A question for the more experienced hand loaders is this. When testing various loads with any rifle how much time between three, four or five shot groups should you allow for the barrel to cool? It is close to 80 degrees in south MS today and after my first three shots my barrel was quite warm. My shooting bench is in the full sun so that doesn't help. I allowed about 10 minutes between three shot groups for the barrel to cool but it never got back to ambient temperature. Before I fired the last three shot group I put the gun in the shade and allowed the barrel to reach ambient shade temp (30 minutes maybe?)I proceeded to fire three more shots with my last load to test and the group tightened up considerably over the previous four. In fact it was half the size of the first four. What is a good rule of thumb to follow when doing this?

Before I devised a shade over my bench, I would put a white towel over the barrel between groups.
And, I would have the rifle propped so that the barrel was tilted upward. the bolt was open of course.

For my hunting rifle I would normally let it sit until I could comfortably firmly grab the barrel with my bare hand. Sure nothing scientific about my method.

My Varmint rifle I would shoot HOT. Figured it would be HOT when I used it.

That is what I do as well; if I can grab it and it doesn't feel hot, I shoot; if not, I wait. And here, it goes from 0 degrees in the winter to 100 in the summer, so, it varies on how long it takes to go from "hot" to "touchable".

Propping the rifle up with the action open helps cool the barrel faster. Ever consider on of those pop up gazebos you can buy at a sporting goods store just to get yourself some quick, cheap shade?

Also consider giving the rifle a few minutes between rounds instead of shooting a group and then waiting for it to cool. If you fire one round, wait a minute or two, then fire the next, the barrel never gets as hot as if you fire off three or more in a row. This way you can shorten the overall amount of cooling time.

quote:

Originally posted by 35whelenman:
Propping the rifle up with the action open helps cool the barrel faster. Ever consider on of those pop up gazebos you can buy at a sporting goods store just to get yourself some quick, cheap shade?

I ended up using one of those umbrellas like you put on an outdoor table.

Rushisright,

I have found that waiting 1-3 minutes between shots, key being, allowing the barrel to cool between each shot, is better than firing 3 or 5 consecutive shots, and then letting it cool.

quote:

I have found that waiting 1-3 minutes between shots

I agree that might lead you to a tight group. BUT, in a hunting rifle do you allow your barrel to cool between shots or do you need a group with 3-4 quick shots?? Target rifles you don't normally have time between shots to cool either.

So question is are you looking for the tightest group? Or are you looking for the tightest group in hunting conditions? "Might" not be the same group at all.

To get best data, I shoot at temperature of anticipated hunting, usually 70 degrees F or less. Three to five shot groups, cooling with action open and upright for "chimney effect" cooling. Others have devised fans, cooling with rubbing alcohol, etc. to get barrel back to ambient when it gets hot outside.

I don't have the patience for benchrest...

Many sporter weight barrels will shoot better groups if the barrel is cooled back to ambient between shots. Others stubbornly refuse to put the first shot of the day on the same POI as the rest of the day. Some barrels go to crap when they are warm, and some shoot better when they are hot. Some will shoot best when they are dirty. Its up to you to figure out the quirks of your barrel, and develop your own philosophy of whats important.

A case could be made for the only important hunting shot being the first one, and the only zero that matters is the first one. Who cares where the shots that you probably won't even take may have theoretically went if they are never taken? Trouble with that is you might die of old age before you get a load developed. The best workable compromise That I've come up with is to shoot 3 shot groups for the preliminary work and rotate through 5-6 rifles. When I think I'm onto something, I'll bear down and shoot groups with the barrel as cold as possible. After that I'll pay special attention to where the first shot of the day goes. A 500 yard steel plate is great for that, and is rather revealing. That may seem excessive, but accuracy of hunting rifles doesn't matter much until the range gets long, and the cold bore shot just might be more important than the group size. The only way to know is to shoot it and look for it. If the cold bore shot is consistently too far out of the group for your liking the fastest and easiest method is to throw the barrel away.

My target rifles are always hot, being as I get 2 foulers and 2 sighters just for showing up. What they do cold doesn't matter all that much for your score, but it is interesting. As a shooter I'm actually more interested in who put their sighters in the middle than who wins. As a side note, can count on my target rifles shooting 1/2 to 1 MOA flatter than the chart at the SPRA range than my private range. Some of that is due barrel heat and some no doubt to evil spirits ride on bullets.

Varmint rifles are similar to target rifles as in you can expect them to be hot. Coyote guns can be counted on to be cold, sometimes a great deal colder than one would prefer.

This may not have helped much, but the bottom line is that if you can work your loads and zero your rifle in the same conditions as you are going to use it you are better off. That and don't assume or believe anything that can't be proven and repeated at the distance you plan on shooting.

quote:

Originally posted by ramrod340:

quote:

I have found that waiting 1-3 minutes between shots

I agree that might lead you to a tight group. BUT, in a hunting rifle do you allow your barrel to cool between shots or do you need a group with 3-4 quick shots?? Target rifles you don't normally have time between shots to cool either.

So question is are you looking for the tightest group? Or are you looking for the tightest group in hunting conditions? "Might" not be the same group at all.

Actually, almost every rifle I have owned will shoot a 3 shot group successively with no problem.

The reason for waiting between shots, is this... I am usually trying multiple loads, and so I wait the time between shots... so the time on the range is meaningful... and it works.