Great video on seating depth testing

[Phil Rizzo]

When starting out at a given seating depth, say .015 off, I always run tests at .003 increments going deeper from there to about .045 off.
Sometimes I use 2 shot groups, sometimes 3.
I'm speaking of Berger Hybrids.

On every gun I see a pattern of tightening, then opening again somewhere in that range.
Am I not supposed to use the best one for setting my depth? Usually there is a pair in sequence that im happy to use.

What is the alternative? Varying powder at a given depth to tighten groups?
What's done to change group shapes?
I hate to change neck tension when the results are desirable, obviously.

 

[SmokinCrow]

Hornady's podcast covered all of this. Seating depth doesn't matter much. Five shot groups are statistically irrelevant.

But that's from Hornady and Those guys are just marketing and all biased! They even put in the caveat that this is what they found with their bullets in "modern chamber designs" like the Creedmoor and such. Hornady said they didn't test with other bullet designs with the likes of the 308. But they still believe that to see actual differences you'd need to mark larger jumps. Those guys are just marketeers so they're stupid, and just because its Hornady many will take what they said out of context and blow things up. That's what I notice more than anything. Hornady being taken out of context and blown up for that because they're marketing machines. Never that they produced a solid product and supported it.

 

[MW204]

@HammerBullets what say you Steve?
I've started shooting the Hammer bullets a couple years ago and I'm shooting a 300 WM for hunting so I had to seat deep enough to get it into the mag well. But once that was done I adjusted the depth and came out with a better load seating it deeper than I started.
I did not start 10 off the lands because again it's a hunting rifle but for $hits and grins I may try that and see what it does. My secret sauce pushes the Hammer 178gr bullet at 3450 fps out of a 26" barrel.

 

[3800fps]

Anecdotally…. I've been "precision" reloading for 50 years. You learn a cartridge's characteristics to a point where its narrow window of best performance becomes known to you…over multiple barrels.
Minimal seating depth testing and powder charge adjustments generally fine tune a load to a particular barrel…which ever so slowly degrades with the shot count.
With a favorite hunting rifle this is usually a lifetime…a competition rifle not so much.

 

[Huntnful]

When starting out at a given seating depth, say .015 off, I always run tests at .003 increments going deeper from there to about .045 off.
Sometimes I use 2 shot groups, sometimes 3.
I'm speaking of Berger Hybrids.

On every gun I see a pattern of tightening, then opening again somewhere in that range.
Am I not supposed to use the best one for setting my depth? Usually there is a pair in sequence that im happy to use.

What is the alternative? Varying powder at a given depth to tighten groups?

Well that's exactly what he did. But this is the first test where the "worst" initial seating depth across the 3 shot group test, was then retested in comparison to the "best" 3 shot group size. But elaborated over a relatively large sample size.

I too would do the test and pick the smallest group. Who wouldn't? But the point is that he then retested in a large sample size to show the ACTUAL difference between the small sample depth testing.

 

[19elkhunter51]

I will say it again. Other than straight competition shooters, who among is going to chase a group from .173 to .150?
I can't afford to do most of what everyone else on this forum does. Can't afford the components, can't afford the time and can't afford to shoot out two or three barrels a year testing all of the different parts and pieces that make up "the perfect load".
If (very big of) I ever decide to wing a shot at an animal at 1000 yards, I doubt very seriously that said animal is going to run away because my shot was of by .375 of an inch.
For 98% of all the HUNTERS on this forum, a .500 group will kill any animal shot at.
It was an interesting video. Someone else said it. Advanced calculus for a two year old baby.
He never did say anything about seating depth. Only confirmed what I believe. There are way too many variables to make all of the variables "perfect".

 

[Huntnful]

Seems pretty self explanatory..... once your groups get down to the .3's it's pretty hard to figure out which one is going to shoot the best.

Now maybe he should try it with a 7 lb 300 win mag and see what the results are.

This is one of the main things I want to see tested. What kind of consistency these guys could get out of a 9-10lb magnum rifle compared to the same exact cartridge, but in a 20lb platform.

 

[Louisiana Reloader]

This was a great watch for sure. Some interesting numbers! Take away from it what you wish




My takeaways:

1. This is a 20lb+ straight shank barreled F class rifle with a smaller cartridge, shot by a shooter with a wall of medals. If I think my 10lb magnum rifle will shoot the same, I'm wrong. And if I think I will see the minute differences that he is seeing, I'm wrong as well probably.

2. Average 5 shot groups of .41-.46". The "best" 5 shot group seating depth shot from a .25" group to a .63" group.

3. Once groups were taken to a sample of 33 shots, the WORST small sample size depth, actually became the best, most stable load.

4. From "worst" to "best", the variation is about 10%. I put those in quotations because you can switch sample sizes around and also vary which one is the worst or the best.

