Extreme spread.

[DKing11316]

Looking for some opinions on how to reduce extreme spread. Reloading process:
1. Trim the brass
2. Neck turn to uniform thickness
3. Uniform primer flash hole
4. Neck size to .002 under loaded neck diameter

After fire-forming I repeat above steps except for neck-turning. As of now I am getting consistent.250 groups
with an sd between 7.5 and 12.0.Extreme spread is between 12 and 20 on average. Redding type S match neck bushing/ seating dies used to load.

Concentricity is is less than .002 at ogive. Check with 21st century.

All rounds loaded with rcbs chargemaster 1500. Thrown to a grain under and trickled up to desired load. Weight checked on rcbs 10-10 beam.

I would like like to tighten up ES for consistency at extended ranges.

Any thoughts or opinions will be appreciated!!! Thanks in advance

 

[spife7980]

Annealing, weight sorting, water sorting, bullet sorting, different powder, better scale, different amounts of tension, different bullet

Eventually you have to draw draw the line though. Sounds like your load is good.

 

[padom]

Your shooting consistent .25" 5 shot groups? If that's the case and your getting single digit SD's how does your load group st distance? If you are maintaining your .25moa accuracy or even .5moa accuracy at say 500-600yds then your splitting hairs here.

 

[DKing11316]

This is only at 100 yards. Still in load development with the burger 140 hybrid seems to shoot good haven’t had a chance to get out past 100 yet but I’m trying to eliminate deviation in velocity while working with what I have.

 

[JWG284]

What cartridge, bullet(assuming 6.5), barrel twist, powder, and case? Everything has to work in unison to get single digit SD much less single digit ES.

 

[TripleBull]

Your shooting consistent .25" 5 shot groups? If that's the case and your getting single digit SD's how does your load group st distance? If you are maintaining your .25moa accuracy or even .5moa accuracy at say 500-600yds then your splitting hairs here.

I recently shot a .5 MOA group at 600 yards and decided I no longer need to shoot at 600 yards. Why spoil an awesome one time event?

 

[DKing11316]

JWG284 Shooting Berger 140 hybrids, CCi 450 primers, Lapua Brass, 42.0 H4350. 1-8 bartlien gap #7 (6.5 creedmoor).

 

[DKing11316]

Sounds like you have a shooter Triplebull!!

 

[DKing11316]

Ttt

 

[Alan Griffith]

The cheap and easy stuff; anneal every firing....try some different bushings and play with neck tension.....try different primers.......don't mix brass/bullet/powder/primer lots.
The expensive stuff; buy an electronic scale that will measure to the 100th of a grain and weigh each charge to what every you feel comfortable with (I go with +/- .02 of a grain and get single digit SD's all the time.

 

[DKing11316]

Alan Griffith I like the idea of annealing every firing, I have been looking into machines and thought I may give the giraud annealer a shot. What do you recommend for annealing units?

 

[Marksman10x]

Looking for some opinions on how to reduce extreme spread. Reloading process:
1. Trim the brass
2. Neck turn to uniform thickness
3. Uniform primer flash hole
4. Neck size to .002 under loaded neck diameter

After fire-forming I repeat above steps except for neck-turning. As of now I am getting consistent.250 groups
with an sd between 7.5 and 12.0.Extreme spread is between 12 and 20 on average. Redding type S match neck bushing/ seating dies used to load.

Concentricity is is less than .002 at ogive. Check with 21st century.

All rounds loaded with rcbs chargemaster 1500. Thrown to a grain under and trickled up to desired load. Weight checked on rcbs 10-10 beam.

I would like like to tighten up ES for consistency at extended ranges.

Any thoughts or opinions will be appreciated!!! Thanks in advance

How many shots are you using to determine your SD and ES?

As I interpret your post, your SD is 12 and ES is 20. I'm assuming the 7.5 and 12 is data from a fewer number of shots. Is this correct? I would shoot at least 10 rounds, but 15 or 20 is much better. If your numbers are still 12/20 roughly, then IMO, your charge weight needs adjusting.

IME, it does not take annealing, weighing to the kernel, neck turning, flash hole uniforming or even cleaning, or really any brass prep (Lapua brass) other than proper sizing, to get single digit SD's over 20 shot strings. Those things CAN help, but are NOT necessary. The key for me has always been finding the whole node I want to work in, then weighing to the middle charge weight. If you really are in the middle of the node, being +/- 0.1 grain will not make any velocity difference, or will be so negligible as to not have an effect on your SD. For my guns, 12 and 20 would definitely represent a charge weight outside my node.

You could try a ladder test at distance. Or try this method, just shoot 3 shots per charge weight, not one. You will want the average velocity of the three shots to compare, one shot does not work.

http://www.65guys.com/10-round-load-development-ladder-test/


Good Luck!

 

[DKing11316]

Thanks marksman10x I think I will try the 3 shot average to find the node. I think you are correct and the charge weight needs adjusting. I will try this out and post results thanks again!!!