6mm Creedmoor ES help (primer problems maybe?)

[prcomte]

Okay, I want to run some things by fellow shooters. I am running a 6mm Creedmoor, and my ES are somewhat high (25 fps range, measured w/ labradar). Though they aren't always high, it'll be one or two rounds that make them go crazy, though this shows up at 1000+ yards.

My load is:

Lapua 6.5 Creedmoor cases necked down to 6
CCI 450 Primer
H-1000 @ 46.8gn 3130 fps avg
105 Nosler RDF ~.060 off lands

My brass prep is:

Amp Annealer
Deprime
Lee Collet Neck Die
Redding Body Die
Trim, Chamfer, Deburr
Clean with Lyman Green Tumbling media
Check flash holes for debris
Prime
Charge (Chargemaster, then a gem pro 250, keeping +/- 1 kernel accuracy)
Seat Bullet (+/- .0005)

I don't want to change powders, I have good velocity and incredibly good barrel life with this powder. I have changed neck tension, brass type, and bullets. Is there any possibility the primers could be the issue? Lapua uses small primers in their Creedmoor brass, and I am running a lot of H-1000. Are there any hotter small rifle primers than CCI 450's? I'm going to try Fed 205M's, Rem 7 1/2's, and Sellier and Bellots Small rifle primers to see if there are any changes, though I'd like to see some first hand experience if there is any. Let me know what you guys think.

Thanks!

 

[Marksman10x]

For reference, what is the standard deviation when you are getting these ES numbers? How many rounds are you measuring?

Does your charge weight need to be tweaked a couple thousandths to put in the middle of your node? Are your primers being seated to the proper depth? Are you marking the cases that give you the crazy results to see if it's just those specific pieces? Have you considered turning your case necks?

Primers are always an easy thing to change, might even want to try another lot of 450's, just to see. Pretty hard to go wrong with anything CCI or Federal, but you never know 'till you try.

I've never used the Lee dies so I can't comment on them, but the good old Redding type-s FL bushing dies have always worked very well for me. Might be something to try, if only to stream line your process.

If you're looking to make a major upgrade, you could look at something like the 21st Century arbor press with pressure gauge, that would almost assuredly bring down your numbers. Here is a link

http://www.xxicsi.com/hydro-bullet-seater.html

Good Luck

edit-might also consider using something like this Sinclair expander mandrel to iron out the necks.

http://www.sinclairintl.com/reloadi...sku749009163-38807-72073.aspx?sku=749-009-163

 

[Rangemaster]

On my 6 creedmoor, I run 40.7GR of H4350 at 3060 FPS and the last ten shots i checked my SD was under 10. I also use a chargemaster then drop the charge on acculab scale and drop the last few grains with a dandy trickler.

Try using a little less powder and try and find a lower node. I was getting flyers when i was pushing them 3150 fps.

 

[Deadshot2]

Over time I've come to the opinion that it's more important to have the proper case volume to charge weight ratio than worry about primers, etc. This is why some powders excel and others suck even when all the rest of the components are top quality.

 

[prcomte]

My SD is typically 7 I'm not running 4350. Lee collet dies size from the inside of the neck instead of the outside of the neck thus doing exactly what you mentioned doing via and expanded die. I've tried redding Bushing dies and will never use them again. They are the biggest PITA I've ever had to deal with. The powder fill for h4350 is less than optimal plus it kills barrels. I might be willing to go to h4831, but that's the absolute fastest powder I'm willing to try. I may try pushing them slower. Or tweaking the powder charge. Though with the amount of powder in the case that shouldn't be an issue. The powder comes up to the shoulder/neck junction.


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[RampedRaptor]

Don't clean the brass. Wipe down the outsides before you lube (I like one shot) and then size. Run a nylon brush inside the necks ever so gently and then charge/seat. I wipe the brass down afterwards to get any lube off before I shoot. I use a micro fiber towel with some rubbing alcohol on it.

 

[Marksman10x]

I mentioned it in my earlier post, but start marking or segregating the pieces of brass that are giving the "crazy" results. Measure and weigh them, try find a reason, this might lead you into neck turning.

ST DEV of 7 with an ES of 23 is actually pretty good and statistically accurate.