5. After 100 rounds of seating depth testing, he almost came to an inconclusive result.



Interesting test for sure. Also why I quit messing with seating depth so much. It'd take me 500 freaking rounds to legitimately prove a 10% change in group size with a magnum rifle. And taking a group from a .7 to a .6 isn't going to kill me any extra animals until you get a LONG ways out.

Huntnful: I agree with you brother--100%. If I was shooting F-class with a barrel that costs more than my UTV, I would absolutely be concerned with seating depth in this manner. However, (before all you guys crucify me), for what I do in the deer woods of Northwest Louisiana, my seating depth of .015" to .017" off the lands produces 1/2" to 5/8" groups (at 100 yards) and considering my farthest shot on my property is about 350 yards, I will take that all day everyday and twice on Sunday. I absolutely give some concern to seating depth; however, I am not going to burn out a barrel chasing a unicorn group that isn't going to matter in the big scheme of things with the shots I take. But again, each and to their own. I know we have guys on this forum that continually ring steel at 1,000 yards and I love you guys because I get good pointers from you. Occasionally, I have found a load that will shoot 1/4" groups but it is definitely not the norm. Considering all my deer rifles are $1,500 and less (I do have my share of $1,500 to $2,500 optics though) I think that with my reloads 1/2" and 5/8" groups at 100 yards when my farthest shot is 350 yards is quite acceptable. I won't call any names of manufacturers but I have seen $2,000 to $3,000 rifles that will not touch my groups with premium factory ammo. So, I am happy with the attention I currently give seating depth--which is some, but not a whole lot. But each and to their own and if you run through 500 rounds getting that perfect seating depth and that makes you happy and gives you the results you want--go for it.

 

[Barehandlineman11]

When bullet manufacturer such as berger says seating depth matters i listen and it shows too work dramatically. Shooting 30+ rounds does nothing more then test your capabilities of shooting in the environment that's consistently changing and your barrels thermal exspansion. If it shoots 5 shot 1/4 moa in different days multiple times you have a solid rifle and load work

 

[nealm66]

Why would anyone think the harmonics of the barrel in the video are going to compare with a magnum hunting rifle? Good grief. If you were manufacturing a bullet, wouldn't you play with the design to shoot the best out of your saami test barrel at around the most common velocity? As soon as you back your bullet off of a hard jam by 20 thousands, your probably different than the manufacturers recommended coal and going to need to play with the seating depth and powder to get things to fall back into tune with an average hunting barrel contour. If not, you have a very insensitive to seating depth bullet. Barrels move before the bullet exits. Let's stop feeding these nonsense videos

 

[Huntnful]

When bullet manufacturer such as berger says seating depth matters i listen and it shows too work dramatically. Shooting 30+ rounds does nothing more then test your capabilities of shooting in the environment that's consistently changing and your barrels thermal exspansion. If it shoots 5 shot 1/4 moa in different days multiple times you have a solid rifle and load work

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.

 

[Lenny Foffa]

Well IMHO!! I think he actually stated clearly he was NOT TRYING TO PROVE ANYTHING, he was simply trying to develop a TEST that could be used to provide information. Then YOU and I decide if the test could supply needed or relevant data to us. Maybe YES , maybe NO!!! WE may decide on our own, that In My particular rifle, with my Bullet of choice, at that velocity , 5/1000 to 10/1000 of seating has no great relevance, or it really does. I'm sure it will vary Rifle to Rifle. I play with seating Depth more that any other variable , but in hunting rifles, I am , as we all know, Limited by the magazine. So if I can make three bullet holes make a ragged hole at 100 yds and maybe touch at 200 yards, the that is acceptable accuracy for my intended use. However, I do appreciate knowing , the rifle will shoot smaller groups if I am nearly touching the Lands .even though I cannot load to that length when hunting. It has long been my Personal humble opinion that all these steps we all take to make the most perfect ammo we can, means very little taken one at a time, but Collectively they result is a more precise load. And we all love that !!!Please remember, " data that is provided but not used , is by definition, Useless. "

 

[Phil Rizzo]

If it doesn't repeat consistently it doesn't count.
Or get mentioned here.
Using selected known components in a given cartridge with my method doesn't seem to give "false hope" groups.? Thankfully. Watching the trend shrink and swell gives a fair indication, in my experience.
The good ones aren't that finicky.
I use these 3 characteristics with rifle barrels, though. For bad or worse…
1-not short
2-not light
3-not CFW.

Works in my case. Plenty others have great success otherwise. Some of my closest friends in fact.

 

[Huntnful]

Why would anyone think the harmonics of the barrel in the video are going to compare with a magnum hunting rifle? Good grief. If you were manufacturing a bullet, wouldn't you play with the design to shoot the best out of your saami test barrel at around the most common velocity? As soon as you back your bullet off of a hard jam by 20 thousands, your probably different than the manufacturers recommended coal and going to need to play with the seating depth and powder to get things to fall back into tune with an average hunting barrel contour. If not, you have a very insensitive to seating depth bullet. Barrels move before the bullet exits. Let's stop feeding these nonsense videos

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.