Base to Ogive Consistency: my setup or my Nosler Ballistic Tips?

[Jgjgjg]

Loading for .250 Savage using 115 grain Nosler Ballistic tips, redding seating die, and RCBS green press. I'm using calipers with a hollow anvil type setup to measure base to ogive length. This lot consists of 5 round groups all using full case prep, primer, powder load, bullet and walking the round back from the lands by ~.005" increments.

I'm finding that right at about 20% of the cartridges are coming in .005-.008" short. Let's say I'm loading a group that has a 2.053" base to ogive length. I'll get four that are pretty much dead on, but sure enough 1 will come out 2.046".

Maybe this indicates that 20% of the projectiles have subtly different geometries causing the ogive "ring" to be lower on the projectile. Or maybe it's me and I'm being inconsistent somehow with my loading technique. Have you seen this? What are your thoughts?

 

[pert near]

Check the bullets themselves base-to-ogive. I've founds some significant variations in hunting bullets, not so much in match bullets.

To determine the best accuracy bullet seating, start with Berger's suggestion & adjust from there.

 

[JFrank]

Loading for .250 Savage using 115 grain Nosler Ballistic tips, redding seating die, and RCBS green press. I'm using calipers with a hollow anvil type setup to measure base to ogive length. This lot consists of 5 round groups all using full case prep, primer, powder load, bullet and walking the round back from the lands by ~.005" increments.

I'm finding that right at about 20% of the cartridges are coming in .005-.008" short. Let's say I'm loading a group that has a 2.053" base to ogive length. I'll get four that are pretty much dead on, but sure enough 1 will come out 2.046".

Maybe this indicates that 20% of the projectiles have subtly different geometries causing the ogive "ring" to be lower on the projectile. Or maybe it's me and I'm being inconsistent somehow with my loading technique. Have you seen this? What are your thoughts?

Briefly
I would look at where your seating stem contacts the projectile.
Try coloring the Bullet and look for that spot.
Neck tension inconsistencies will do It also
Thirdly- your tools may not be up to the task

 

[fguffey]

You need another tool, and you need to understand there are two diameters. I have no problem accepting the two diameters for the 308 is .300" and .308". And then there is the distance from the beginning of the rifling to the bolt face.

F. Guffey

 

[JFrank]

I thought we were talking about a.250 Savage

 

[Nature Boy]

I thought we were talking about a.250 Savage

In 1997, over 60 years ago, Teddy Rosevelt did something to make my mule do another thing and I did not sleep in my car.

 

[JFrank]

Now I’m really confused!

 

[fguffey]

I thought we were talking about a.250 Savage

If the 30 caliber barrel has two diameters the 250 caliber barrel has two diameters. I use a different method/technique for determine where the rifling begins. I use a different method for seating bullets, the OP said he adjusted the seating depth in .010" increments; that means he does not know the distance from the beginning of the rifling to the bolt face.. .

F. Guffey

 

[murf]

crooked bullet seating twenty percent of the time is my guess.

murf

 

[Chuck R.]

Check the bullets themselves base-to-ogive. I've founds some significant variations in hunting bullets, not so much in match bullets.
To determine the best accuracy bullet seating, start with Berger's suggestion & adjust from there.

This would be my 1st step also.

I've found that unless you're dealing with match bullets, very good match bullets you'll find that the bullets themselves are inconsistent to some point. Then it gets to be an issue with stacking tolerances. I've gone to using averages for 5 bullets or loaded rounds to calculate my adjustments.

For the precision guns I've replaced my Hornady OAL aluminum inserts with Brownell's steel inserts.

 

[JFrank]

If the 30 caliber barrel has two diameters the 250 caliber barrel has two diameters. I use a different method/technique for determine where the rifling begins. I use a different method for seating bullets, the OP said he adjusted the seating depth in .010" increments; that means he does not know the distance from the beginning of the rifling to the bolt face.. .

F. Guffey

Humm
your the only one saying.010 and I’m not sure how that translates to the op not knowing the DFRTBF
But hey your the expert not me.

