Does Berger Make Jump Irrelevant?

[hemiford]

Same as any other.
Seating tests also do not have to be taken to lands. We don't even have to know where the lands are.

I may have been confused on this issue. I thought seating depth was only critical for peak pressures and accuracy
when nearing the lands. Evidently not so. Or, does it simply make less difference, but still SOME difference,
even when no where near the lands ?

 

[Phil Rizzo]

Depends on what bullet you use. For instance, on my .257 WBY, below are bullets I have. From L-R, 110 Sierra, 145 Black Hole, and 163 Chinchaga. With the 145 and 163, it has no problem touching the lands.

I bet !

 

[HARPERC]

Once I've met my needs, seating depth means little to me. Chasing seating depths can be fun, but it depends on the goal(s) one has. If aggregate reflects your small results don't stress.

 

[fruitnut]

With VLD Hunting bullets, in my hunting rifle, seating g depth mattered huge.

Jam= 1.75 moa
.01 off= 1.75 moa
.02 off =1.25 moa
.03 off = 1moa
.04 off = .5moa
.05 off = 1.25 moa

.043 off = .25moa rifle will shoot sub 1" 5 shot groups at 400 yards with my son shooting it. With me, 2 inches at 400.

Tell me if my math is wrong. A very mild cartridge eats lands at the rate of 0.003 per 100 rounds. A barrel burner eats that in 20 rounds. That's more than 0.01 in 100 rounds for a barrel burner like say 264 WM. I can't see how chasing 0.003 inch seating depth adjustments makes sense.

Please tell me where I'm wrong?

How Fast Does A Barrel Erode?

A match-grade barrel is a big investment for many shooters, so how much life you can expect from it...

precisionrifleblog.com

 

[Phil Rizzo]

I let the target tell me.
And it does just that. Like the above example I see widening and narrowing with each adjustment, and it very visibly forms a trend!
When I get excited is when 2 different depths show basically the same tight group size.
I jump somewhere in the middle and go a while.

I don't load hundreds of rounds at a time, though. Probably more like 30-40

 

[fruitnut]

I let the target tell me.
And it does just that. Like the above example I see widening and narrowing with each adjustment, and it very visibly forms a trend!
When I get excited is when 2 different depths show basically the same tight group size.
I jump somewhere in the middle and go a while.

I don't load hundreds of rounds at a time, though. Probably more like 30-40

So, you adjust seating depth every 30-40 rounds? If you actually test seating depth every 30-40 rounds, about all you ever do with the rifle is chase the lands.

 

[Phil Rizzo]

No. But I may bump powder up to compensate if needed, to raise pressure.
I've wiggled it out a tad also,
No need to do a full seating test if you KNOW you are very, very close to what it prefers.

This what I call a stable area. Node. Whatever the name.

 

[fruitnut]

Maybe you're close because seating depth with a good rifle doesn't make much difference most of the time. It would take 30 shots at each depth to really tell if 0.003 makes a difference. After 60-90 rounds of testing the rifle needs another depth.

3-5 shot groups lead people astray every day. Well except if seating depth doesn't matter. Then any answer is correct.

 

[Phil Rizzo]

Not when they repeat over multiple days and different conditions.
Guess I'm not a stats guy.
But if I get the results I want repeatedly and the load doesn't fall apart, I really could care less about stats, methods, weather or anything else.
Results trump all the rest for Me.
When I start out tight with a load, like above, and use consistent methods of producing it, I have a little wiggle room for a bad day.

Somebody else can use most of their barrel life proving and disproving. Or not.
That's up to them and their requirements.

 

[Phil Rizzo]

Seems if Berger could get away with it, every box of whatever hybrid would state that seating depth doesn't matter as long as it's not jammed.
They don't say that, or pretend.
But they DO state guidelines for finding your gun's preferred depth. For a reason.

 

[FEENIX]

I bet !

How much do you want to bet?

 

[Phil Rizzo]

I'm betting with you, not in opposition!

Any bullet 13 to 28 grains heavier than the largest Berger has no choice but to use added length, right?
Unless they contain something heavier than lead I suppose.

What's the OAL? Do you single feed?

 

[FEENIX]

What's the OAL? Do you single feed?

At .015" off the lands, 145 = 3.34", 163 = 3.42"; No!

 

[MagnumManiac]

How do you test seating depth on a Weatherby with 3/4 of an inch freebore ?

I have my own Weatherby reamers in 300/340/375 Weatherby, all have .500" of freebore just how Roy Weatherby designed them before they were submitted to SAAMI, the only list of these original proprietary specs are held by CIP. 378 Weatherby was .750" and 460 Weatherby was 1.00" freebore when developed.
Seating depth tuning is not governed by distance to lands, it is the harmonics of the bullets BARREL TIME that is changing with seating in or out.
There are many seating lengths that will be apparent when tested within a magazine length restriction, often being .020"-.030" wide.
Even .100" off the rifling can be just as accurate as .010" off.

Cheers.