Advice Needed - ES & SD

[Ccrider]

If you are getting those numbers consistently after your barrel has settled down from a good cleaning, you should reassess your brass prep and reloading process. What type of brass are you using. Have you checked to make sure it has not outgrown your chamber? Has all of the brass been fired the same number of time? What do you anneal with?
Was your es this bad with new brass?

Forgot this one- what are you doing to remove the lube you are putting around the neck to size? Are you doing anything to the inside of the neck?

 

[JFrank]

I have a 6.5 Creedmoor, M70 Win w/Bartlien 1:8", 5R barrel (350 rds). I can't get the extreme spread and the standard deviation down where they need to be (see below). Here is my loading procedure - tumble, deprime, anneal, FL resize (Whidden FL bushing die - set to .0025 under size the neck), lube inside of neck, size neck with mandrel (-.001 neck tension), prime, charge (RCBS CM1500), seat bullet (Whidden Micrometer). I've done a ladder from 43.5gr to 45.3gr of H4831SC and found a node between 43.7 and 44.3, so I settled on 44.0. In limited testing I have been able to get the Hornady 140gr ELD Match to about 50% of ES & SD of the Bergers. Problem is I have a bunch of 140 Hybrids and few 140 ELDs.

Any suggestions would be appreciated!

View attachment 1258824

I don't think its Ballistics, I would concentrate on combustion /ignition as others posted a good scale really helps.

 

[Straightshooter1]

I've never had much confidence in the CM1500 rounding algorithm. I have done some comparisons using my GemPro 500 and they were never as far off as you've found, however I believe the GP 500 only resolves to 0.05. So it could be rounding errors compounded. I will look into that further. Maybe load a series trickling onto the GP 500.

Thanks!

Good idea to load a few using your GP-500. Going to a scale that can resolve to 0.05 made a big difference for me and got me where I felt I should be with single digit SD's and mid to low teen ES's.

If you haven't see or read the PricisionRifleBlog.com's test on 6.5CM factory match ammo, you might find if of some interest and see how those numbers compare to yours (not that you shouldn't be doing much better that what's shown there ):

6.5 Creedmoor Ammo Test Part 3: Live-Fire Muzzle Velocity & Consistency Summary

Welcome to Part 3 of the results of a massive 6.5 Creedmoor ammo field test, where I tested multipl...

precisionrifleblog.com

 

[wkdickinson]

First try other loading equipment and see if the problem persists.

4831 may just be a little slow.. You may want to try to raise your initial pressure by adding more neck tension, maybe mag primers, park bullet closer to lands, or add more powder and see if there is a node higher in pressure.

Whats ur barrel length?

28"

 

[wkdickinson]

If you are getting those numbers consistently after your barrel has settled down from a good cleaning, you should reassess your brass prep and reloading process. What type of brass are you using. Have you checked to make sure it has not outgrown your chamber? Has all of the brass been fired the same number of time? What do you anneal with?
Was your es this bad with new brass?

Forgot this one- what are you doing to remove the lube you are putting around the neck to size? Are you doing anything to the inside of the neck?

I am using Peterson LRP brass, all of it is 3X firings. No resistance closing the bolt. I use an Annealeez. My ES has never been any better than it is now - that is what sent me down this rabbit hole.

Interesting - I don't try to remove the graphite from inside the neck before seating the bullet. What would you suggest?

Thanks!

 

[wkdickinson]

I truly appreciate all of the comments and suggestions - thanks a bunch!!!

 

[BasicMagic]

28"

I'm getting 2800 fps with a hornady 147 and reloader 16 out of a 26" with lapua brass.

How far away from pressure signs was this load? I'd do the other suggestions first, load with a different scale, add some more neck tension, get closer to lands.

Then lastly I'd try a mag primer, and if that don't work see if there is a higher pressure node.

How many shots at each charge level did you chrony to determine the load you wanted to use?

 

[INTJ]

I am using Peterson LRP brass, all of it is 3X firings. No resistance closing the bolt. I use an Annealeez. My ES has never been any better than it is now - that is what sent me down this rabbit hole.

Interesting - I don't try to remove the graphite from inside the neck before seating the bullet. What would you suggest?

Thanks!

The carbon from firing is one of the best neck lubes out there. All I do is run a nylon brush in the neck right before powder charge and seating, and I get very consistent seating pressure.

The only case cleaning I do is to quickly polish the neck shoulder area with 0000 Steel Wool right before annealing.

After sizing, I wipe the lube off the case with a micro-fiber towel.

 

[CharlieNC]

So you know you get a 50% reduction/improvement with a different bullet, using the same equipment and procedures. But you want to change everything except the bullet? Some bullet/barrel combinations just don't work. I bet you would have little problem trading those Bergers for Hornady.

 

[wkdickinson]

So you know you get a 50% reduction/improvement with a different bullet, using the same equipment and procedures. But you want to change everything except the bullet? Some bullet/barrel combinations just don't work. I bet you would have little problem trading those Bergers for Hornady.

Hard to argue with that logic! Unfortunately, for me at least, these things often become more of an obsession to find "the reason", rather than moving on to something else that works. My dilemma has also been not being able to buy bullets - I never thought of trading.

Thanks for the help!

 

[wkdickinson]

I checked my CM1500 against my GemPro 500 (only weighed charges that the CM 1500 said were exactly 41.0gr):

​

So it's not my powder weights. However I did discover something else interesting - my Berger 140gr Hybrid bullets measure 0.2635" in diameter, while my Hornady ELD Match bullets measure 0.264", as do my Sierra 140 Match Kings. Thanks for everyone's help and patience. I think I will take CharlieNC's advise and get more Hornadys.

