Optimum Barrel Cool-Down Time

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BigN

BigN

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How long does everyone wait between shots while testing reloads? I'm at about 90 seconds now and it may not be enough. I was at 3 minutes which worked well but seems like a long time to wait. Anyone inbetween? Barrel heat (at least my guns) makes the bullet strike crawl up the target like an ant, several inches per shot. Just for giggles tonight I loaded 5 rounds in a 223 and shot one after the other. My first round hit on top of the bullseye (100 yards) and the next 4 shots were perfectly centered but each about 2 inches higher than the previous one, while maintaining the same point of aim.
 
If you want to wait for your barrel to cool down during these summer temps >90 deg F, you will be waiting a while, especially after about the 5th round. The chamber heats up and so does the round that is in the chamber. Depending on the powder, some are more sensitive to heat than others. For a reasonable cool down between shots, I would wait 5 minutes and leave the bolt open so some air can flow through. When you shoot the next round, don't let it sit in the chamber any longer than you have to, else it will heat up some even after a 5 minute cool down.
 
Optimum Barrel Cool-Down Time

That would depend upon ambient, local wind speed, surface area of the barrel, etc. Might be better just to take a shot every 2-3 minutes.
 
There ain't no such thing!

Get an oxygen bottle and install a tube that will fit your chamber, after the barrel gets to hot to hold, (you can't touch the barrel without burning the skin on your hands), turn on the bottle and let the relativley cool air reduce the temperature of your barrel until you can holld on to it!
 
I use 1, 3, 5, 7, for 5 rd group testing. Fire a round, wait 1 min, fire a round, wait 3 min, fire a round, 5 min, fire a round, wait 7 minutes, fire a round. I usually have two rifles set up at a time as long as they are not similar calibers, so I am shooting while another is cooling, or I will plink with the .22lr while the rifle is cooling.

t2e
 
If your bullets are climbing that much you may want to float your barrel - sounds like there is a pressure point somewhere.

Cool to the touch was the old rule years ago
 
I was at my ole Man's range and was watching a high power competitor shoot reduced targets with an M1 or M1A. After a string he had a 12v blower hooked up to a battery with hose that he could stuff into the open action to cool it down. The unit had it's own homemade box with handle, he had put some thought into the contrapcetion(sp).
 
works the same way with most of my rifles. some are worse than others. ideally, we all would be able to walk out our back door and shoot. when the barrel gets warm, just run the hose across them. but very few of us have that luxury. the rest of us just have to sit and wait. i typically take 3 or 4 rifles with me when i go shooting. i set up multiple targets, that way it gives each one a chance to cool off between rounds. depending on what i am trying to accomplish, sometimes i will also take cleaning equipment with me, and clean the rifle(s) between loads. all of these create cool down time for the guns. shooting pistols between rounds also helps. once i took every gun i own to the range, but that is way to much trouble.
 
I've never let my barrel cool down. Then again, I'm not a sub moa shooter (not sure about the rifle, but I have NEVER shot below 1 moa regardless of rifle).

My break action takes me the longest to load, about 30 seconds when I'm at a bench, and it keeps the center of the group where it was for 2 boxes of ammo. It's not a bull barrel. My grandfather would shoot matches with very high quality .22lr's and it would take him 10 minutes to do 10 shots... an average of 1 minute each. He barrels were bull barrels, but his groups were phenominal... I can only dream of being that accurate (I'm not as accurate from a rest as he was from the prone... technique problem on my end for sure).
 
The first thing I would address is your barrel, it is in need of floating. As much stringing as your experiencing, I would venture to guess in desparate need of floating.
Barrel cool down is not an issue really, unless your taking it to damaging temparatures, which is going to be hotter than what 3 or 4 rounds will produce. With my high powered rifle I'll shoot between one and two 5 shot groups before I cool down. I especially like the second 5 shot group because my barrel is shooting more consistently at that temparature. I don't usually go beyond 10 rounds before cool down though, but not because I'm concerned about damaging the barrel, but because I don't want to damage or change the stock bedding. But in general, I personally feel a barrel will group best when it has sufficiently warmed up, after the first 2 rounds at the very least.
Your 2" strings are a sign of the barrel in serious need of floating. I float my own barrels and bed my actions too. But if your not feeling confident to do it your self, just take it to a smith and have it done, it shouldn't be an expensive job.
Another area that can effect groups is your stock mounting tork. It's not good enough to just tighten a stock down snuggly. It needs to be torked down to specific inch pounds or it can have a significant effect on how the rifle groups.
 
Gamestalker: I just did the dollar bill test to check the barrel float and it passed with flying colors. I even used 2 dollar bills and there is no stock contact with the barrel anywhere. I also have a 7 Mag, a 220 Swift, and a 270 that are all sub moa with the stock touching the barrel on all three, all the way back. I don't know about the bolt bedding though. I'll check it and see what it entails.
 
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It may need to be bedded. I also ran across a 700 that wouldn't hold a group because it needed that contact point at the end of the stock.
Have you lapped the barrel? And what condition is the crown in?
I don't know what syle of reloading you use but it might be your too far off the lands. This can cause more than acceptable harmonic distortion, which can casue an action in need of bedding to become more noticable by doing things suck as your describing?
And don't forget to rule out an optic problem, bases and rings too. I recently went through grouping hell with one of my newer 700's, and it turned out to just be the rings that I put on it were crap! In fact, it was doing the same exact thing as what your describing except not to that extent, 2" stringing is a lot. I was suffering 1/4" to 1/2" stringing. I switched my Leupold from another 700 and nothing changed at all. I won't devuldge how much time passed while I was trying to diagnose the problem, because it is embarrassing. But let me just say it took some time because I didn't even consider rings to be the culprit.
Good luck and I hope you get the puzzle solved quickly.
 
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