Thread: Cold Bore First Shot

Come back from a Ruahine trip last weekend, dog had knocked over my rifle in river on way out so went out to check zero today.

I’d fired 5 rounds on the Ruahine trip and when I come home did one light patch of Boretech eliminator then straight away patched dry then light oil patch for storage. This is what I’ve always done. I dry patch before going shooting again.

These were results today. First shot was the outlier, next three were bloody tight. I normally dial for longer ranges so run a 100 yard zero. Now I’m unsure whether to adjust or not. Do I base it on the tight group and bring it down a couple clicks, or just base it on the cold bore zero.

The barrel should still have copper in it, I hardly ever scrub it right out and I find the one patch of boretech keeps the copper at a good level.

What do you guys do? First shot felt good so now I’m unsure whether it’s a cold bore thing, a copper thing or my shooting.

If I get a result like this I always fire another group just to check if it was a 'cold bore' shot.

Since you didn't (and I suspect you may not be at the range for a while), I would personally go off the tight group as the zero (and adjust the scope down).

No more light cleaning,see if the next 3 shots tight group,no flyer.If so,thats yr group centre.With the above 4 shot group,you are not going to miss a deer anyhow.

At 100-200 & even 300 yds the deer won’t know the difference. If the “low left” POI for clean & cold shot is consistent & reproducible then you could dial up for 1st round. Or fire a fouling shot before you start hunting.

Originally Posted by Hermitage

If I get a result like this I always fire another group just to check if it was a 'cold bore' shot.

Since you didn't (and I suspect you may not be at the range for a while), I would personally go off the tight group as the zero (and adjust the scope down).

Yea the weather was only just holding on for us and the neighbours get a bit touchy at a mates place.

Or adjust the center of that group including the cold shot if that makes sense...

Save the next ten bullets for ten deer.You not going to miss out to 300yds.

having a quiet chuckle having trained many shooters the whole group is better than many can do - me if that was my .222 I would adjust a little left and a little down and you wont be missing if your shot is good - great to see someone else fussy about zero

Originally Posted by Trout

Save the next ten bullets for ten deer.You not going to miss out to 300yds.

Not always in that 0 - 300 sweet spot

your cold-bore shot it the one that gets the deer. That one would be plenty good enough for me.

Originally Posted by sportco62

your cold-bore shot it the one that gets the deer. That one would be plenty good enough for me.

I’m just fussy and like to learn when I can.

Take it to the range, fire one shot as you would when hunting (hopefully) then don't mess with it at all. take it home and do what you do to store it and repeat (using same target helps) you will soon see a pattern if there is one.
The issue is if the first shot is not where you expect then fire more then tutu a bit with the adjustments you can end up going in a endless loop.

It pays to remember there are always a lot of variables in shooting, and if you are anywhere but zero on the OCD scale they (the variables) can play havoc with your confidence.

It could be a cold bore shot but it could also be a lot of other things, things within your control e.g. inconsistent reloading practise environmental such as a drought on scales or human like misreading scales. Or outside your control e.g. a manufacturing fault in the primer, case or projectile. Could be an unnoticed shooting error such as tension in a hand . . . . Need I go on?

Personally it wouldn't bother me a jot, I'd note the very slight error in zero and maybe put an offset in the ballistic calculator. The two clicks to correct the zero will easily be exceeded by atmospheric variables at distances past 300 or 400M

PS - be particular rather than fussy.

Also likely a slight amount of bore chemical left behind which can act as a lubricant - lower pressures due to the presence of a lubricant = reduction in velocity. May help to explain the elevation error you are seeing?