Should I Jump Into The Arbor Press World? (To Improve Seating Depth Consistency)

[CarlGeorge]

I measured 5 bullets - comparing comparator measurements with measurements using the VLD stem as a comparator.

All 5 bullets had same base-to-ogive measurement. (BVLDS is Base-to-VLD-Stem)

CBTO BVLDS
.787" 1.067"
.787 1.065
.787 1.0655
.787 1.067
.787 1.066

With just 5 bullets I'm getting an ES of .002" before the bullet has even made it into the press and die.

Add in linkage deflection from differing neck tensions.....I can see how the inconsistencies add together.

 

[hambone1971]

With a tiny arbor press and a Wilson die you can FEEL all the seating tension flaws. A standard press is a barbell by comparison. Being able to feel the problems is the first step to solving them.

Amen.....HB

 

[JFrank]

I leave the carbon inside the necks, just a spinning nylon brush smooths out the rough to where my seating is near identical.

 

[CarlGeorge]

What are the size of the groups at 300/600/1000 yards now?

I've only had this rig on the 1,000 one time - last September. I was by myself and learning as the day went on. (I'd had a little exposure on the 1,000 before this - some with a .243 I was loading for long range and another with my BIL's F-Class .308.). All load development has been done at 100 and 200.

My best 10 shot string was my last:
2x9; 5x10; 3xX
1.19 MOA
SD at target (thanks to ShotMarker) was 16.4.

Haven't had it on the 300 or 600.

 

[skeeljc]

Has anyone experimented with seating bullets in a lubricated case neck? I would think Imperial dry neck lube would improve seating. It seems to me that carbon build up is a lubricant.

 

[dgeesaman]

Has anyone experimented with seating bullets in a lubricated case neck? I would think Imperial dry neck lube would improve seating. It seems to me that carbon build up is a lubricant.

Flake graphite and amorphous carbon deposits are very different animals in terms of dry sliding friction. I see a huge improvement using dry neck lube.

David

 

[Fast14riot]

Has anyone experimented with seating bullets in a lubricated case neck? I would think Imperial dry neck lube would improve seating. It seems to me that carbon build up is a lubricant.

I saw on Facebook some one with the new AMP seating press do some testing of dry, brushed, lubed and the curves were different. I think it was Lou Murdica that did it, but don't quote me on that. I'll see if I can find the pics and post them here (with permission).

 

[Dub]

Has anyone experimented with seating bullets in a lubricated case neck? I would think Imperial dry neck lube would improve seating. It seems to me that carbon build up is a lubricant.

I use imperial dry lube and measure seating pressure with my K&M Arbor press to insure consistency on my LR BR rounds

 

[6ShotsOr5?]

A friend advised me to start using the Arbor press when I ordered tools for my 30 BR. I haven’t used the new tools yet so I can’t say for sure whether it will be better, but after buying the arbor press (a one time cost), the Wilson seaters are a lot cheaper than the Redding competition seater dies that I have been using.

 

[AlNyhus]

Seat a few different style bullets and see if the inconsistency remains. -Al

 

[eric n]

Another benefit is being able to develop your seating depth at the range. Once you find a powder node, load a bunch long and then tune your seating at the range. Same day, easier to follow the conditions more or less, and saves gas and fees from multiple range trips while the conditions changed from the previous range day.

 

[Dusty Stevens]

Another benefit is being able to develop your seating depth at the range. Once you find a powder node, load a bunch long and then tune your seating at the range. Same day, easier to follow the conditions more or less, and saves gas and fees from multiple range trips while the conditions changed from the previous range day.

Tons of good presses out there people use at the range. I suggest a hood press from arkco machine. You can get 2 threaded rams or an arbor press and threaded spot- whatever you like

 

[acloco]

I've only had this rig on the 1,000 one time - last September. I was by myself and learning as the day went on. (I'd had a little exposure on the 1,000 before this - some with a .243 I was loading for long range and another with my BIL's F-Class .308.). All load development has been done at 100 and 200.

My best 10 shot string was my last:
2x9; 5x10; 3xX
1.19 MOA
SD at target (thanks to ShotMarker) was 16.4.

Haven't had it on the 300 or 600.

Is this a full on custom gun? 14" group at 1K is nothing to sneeze at....

I am not saying you need a 5 or 10K stick to do better....but....

MANY variables - the person, the equipment (scope, rings, trigger, and...and...and), the person (yes...I mentioned the human twice), and....and...and.

Not saying you, in particular, but the internet is good and bad. MOST people believe they can purchase brand X gun, using brandy Y bullets, with double O primers, and single base powder, in Harry's brass....and they EXPECT to shoot MOA at a mile. It is not going to happen.

