zero'ing at 100 - barrel condition and effect on bullets?

[mazzgolf]

Took the new .308 to the range again today to try to zero it at 100 yards. Last night I used my buddy's Wheeler Reticle Leveling kit and got my scope leveled pretty good now. I also started with a very clean barrel (patches came out clean, white, and dry).

Here's what 11 shots looked like:

Notice bullets 1 and 2 were high. After those shots, I adjusted the reticle down 1 inch. Yeah, I know, you should really only adjust after a 3 or 5 shot group - but I didn't want to shoot a lot. (Note to self, don't wear a T-shirt when shooting the .308, recoil is killer. Wear a padded jacket or heavy sweater next time. Could only shoot 11 before my arm started falling off  ) So the scope is 1/4 MOA per click adjustment at 100 yards. I went down 4 clicks. That's when I shot the main shots and those look 0.5" to 1" low. By the time I shot #9, 10, 11, my arm was dead  so I'm discounting those last few shots.

I'm not an expert on the whole ballistics stuff. So, I have some questions...

1. When going on a hunting trip or just shooting for accuracy, do you first shoot one or two rounds to foul up the chamber? I don't know if those first 2 high shots were due to a "clean barrel". Notice I adjusted only 1" down but the main group went down 1.5" to 2". Seemed weird those first two shots were high like that, but I always heard that you might get flyers out of a clean barrel, and that you should take a couple shots first before taking shots "that count." I don't know how true that is - I'm curious what people's experiences are.

2. The barrel was extremely hot after those 11 shots. I definitely waited a minute or two between most shots. I don't know if that affects the bullet either, but I heard a hot barrel causes flyers too (and that might account for that last high-right shot). How often do you wait between shots? Do you wait for the barrel to cool down? I have noticed my .223 gets flyers when its barrel gets hot, I assume the same thing happens with these big game bullets?

I was using cheap ammo for now. I have another box of cheap ammo so I can shoot a bunch more to get used to this gun first and try to be more accurate. Once I feel I can confidently shoot this gun straight, I plan on using the more expensive stuff to see what this gun likes. I have a box of the new Remington CoreLokt Tipped that I plan on trying first.

[nmc02]

Obviously, make sure you same ammo to sight in as you do hunting. 

Those groups need to be tightened up. I strongly recommend shooting at a closer range to sight in....50 or even 30 yards. Once groups are tight....put out to 100.

Lastly, always hunt w a fouled (dirty) barrel....so shoot before a hunt and don't clean.

[Tater1973]

Congrats on the new gun.  Could be many reasons why you were not seeing better results.  100% agree that a fouled barrel is what you want for hunting and accuracy.  Take note of where your Cold Bore shot hits (first shot).  The gun should settle in after that.  Where you waiting at least 5 minutes between shots so that barrel heat wasn't a factor.  Lastly, you need to find what the gun likes as far as ammo.  Try different bullet weights and if you reload then the sky is the limit.

[Pathman]

All the things you mentioned may have a slight impact at 100 yards, but I believe your main issue is your recoil sensitivity. 
After the first two shots, and your slight adjustment, I think you then started “flinching” which will cause your barrel to drop, which would result in your shot impact being lower on the target. 
You should work on getting your  recoil aversion under control before wasting more ammo chasing a variable (depending on degree of flinching) POI that will drive you nuts. 
 

 

 

[barrike]

Your "main shots" looks real good for cheap factory ammo imo.  I've seen way worse.  Don't worry about sighting in your gun exactly where you want it yet.  Worry about getting tight groups first.  You definitely need to get your recoil sensitivity under control or your groups will only get worse.  Maybe try a lite load or add a better recoil pad.  Lighter guns kick harder too.  I don't know what your budget is, but if your stock is plastic, you may want to look into a getting a heavier wood one.  Boyds makes good ones.  If it's still too much to handle, put the .308 in your safe and get something with lighter recoil for now.  Whatever you do, don't sell your .308!  You'll regret it later!

