Extreme Spread

[saxeTshooter]

Looking for some help in reducing ES for my 6.5 CM. Just got the Garmin Xero. Pretty neat tool. Worked on every shot and didn't pick up the 6.5 PRC next to me today using a brake.

My reloading process:

Bullets: 140 Berger Elite Hunter
Powder: N550, 40.9 gr (have been using H4350 but ran out)
Primer: CCI BR2
Brass: Lapua LRP

Press: Lee Cast for resizing
Die: Redding FL S die with bushing and carbide ball
Trimmer: Giraud
Dry tumbler with rice
Scale: RCBS Chargemaster Lite
Seating press: KM with LE Wilson Die

This is a newer powder for me so I ran 3 loads at 39.9, 40.9, & 41.9. First and last had a bit of vertical and 40.9 had shot the same hole @ 100 yds.

1- deprime & tumble
2- wax and resize
3-tumble wax off
4- trim w/ Giraud
5- prime with lee press
6- powder with RCBS (if it goes any amount over, I do not load it)
7- seat bullets

I shot an F-class comp the other day for the first time with this rifle to see what it was all about. Didn't get to see my ES but SD was about 7 using the 4350 load and Hornady 143 ELDX.

Today's chrono results (causing my concern): 20 shots total but I took out the clean barrel shot which was a Hornady case but it was 2,731. Thanks for any help!

Shot #	Speed
1​	2,858.00		Average	2,849.4
2​	2,848.00		Max	2,869.0
3​	2,822.00		Min	2,822.0
4​	2,841.00		ES	47.0
5​	2,844.00		STD	10.8
6​	2,856.00		Median	2,848.0
7​	2,849.00
8​	2,869.00
9​	2,861.00
10​	2,858.00
11​	2,847.00
12​	2,848.00
13​	2,840.00
14​	2,866.00
15​	2,844.00
16​	2,838.00
17​	2,855.00
18​	2,840.00
19​	2,854.00

 

[Straightshooter1]

Looking for some help in reducing ES for my 6.5 CM. Just got the Garmin Xero. Pretty neat tool. Worked on every shot and didn't pick up the 6.5 PRC next to me today using a brake.

My reloading process:

Bullets: 140 Berger Elite Hunter
Powder: N550, 40.9 gr (have been using H4350 but ran out)
Primer: CCI BR2
Brass: Lapua LRP

Press: Lee Cast for resizing
Die: Redding FL S die with bushing and carbide ball
Trimmer: Giraud
Dry tumbler with rice
Scale: RCBS Chargemaster Lite
Seating press: KM with LE Wilson Die

This is a newer powder for me so I ran 3 loads at 39.9, 40.9, & 41.9. First and last had a bit of vertical and 40.9 had shot the same hole @ 100 yds.

1- deprime & tumble
2- wax and resize
3-tumble wax off
4- trim w/ Giraud
5- prime with lee press
6- powder with RCBS (if it goes any amount over, I do not load it)
7- seat bullets

I shot an F-class comp the other day for the first time with this rifle to see what it was all about. Didn't get to see my ES but SD was about 7 using the 4350 load and Hornady 143 ELDX.

Today's chrono results (causing my concern): 20 shots total but I took out the clean barrel shot which was a Hornady case but it was 2,731. Thanks for any help!

Shot #	Speed
1​	2,858.00		Average	2,849.4
2​	2,848.00		Max	2,869.0
3​	2,822.00		Min	2,822.0
4​	2,841.00		ES	47.0
5​	2,844.00		STD	10.8
6​	2,856.00		Median	2,848.0
7​	2,849.00
8​	2,869.00
9​	2,861.00
10​	2,858.00
11​	2,847.00
12​	2,848.00
13​	2,840.00
14​	2,866.00
15​	2,844.00
16​	2,838.00
17​	2,855.00
18​	2,840.00
19​	2,854.00

How many times has the brass been fired?

Is the brass annealed? How often or how many times?

 

[saxeTshooter]

How many times has the brass been fired?

Is the brass annealed? How often or how many times?

2nd firing. No annealing

 

[Ned Ludd]

Just remove brass piece #3 from the group (i.e. 2822 fps) and your ES will decrease by 16 fps. Never use that piece with these other cases again.


Seriously, what you have here is an instance where the velocity from a relatively small number of cases comprise the lion's share of the ES. This is not a bad place to be as you might be able to tighten things up nicely with a sorting step or two, a little primer testing, a little brass work; i.e. relatively simple things, and it's not even a fully developed load in brass that wasn't annealed, if I'm understanding you correctly. With a very little work you can probably tighten that right up.

 

[Ranger188]

Just me but, your running your loads 1.0g apart.
You could be missing a node in-between those powder charges.

You said you had 3 loads per charge, thats 9 shots,
where did the other 11 come from?

Why not just buy some more H4350 and Hornady 143g eld-x if it shot good?
Both are available.

 

[saxeTshooter]

Just me but, your running your loads 1.0g apart.
You could be missing a node in-between those powder charges.

You said you had 3 loads per charge, thats 9 shots,
where did the other 11 come from?

Why not just buy some more H4350 and Hornady 143g eld-x if it shot good?
Both are available.

