finally learning the importance of seating depth

[Alex Wheeler]

I disagree. Done it many times over. You cant make a rifle shoot the wrong seating depth no mater what powder charge you give it. The idea that you tuned to the seating depth your started at is not something that plays out in my experience. I have done the testing from .020 in to .120 off the lands. The Berger method is moving the bullet so much that its changing pressure as well as exit timing. It painting with a very wide brush, and is more of a poke and hope method. You may get lucky and you may get aggravated. I recommend a methodical approach that will give you a trend to draw data from.

 

[Gater]

I disagree. Done it many times over. You cant make a rifle shoot the wrong seating depth no mater what powder charge you give it. The idea that you tuned to the seating depth your started at is not something that plays out in my experience. I have done the testing from .020 in to .120 off the lands. The Berger method is moving the bullet so much that its changing pressure as well as exit timing. It painting with a very wide brush, and is more of a poke and hope method. You may get lucky and you may get aggravated. I recommend a methodical approach that will give you a trend to draw data from.

Well in my 35 years of reloading it takes a combination of both just because you can get a bullet to go fast don't mean it's going to be the best powder or powder charge. And as far as seating depth every gun and bullet combination is different That's what keeps all of us going to the range if it was easy it wouldn't be fun.

 

[aushunter1]

started reloading about a year ago and have never really messed with the seating depth of bullets,

As the old saying goes knowledge is power!

I think firstly generally speaking many people entering the reloading world do not do nearly as much reading, research & background information checks as they should on both reloading processes or equipment or they just say to themselves I can only load to max magazine length so I don't need to know about COAL or CBTO etc.

I would guess that 75% of reloaders don't have the right equipment to even take proper measurements like CBTO or headspace.

Before I even bought my 1st bit of reloading equipment some 13 years ago I did 3 months of solid research on equipment & processes so I knew what I actually needed to buy & to do to make the best quality ammunition possible for my hunting.
And while I am not a BR shooter I still understand what I need to buy & do to take my reloading to the next level if need be.

Anyway its great that you have seen the light but I would suggest if you haven't yet done so is keep reading & adding to your knowledge & the results will only get better & better.​

 

[Alex Wheeler]

Well in my 35 years of reloading it takes a combination of both just because you can get a bullet to go fast don't mean it's going to be the best powder or powder charge. And as far as seating depth every gun and bullet combination is different That's what keeps all of us going to the range if it was easy it wouldn't be fun.

Yep, the powder charge, seating depth, and neck tension are are critical as well as feeding the barrel the right components. Give it some thing it doesnt like and it will never shoot no matter how hard you try.

 

[FURMAN]

Absolutely opposite of truths.
I can take well built gun and run through many charges with several powders and never break 1/2moa in the testing. But with seating alone, any load, the same gun can be taken beyond 1moa and back. SEATING IS COARSE, POWDER IS FINE.
With anything calibrated, coarse is adjusted before fine.
And best seating does not change with powder.
Seating is independent of powder

That any rifle any powder charge half minute is the biggest line of bs I've ever read. This becomes even more obvious at 1k. You and I are done "discussing". If others want to buy this trash fine.

 

[FURMAN]

I disagree. Done it many times over. You cant make a rifle shoot the wrong seating depth no mater what powder charge you give it. The idea that you tuned to the seating depth your started at is not something that plays out in my experience. I have done the testing from .020 in to .120 off the lands. The Berger method is moving the bullet so much that its changing pressure as well as exit timing. It painting with a very wide brush, and is more of a poke and hope method. You may get lucky and you may get aggravated. I recommend a methodical approach that will give you a trend to draw data from.

This is fact. NOT opinion. Others can disagree I could not care less. To be honest I am surprised you still waste your time trying to help others.

 

[Mikecr]

You don't really 'tune' with coarse seating. You tune with powder.
That is, you can't just pull a powder charge out of your butt, and tune the gun with seating alone. In contrast, you can fully tune a gun with powder, regardless of seating.
Yet, seating can open and close grouping way way more than powder. Anyone who's ever done FULL SEATING TESTING (Berger's recommended) has seen it.
And this shows seating and powder being separate and different.

Best coarse seating is prerequisite to best results. If you're not in tune while at best seating, then overall results won't be the best possible. This is usually obvious.
But if you're not at best seating while at tune, you may think you're results are best possible. Problem being, there is a chance that it's not.

Again, finding best coarse seating is not tuning. In fact, it's best done as far from tune as possible. Seating testing is for clearing a detrimental condition -that is bad seating for the bullet/throat. Change either one, bullet or throat, start over to find best seating.
This, having nothing to do with powder.