PRACTICE. GOOD equipment. ...and REPEATABILITY is what makes all better.

 

[CarlGeorge]

Is this a full on custom gun? 14" group at 1K is nothing to sneeze at....

I am not saying you need a 5 or 10K stick to do better....but....

MANY variables - the person, the equipment (scope, rings, trigger, and...and...and), the person (yes...I mentioned the human twice), and....and...and.

Not saying you, in particular, but the internet is good and bad. MOST people believe they can purchase brand X gun, using brandy Y bullets, with double O primers, and single base powder, in Harry's brass....and they EXPECT to shoot MOA at a mile. It is not going to happen.

PRACTICE. GOOD equipment. ...and REPEATABILITY is what makes all better.

Yes - custom gun: Kelbly Atlas action, Brux Barrel, McMillan Stock.

I'm happy with how it's shooting. I think I've gotten things to the point where the nut behind the trigger is probably the weakest link in the chain.

That being said, my motivation in resolving this inconsistent seating issue is more my own peace of mind....and reducing the frustration with not having confidence in the seating depth when taking a round out of the press. Plus, I just like figuring out why things are the way they are....and why things happen the way they happen. So puzzling out this inconsistency is just kind of driving me crazy in general.

 

[acloco]

Yes - custom gun: Kelbly Atlas action, Brux Barrel, McMillan Stock.

I'm happy with how it's shooting. I think I've gotten things to the point where the nut behind the trigger is probably the weakest link in the chain.

That being said, my motivation in resolving this inconsistent seating issue is more my own peace of mind....and reducing the frustration with not having confidence in the seating depth when taking a round out of the press. Plus, I just like figuring out why things are the way they are....and why things happen the way they happen. So puzzling out this inconsistency is just kind of driving me crazy in general.

AH....I understand. Yes....keep on keeping on then.

 

[aschuler]

I measured 5 bullets - comparing comparator measurements with measurements using the VLD stem as a comparator.

All 5 bullets had same base-to-ogive measurement. (BVLDS is Base-to-VLD-Stem)

CBTO BVLDS
.787" 1.067"
.787 1.065
.787 1.0655
.787 1.067
.787 1.066

With just 5 bullets I'm getting an ES of .002" before the bullet has even made it into the press and die.

Add in linkage deflection from differing neck tensions.....I can see how the inconsistencies add together.

I'm not the sharpest tool in the shed so keep that in mind as I ask this question.

How does base to stem length inconsistency translate to seating depth inconsistency?
The bottom of the bullet is "floating" in the case so wouldn't that measurement be irrelevant when talking about cartridge base to ogive measurements?

 

[mikecr]

You're right aschuler, the seater stem datum means nothing to desired CBTO.
The datum difference is likely due to variances in ogive radius, but does not predict resultant CBTO with seating. That just has to be measured to know.

 

[aschuler]

You're right aschuler, the seater stem datum means nothing to desired CBTO.
The datum difference is likely due to variances in ogive radius, but does not predict resultant CBTO with seating. That just has to be measured to know.

Cool, thanks for confirming that for me.

 

[CarlGeorge]

This is what I was thinking with that data. Correct me if I'm wrong.

Let's say on bullet A the distance from where CBTO is measured (the bullet comparator) and where the seating stem impacts the bullet is .275". And on bullet B that same measurement (the distance from where the stem impacts the bullet to where CBTO is measured) is .265".

When the bullet is seated it is seated to the height as specified by where the stem impacts the bullet. The stem knows nothing about the ogive, since it is physically below where the stem contacts the bullet.

Therefore, when measured with the bullet comparator to determine CBTO the round with seated bullet B will have a CBTO .010" LONGER than the round seated with bullet A......since in bullet B the ogive is .010" closer to where the seating stem impacts the bullet as compared to bullet A.

I agree - the bullet base is floating in the case and doesn't impact CBTO measurement. What I'm pointing out is inconsistency in the difference between where CBTO is measured and where the stem contacts the bullet.

That's the model I have in my head. Please chime in if I'm off base.

 

[mikecr]

It's complicated & I'll try to show with pics tomorrow.
Basically, the datum offset is due to different ogive radius (nose slope).
With this, both datums actually shift, but different amounts.
Then, luckily, their function differences (measure point -vs- seating push point) counter each other so that measured CBTO is still pretty consistent -even while the bullet is pushed from a point more or less up the nose.

This is when the radius variance remains of the same type (more or less tangent radius, more or less secant radius).
If a variance is a hybrid shift the outcome may be different, possibly opposite of expected.
Stem wedging also changes with different contact ANGLES as amplified with different seating forces.
That's why I suggested CBTO has to be measured to know, as it cannot be fully predicted and should not be assumed.