Ogive to base length

[Poconolg]

When shooting at 100 yds does a difference of .002 of ogive to base matter?

 

[K22]

What discipline are you asking about?

Most standard hunting bullets to today, even the high-quality ones such as Nosler and Sierra will have that amount of variation in my experience. Also, your measurement method and seating die will have some variation.

I have not noticed any significant difference with that amount of variation you mentioned but I am not a competitive bench rest or F class long range shooter. I will defer to those guys on those disciplines. The few guys I knew that sought benchrest level accuracy used match bullets and sorted them by weight and ogive.

But for precision varmint hunting and informal precision range shooting, I haven't experienced any measurable effect at that level of variation.

 

[Bc'z]

BBTO or CBTO?
Not so much.
Your seater is a inanimate tool it only recognizes the relation in where the stem contacts the bullet provided its not letting the bullet tip/meplat bottom out in the stem giving inconsistent seating depths.

When I sort, I sort by OAL in .003 groupings, my CBTO only varies by +or- .0005 for a whopping .001 in variation.

Edited to add
This target was shot with unsorted right out of the box Berger 140 VLDH
with my hunting rifle @ 100.
Any length variation in BBTO is seated deeper into the case, remember the seater is a inanimate tool and only recognizes its contact at the front of the bullet.

 

[Bill Norris]

According to Jack Neary .001 will affect accuracy in short range benchrest.

 

[Larry Koch]

I would say wind flags reading would have more value. If you tune your rifle in a window of (.003) and stay in the middle of that.

 

[Zero333]

Like others have said and also the accuracy of the rifle and the shooter matter more than a variance of 0.002"

 

[DLT]

BBTO or CBTO?
Not so much.
Your seater is a inanimate tool it only recognizes the relation in where the stem contacts the bullet provided its not letting the bullet tip/meplat bottom out in the stem giving inconsistent seating depths.

When I sort, I sort by OAL in .003 groupings, my CBTO only varies by +or- .0005 for a whopping .001 in variation.

Edited to add
This target was shot with unsorted right out of the box Berger 140 VLDH
with my hunting rifle @ 100.View attachment 1492838
Any length variation in BBTO is seated deeper into the case, remember the seater is a inanimate tool and only recognizes its contact at the front of the bullet.

Damn. Is it for sale ? Nice

 

[Bc'z]

Damn. Is it for sale ? Nice

Thank you.
I could never replace it

 

[Scott haywood]

The target will tell you, shoot a ladder test over a spread of seating depths at .002" each and you will find your answer. Keep in mind that it may or may not show a change with every .002"s, depending on the bullets, your load and your chamber, you may have a wider window that works.

 

[Bill Norris]

The target will tell you, shoot a ladder test over a spread of seating depths at .002" each and you will find your answer. Keep in mind that it may or may not show a change with every .002"s, depending on the bullets, your load and your chamber, you may have a wider window that works.

Seems like from my testing the B T bullet has given a wider tune window than the flat base.

 

[Ned Ludd]

When shooting at 100 yds does a difference of .002 of ogive to base matter?

Measure a few bullets, load them, and then determine the answer in your own hands using your own setup. Then you will know with certainty whether .002" of bullet BTO makes a measurable difference in precision at 100 yd with your setup.

 

[mikecr]

When shooting at 100 yds does a difference of .002 of ogive to base matter?

No, and you couldn't prove otherwise.
This, because BTO includes base length, bearing length, and ogive datum in summation.
So where does the 2thou difference come from, and what would it cause?

Even if you isolated these attributes to determine a 2thou difference in just one of them, think about it,, what exactly would it affect:
-Base length?
-Bearing?
-Ogv radius datum shift?

 

[JEFFPPC]

The name of the game is to remove variables.Totally dependent on how much work your willing to do. Lot of excuses, often misrepresented as reasons, to eliminate steps. All dependent on a willingness and ability to interpret flags and conditions. I bet the guys consistently in the top 20 percent match after match do the work.

BBTO or CBTO?
Not so much.
Your seater is a inanimate tool it only recognizes the relation in where the stem contacts the bullet provided its not letting the bullet tip/meplat bottom out in the stem giving inconsistent seating depths.

When I sort, I sort by OAL in .003 groupings, my CBTO only varies by +or- .0005 for a whopping .001 in variation.

Edited to add
This target was shot with unsorted right out of the box Berger 140 VLDH
with my hunting rifle @ 100.View attachment 1492838
Any length variation in BBTO is seated deeper into the case, remember the seater is a inanimate tool and only recognizes its contact at the front of the bullet.

The first part of your last sentence is an inaccurate statement. Looks like a good hunting rifle.Nice shooting.

 

[Evan]

I saw a huge improvement in consistency when I started seating and measuring from the shoulder to bullet ogive directly, which is what the gun actually cares about. Seating and measuring to the base of the case is and only ever has been a convenient proxy for what actually matters.

0.002 matters. My windows seem to be about 0.002 or 0.003 wide and an increment of larger than that can skip me right over the sweet spot for 1000yd benchrest.

 

[Olde Man]

Try This. Debur a small flat washer the same od as your case and locktight it into the bottom of your die holder. It will make the die sit on the case shoulder instead of the base when seating the bullet. This eliminates any BTOG variations in the brass and the firing pin striking force should move the case forward until the shoulder seats in the chamber.

 

[Texas Solo]

Nobody has mentioned a node.
Just like powder charges, there's a seating depth node. Mine is .005".
So I load for the middle of that node and don't worry about a variation of .002".

 

[LHSmith]

When shooting at 100 yds does a difference of .002 of ogive to base matter?

IME (SR BR Registered Competition):
If hard jam -No.
If seating to "just touch" maybe. Since BTO of the bullet itself often varies by 0.003" among the best without sorting- then that additional 0.002" could be the difference of contact vs. no contact.
If jumping any appreciable amount >0.015"-No
We are talking 100 yards -right?