I’ve developed a pretty decent load using 130g ELD-M , 45g of Staball 6.5. Seating my tips 20 thousands back. Hornady brass.
The issue I’m having is SD and ES numbers. One range trip I’ll be getting 8 SD or better then the next it will be in the 15-20 area.
One range trip I’ll get .34 5 shot groups the next I’ll get .75 5 shot groups.
My suspicion leans on those primers right now. Wondering if anyone has played with these
Posted Jul 24, 2023, 1:21 AM UTC
What caliber? Also, I'm gonna guess your sample sizes are not statistically significant
6.5 creedmore . I have around 100 rounds of data on this now. I get even here sample size is small but it’s enough to get worried
Is the problem (variability you're seeing) staying the same, improving or getting worse and you shoot cases with more and more loads on them?
I’m going to have to say it’s getting worse after todays 10 shot groups. I was getting baked in 95F today and I’m a little concerned barrel heat started to play a factor after 5 shots as far as moa results. I can accept group size increase with bigger groups but am really looking for experience with these primers and wondering if anyone can corroborate there experience with them.
I've never a detailed primer comparison test - but I'd bet the primers are not your problem.
I may acquire some downvotes because it's happened before when I've brought this up: If you're not annealing every loading you might be dealing with increased neck tension from brass work hardening. Before I started annealing I started getting issues with inconsistent bullet seating depths and bullets being seated needing greater and greater amounts of force in the seating process. I wasn't checking velocities at that point so I can't say I saw changes at that level. But I remember being EXTREMELY frustrated.
Once I started annealing these issues went away.
I anneal every time I shoot. Simply to try to extend brass life. If it improves anything else that’s great but not my aim
OK - scratch that idea off the list. :-D
I have a friend who shoots Staball (he loves it) in his 6.5. He did have to go to a Magnum primer for some reason. I wish I could recall what symptom he was experiencing that lead him to that. He has a very good friend who loads custom ammo (professionally....has all the licenses and certifications) and has been doing so for many decades. He's the one that had him go to magnum primers and his issue went away.
I learned from a long range class, leaving your ammo in the sun can really fluctuate you group and SD . Brass heats fast in the sun ,hot spots . Keep you ammo covered if you aren’t already.
And don't let it soak in a warm barrel for random/inconsistent amounts of time before shooting.
And don't let it soak in a warm barrel for random/inconsistent amounts of time before shooting.
Is there an average velocity difference between the low SD and higher SD results?
While Staball 6.5 is supposed to be less temperature sensitive than other ball powders, that doesn't mean it's great. And if you're at the edge of an accuracy/low SD node, maybe outside temperature changes are impacting your results. If so, a couple of tenths of a grain change in your load could put you back in the "good" area over a wide enough temperature range.
Even things like how consistently you are timing your shots can make a difference, e.g. if you are letting some rounds soak up heat in a hot barrel longer than other rounds, that can make your SD go up.
I keep track of the temperature every time I'm at the range (automatically recorded by my cheap chrono's software). And I try to shoot groups with consistent timing (e.g 1 shot every 45 seconds) after warming up the barrel.
I tend to shoot in strings of 5, let it cool for a good 10-15, another 5. I make separate series in my chrono occasionally and had one set of 5 get a 8 SD, second set same load a 20 SD
Have you tried waiting 3-5 minutes between each shot? Maintain barrel temp for all shots of all groups. Otherwise, as others have suggested, try different primers or try a different powder charge. Your barrel might not like that velocity node.
Come on man. I don’t want to make a range trip take 10 hours. I appreciate all the advice. I plan to try H4350 and try not to let my bullets sit in the sun next time. I may wait a couple weeks to let these 100% temps pass by here in the Dakotas
I’ve been experimenting with 6.5 StaBall in my 7mm-08 - similar charge weight and bullet weight to the Creedmoor. Been getting super good SDs and velocities, but poor groups - even at various seating depths. I am very much unsold on 6.5 StaBall.
Outside of environmental changes, the Hornady ballisticians have some news for you.
https://youtu.be/QwumAGRmz2I
That’s a great video. I’m truly thinking of loading up 30 shot groups for next weekend after watching this