I really think it's going to take an effort on your part to expand your loading process and base of knowledge to include things like neck turning. I don't see you shrinking those numbers without adding new steps, assuming everything else is already correct.

good luck

 

[Marksman10x]

This is a good summary

http://precisionrifleblog.com/2015/04/18/how-much-does-sd-matter/

 

[Milo 2.5]

My SD is typically 7 I'm not running 4350. Lee collet dies size from the inside of the neck instead of the outside of the neck thus doing exactly what you mentioned doing via and expanded die. I've tried redding Bushing dies and will never use them again. They are the biggest PITA I've ever had to deal with. The powder fill for h4350 is less than optimal plus it kills barrels. I might be willing to go to h4831, but that's the absolute fastest powder I'm willing to try. I may try pushing them slower. Or tweaking the powder charge. Though with the amount of powder in the case that shouldn't be an issue. The powder comes up to the shoulder/neck junction.


Sent from my iPhone using Tapatalk Pro

Your numbers are most likely skewed by your seat depths, your load has to be heavily compressed and unless you're running an ungodly amount of neck tension, your seat depths aren't all holding and you have a variance.

 

[prcomte]

I mentioned it in my earlier post, but start marking or segregating the pieces of brass that are giving the "crazy" results. Measure and weigh them, try find a reason, this might lead you into neck turning.

ST DEV of 7 with an ES of 23 is actually pretty good and statistically accurate.

I really think it's going to take an effort on your part to expand your loading process and base of knowledge to include things like neck turning. I don't see you shrinking those numbers without adding new steps, assuming everything else is already correct.

good luck

I have tried neck turning. Just not on this brass. I use a k&m neck turner with their carbide pilot to cut donuts out, though with this gun I haven't seen a real need for it. I run a .275 neck and the OD of a loaded round measures .273 and some change. I'm going to take a sharpie to the range next time I go and mark the ones that give me crazy velocities. I have some primers to try on Monday. I'm trying to avoid turning necks, the less time in the reloading room the better. I'm also trying some large Primer brass on Monday. I have some alpha brass I haven't done much with.

 

[prcomte]

Your numbers are most likely skewed by your seat depths, your load has to be heavily compressed and unless you're running an ungodly amount of neck tension, your seat depths aren't all holding and you have a variance.

I have checked them and double checked them at the range before. No change. And it's really not that compressed.

 

[RampedRaptor]

Double

 

[RampedRaptor]

If the RDF is similar to the Hornady 105gr than he is correct and the load is not very compressed. I actually played with this lastnight because I was impressed with the ops reported velocity

 

[Milo 2.5]

I have checked them and double checked them at the range before. No change. And it's really not that compressed.

OK, what is your targets down range telling you, a guy simply cannot load develop off a chrono?

 

[Sig Marine]

ES of 25 and SD of 7, do the math...using 3130 at 1000 yards with an ES of 25, the total amount of vertical drop from your highest to lowest velocity would be 4.6 inches. Since you're shooting the average MV, this amount is divided by two. Meaning that from your point of aim, the vertical impacts could be as much as 2.3" high or 2.3" low, total of 4.6, at the extremes of your velocity spread. That's less than 0.1 MIL from your POA. This means groups of under 5 inches at 1K. Load 'em up and go shoot, you'll miss by more with wind calls.

 

[prcomte]

OK, what is your targets down range telling you, a guy simply cannot load develop off a chrono?

The targets down range look great to 1000 yards. It's after 1000 where I start to see the large vertical dispersion due to the es. It only takes one flyer to ruin a good group. I'm just trying to minimize those flyers.

 

[Milo 2.5]

The targets down range look great to 1000 yards. It's after 1000 where I start to see the large vertical dispersion due to the es. It only takes one flyer to ruin a good group. I'm just trying to minimize those flyers.

You 100% sure it's not your bullet?

 

[Milo 2.5]

Plus it's virtually impossible to have all your necks tensioned the same, cull ones that don't feel right when seating(soft-harder), shoot the normal only here.

 

[Fursniper]

From Brian Litz's "Modern Advancements in Long Range Shooting", volume II.........;

"The importance of proper ignition cannot be ovetstated. Primers can matter a great deal"!

"If you're weighing your powder to the .01 gr with a Chargemaster class scale and your SD'S are much above 10fps, THEN TRY A DIFFERENT PRIMER!"

"I wouldn't say any brand (primers) is the best but there are some that are better matches for a given cartridge/powder/bullet combination"

 

[prcomte]

You 100% sure it's not your bullet?

I don't think it's the bullet. I've tried 107 matchkings and had similar results. On Monday I am going to try CCI 41's, federal 205M, seller and bellots, and I'm going to try some large Primer brass, though I'd rather stay with the small Primer Lapua.