 

[243winxb]

Try a Lee dead length bullet seating die. It will make contact with the shell holder, removing any slop from the press linkage.

The Redding competition seating die , tech tips suggest allowing the bottom of the die to "lightly" make contact with the shell holder.

20% of the cartridges are coming in .005-.008" short.

Is the gun accurate enough to notice the difference.

 

[Demi-human]

Is the gun accurate enough to notice the difference?

I agree with this.

I accept my seating length as a range and limit resources to get it more precise than that.
Even if I am able to get seating depth to zero tolerance, is my rifle going to appreciate the endevor?

Heck, am I able to shoot the difference? Probably not. But who doesn't need fun new tools?

I also did not sleep in my truck last night.

Now I’m really confused!

Mr Guffy's pastime is finding some human needing help and confound their efforts with disinformation and double speak, while inflating his ego.

But an inarticulate genius, is not one...

(Who cares how much you understand if you are unable, or unwilling, to pass on the information to the next human?)

In-depth and rousing discussion can be had though, if one is willing to overlook his inability to use common terms and the usual banter associated with it.

Indeed, I may know more now about Handloading and the measuring involved after being thoroughly confused by the aforementioned at Accurate Shooter.

Of course only after being straightened out here! (Thanks Y'all!)

 

[Jgjgjg]

Good tips, thanks. Probably not, but if I can easily remove a variable. You know how it is. 4 shot group is 3/4 moa, and one round “over there” or one round with 150fps high or low from the group and you wonder, “did I do that now, or did I do that on the bench”?

The other day I was shooting a load without a chrony. One group was 1/4 moa vertically and 4 moa horizontally. The tragedy is that group was an old loafing where I’d lost the notebook in a flood.

So I put more sand bags in place. The next group, which I did chrony, was ~1.5” horizontally, and 3” vertically with a lot of concomitant variance in velocity.

Now, these rounds were ones where I had carefully prepped the cases and assured +\- .1 grain charge weight. But what I didn’t do on those was sort for case volume, weigh the projectiles, or measure ogive the length round by round.

So I can’t answer whether the rifle is sensitive enough to pick up “that’s”. But it is sensitive enough to pick up something.

 

[Demi-human]

Good answer.
We would have also accepted "because I want to".
Ten points.

I like the Dead length seater idea.

Differing neck hardness will still have some influence, as well as bullet nose profile. Where the seater touches the bullet may be more variable then where the ogive begins.

I lubricate each neck the same before seating, too.

 

[Jgjgjg]

that means he does not know the distance from the beginning of the rifling to the bolt face.. .

F. Guffey

I do, actually. This rifle doesn’t like having the round seated at the lands. I’m looking for this rifles sweet spot.

For each rifle/ammo combination, I’ll take a projectile type and weigh out a couple of dozen projectiles to find a group that is dead nut. Then I’ll measure each from bullet base to ogive and select one that is dead in the group middle.

From there I take a fired case and neck size it and wipe a little epoxy on the inside of the neck. Load a the projectile way long, and gently load the round and weight. Now I have a “gauge” for each brand/bullet/weight.

I find that if do this and ogive measure another round, then coat with dyechem, and load, the dyechem marks pick right up at the ogive circle. Thus, I believe it to be an accurate way to make a gauge and faster/easier than tools or eutectic. The bonus is that when I’m loading, I can zero the calipers with the measure insert into the gauge round: very fast, and the target rounds read as a +\- from “zero” during reloading.

This won’t work in my semi’s as the lands are too far forward to load a near the lands round that also fits in the mag.

 

[Jgjgjg]

Good answer.
We would have also accepted "because I want to".
Ten points.

I like the Dead length seater idea.

Differing neck hardness will still have some influence, as well as bullet nose profile. Where the seater touches the bullet may be more variable then where the ogive begins.

I lubricate each neck the same before seating, too.

Neck hardness. Just when i think I’ve hit all the variables...

You also raised another question in my mind. I’ve never had that seating die apart. I don’t actually k know what the seating profile looks like. Hmmm...I have a lathe. Wonder if I should make a seater that picks up on the ogive diameter rather than “somewhere” else.

