Great video on seating depth testing

[MagnumManiac]

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

This is the most notable outcome for this test.
I have been saying this here for years. If you take the load/seating depth that produces occasional .25” groups and swings to .5” groups the rest of the time, your aggregate will suffer. If you take a load that is constantly a 3/8” group performer, you’ll be bounds ahead and your aggregate will show this.
Sample size and stability in loads, which translates to a wide node, will always win out in the end.

Cheers.

 

[Gorill@]

All things being equal, accuracy of a given barrel increases after every round till full break in, then degrades till worn out. The trick is to manage the accuracy….

 

[Bang4theBuck]

I've watched this guy's content a few times. He's very dialed. I feel like he's giving advice on how to race funny cars with a pro sponsored team while I'm still trying to get my hoopty to run a 12 second quarter mile.

I've had great luck with adjusting seating depth.

These were my thoughts exactly. And I got a great chuckle out of your reply

 

[Lenny Foffa]

Excellent video, presented in a Clear Non Biased manner. I really loved it, and I learned a great deal. !! Its so nice to have someone present on a subject with no Bias for or against any particular Caliber, Rifle or Bullet company!! Very well done. I have subscribed to his You Tube channel, if I said that correctly.

 

[Hydra6]

Several top PRS shooters are slaying some sacred cows on "precision" reloading. Seating depth is one of them. These guys/gals consume multiple barrels per season. They have a set load that they use for season after season consuming multiple barrels. They use quality brass, quality projectiles (mostly Bergers but not always), mostly CCI450s, and quality powder (lots of Varget and H4350 but others). They replace barrels at 2000 rounds or so (or relegate the higher count barrels to practice). They do try to use same chamber reamer specs for the barrels.

That barrel throat is changing throughout the life of that barrel and they are not tweaking seating depth. They have a set OAL and they jump the projectile.

Federal Gold Medal Match 308 and 223 are known for great accuracy across multiple platforms - they use quality components and standard OAL.

 

[DiscoDan04]

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.

My take is that you can save 16 minutes of your morning and not watch this video. He could have said at the onset what we all say all the time, your rifle your testing matters for your rifle. Searing depth for each rifle changes, as with each load.
Cortina is trippin right now…..

 

[shinbone]

That is a well done video. I bet the relationship between group size and seating depth will depend on the bullet type, though. Concluding seating depth never effects group size based on this one video would be a mistake.

JMHO

 

[M16]

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

 

[Splitt]

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.

So my questions regarding young loaders (less experienced)…

If I’m shooting around a .3-.4 grouping in a 5 shot string, what would suggest to me to examine seating depth and also neck tension. I’ve seen lots of videos saying neck tension and seating depth matter, and like he said, crap tons of anecdotal evidence, but I can’t ever figure out what would trigger me to look at those adjustments in the first place.

 

[FireFlyFishing]

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.

Obviously, I’m replicating the quarter inch group for more testing.

 

[Hydra6]

So my questions regarding young loaders (less experienced)…

If I'm shooting around a .3-.4 grouping in a 5 shot string, what would suggest to me to examine seating depth and also neck tension. I've seen lots of videos saying neck tension and seating depth matter, and like he said, crap tons of anecdotal evidence, but I can't ever figure out what would trigger me to look at those adjustments in the first place.

Why do you want to tighten up a .3 group? Are you loading for hunting?

 

[bluedog69]

This one goes along well with this thread. Scroll towards the end to see what.003” makes.

 

[cjuve]

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.

 

[Splitt]

Why do you want to tighten up a .3 group? Are you loading for hunting?

“Chasing the accuracy rabbit”. It’s not for hunting. I just want to understand more. The more I can learn, and verbalize to the kids, the more I can pass down so they can do the same for theirs.