Personally, for hunting I only care about what my 3 shot groups look like.  I've never taken more than 2 shots at any deer.  They are either dead by then, or out of sight.  I usually take my hunting rifle to the range a week or two before hunting season to get reacquainted with it and make sure it's on target.  POI usually shifts a little between clean and fouled barrels.  I'll shoot 2 or 3 shots through the barrel to foul it.   Then I'll run a boresnake through it and let the barrel cool down for several minutes.   I have  a barrel cooler that helps speed up the cooling process.  Your barrel won't be warm when you're in the woods after all.  Then I shoot a 3 shot group and run a snake through the barrel again.  Adjust sights if necessary and repeat.  I always run a boresnake through at the end of my groups.  I feel it keeps the fouling level consistent.  It might be overkill, but it works for me.  (I got in this habit several years ago.  I used to have handloads for my .270 that would leave LOTS of powder residue in the barrel after only a few shots.)  I never clean my gun thoroughly until after the season is over and my gun is going into storage for a while.   Also, if you sight in your gun in the summer, don't expect it to be on target in the winter.  Some powders are very temperature sensitive.  

Edited May 31, 2022 by barrike

[archer36]

Scope not holding zero?

[Bucndoe]

Boresight, shoot at 50 yards, adjust to be a little high. After that move out to 100 if you wish

[MikeStaten]

Those main 5 shots aren’t awful.  The first thing I’d do is adjust your rest so that everything is comfortable as a 308 should not be beating you up that badly.  You may also want to try reduced recoils loads, Hornady and HSM make them in 308 and others probably do to.  I leave my deer rifles fouled for the whole season.  

[308federal]

Look into this:” PAST Super Mag Plus Recoil Pad Shield Ambidextrous”.

Use it always in the summer and tee shirt weather. No need for any heroics.

What kind of glass did you put on it?

Those first two shots out of a new cold barrel shows the rifle has much promise.

 

[308federal]

Just saw your Tikka post with the particulars. Very nice setup.  Surprised you were able to score a left-hand model. Friend has a Tikka and it's a very good shooter for the money. Good luck with it.

[bushden]

Zero at 25 yards, once you can shoot 1/2" group or better at 25 then move out to 100 yards and you should start adjusting from there. 11 Rounds will not foul a barrel to a point where it will affect a significant shot group however an over heated barrel will.  Let the gun cool a little after  3 rounds. Again 100 yards is close for a 308 and you should be able to shoot tight groups;

[BCsaw]

The latest close range on rifle range is 50yds.
Really you can bore sight at 100 and still be on paper. Seeing it is another thing!

Sent from my SM-N975U using Tapatalk

[B B]

New rifle = Barrel Break In, take the time to do it!

Recoil Sensitivity - Man up it's only a .308

Fouled Barrel - If your gun needs to be dirty to be accurate there's something wrong.

Yes, a hot barrel will cause it to shoot high

The gun will shoot 1" groups @ 100 all day long you just need to be able to make it do it.  Don't over think it.

Edited June 1, 2022 by B B

[B B]

2 minutes ago, B B said:

 

 

Edited June 1, 2022 by B B

[MPSR]

I own a custom Christensen Ridgeline FFT Titanium in 300 PC, topped with a Carl Zeiss 4x16x50, Tally Mounts and rings.. If you know you know.. This gun shoots MOA accuracy at 200 yards all day long and sometimes same hole shots are common.. 3  biggest factors that rob accuracy are "consistency" in ammo quality, heat along with wind.. The second shot group is great for weather like this and cheaper ammo. Once the barrels heat up and you can see the mirage in your scope its time to take a break and or clean the gun and take another break. Don't get frustrated at any gun unless you are sure you have broken the firearm in. and rechecked "all tightness on everything after first box.. Especially in the heat. I have a Tikka T3 like your set up.. Awesome set up, however I would not heat any barrel in this weather. The last thing I do after each season is put my firearms through my neutralizing tank and clean every single part.. What comes off these firearms would suprize you.