20+yrs ago I argued this with BR folks who insisted that VLDs had to be in the lands to shoot. I tried to get them to understand that best seating could anywhere else. They just needed to do full seating testing to see it. And while everyone claimed they did seating testing, and that everything shot best in or near lands, the truth was that they never did full seating testing -ever.
What they were doing was pulling a starting seating out of their butts(assuming it needed to be close to lands), then tuning with powder, and tweaking seating in a narrow sense while at that tune.
Well tune is an amplified condition, and tweaking seating much from that serves to cause a falling out of that condition. Something always seen as going in a bad direction. So within ~20thou of seating they had tuned at, they gave up, declaring BS on my notions. After all, 20thou seemed a huge way to go with seating, and things never got 'better'.

I realize that for ~100yrs everyone tuned with powder, and tweaked seating for shaping. And all of them had guessed about initial seating to begin. Relatively few did a broad, full seating testing to begin.
I couldn't get anyone to do it.
It wasn't until Berger put out a seating testing procedure that the light bulbs started coming on. But some bulbs are just not lighting I guess.
So I suppose Berger will have to explain to folks what seating is actually doing, before more folks understand what I've been saying for decades..

 

[Alex Wheeler]

One of the reasons I do all my tuning at 1kyds, even the sporters. You see what is really happening with the tune at that range. You can make groups way bigger with the wrong powder charge than the wrong seating depth (not es dependent either). Its not even close. They are both important, but Id rather be off on my seating depth than powder at 1k. But you will never get it small at the wrong depth or it will be very picky. BR folks are actually very open minded and will change things overnight, all you have to do is beat them.
Theres a lot of different ways to tune, and guys have success with many of them.

 

[DJ Fergus]

started reloading about a year ago and have never really messed with the seating depth of bullets, i typically just left them 20 thou off the lands and if it I did not find a good load would assume did not like that bullet. Yesterday I was doing the same for my 6.5 sherman short and for fun decided to try bergers suggestion on seating depth with the 140 vld bullet. glad i did. this particular barrel like the .150 off the lands. No telling how much time I have wasted as I would have never pushed the bullet in that far in the past.



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My questions would be are most bullets this sensative to seating or are the vld's that much more extreme?

I found the original vlds to be quiet sensitive to seating depth. But even bullets that are so called less sensitive to seating depth can be made to shoot even better when the right depth is found. Sometimes as little as .003-.006 depth Change can turn a 1moa load into a 1/2 moa load. If it's a custom rifle put together right, sometimes you can get a 1/2 moa load down to 1/4 or 3/8 moa by just a small change in seating depth.

 

[Tulsa Reiner]

Depends on the design on the bullet. Secant ogive bullets like modern vld bullets tend to be less forgiving and are nit picky about seating depth. while tangent ogive bullets are not as picky on average. I've found hybrids tend to take after secant ogive bullets when it comes to seating depth. I've also found some bullets won't shoot well unless they are jammed. I try to stay away from those loads for the most part but some people have great luck with them.

Please describe or show pics to illustrate the difference between secant and tangent ogive bullets. This is the first time I've heard encountered these terms. I'm very interested because I too have just started exploring the seating depth world.

 

[Mach 1]

QUOTE="Tulsa Reiner, post: 1735385, member: 75815"]Please describe or show pics to illustrate the difference between secant and tangent ogive bullets. This is the first time I've heard encountered these terms. I'm very interested because I too have just started exploring the seating depth world.[/QUOTE]

 

[nksmfamjp]

Absolutely opposite of truths.
I can take well built gun and run through many charges with several powders and never break 1/2moa in the testing. But with seating alone, any load, the same gun can be taken beyond 1moa and back. SEATING IS COARSE, POWDER IS FINE.
With anything calibrated, coarse is adjusted before fine.
And best seating does not change with powder.
Seating is independent of powder

Interesting viewpoint....When I start over on my new 300 WSM barrel, I may try your way first! How do you pick a start charge weight? I ask because pressure is a key factor. If you start at min charge, and adjust seating, when you adjust charge, IMO, you will end up at or near min charge, which effects velocity quite a bit.

If you start at max....well nobody would start at max charge weight....hence my start at 0.030" or 0.005" under mag length.

 

[SergeantD]

Yes the VLDs are sensitive to bullet seating depth in both my 7mm RM and 308. In fact they were so sensitive I gave up on them exclusively. I have never had such problems with any Hornady bullet! This is in my gun other guns may love them. It takes time developing loads; take your time.

 

[Mikecr]

How do you pick a start charge weight?

Look around for common nodes with your cartridge/bullet/powder. It used to be a lot easier to do this when ReloadersNest was online. Choose a charge that puts you between them. I choose a charge between upper & mid nodes, and do this testing while fire forming brass. This is also a good place & time to do some primer swapping.
Run full Berger recommended testing in phases coarse toward fine. Basically, find a good seating window that is preferably well off the lands.

Then with fire formed cases, bullets seated in best window, and primers showing good promise, move to powder testing, OCW or ladder (depending on what you want).
After powder go back to fine adjustments of seating, within it's window, for tightest group shaping. I go another stage to adjust sizing length of necks to dial in tension.

If your best seating ended up well off lands, you will never need to change seating again for the accurate life of that barrel. Keep that in mind before deciding to rely on a touching land relationship..