1971 made Winchester 70 in .270 Win. Barrel free floated, screws torqued, barrel cleaned, Swarovski rifle scope. 3 foulers, this is the second volley of 3 rounds.

Winchester virgin brass
CCI-200
H-4831 SC
150 gr Nosler Accubond LR



The barrel was completely Cooled off. Mirage straight up. A flagging ribbon on the 200 uard target board was laying down.




Test them farther than 100 yards. If you can, and if you're going to need to shoot it farther than 100 yards, in the future.

The problem is the 150 LR AB bullet. It's barely stable in a 1:10" twist barrel. That bullet is also often under sized. I gave up on that bullet in my 270 Win after multiple range trips with it.

I warned him. He wanted to use them anyway.

Flatten those primers. That’ll fix it!

Twas a joke

Guess my Henry Long ranger 308W does OK then. 185yds (googled) at a paper plats, 2 in the lower left. Pulled the top right one. Sitting in a cheap plastic patio chair. 2500+ fps, 168 Amax, LC07 brass, H4895.

What?

Is the idea that bullets deviate more at longer distance (i.e. a 1 moa group at 100yd becomes >1 moa farther)? Brian Litz strongly disputes this.

The more likely scenario is that a single 3rd group barely captures any of the statistical variance in a load.

I was wondering stability too. Sure wish my 270 had a little more twist.

Litz certainly knows his way around better than most and I’ve heard his argument on this, but a high ES and SD can print ok at 100 yards and look like crap at 500+. At least in the vertical. Although that erratic group is a horizontal string.

Sub 1 MOA became almost 2 MOA at twice the distance. The pics are there for you to see.

The idea is to tune the load that works best with the barrel harmonics. 200 yards and greater is going to give you more reliable information.

I may be wrong, its been a while since I read it, but I recall thinking Litz disputed groups getting better at distance, and would pay money to anybody that could prove it.

The theory of the big bullets needing some RPMs to get stable. Chad says he's seen it. I've also seen it. So I am in disagreement with Litz on that one.

200 gr ELD-X from a 300 Win Mag for example. 1/2 MOA at 200 yards, 1 MOA at 100 yards. So, it shoots 1" at both distances.

I’m not saying it’s not true, but that’s one I’d have to see to believe.

I know it seems odd, but it has happened several times, across different cartridges. One was also a 7mm-08 1:8 loaded with 168 Bergers.

Maybe ALL of that is due to barrel harmonics. They're using tuners in competition for a reason.

I gave up testing loads at 100 yards several years ago because I saw so many loads that looked great at 100 were actually dogs at 200. I test everything at 200 these days.

I think that *maybe* the recipe I come up with gives up a little at 100 yards due to harmonics. I don't know that, and frankly don't care one way or the other so I'm not going to do a lot of loading and shooting to prove it for myself. I figure I can afford to give up a little bit of MOA at 100 to gain a little bit of MOA at 200 for hunting purposes.

Agreed.

99% of the time I'm also running these rigs out to 800 yards. After 200 yard load development, hitting every hundred to 800 is no problem. And 99% of the time I hit every steel in only one shot.

Several shooters claim the 'going to sleep' at longer range, never seen it myself. I'm sure there are bad bullets but my experience it's the shooter not the equipmant. My only example is stock dpmsAR10 308 carbine - with a drop in trigger. Steel is 200 yds in a sunflower field sitting between dove hunts, other is 35F prone with bi-pod. 168gr cast @ 2400, both targets. Scope is old Nikon with the circles below the cross. Centered the 3rd circle for the 200yrd one. First time shooting 200. Lower shots are friend tryng it. Big one is old from his 300 win mag.

Until someone can explain how a bullet changes its path between 100 and 200 I’m out on this theory. You shoot through a piece of paper at a 100 into a target at 200 and show me a reduced moa and I’m sold. I’ll take your word for it,but you gotta show the proof. My rifle will shoot sub .4s at 500 but they’re tighter than that at 100 because I can’t get my ES and SD down lower, or maybe that’s all it will do.

It doesn't change its path. It all has to do with the exact position of the muzzle (IOW, where it's pointed) in its vibration cycle at the time the bullet exits the muzzle.

I mean that's still an angular deviation, meaning if it's 1 MOA at 200 then it's 1 MOA at 100.

I'll once again point out that people just don't shoot big enough sample sizes to really evaluate group sizes. That's way more reasonable than bullets curving in flight and converging towards your bullseye at 200 yards and beyond.

True if your assumptions hold up, but they do not.

They ALL curve in flight, and they may or may NOT converge on a POI depending on velocity variations and barrel harmonics.

People may not shoot big enough sample sizes when developing loads to really know what they've got, but there is no deficiency of sample size in competition. Tuners work, and they work for the reasons I've laid out. Hop on Erik Cortina's Youtube channel and tell him otherwise. Talk to John Meyers and tell him otherwise.

How many sheets of paper fit in a 3" 3 ring binder? Every sheet of paper is the load development for a rifle.

That's my sample size.

Regardless of tuner or not, what I'm getting at is if you solve the "harmonics" problem at 100, you have also solved it at 200, 300, and beyond. This is because variation due to harmonics would express itself at all distances, because it is no longer affecting the bullet once it leaves the muzzle. If the bullet leaves while the barrel is whipping upwards, for example, that angular variation would be seen at all distances.

It is not a sufficient explanation of how bullets could have a wider (in terms of angle) cone of fire at closer distances than long.

What Litz said in his class was actually the opposite of what y’all seem to be discussing.

His research was showing that groups couldn’t get smaller at distance due to bullets going to “sleep” which was proposed by many. Ex. A 1 MOA load at 100 can’t be a 1/2 MOA at 200 yds.

When the 150 LRAB came out Litz actually used it as an example of its advertised BC was not achievable unless you went to a faster twist barrel than was currently available on the market and that it was only marginally stable. Your rifle may be a button rifled barrrel and thus twist rate may be slightly slower than advertised

Slightly OT but I recently read somewhere that barrel whip is not just up and down like I assumed, but is spiral similar to the rifling. My assumption was based on one slow motion camera from the side and never viewing another angle. If this is true so much for the dwell at the top theory.