Seating depth advice

[pukeleeland]

If both loads perform equally well, then I will go with the longer load so that I stay within that node longer with throat erosion.

 

[cahunter805]

I just wanted to revisit that charge now that I have settled into a seating depth range...more curious than anything.

Based on your original data 3.600 seems to be your best node depth currently. I’d be curious to see the targets though.
When testing I’ve found what works best for me is to shoot at a target with all the different targets the same POA and watch for POI shifts and it’s much easier to see your node windows.

 

[pukeleeland]

Based on your original data 3.600 seems to be your best node depth. I’d be curious to see the targets though.

The flier really concerned me with the 3.600" load. The 3.595" load actually had two shots that were touching. Their speeds were only 1 fps different and the 3rd shot was off a little.

All I can say, the rifle is shooting much better than the 1.25"--1.5" groups it was giving me the last couple of years. It was about to go down the road. This is the first time I have had to mess with seating depths to get sub MOA.

 

[cahunter805]

The flier could’ve been any number of things but since you already have those test rounds loaded I would shoot them and see what happens.

 

[VikingsGuy]

The flier really concerned me with the 3.600" load. The 3.595" load actually had two shots that were touching. Their speeds were only 1 fps different and the 3rd shot was off a little.

All I can say, the rifle is shooting much better than the 1.25"--1.5" groups it was giving me the last couple of years. It was about to go down the road. This is the first time I have had to mess with seating depths to get sub MOA.

If you generated a plot of 50 shots with the same load even a 3.0" MOA pattern would likely have two touching somewhere in the mix. The "two were good" temptation pretty much throws out any statistical or scientific approach to reloading. You only get to remove a shot if you called it as a flier at the time you pulled the trigger, not when you saw the result.

 

[blueridge]

I would personally shoot more shots at fewer seating depth variations, and lengthen those variations to .15-.20. As @VikingsGuy rightly pointed out (he knows his stuff), 3 shot groups don't come anywhere close to giving you statistically significant data. 3.600" looks good to me.

 

[Don Fischer]

Groups of 3 shots do not prove anything of the sort (heck one of them is 2 shots as he declared a flier). There are competitive shooters that use 10-30 shot groups which clearly show the correlation between low SD and MOA. There is no serious doubt of the connection. But again, for hunting, it may not matter to you.

So, are we talking competitive shooter's here or hunter's? In hunting pretty much the only shots that count are the first two! Sometimes the animal will give you a third!

 

[VikingsGuy]

So, are we talking competitive shooter's here or hunter's? In hunting pretty much the only shots that count are the first two! Sometimes the animal will give you a third!

I was referring to your suggestion that their is no correlation between ES and accuracy.

And you are missing the point of accuracy in hunting - it is to make sure the first shot goes where you want it - not to ensure a good third shot as you seem to imply. But to have confidence that the first shot goes where you want it to you need to test more than one shot due to variance.

 

[JohnyRingo]

Which CBTO tool do you recommend using? I have just been using the OAL.

 

[std7mag]

I'm with Vikingsguy on this one.
Powder charge first. I like the ladder test, but whichever method you use, powder charge is first.
When i'm doing my ladder, i don't even take the chrono with me. I find myself getting too hung up on velocities.
Then seating depth from jam to 0.040" off the lands going in 0.010" increments. If i don't get good groupings from that, i'll explore a bigger jump, or try a different powder or bullet.

If i find one that's acceptable to me, then i'll load 10 & break out the chrono.
I do pay attention to both ES & SD, but more so on SD.

If you haven't done it yet, then after you've chosen your best grouping load, tune your action.

I'm also one of the odd ducks that will test my cold bore grouping. Hang 1 target, take 1 shot. Take target down.
Next day hang same target from yesterday, same POA and shoot 1 round.
I do this 3 times.

I don't own a CBTO tool, or cartridge comparater. More threads have started with "need help, i'm using my comparator"!

 

[VikingsGuy]

I'm also one of the odd ducks that will test my cold bore grouping. Hang 1 target, take 1 shot. Take target down.
Next day hang same target from yesterday, same POA and shoot 1 round.
I do this 3 times.

Great point. If all a hunter is interested in is making sure you hit your elk as precisely as possible with the first shot, then this is the real test, not 5 shot groups out of a hot barrel. In fact, if you don't find the tweaking of handloading enjoyable buy a few different bullets in factory loads and do the same test - if any of them provide combined grouping over 3-5 trips to the range of less than 1.5 MOA you are ready with that brand to hunt at all reasonable distances.

