Do you zero cold bore or follow up shots

[E.Precision]

Wondering what you zero with. Your cold bore shot, since the first shot is the most important shot, or do you zero your standard group zero's. I know competition guys zero their group zero's, but want to know for long range hunting, you only need that first shot to count if you do your part. So basically how do you zero your rifle for your long range riggs?

Erik

 

[Broz]

I zero at 600 or 700 cold bore and then count back down what my program says for that distance and conditions. Then move my knob to zero. Then I check it at 1000 another calm day with one cold bore shot. Then I hunt.

Jeff

 

[4xforfun]

I have 2 guns I use during season. My carry gun and ammo I let sit out side and cool for a half hour before I shoot my first shot. It is usualy cold up here in N.D. by the first of Nov, so the gun comes out of the truck warm. Then I wait a 1/2 hour between shots. I usualy have other guns to work with so waiting is not a problem. I only worry about my elevation at this time, as the wind WON"T be the same by the time you finish.


The other gun I use is my 1K match gun. It never leaves the warm cabin, so I test it first out of a warm pickup/hard case, or, if I can't shoot it right away, I shoot one warm up shot first.

Also, I usualy chrono my cold shots. When things warm up I gain around 30-50 fps over the average of a cold gun! This is very important at four digit ranges. A gain of 40 fps at 1000 yards is a 1/2 min gain in ele. in my gun. Keep that in mind if things don't go as planned and you need to fire multiple shots.

All of my guns are zeroed at 300 yards. And I either use the hash marks or dial up for anything over 400.

 

[Michael Eichele]

Personaly I do not sight in for the cold bore shot. Most of the time a true cold bore shot is unpredictable anyway. I sight in for a warm barrel. None of my barrels are that affected by it that much anyway. That is I have a new barrel on one of my rifles and have not yet had a chance to see how bad it is or isnt. I have tested my 308 at -3 degrees F and have not seen enough effects to warrent a change and at 20+ degrees it is dead on. My old 300 RUM barrel was minimal as well at 10 degrees and warmer. Once things got to th 30's it wasnt an issue at all. I have had rifle that suffered a conciderable amount from the CBS but was never concistent so zeroing for the CBS was pointless. I do not have any of those rifles anymore.

Shorter fatter barrels are typically affected a lot less than long skinny barrels. Big magnums are also more affected than smaller cartridges.

 

[ss7mm]

All of my long range rigs shoot symmetrical 3 shot groups. I use 3 shot groups for all of my hunting rifles. By symmetrical I mean that I might shoot a 3 shot group and the hits may be at 12 o'clock, 4 o'clock and the third at 8 or 9 o'clock. The next time the same symmetrical 3 shot group may have the shot hits reversed etc. etc.

I sight my stable, long range rigs using a zero based on the center of the 3 shot group. You can see how, if you picked a single cbs, your potential zero might be a little off because shots 1-3 don't always hit in the same order, in the same place, but by using the center of the group then I am sighted for the average CBS from my average group.

The groups from my main dedicated long range rig run under 1" typically at 300 yards under ideal conditions so the difference in the 3 shots of the group is pretty small.

You can see how that if you had a gun that only held 3"-6" at 300 yards that you may have problems at looong range. The only way to eliminate entirely the difference in your poa and your poi would be to shoot only one hole groups at all ranges.

 

[Boss Hoss]

When I used factory rifles I always sighted from a fouled bore. Now that I no longer use factory rifles the tubes mostly Krieger change very little if any. Even on my competition rifles the difference is minimal.

Factory tubes are not consistent and so the old process was---"leave it dirty for the season"..

 

[RockyMtnMT]

Boss,

Is there a problem w/ leaving the barrel fouled in a custom barrel? During hunting season, if I go to the range, I always clean after the session, then fire one shot to foul. My barrel is a Lilja. I just did not want the risk of it being different than the range session.

Steve

 

[Boss Hoss]

Steve---in my sporter rifles there was no point in leaving them dirty --- POI is virtually the same from a clean tube. Do not like to leave fouling in the tube longer than I have to. When I got a bore scope then it became a mental thing with me but I have never done any testing to prove one way or another.

 

[RockyMtnMT]

Thanks for the reply. Sorry for the hijack.

Do clean between trips afield? How about oil in the barrel? After hunting season I don't worry abut any of this, but during season I don't want to give the rifle any excuse for an arrant shot. It's mostly mental I'm sure, but without full confidence in the equipment I don't deal well.

As to the cold bore zero, I try several different ranges on my drop chart, w/ the rifle totally cooled down before the shot, for conformation of my zero. I am more interested in where the 1st shot hits than the group per say.

Steve

 

[Boss Hoss]

Steve---I always have a clean bore during the season but that is just me and my rifles. If the rifle I was using shot to a different POI on a clean bore then I would leave it fouled just like it was after the first of season sight in...

Much rather have a dirty tube than have the issue of wondering where the first shot will hit. Always store barrels with a coat of oil then prior to shooting just patch it out with some Butches then shoot.

 

[RockyMtnMT]

Thank you, I just wanted to make sure I was not making some miss-informed error.

Steve

 

[cross]

I follow Hart's instructions about using Hop-Up-and-Down Number 9 (Hoppes #9) for cleaning and a wet patch of the same for storage. John Burns advocated using Hoppes Elite Gun Cleaner (the spray not the gel) to clean your bore because it would leave it "dry" and his experience was that a dry bore would shoot the same as a fouled bore. I've adopted a combination of the two approaches, using #9 to clean and store the BBL and then before I take it hunting, dry the bore with a couple of patches of Hoppes Elite. It seems to work well and I'm unable to tell the difference between my 1st shot and my Nth shot. (Of course drying your barrel with Hoppes elite before hunting only works with stainless barrels, blued ones rust like no tomorrow with no protection on them).

 

[rem300ultra]

I always zero from a cold bore.