Heating up barrel before testing accuracy

[bwsmith]

Wondering if everyone is taking a couple shots of cheap ammo to warm up the barrel before testing different loads for accuracy. It seems that once the barrel gets warm tot he touch, my groups tighten up and I want to test the loads for accuracy, not the barrel and not me. I was thinking of taking 3 shots with garbage rounds (inaccurate loads rather than pulling the bullets, use them for warming up) before trying new accuracy loads. I would hate to discount what might be the most accurate recipe because I was shooting a cold barrel and an open group. Or is it even worth the trouble for the amount of difference?

 

[Kuyong_Chuin]

Wondering if everyone is taking a couple shots of cheap ammo to warm up the barrel before testing different loads for accuracy. It seems that once the barrel gets warm tot he touch, my groups tighten up and I want to test the loads for accuracy, not the barrel and not me. I was thinking of taking 3 shots with garbage rounds (inaccurate loads rather than pulling the bullets, use them for warming up) before trying new accuracy loads. I would hate to discount what might be the most accurate recipe because I was shooting a cold barrel and an open group. Or is it even worth the trouble for the amount of difference?

If you are using the gun for hunting you want to check for accuracy with the barrel cold since it is the first shot that is going to count. Fire a shot then let the barrel cool down again be for firing again when sighting in your rifle or handgun. As your barrel heats up it expands and will not be as tight of a hold on the bullet as it will be on a cold barrel. The barrel should be less accurate the hotter the barrel gets due to less grip on the bullet.

 

[Conservidave]

I assume you're talking rifle rounds. I always put 3-4 fouling rounds down the barrel before switching to the workup loads. My experience has always been that the groups open up the more i shoot (barrel heats up). YMMV. I Put the fouling rounds on paper as well, i don't shoot any garbage rounds.

 

[gamestalker]

I agree with Kuyong_chuin if it's a hunting load. But that can be difficult at best being that you would have to let the rifle sit for extended period of time between shots, not very practical in this respect. But it does make a lot of sense.

But to find the most accurate paper punching load, I always fire at least on cold bore shot before I begin putting groups on the paper. And then I work in either 3 or 5 shot groups and allow the barrel to cool for several minutes between shots.

GS

 

[ArchAngelCD]

I also agree...

You should know what your hunting rifle will do under several different conditions. You need to know "cold clean bore", "cold fouled bore" and "warn fouled bore" because with most rifles all 3 will deliver different POI.

 

[Dave Bulla]

I also agree with archangelcd.

In my experience, it's not a matter of cold vs hot on the barrel but rather clean or dirty hence the common practice of taking a couple "fouling shots". Also, many people purposely do not clean their rifle after it's sighted in until they notice accuracy starting to drop off. Some guns like to be shot dirty, some don't though so the only way to know for sure is to shoot yours and see. On many guns, groups will tighten up noticeably a certain number of shots after it was cleaned.

Punching paper is a whole different game than hunting and to be good at it, you have to purposely shoot the various conditions, keep records and use what you learn later. Many hunting rifles will throw the first shot a little high then put the next 5 or so rounds in a nice tight group but then start to open up as the gun gets hot if you are just sitting there shooting round after round. This is why target guns and hunting guns are not built quite the same. Well, they didn't used to be. Today many target features are found in sporting rifles.

 

[Brake Weight]

Before my father in law passed we would go shoot. Anything that was for hunting we would always cold bore sight. We'd take 5-6 guns a piece and shoot no more than 3 rounds at a time. Take notes and make an afternoon of it. After it turned cold we'd do it again, some repeat guns some not. But the notes let you know which ones were sighted when and with what. But he liked making one hole using three rounds.

 

[TheCracker]

I want total cold bore for my rifles. Hunting u might be lucky to get off 2 shots unless u are hunting in a pen. The 1st shot is by far the most important.

I really don't see why you would want to do accuracy testing with a hot barrel unless you though you were going to be in long fire fights (plan on going to Afghanistan ? Lol) in or some kind of extended fire competition.

 

[Grumulkin]

I agree with the know what your rifle will do under various conditions thing.

For most of my guns, accuracy is the same whether the barrel is lightly fouled or clean. With some guns, POI will change when the barrel gets warm and on many it won't.