I went with 1 gr apart to try and expedite things out of frustration bc the shop I go to ran out of 4350 and needed something for deer. I have a property with MLD and like to start stacking them early so I don't need to catch up later in the season (our quota is north of 50 deer). I did a quick charge test at 100, and picked 40.9 gr, then loaded 99 (kept a Lapua case back for measurement reference). The shots you see above are all from that lot.

My 4350 load is 42.2 gr and gets 2762 fps when I checked on a friend's LR. Bought the Garmin this week so I have only tested the N550 with it.

Today's loads were still hitting all targets at 600 (well beyond any deer distance), so I'll use them for that. Just looking for guidance in case I try another F-class comp. I understand their expectation is something in the 10-20 range for ES.

Thanks for the tips! I was very surprised with the velocity avg of 2850. Berger data had me thinking it would be slower.

 

[Straightshooter1]

2nd firing. No annealing

Now that they're fired a 2nd time, they're probably fire formed much better now and that should help some. Just keep in mind that after 4 or more firings, your neck interference will be increasing enough to change your numbers, maybe for the worse.

You can probably improve your ES's and SD's a little more using your ChargeMaster Lite, but I wouldn't expect to a big difference. The ES's could probably get into the 30's and SD's might just barely break into the single digits and that's about as good as you're going to get with that scale, IMHO, based on my experience with my ChargeMaster. If you really want to see a dramatic difference in ES's and SD's, you'll need a better scale. That low and that high from the median leads me to think this and that it could be just a wayward measurement for both. But . . . ES's and SD's aren't everything.

Ned Ludd makes a good recommendation. Though before I toss the case, I'd run a test to confirm whether or not the case is out of sync with the rest.

Also, Ranger188 make a very good point, in that with such big distance between those powder charges you tested, you likely haven't found the best load (unless you just got really lucky). For a case of this size, increment that work best is at .3 grs or even .2 for some people. So, you might want to run a test around the load you've used here (like, 40.3, 40.6, 40.9, 41.2, 41.5) and see what you get.

 

[saxeTshooter]

Just remove brass piece #3 from the group (i.e. 2822 fps) and your ES will decrease by 16 fps. Never use that piece with these other cases again.


Seriously, what you have here is an instance where the velocity from a relatively small number of cases comprise the lion's share of the ES. This is not a bad place to be as you might be able to tighten things up nicely with a sorting step or two, a little primer testing, a little brass work; i.e. relatively simple things, and it's not even a fully developed load in brass that wasn't annealed, if I'm understanding you correctly. With a very little work you can probably tighten that right up.

Might be a good idea. On the way to the range today I was listening to Cortina podcast where he interviewed a Hall of Fame BR shooter. He would segregate individual cases based on their deviation from others instead of sorting by weight.

 

[saxeTshooter]

Now that they're fired a 2nd time, they're probably fire formed much better now and that should help some. Just keep in mind that after 4 or more firings, your neck interference will be increasing enough to change your numbers, maybe for the worse.

You can probably improve your ES's and SD's a little more using your ChargeMaster Lite, but I wouldn't expect to a big difference. The ES's could probably get into the 30's and SD's might just barely break into the single digits and that's about as good as you're going to get with that scale, IMHO, based on my experience with my ChargeMaster. If you really want to see a dramatic difference in ES's and SD's, you'll need a better scale. That low and that high from the median leads me to think this and that it could be just a wayward measurement for both. But . . . ES's and SD's aren't everything.

Ned Ludd makes a good recommendation. Though before I toss the case, I'd run a test to confirm whether or not the case is out of sync with the rest.

Also, Ranger188 make a very good point, in that with such big distance between those powder charges you tested, you likely haven't found the best load (unless you just got really lucky). For a case of this size, increment that work best is at .3 grs or even .2 for some people. So, you might want to run a test around the load you've used here (like, 40.3, 40.6, 40.9, 41.2, 41.5) and see what you get.

They're definitely formed after this firing! They didn't grow but maybe .001 after 1. I just measured and they are +.004 now. I'll probably not buy the N550 again as I have way more experience using 4350 and feel the new chrono could help me better there than starting over with a new propellant.

Its funny, I bought a borescope a few months ago and became anal about cleaning. Now I have a chrono and will become anal about speed. Enjoying the process though!

Thanks for the help!

 

[JFrank]

While low ES won’t ensure smallest groups it certainly can be an indicator of reloading practices. I also sort cases by FPS, ( picked up that tip from @BartsBullets ) it’s easy to see as @Ned Ludd pointed out that just setting a case aside for a separate reshoot can pay dividends. Just don’t read too much into chronograph numbers when load developing.

Believe the target.

 

[B Nettesheim]

It’s not always the ammo causing high es numbers
I would start by checking the bolt for the obvious problems then the same with the trigger

 

[saxeTshooter]

It’s not always the ammo causing high es numbers
I would start by checking the bolt for the obvious problems then the same with the trigger

I'd hope thats not the issue, as I would have no idea how to check or resolve it. Defiance Deviant action with Timney trigger. Built by a well-recognized gunsmith in HTX area.

What obvious problems would you think? How would I go about checking?