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

[MGHunter66]

You have to take your time especially in the heat. Shoot a 3shot group then wait until the barrel is cool. I know the tendency is to keep shooting trying to dial in but you’ll just chase groups all over due to hot barrel and perhaps even scope mirage. 
I always put up two targets, one is my “first shot” target. Shoot the first bullet of the day at it and all others at the other target. Take that first shot target with you every time and you’ll develop a group of first shots at various temps/ barometric pressure, etc. That will become your overall bible of your gun. Keep in mind this is after you get it dialed in to where you want to hit

[mazzgolf]

6 minutes ago, MGHunter66 said:

I always put up two targets, one is my “first shot” target. Shoot the first bullet of the day at it and all others at the other target. Take that first shot target with you every time and you’ll develop a group of first shots at various temps/ barometric pressure

 That's a really great idea. Never heard that tip before. You win a hat-tip for that 

[Swamprat]

As already said, don't overthink it. Guns will shoot better than the shooter. When I drew my elk tag couple years ago I had to scramble and get a rifle. I already had a boresite tool. I didn't worry about moa or 1" groups. 

I boresighted inside my house. Went to gun range. Fired at 25, 50, and 100 yards. Wait 5 minutes between shots. I kept it sighted in at 1 1/2" high at 100. Firing from a bench but not in a sled. From there all my shots were standing and using sticks or on the ground using a backpack as a rest. Odds are you ain't going to have a rest. Practice the way you think you will shoot when hunting. My groups were 1 1/2-3" groups. Plenty good enough for elk and even deer. 

Most high powered rifles when sighted in 1-2" @100 yards will be dead on accurate out to 250-300 yard. I can't speak for beyond that.  Lol. 

[mazzgolf]

Third session today at 100 yards - much better.

First off, I took @308federal's suggestion and bought one of those PAST Super Mag Plus Recoil Pads. Flipped it inside out to fit for lefties, and I could have shot all day -- didn't feel a thing. Was great! Thanks for the tip.

I also took @MGHunter66's advice and took a couple shots at a separate target that I'll try to keep a record (or at least document the shots) of the first few shots out of a clean barrel. Here's the first two shots - the first was actually fairly on target, the second was low 1.5", which is strange because the last couple "clean barrel" shots I fired were high. I'll keep an eye on that and see if I can detect some kind of pattern (if there is a pattern at all).

Here's the next 8 shots. First was high 3/4" and second right just over an inch. It was windy today - so I'm going to blame the wind  Or maybe I can blame it was still a relatively clean barrel? Actually, I'm going to say these were still affected by flinching - I had to get over that and trust that the recoil pad over my T-shirt was going to help. I did get over that and the next 6 were inside an inch (4 were 1/2" or in).

So, I'm pretty happy with this. I suppose I could adjust the scope 1 or 2 clicks up. I'll see my next time out if I get similar results before I adjust more.

I know a couple peeps that are members of ranges with 300 yards. So I'll try to get on a 300 yard range in the near future.

[MGHunter66]

Nice Mazz, that first shot group in time will tell the tale

[Bigmac]

That’s all dead deer, couldn’t hurt to raise it up a little bit though

[Pathman]

17 minutes ago, mazzgolf said:

Third session today at 100 yards - much better.

First off, I took @308federal's suggestion and bought one of those PAST Super Mag Plus Recoil Pads. Flipped it inside out to fit for lefties, and I could have shot all day -- didn't feel a thing. Was great! Thanks for the tip.

I also took @MGHunter66's advice and took a couple shots at a separate target that I'll try to keep a record (or at least document the shots) of the first few shots out of a clean barrel. Here's the first two shots - the first was actually fairly on target, the second was low 1.5", which is strange because the last couple "clean barrel" shots I fired were high. I'll keep an eye on that and see if I can detect some kind of pattern (if there is a pattern at all).

Here's the next 8 shots. First was high 3/4" and second right just over an inch. It was windy today - so I'm going to blame the wind  Or maybe I can blame it was still a relatively clean barrel? Actually, I'm going to say these were still affected by flinching - I had to get over that and trust that the recoil pad over my T-shirt was going to help. I did get over that and the next 6 were inside an inch (4 were 1/2" or in).

So, I'm pretty happy with this. I suppose I could adjust the scope 1 or 2 clicks up. I'll see my next time out if I get similar results before I adjust more.

I know a couple peeps that are members of ranges with 300 yards. So I'll try to get on a 300 yard range in the near future.

It was all the recoil, nothing else. Once you get really comfortable and no longer even think about recoil, your groups will tighten up further. 
 

[Jcol6268]

Also Mazz, make sure your shooting form is good. Your arm shouldn’t hurt you after shooting. I’m glad you got the pad, but if your arm is hurting for the first go around, it sounds like your butt is sitting on your arm, which is a common problem. 

[trapoholic]

A lot of good advice here! And a lot of great suggestions!

Every firearm is different. I had a Browning BAR in 30-06 a few years back that would "Key Hole" the first two shots at 100 yards with "0" MOA. The third, fourth and fifth were all over the map. In fact, I did not know it was Key Holing until I started taking one shot and then covering that hole with a small piece of masking tape. Initially, I could not figure out where the second shot went. That rifle liked a cold freshly cleaned and oiled bore. Once it was fouled, it lost all accuracy. I ended up trading that rifle in for a Remington 700.

Also, the Past Recoil shoulder pad is the way to go. Been using them for longer than I can remember.