OAL ?

[RCMSTER]

Just a guess, but I think some of your actual base to ogive variance may be due to differences in neck tension. Especially with the group of bullets you selected for OAL. If you're using traditional sizing die with a neck expander, be very sure to lube the inside of the neck by some means. -Ed

I'm using a redding bushing neck die with no expander. Brass is 2X fired norma.

 

[RYEWSKY25284]

So, my question is this. Will OAL variance of .030 make a significant difference in accuracy from shot to shot? Rifle is a Winchester 25-06. Bullet is a remington ultra-bonded 115 grain. Powder is 52.0 grains of Norma MRP and primer is federal 210M. BTW, I'm not measuring to ogive, I'm measuring bullet tip to case head. Yes, I know I should measure to ogive, just dont have the hornady tool to do that. Thanks for any input.

an OAL measurement will drive you crazy. To answer your question....yes it WILL affect accuracy.
The bullet will be engaging the lands at different times of pressure curve.
IMHO

 

[P7M13]

See how they shoot to 200 or 300, groupings don't lie.
Ive shot 6.8 SPC & 6.5 Grendel with deformed SP tips that probably varied by >30 mils OAL, sub moa @100, but wouldn't trust further because if B.C. variance.

22Mag or 22LR may work as long as you keep it square.

 

[Treeslug]

Yeah, I need to get one, but I may have to start saving for higher price gas and more taxes.

Don't worry about buying a new gauge. Just take lots of pictures of your guns before Bozo O'roark becomes the new Gun Zar and comes and takes all your guns away from you and the rest of us, too. The pictures will bring tears to your eyes, but some future generation will look at them and stare with wonder and amazement at what this country once was and what free people used to be allowed by constitutional law to possess.

 

[RCMSTER]

See how they shoot to 200 or 300, groupings don't lie.
Ive shot 6.8 SPC & 6.5 Grendel with deformed SP tips that probably varied by >30 mils OAL, sub moa @100, but wouldn't trust further because if B.C. variance.

22Mag or 22LR may work as long as you keep it square.

Just tried your method of using an empty 22 shell. OAL variation went from .030 to .010. Ok, I'm amazed. Learned something new tonight. Thank You.

 

[P7M13]

Just tried your method of using an empty 22 shell. OAL variation went from .030 to .010. Ok, I'm amazed. Learned something new tonight. Thank You.

Credit to @DUSTY NOGGIN, not me, as it was his suggestion.

 

[Philward]

If the oal varies because of bullet tip damage, but your die was locked down in the press, there should not be any difference in shooting. Now if you're short stroking the ram or something movable inside the die is binding or sticking and the bullet is seated deeper they may shoot a little different but they probably won't be 5" away from the rest of group. Should still be pretty close

 

[RCMSTER]

if you had a spent 22 LR brass case .. you could put the bullet tip in the opening and measure from case head to case head to get and ogive measurement

im sure there is something in your junk drawer would work

Thanks for the 22 case advice. Used a 22 magnum case, as I dont have a 22LR, and my variance shrunk from .030 to .010. I learned something new tonight. Thanks again.

 

[AZShooter]

You could make one of these:

SINCLAIR INTERNATIONAL SINCLAIR HEX STYLE BULLET COMPARATORS | Brownells

We have been making these hex style bullet comparators for over 20 years, and believe we make the most accurate tools available. The holes in the Sinclair Bullet Comparators are cut with throating reamers to accurately duplicate the actual throat ...

www.brownells.com

 

[RCMSTER]

You could make one of these:

SINCLAIR INTERNATIONAL SINCLAIR HEX STYLE BULLET COMPARATORS | Brownells

We have been making these hex style bullet comparators for over 20 years, and believe we make the most accurate tools available. The holes in the Sinclair Bullet Comparators are cut with throating reamers to accurately duplicate the actual throat ...

www.brownells.com

Out of stock. Probably could make one, like you said.