• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more

  • Having trouble using the site?

    Contact support

Virgin Brass and Projectile Measurement Tolerances

Rommel Garcia

Rommel Garcia

Private
Minuteman
Sep 4, 2023
32
2
Georgia
#1
Question for our experts here. The virgin cases I’ve measured are 260 rem Peterson and the bullet is Nosler ABLR 142gr. Here are the ES for each measurement.

Brass:
Length : .006”
Neck Diameter: .004”
Neck Thickness: .0035”
Weight: .8gr

Bullet:
Length: .0065”
Diameter: .0035”
Wright: 1.4gr

Are these ES measurements within acceptable tolerance? I’ll be shooting at least 600 yards and upto 1K.
 
#2
Respectfully, check your measurements. I find it hard to believe you have bullets that are +/- 0.00175” off nominal diameter. Are you using a digital caliper? I can make those read anything I want +/- 0.0015” Check your measuring techniques and try again cause those numbers aren’t close to right
 
#3
I’m using a digital caliper and measuring the diameter of the bullet in the middle where it’s flat. I don’t squeeze/pinch the bullet that much. When it contacts that’s when I measure. I can re-measure. How do you typically do it?
 
#7
Applying constant and even pressure roll/rotate what is being measured. This will help eliminate error. Tokay444 is right, calipers get you close but not exact even for a quality brand like Mitutoyo
 
  • Like
Reactions: Rommel Garcia
#9
Based on this certification it appears my
caliper error range is between -0.001 to +0.0005. This should be fine. Might be my method of measuring. Any thoughts on the brass measurements?
 

Attachments

  • IMG_2978.jpeg
    IMG_2978.jpeg
    393.6 KB · Views: 15
#13
Rommel Garcia said:
Based on this certification it appears my
caliper error range is between -0.001 to +0.0005. This should be fine. Might be my method of measuring. Any thoughts on the brass measurements?
Click to expand...
Yes, at one diameter of 4mm.
Would you at all mind posting pics of how you're positioning your caliper jaws while taking the measurements?
 
#14
Marv_2101 said:
So your Lee Perfect powder measure does good will ball powder? For $25-30 I’m strongly considering giving it a shot.
Click to expand...

Rommel Garcia said:
Question for our experts here. The virgin cases I’ve measured are 260 rem Peterson and the bullet is Nosler ABLR 142gr. Here are the ES for each measurement.

Brass:
Length : .006”
Neck Diameter: .004”
Neck Thickness: .0035”
Weight: .8gr

Bullet:
Length: .0065”
Diameter: .0035”
Wright: 1.4gr

Are these ES measurements within acceptable tolerance? I’ll be shooting at least 600 yards and upto 1K.
Click to expand...
You are getting lost in the finer details of reloading for precision. As for your data, posting the ES is meaningless without knowing what the standard deviation and mean are. You're only giving us data based off 2 pieces.

On the surface you measurements don't appear correct. I would not expect the neck thickness to vary by 0.0035" in just about any brass that is from the same lot nor would I expect neck diameter to vary by 0.004". Is this as-received brass or have you sized it.

You also are shooting a hunting bullet. The AB is a great bullet but it is not a bullet most would choose for 1000 yds if precision is what I was concerned with.
 
#15
A caliper is not the correct tool to measure neck wall thickness, because of the flat land on the blades. You end up with 3 points of contact rather than the 2 points the tool is designed to read from.
 
  • Like
Reactions: Evintos and Baron23
#16
Doom said:
You are getting lost in the finer details of reloading for precision. As for your data, posting the ES is meaningless without knowing what the standard deviation and mean are. You're only giving us data based off 2 pieces.

On the surface you measurements don't appear correct. I would not expect the neck thickness to vary by 0.0035" in just about any brass that is from the same lot nor would I expect neck diameter to vary by 0.004". Is this as-received brass or have you sized it.

You also are shooting a hunting bullet. The AB is a great bullet but it is not a bullet most would choose for 1000 yds if precision is what I was concerned with.
Click to expand...
As Tokay44 mentioned caliper with the wrong tool to measure neck thickness. Neck tension matters more than neck thickness anyways o I think I’m just gonna skip measuring the neck thickness.

Brass is brand new ordered from Brownells.
 
#19
Rommel Garcia said:
I’m using a digital caliper and measuring the diameter of the bullet in the middle where it’s flat. I don’t squeeze/pinch the bullet that much. When it contacts that’s when I measure. I can re-measure. How do you typically do it?
Click to expand...
Tube micrometer for neck wall thickness, outside micrometer for bullet diameter.

If you really wanted to sort bullets though, the thing you should check initially is bullet base to ogive rather than bullet overall length. For that you'd need a bullet comparator.
 
#20
Rommel Garcia said:
This makes sense. What do younger to measure thickness?
Click to expand...
Neck walls aren't always single thickness, which is another part of the problem. They can vary around the mouth and along the length.

In general, for this work you need micrometers not calipers, and you need anvil-shapes that work with concave+convex shapes, not just flat surfaces.so there's both some basic tools and basic techniques involved that are worth brushing up on.

its worth reading some of the 6mm br .com articles if this stuff is all new.

alternatively, this vid of UR doing a/b comps maybe is useful?

 
#21
Evintos said:
Tube micrometer for neck wall thickness, outside micrometer for bullet diameter.

If you really wanted to sort bullets though, the thing you should check initially is bullet base to ogive rather than bullet overall length. For that you'd need a bullet comparator.
Click to expand...
I have the bullet comparator and have used it pretty good so I’m good there. Thinking of tools to use never ends 😮‍💨
 
#22
ma smith said:
Neck walls aren't always single thickness, which is another part of the problem. They can vary around the mouth and along the length.

In general, for this work you need micrometers not calipers, and you need anvil-shapes that work with concave+convex shapes, not just flat surfaces.so there's both some basic tools and basic techniques involved that are worth brushing up on.

its worth reading some of the 6mm br .com articles if this stuff is all new.

alternatively, this vid of UR doing a/b comps maybe is useful?

Click to expand...

This is awesome. Thank you for sharing this!
 
#23
ma smith said:
Neck walls aren't always single thickness, which is another part of the problem. They can vary around the mouth and along the length.

In general, for this work you need micrometers not calipers, and you need anvil-shapes that work with concave+convex shapes, not just flat surfaces.so there's both some basic tools and basic techniques involved that are worth brushing up on.

its worth reading some of the 6mm br .com articles if this stuff is all new.

alternatively, this vid of UR doing a/b comps maybe is useful?

Click to expand...

What kind of Micrometer is that? Can’t seem to find it online.
 
You must log in or register to reply here.

Similar threads

Rommel Garcia
Tikka 260 Rem - First 9 Shots With Different Charge Weights Have Flyers
Replies
36
Views
500
Rommel Garcia
Rommel Garcia
Z
6.5CM resized brass Comparator 0.400 measurement ?
Replies
36
Views
1K
Mike Casselton
Mike Casselton
N
Extractor failing to catch rim of brass and rifling marks on projectile
Replies
1
Views
420
smoooth1
S
W
Brass Resizing Dillema
Replies
40
Views
2K
1bamashooter
1bamashooter
Superchunk72
F-Class Open with PRS rig? You better believe it.
Replies
20
Views
4K
CaseFinder
CaseFinder
Top Bottom
Back
Home
Forums
Merch
Alerts