Cold ( and clean ) Bore Zero in a Hunting Rifle

Congrats, you have learned a valuable lesson! I just had that conversation again with my SIL. We got his rifle stacking shots in the bullseye and he wanted to clean it. I convinced him to wait until he's done hunting or else shoot it a few times after cleaning and check zero again.

That isn't unusual. The key to accuracy is consistency and the only shot fired from a clean barrel is the 1st one after cleaning. Every shot thereafter will be though a dirty barrel. Accuracy is usually consistent until the barrel gets too dirty. And too dirty could be after 20 rounds, or 200 rounds. It depends on the individual rifle.

I'm not anal about keeping the barrels clean. I will clean the action of any crud that could lead to a malfunction and wipe down the exterior. But barrels are only cleaned as needed.

There's two schools of thought:

"Cold shooter" VS "cold barrel" thing.

Taking the cold shooter out of the equation, I believe that cheaper, non-stress relived barrels can walk as they heat, but I believe that the clean VS fouled barrel has a larger impact. My SOP is to practice with my rifle throughout the year, clean before the season starts and then fire 3-5rds to confirm zero and foul the bore. The rifle then stays in that condition until it needs to be cleaned.

Should something happen, rain, taking a spill etc that get's moisture in the barrel, I will clean immediately, then again confirm zero with 3-6 rounds. Bottom line is I'm not hunting with a clean bore.

Turkeytider said:

.... have a science all their own.

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Science, yes, but art, too, and art takes practice and experience, not just what the book says, because what the book says doesn't always work exactly the way it says it should in real life, and it's the art that takes over and compensates for that. OK, enough philosophy. Have a Merry Christmas!!

wiscoaster said:

Science, yes, but art, too, and art takes practice and experience, not just what the book says, because what the book says doesn't always work exactly the way it says it should in real life, and it's the art that takes over and compensates for that. OK, enough philosophy. Have a Merry Christmas!!

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This is very true. Expect the unexpected at times. I have a Savage Model 12 with the heavy varmint barrel that goes against the norm here. A cold bore shot has the same POI as the 5th or 10th round fired. Most of my other rifles will not do that.

My muzzleloader will shoot a full 12" lower at 100yds if I clean it. So I don't clean it after zeroing it for a season of hunting. I load it then seal the muzzle of the barrel with a piece of tape to keep moisture out & keep the corrosion down to a minimum.

“Cold Shooter” is often misidentified as “cold bore”.

If a rifle does walk when the barrel gets hot, fix the rifle.

“Clean bore” offset is real, and clean bore hunting is asking for trouble. Foul the bore, leave it fouled through the season.

Hunting or target, I always foul a clean barrel before shooting. Hunting, I want the rifle dead on from a cold barrel. Happy hunting!

Varminterror said:

Clean bore” offset is real, and clean bore hunting is asking for trouble. Foul the bore, leave it fouled through the season

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This is my method as well

“Taking the cold shooter out of the equation, I believe that cheaper, non-stress relived barrels can walk as they heat, but I believe that the clean VS fouled barrel has a larger impact. My SOP is to practice with my rifle throughout the year, clean before the season starts and then fire 3-5rds to confirm zero and foul the bore. The rifle then stays in that condition until it needs to be cleaned.”

I completely agree and that is what I do.

The bores of my rifles stay fouled until accuracy falls off too much. Test mark is different for all of my rifles.

Getting ready for deer season this year I took my .308 to the range to verify zero. Starting with a known load and clean bore I took 5 shots at 100.

Next I went to 200, made a small adjustment to the scope, and fired this shot.



I put it back in the case and didn’t futz with it any more. It’s ready to hunt. It will get cleaned when my hunting season is over

Turkeytider said:

Just curious as to opinions on the accuracy of this statement: “ IN GENERAL, with factory loads, for consistent performance, with a .223, 300 yards is about maximum. “

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Really depends on the gun and the ammo, neither are created equal. There are some very good match 69-77 grain .223 ammo available and also some very good varmint ammo. I run a 'thrown together' load of TAC, Sierra 77 grn OTMs, CCI BR4s and PMC brass that's just FL sized and run through a TrimmIt2. It will hold sub MOA out to 600.

100 yds:



307yds, 3rds, stop shooting when I broke the carriage bolt off:



This fall I had a couple guys out that I shoot IDPA with to have a .223 shoot. We shot steel out to 600 and a couple of the guys were using factory match, one was using factory varmint. None had issues out to 600.

Turkeytider said:

Just curious as to opinions on the accuracy of this statement: “ IN GENERAL, with factory loads, for consistent performance, with a .223, 300 yards is about maximum. “

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It depends on the factory load and your barrel. Hornady black 75gr bthp's shoot 1-1/2" groups at 300yds in my Ar15 with 1/7 twist barrel and still give nice groups well past 300.
Other factory loads in the same gun will not group so well. If the bullet stays stable and doesn't tumble or oscillate, the gun should be able to make accurate shots out to 600yds or more, but the shooter might not.

I have a Winchester model 70 featherweight in .243cal. With a clean barrel (I always finish with light oil patch) it will hit 2-3” high. But with a cold and fouled bore it will punch center every time predictably and wonderfully accurate when it counts.
The light barrel will walk if it heats but that isn’t how it gets used.
Clean bores are for long term storing, not hunting.

For decades I clean my hunting rifles after the season. Before I hunt I shoot them to check zero and leave them dirty. Usually they shoot the same, dirty or clean. Cold or hot. I don't like rifles I can't trust.