Hi,
how does barrel heating affect accuracy/consistency? When trying a new load, I ususally create three or four batches of four rounds per load up to max and then testshoot but I am concerned that the batches will be tested with a barrel that is in different temperature, thus not "comparable". I now "compensate" this by using multiple targets and shoot one shot at a time from all batches in turn until done but it is quite laberous. Any thoughts?

How temperture of a barrel affects accuracy depends on the stresses in the barrel's metal and, in some cases, the bedding. No rising temperature change helps accuracy.

Test your ammo the way it will be used in the field or range. If you expect to shoot single shots from a cool barrel, wait until it has cooled between shots. If you expect to shoot a string of shots rapidly, shoot your tests that way.

My brother went to a tropical fish store and bought me a palm sized 2-AA battery air blowing device to blow air bubbles into the water of a fish tank. It came with a thin, hollow flexible tube that I insert into the chamber after a couple shots to run air through the barrel. I didnt run any sort of temp.tests and my method is not scientific as to whether it really cools the barrel any faster than not using it. Guess you'll just have to be patient like the rest of us if heat is a concern to you in working up loads.

Yeah, been thinking about some fan or something to speed the cooling down of the barrel between shots.

If you have a good barrel, barrel heating will make little if any difference in accuracy.

Of course, shooting a very hot barrel frequently will increase its rate of wear. I would worry about this more with very overbore high velocity cartridges such as 7mm STW, 30-378 Weatherby, etc.

This is a good question.
I pondered this also.
I read an article in a magazine one time and I'll give the overview:
Start with the minimum load and work to the maximum load increasing by 0.2grains for small calibers or 0.5 grains for magnum calibers. Reload one (1) of each weight. When at the range start low and shoot each load, waiting between each shot. (say 5 mins. or so) After you are done shooting all the rounds the pattern will be a line moving up and then horizontal and then up again. The loads that formed the horizontal line are the ideal loading range.
It has worked for me in the past.

quote:

Originally posted by mike olen:
. Guess you'll just have to be patient like the rest of us if heat is a concern to you in working up loads.

How true. However, part of working up loads, sooner or later should include a test on whether
the heat does make a difference and how much.

But for starters I'd shoot at least 3 reasonably quickly, that should indicate something, maybe 5 if things are going well. Then let it cool before the next batch.

If you got a good group in there somewhere, you'd then have to try it with a clean and cold barrel to see if it's similar.

Things don't always stay the same even with the same load: temp,wind,shooter, etc.
Not very often I get the same size group with the same ammo.

If this is a hunting rifle it's the first shot from a cold barrel that counts NOTHING MORE.

You can control the barrel temp with cold water.

If your a piss poor shot and miss alot you might need 3-4 rapid shots.

quote:

If this is a hunting rifle it's the first shot from a cold barrel that counts NOTHING MORE.

Yea, the first shot is the most important but occasionally those less competent than you will need another shot or two. In my opinion, a good barrel should put the first and subsequent shots in about the same place whether cold or hot.

Agree, first shot counts in hunting situations but (big) part of the fun with reloading is finding that "golden" load. When I chose my first .338 load, one of my batches shot 3 hole-in-hole and the fourth an inch away:



that on a regular sandbag on 100 yards. You bet that was the load i picked! Will that make me a very much better hunter? No, too many other factors involved in real life of course but it feels good to go out on a hunt and know that the ammo works exceptionally good.

He that says the first shot from a cold barrel is the only one that counts in hunting...

Has never been groundhog/pd hunting

Du får skriva Göran, Goran, det är helt ok, även om det är ett int forum!?


There are quite a few swedes as i assume that you are her..


Best regards Chris.

Christian,
tack för tipset. Är ganska van i jobbet att vara "Goran", slipper "vad är Ö"-frågorna plus att man vet aldrig om Ö-et bara blir garbage-kod hos mottagaren.

As posted, the ladder method is a good way to get into your sweet spot but to be effective, it requires a shooting range in excess of 100 yards. And then, it doesn't give you your very best one-holer load.
I wouldn't angst about it too much. Load groups of three and fire them at a measured pace. Avoid overheating your barrel. You should be able to pick your rifle up by the barrel at any time. If you want to be really anal, clean the bore between groups. If not, the better load will still stand out for further refinement.
For the poster that sez "only the first shot counts", I hope when you find the fallacy of that remark, there isn't something toothy and pissed heading your way.

stillbee, shooting ladder at 200 or more yards is better for selecting best loads for those ranges for sure BUT it can easily be done at 100 too.

The hard part is keeping track of exactly which hole came from which load, expecially when they are close together. So, I just shoot one round into a series of numbered targets, usually drawn on 5x8 file cards, with the load data for that round prewritten on it. I just add the chronographed velocity at the range. Later, it's easy enough to make a "composite" target that shows where it round hit and pick the best powder range from that. After that charge range is estabilished, I do it again in smaller charge increments to find the best actual load. Then I do it again with small changes in seating depth. All the original targets are discarded but I file the composite, including the velocities and other pertinent data.

It usually takes me about 30 to 40 rounds to find the best combo for any given powder and bullet, all done at 100 yards which is as far as my little private range permits.

I generally shoot a 5 round group with .45 seconds to 1 minute between shots . Out of most all my weapons . Then check and reset my target or patch holes ( I walk the 100 Yd. then back ). This allows my weapon to cool for my next group .

When I leave the range bench or shooting area my weapon is covered ( Ie not exposed to the sun ) which can get very warm out south west come spring summer or fall !.

Seems to work as well as anything else I've tried . Hunting well most often 1 shot is all I need , once in a great while I've had to take 2.

Now you folks that shoot them furry little bushy tailed rats that live in towns with holes in them . Well your on you're own !.

We don't have them out my way , maybe we're just better shots out here and whacked them all !?. Just kidding !. .

If you want some real fun for Night shooting ?.

I've found this to be real challenging . Air pistol or rifle with a rail mounted light on it . For shooting real rats , especially around chicken ranches or garbage dumps of where ever they hang out. People tend to not be upset if one is using Air guns rather than the 44 mag !.

You get REAL world quick moving target acquisition experience !.
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