 

[Don Fischer]

All other things being equal how much will a 300 fps difference change the POI on a target 100 yards away? A half inch? One inch?

Depends mostly on the human element. Why if you have a rifle that will fire say a .250" group, won't it do it every time? Human element! Why does the rifle that never fired a group smaller than 1" all of a sudden come up with a 1/2" group? Human element. For all we know, that bad group you shoot the other day was your fault!

 

[Don Fischer]

I'm with Vikingsguy on this one.
Powder charge first. I like the ladder test, but whichever method you use, powder charge is first.
When i'm doing my ladder, i don't even take the chrono with me. I find myself getting too hung up on velocities.
Then seating depth from jam to 0.040" off the lands going in 0.010" increments. If i don't get good groupings from that, i'll explore a bigger jump, or try a different powder or bullet.

If i find one that's acceptable to me, then i'll load 10 & break out the chrono.
I do pay attention to both ES & SD, but more so on SD.

If you haven't done it yet, then after you've chosen your best grouping load, tune your action.

I'm also one of the odd ducks that will test my cold bore grouping. Hang 1 target, take 1 shot. Take target down.
Next day hang same target from yesterday, same POA and shoot 1 round.
I do this 3 times.

I don't own a CBTO tool, or cartridge comparater. More threads have started with "need help, i'm using my comparator"!

That cold bore test sounds like a good deal. I've read that some guy's actually shoot one shot a day to test their load. For some reason some people think the best shot your gonna get is that first one! Go figure. That's not to say I've ever done it, haven't. something I noticed over the years though, or so it seems, get your rifle to clean and the first shot or two are not in the same group as the next shots!

 

[VikingsGuy]

something I noticed over the years though, or so it seems, get your rifle to clean and the first shot or two are not in the same group as the next shots!

Before I go on a hunt I thoroughly clean and inspect my rifle. And then I go out and put 5 rounds through it. Ready to hunt. Not all rifles react to a first clean barrel shot oddly, but I have seen it enough that I make it my routine.

 

[cahunter805]

I’ve seen factory barrels that wouldn’t group well until at least 8-10 rounds down the barrel. It seems like those were probably a rough or loose barrel and needed some more fouling.

 

[RaiderRich]

First of all, maximizing performance can be fun - tinkering for some of us is fun. Second, the lower your fps SD and the better your groupings and the better your technique, the more room for error you have in the field when conditions are outside of your control. The odds of successfully and humanely shooting an animal in the field is a series of stack variances ("errors"). The more you choose to eliminate the less the chance of unacceptable error. Thirdly, fun.

 

[std7mag]

I’ve seen factory barrels that wouldn’t group well until at least 8-10 rounds down the barrel. It seems like those were probably a rough or loose barrel and needed some more fouling.

I've heard of some Rugers that liked 20 or more for the copper.
Then you have the person that puts a borescope down a factory Savage barrel.
Never borescope a factory Savage barrel!

 

[ImBillT]

From a load development standpoint, three shots isn’t enough to draw conclusions from velocity variation. 3.605” is obviously in the middle of your three small groups. If you’re not going to load up too much ammo before making an adjustment, I’d load it right there. I’d you’re going to load up 100-200 rounds, I’d load at 3.615” in anticipation of throat erosion.

From a reality standpoint, AB’s aren’t terribly sensitive to seating depth, and three shot groups are only statistically meaningful in highly accurate rifles. There’s a fair chance that you have a 1 MOA rifle and load on your hands, and that if you shot seven groups with three shots in each of them, at your 3.605” seating depth, that your seven groups wouldn’t be vastly different from your seven groups at seven different seating depths.

Your huge fliers could be you. Rifles with hunting stock profiles and heavy recoil can be extremely sensitive to gun handling. Shooting prone and/or using very thick soft sandbags can reduce that significantly.

 

[ImBillT]

Groups of 3 shots do not prove anything of the sort (heck one of them is 2 shots as he declared a flier). There are competitive shooters that use 10-30 shot groups which clearly show the correlation between low SD and MOA. There is no serious doubt of the connection. But again, for hunting, it may not matter to you.

You will never convince Don of anything logical.

 

[VikingsGuy]

You will never convince Don of anything logical.

Often I don't reply to convince an individual poster, sometimes it is just to clear the record for the other readers.