 

[bozo699]

The carbon from firing is one of the best neck lubes out there. All I do is run a nylon brush in the neck right before powder charge and seating, and I get very consistent seating pressure.

The only case cleaning I do is to quickly polish the neck shoulder area with 0000 Steel Wool right before annealing.

After sizing, I wipe the lube off the case with a micro-fiber towel.

100% same process
Wayne

 

[Kracken McGraw]

The only case cleaning I do is to quickly polish the neck shoulder area with 0000 Steel Wool right before annealing.

Lately I have been using this method of polishing the neck shoulder area on Lapua virgin brass. Seems to me the new brass necks seem grabby or a little lacquer feeling, for lack of better words. Doing this and wiping off with a older used micro fiber towel before the usual lube-sizing process sure seems to make things work easier on no turn virgin brass.

 

[Ned Ludd]

Charge weight variance of +/- 0.1 gr shouldn't be the problem. It may not be desirable, but in such a case you'd expect to see an effect on velocity the same as intentionally adding or subtracting 0.1 gr of powder, maybe +/- 10 fps or so, ballpark. Your velocity data show an extreme spread of 61 fps, far beyond the effect expected from +/- ~0.1 gr charge weight variance.

In the velocity string, the high value was shot #6 (2812 fps), the low value was the next shot (#7 - 2751 fps). There were no other shots with a recorded velocity greater than 2798 fps, but there were three additional shots with a recorded velocity of less than 2760 fps (#9 - 2755 fps, #10 - 2757 fps, #13 - 2754 fps). Have you ever tried determining the water volume of the cases that produced the highest/lowest velocity values within a string? Even simply weighing cases as a surrogate for determination of water volume, which is not a perfect approach although it certainly works, might provide a clue as to whether case volume variance may be a contributing factor in your ES/SD issue. The bottom line is that analyzing the velocity outlier cases can sometimes help point at a particular problem that needs to be rectified. When you have a few loaded rounds that exhibit abnormal velocity values, trying to find out whether there is something specifically associated with those specific cases that is different than the rest and can be identified is usually not a wasted effort.

As Ccrider mentioned above, I was also wondering what type of lube you used prior to setting neck tension with a mandrel, and whether you removed it prior to loading rounds. My first guess would be that graphite in the neck is probably not the issue, as I know a number of shooters that purposely lube the inside of the necks with graphite prior to seating bullets. However, you can easily test whether wiping it out has any effect on ES. More importantly, I would be thinking about whether a dry lubricant such as graphite is necessarily the best lubricant for expanding the necks with a mandrel. I'm not stating it doesn't work, just asking the question. I routinely size necks with a mandrel as the last step in the sizing process and I literally soak the inside of the neck with Hornady One-Shot lube. The amount I use requires that the cases be cleaned again prior to reloading, but I am never concerned about possibly scoring or unevenly roughing up the inside of the neck wall where the bullet bearing surface makes contact. Something else to consider, at any rate.

Several forum members have indicated that H4831sc is on the slow side for the 6.5 Creed cartridge. Have you tried a different powder such as H4350? That might be one approach. Alternatively, testing different brands of primers if you have them, or even a different Lot# of the same primer might tighten up the velocity numbers. When attempting to diagnose an issue such as excessive ES/SD values in a case where it is clear that a relatively small number of shots within a given string are the ones responsible for the high values, it is usually necessary to isolate and test single variables at a time, until you find those specific variables that are the major contributors. It can sometimes be painful, but will give you the best chance of identifying the underlying issue(s).

 

[barefooter56]

I have a 6.5 Creedmoor, M70 Win w/Bartlien 1:8", 5R barrel (350 rds). I can't get the extreme spread and the standard deviation down where they need to be (see below). Here is my loading procedure - tumble, deprime, anneal, FL resize (Whidden FL bushing die - set to .0025 under size the neck), lube inside of neck, size neck with mandrel (-.001 neck tension), prime, charge (RCBS CM1500), seat bullet (Whidden Micrometer). I've done a ladder from 43.5gr to 45.3gr of H4831SC and found a node between 43.7 and 44.3, so I settled on 44.0. In limited testing I have been able to get the Hornady 140gr ELD Match to about 50% of ES & SD of the Bergers. Problem is I have a bunch of 140 Hybrids and few 140 ELDs.

Any suggestions would be appreciated!

View attachment 1258824

Are you seating these bullets to magazine length (COAL). Or doing bullet seating depth testing ( CBTO) . In either case. I suggest hat if you do not have one. Get a VLD bullet seating stem for your seater die. Ans also be sure to check that the tips of the bullets are NOT BOTTOMING OUT in the bullet seating stem cavity on occasion !

 

[Fast14riot]

One thing I haven't seen mentioned, aside from the stats, are YOU capable of shooting itty-bitty groups? Not to demean you or anything, but have you put a known good shooter on the rifle to see if it's gun handling or something else?

 

[Exercion]

I am curious about the neck tension, because it seems to me that using the mandrel cancels out the bushing in the full length die, leaving you with only 0.001" of neck tension. I don't shoot a Creedmoor, I shoot the big brother it looks up to, the 6.5x55 (sorry couldn't resist) and I run Lapua brass, anneal each time, full length size with bushing to set my tension @ 0.003". I specifically do not use expansion. Now I will say my brass has turned necks, but FWIW I shoot no-turn 6BR's and also do not expand. All of that said, by refining that technique (and using a chargemaster to dispense, checked with a MXX-123) I have been getting mid single digit SD's.

Eric