe read a magazine while waiting.

 

[FEENIX]

find something to do for a couple minutes.

+1! That what .22s are for ... granted you have ammo. gun)

 

[AZShooter]

Or that is what CO2 is for. I usually shoot one or two then use the CO2 to get the barrel back to ambient. It speeds up the load development times immensely. It can take a very long time to let the barrel cool when it is in the 80s or hotter and S. Az is warm almost the entire year.

 

[Deleted member 46119]

+1! That what .22s are for ... granted you have ammo. gun)

Yup. 10-4, pray.

 

[Reloader222]

When testing loads I would shoot the first shot, then open the bolt to allow air in, wait 1 minute and then fire the 2nd shot. Hereafter I open the bolt again and wait 2 minutes before I shoot shot no 3.

 

[4xforfun]

As to the OP.....

1st, is it ALWAYS the third shot in a group that is out?

2nd, does the shot ALWAYS go out of the group in the same direction and by the same amount?

3rd, have you ever fired a fourth, fifth and sixth shot to see if the string continues to walk?

 

[UIBassWrangler]

1 yes it is always the 3rd shot. The reason I was curious is if I don't take enough time between the first and second shot the second shot will walk in the same direction. I Was mostly wondering because in a real situation if you need a follow up shot in the field, you most likely don't have time to read a book or shoot a 22 lol.

2. Yes always in the same general direction.

3. Most times once I go to shoot a fourth shot I have let my barrel cool down and the shot is back in the group.

Like I said I was mostly curious to see what other guys were doing and if I should be concerned with a walking group after barrel heating or not.

Thanks again guys

 

[justgoto]

I don't have stringing problems no matter when I take the shots. If I do find a precision problem; I look to the load, then the scope/mounts/rings, then the bedding.