 

[243winxb]

But what I didn’t do on those was sort for case volume,

After depriming, sizing, trimming, cleaning, sort by case weight. Make groups within 3/10th grs.

Brass all from the same lot, fire and loaded the same. Or best, from a lot of brand new factory brass.

FL sizing bushing die may help also.

 

[JFrank]

Neck hardness. Just when i think I’ve hit all the variables...

You also raised another question in my mind. I’ve never had that seating die apart. I don’t actually k know what the seating profile looks like. Hmmm...I have a lathe. Wonder if I should make a seater that picks up on the ogive diameter rather than “somewhere” else.

Personally I use a vld seating stem, also I make a pass with a spinning Nylon brush inside the necks for a more consistent seating session

 

[JFrank]

I’m quite familiar with Mr. Guffey it’s Nature Boys post that threw me

 

[Nature Boy]

I’m quite familiar with Mr. Guffey it’s Nature Boys post that through me

 

[Nature Boy]

https://thinkzone.wlonk.com/Gibber/GibGen.htm

 

[JFrank]

https://thinkzone.wlonk.com/Gibber/GibGen.htm

Appropriate “
Save to Favs

 

[Poper]

Loading for .250 Savage using 115 grain Nosler Ballistic tips, redding seating die, and RCBS green press. I'm using calipers with a hollow anvil type setup to measure base to ogive length. This lot consists of 5 round groups all using full case prep, primer, powder load, bullet and walking the round back from the lands by ~.005" increments.

I'm finding that right at about 20% of the cartridges are coming in .005-.008" short. Let's say I'm loading a group that has a 2.053" base to ogive length. I'll get four that are pretty much dead on, but sure enough 1 will come out 2.046".

Maybe this indicates that 20% of the projectiles have subtly different geometries causing the ogive "ring" to be lower on the projectile. Or maybe it's me and I'm being inconsistent somehow with my loading technique. Have you seen this? What are your thoughts?

Well, Jgigig,I'll toss out the method I use for consistent base-of-case-to-bullet-ogive length just because it works for me. Please note I have the Hornady OAL tool but prefer to work with the RCBS Precision Mic whenever possible. Please note RCBS does not make the Precision Mic for every caliber.
All components must be from same lots.
For precision loads where I desire eeking the best possible groups out of a rifle, I sort a new, single lot of brass according to weight after sizing and prepping (trim, chamfer, debur, neck turn, flash hole and primer pocket uniform). All cases must be to identical length and (for the typical 6.5x55 SM) within 3 grains.

All bullets are measured using the Hornady OAL From bullet base to ogive after sorting by diameter and weight. Only "perfect" bullets make the cut. With the typical hunting bullet, expect about a 12% to 15% yield. Some lots, of course, will do better than others. I have had excellent results with Berger's match grade bullets and consistently achieve 60% and better yields. It's rarely less than 50%. If I use soft point bullets, (very, very rarely) they must be run through a meplat uniforming tool.

When it comes to seating the perfect bullet in the perfect case, I set my Redding Competition Bullet Seating Die about .005" long of my target length and seat all the bullets in the batch long. Then with my Precision Mic, I measure the exact length to the ogive of each round and adjust the seating die for each round one at a time as necessary to get the perfect length.

Very time consuming, but it is a hobby, isn't it?

 

[fguffey]

[

Humm
your the only one saying.010 and I’m not sure how that translates to the op not knowing the DFRTBF
But hey your the expert not me.

He said he did know, and then he said he started with the additional +.010" and then started by seating the bullet to get the perfect length one at a time.

I want to know the distance from the beginning of the rifling to the bolt face. For me there is nothing entertaining about seating the bullet into, at or close to the rifling, Again, I am the fan of the running start, I want my bullet to have that 'jump', Again, the first thing I do is measure the distance from the beginning of the rifling to the bolt face, after that when I want to seat the bullet .040" off the rifling I adjust the seating die to seat the bullet .040" off the rifling.

F. Guffey