Seating depth or powder charge

[Buckshot85]

I am not a reloader.
I’m curious which is more important.
seating depth or powder charge.
I’ve been measuring factory ammo for length just for helluva it.
Ive measured Winchester, Remington, Nosler, Federal and HSM.
A couple different types in a few of those listed.
Even the Nosler Trophy grade varies up to .020” in length.
Now, I’m sure some of the differences are likely from the variations in polymer tips or the soft point tips.
But, again, just for curiosity sake, is one more important than the other.

 

[gelton]

generally speaking, one will settle on a powder charge first and then work on seating to see if it can be improved.

 

[bradb]

You also need to take your measurements base to ogive
With a new barrel I tend to take a random load to sight in at 100 and shoot a quick seat test at 200. and I can run and do that quick That is as far as the local range goes. Then I go out to a field and test powder at farther distance, then tweak depth a hair at distance after that. That is the short of it

 

[Buckshot85]

Some of the Remington 180 BT Accutip varied .030”. That just seems like a lot.

 

[JakeSCH]

like previously said....powder charge for velocity node (you want small change in velocities across multiple shots) and CBTO (Cartridge Base To Ogive) for group size at 100y. Overall length is less important.

The ogive is approx the part of the bullet that touches the rifling in the barrel first.

 

[N2TRKYS]

Neither and/or both

 

[Rob5589]

I go charge, then depth, if needed. You really should measure from the ogive as mentioned above. Tips can be all over the place from what I have seen.

 

[Buckshot85]

Thanks, guys. Appreciate the input.

 

[fightthenoise]

I’ve done both with success. The argument for seating depth is that if you are jumping your bullets a distance they don’t like, no amount of powder charge adjustment will fix it. Conversely, you can tune any powder charge to shoot well with small adjustments in seating depth. When you shoot a bunch of factory ammo to find what your rifle likes…that’s just a seating depth test.

The reality of the matter is that rifles these days just aren’t picky enough to need to agonize over it all. The nodes are wide and you’re probably in one.

 

[Ucsdryder]

I go charge, then depth, if needed. You really should measure from the ogive as mentioned above. Tips can be all over the place from what I have seen.

Unless you’re shooting eldx, then the ogive is all over the place too! Oh and if you call them they say ogive variation isn’t an issue and even at .010 you won’t see an issue out to 1000 yards.

 

[Rob5589]

Unless you’re shooting eldx, then the ogive is all over the place too! Oh and if you call them they say ogive variation isn’t an issue and even at .010 you won’t see an issue out to 1000 yards.

You're right. For sure better, but certainly not perfect.

 

[4ester]

Unless you’re shooting eldx, then the ogive is all over the place too! Oh and if you call them they say ogive variation isn’t an issue and even at .010 you won’t see an issue out to 1000 yards.

Kinda a big deal if they shoot best at .010 off the lands...... that’s not acceptable to me.


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[Ucsdryder]

Kinda a big deal if they shoot best at .010 off the lands...... that’s not acceptable to me.


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Guy I talked to said he shot PRS and said he would shoot up to .010 variation, in competition, without giving it a second thought.

 

[JRMiller]

generally speaking, one will settle on a powder charge first and then work on seating to see if it can be improved.

This^

 

[Rob5589]

Guy I talked to said he shot PRS and said he would shoot up to .010 variation, in competition, without giving it a second thought.

I wouldn't sweat that either in PRS. F class, benchrest, then I definitely would.

 

[4ester]

Guy I talked to said he shot PRS and said he would shoot up to .010 variation, in competition, without giving it a second thought.

The problem is when you get close to the lands with a stout load. Now you risk touching and pressure signs. Otherwise they are probably fine for most shooters.


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[Harvey_NW]

In a factory load powder charge and velocity are what they are, so seating depth would be more important. You could change the seating depth and get different results.

For a custom load I think their exact significance depends on the end goal of the developer. Powder will affect velocity, and potentially accuracy. When I work a load up I primarily care about velocity with powder, and accuracy with seating depth. Sometimes I'll test some powder charges in tight increments within my velocity node to see if it has any reasonable positive effect. A shooter with a goal of 1 hole groups at 100yds would likely consider powder charge to be a more significant factor.

 

[Patty]

my process typically goes powder charge > seating depth > powder charge. i find if either the seating depth or powder charge are not optimal it will skew results. Once you find the best SD/ES powder charge (which may still not be great at this point) seating depth will fine tune the accuracy, then revisit the powder charge at that new seating depth to complete the circle.

 

[woods89]

There have been some interesting discussions on Snipershide recently about this. An argument is being made that for practical shooting, unless you are finding velocity nodes with a sample size of 20-30 shots per charge weight, those nodes may not be repeatable. To say it in another fashion, if you shoot 20-30 of each charge weight you will find that both accuracy and SD/ES will be much closer than we think. This assumes fairly good reloading practices.

Honestly, I'm moving more towards picking a velocity I want to shoot and, unless I'm not happy with the results, loading that charge weight to mag length and shooting. Especially in my Hawk Hill barreled rifle it just seems like everything shoots to an acceptable level, and the limiting factor is almost always my skills at anything other than a bench type of situation. Obviously for benchrest and similar comp situations this wouldn't apply. YMMV.

 

[wind gypsy]

There have been some interesting discussions on Snipershide recently about this. An argument is being made that for practical shooting, unless you are finding velocity nodes with a sample size of 20-30 shots per charge weight, those nodes may not be repeatable. To say it in another fashion, if you shoot 20-30 of each charge weight you will find that both accuracy and SD/ES will be much closer than we think. This assumes fairly good reloading practices.

Honestly, I'm moving more towards picking a velocity I want to shoot and, unless I'm not happy with the results, loading that charge weight to mag length and shooting. Especially in my Hawk Hill barreled rifle it just seems like everything shoots to an acceptable level, and the limiting factor is almost always my skills at anything other than a bench type of situation. Obviously for benchrest and similar comp situations this wouldn't apply. YMMV.

It seems like some of the "there are no nodes" thoughts come from people shooting 6br based cartridges through truck axle barrels. I don't have experience with that but I have had a couple heavier barreled 6.5x47s and I have yet to find a load in either that doesn't shoot tight with fairly decent velocity spreads but I have found definite powder charges that show consistently lower velocity spreads.

IMO this doesn't translate well to developing loads for overbore cartridges in lightweight barrels.