Great video on seating depth testing

[Huntnful]

Here's a real world example from a few days ago. This was my REM 700 Sendero SF 2 factory rifle shooting 220 grn SMKs. The upper left target was a pressure ladder for a different rifle. I changed the seating depth 0.006" for each group. As you can see, there are differences and the barrel like different seating depths over others. The SMK is a very forgiving bullet too. I used three shots per group to save on ammo. If it can't shoot 3 shots well, it won't shoot 20 well either. The smallest group pictured was 0.256". The next smallest was 0.40". I'm not saying the gent in the vid is wrong by any means. I'm just showing what has worked for me in my rifles doing load development.
View attachment 576791
View attachment 576792
Obviously, I'm replicating the quarter inch group for more testing.

Cool comparison! Genuinely curious to see what more testing does. Based off the POI shift between groups and the substantial widening and opening between groups. It seems fairly unstable. But I could definitely be wrong. I have many times before lol.

 

[Barehandlineman11]

He says he fully believes seating depth matters. And that he tests it thoroughly. I don't think that's the argument. He's showing how the small sample of seating depth testing actually relates to a large sample. 100 shots round robin in an F class rifle to show the true differences is a better test than anything I've ever seen done by anyone. There is a 10% difference in his rifle, and the initial small sample testing got the best depth wrong.

I'm sure he's shot literally hundreds if not thousands of 5 shot .25 MOA groups. More than probably anyone on this forum. His information is valid and un biased. He's just sharing it.

Not many people will put the time in to prove their worst depth is actually the worst depth in a small shot group test. They pick the best one and move on. He's proving that that info isn't always as it seems is all.

I understand what he was saying but my point is over 30 rounds shooting test becomes void. By time i get 30 rounds fired here its ten degrees hotter then it was when i started. N570? Barrel speed up on you around 30 rounds. Let alone 100. Most big magnums throat will move shooting it too 100. Thats why you find that node and ride it till wheels fall off

 

[nealm66]

You can correlate it however you want to. It's a gun, that is designed to shoot the tightest groups possible, doing a test multiple times to show the validity of it.

I never watched the video. Why would I? It has absolutely nothing to do with load development for hunting in my opinion. I was just pointing it out. That’s how I correlated it

 

[nealm66]

I understand what he was saying but my point is over 30 rounds shooting test becomes void. By time i get 30 rounds fired here its ten degrees hotter then it was when i started. N570? Barrel speed up on you around 30 rounds. Let alone 100. Most big magnums throat will move shooting it too 100. Thats why you find that node and ride it till wheels fall off

Well said!

 

[FireFlyFishing]

Cool comparison! Genuinely curious to see what more testing does. Based off the POI shift between groups and the substantial widening and opening between groups. It seems fairly unstable. But I could definitely be wrong. I have many times before lol.

Yep. Waiting for a non-windy day to try out the following loads. If they work well, I’ll zero the rifle to the load as well.

As a side note, I used the same process for my .308 shooting 168 SMKs. This is what it does at 600 and it hits anything I point it at.

 

[Huntnful]

I never watched the video. Why would I? It has absolutely nothing to do with load development for hunting in my opinion. I was just pointing it out. That's how I correlated it

Fair enough. I also hunt, load for hunting rifles, kill plenty of stuff, and still thought the test was interesting and will continue to share them for anyone that finds larger data sets interesting. The standard picture of the small 3 shot group or a picture of a chrono with low ES over 3 shots is far less interesting and means far less, if not literally meaningless all together.

 

[Barehandlineman11]

One 3 shot random group doesnt mean anything i agree. It does if it repeatedly shoots that small. Especially if were talking hunting rifle only.

 

[Huntnful]

One 3 shot random group doesnt mean anything i agree. It does if it repeatedly shoots that small. Especially if were talking hunting rifle only.

Completely agree!

 

[nealm66]

Well, we all are here to learn and share. That’s what make this a great forum. I guess it’s not a bad thing to dig through these videos and see if there’s something that will improve our success. I will say every time I hear these topics where it feels like the intent is to show that any efforts towards improving accuracy is futile it really bothers me for some reason.

 

[Rick Richard]

Fair enough. I also hunt, load for hunting rifles, kill plenty of stuff, and still thought the test was interesting and will continue to share them for anyone that finds larger data sets interesting. The standard picture of the small 3 shot group or a picture of a chrono with low ES over 3 shots is far less interesting and means far less, if not literally meaningless all together.

The proof is in the target most times…waaaay down range.

 

[Huntnful]

Well, we all are here to learn and share. That's what make this a great forum. I guess it's not a bad thing to dig through these videos and see if there's something that will improve our success. I will say every time I hear these topics where it feels like the intent is to show that any efforts towards improving accuracy is futile it really bothers me for some reason.

You know what, that’s a very valid view point. And sometimes it certainly does come across that way!

So I’m probably slightly biased in my view point. All of my guns, especially as of late since @Barehandlineman11 has been building them, have shot extremely well. With a variety of bullets and powders. So much so, where I literally cannot consistently shoot a positive difference in small seating depth changes or charge weights. The last 4 barrels have shot sub .5 MOA 5 shot groups with the first charge weight and seating depth of several bullets and powders.

Thinking I will tune that down to a .4 and be able to repeat it and prove it, is honestly unrealistic IMO. They’re magnum hunting rifles, with much more volatility than this guys’ benchrest rifle. And with the same load in his rifle, he shot 5 shot groups ranging from .25” to .6”. Yes there could be some variables over the shot strings and changing conditions and what not. But that’s the real world and real testing. Doing a 30 shot seating depth test takes time and happens over varying conditions as well.

 

[nealm66]

I’ve seen a few of those rifles. I’ve seen a lot more that were the opposite and took some time and effort to get them to cooperate. Those are the ones where I learn(ed) the most. Definitely still learning.

 

[Beluebow]

What is amazing is how some disregard the platform and test procedures being used because it's not some sort of loudenboomer hunting rifle.

The fact that this is LONG RANGE HUNTING shooting small should be a consideration. No one is saying this is how you should tune your hunting rifle. It's about showing how much a seating depth change could make or doesn't make in that particular firearm.

IMO the correct powder charge is 88% of the equation to make a rifle shoot small with hybrid style bullets. If it isn't shooting small adjust the seating depth until it improves.

 

[Phil Rizzo]

What is amazing is how some disregard the platform and test procedures being used because it's not some sort of loudenboomer hunting rifle.

The fact that this is LONG RANGE HUNTING shooting small should be a consideration. No one is saying this is how you should tune your hunting rifle. It's about showing how much a seating depth change could make or doesn't make in that particular firearm.

IMO the correct powder charge is 88% of the equation to make a rifle shoot small with hybrid style bullets. If it isn't shooting small adjust the seating depth until it improves.

As a percentage of charge weight, what increment change do you consider significant?