Problems with 308 velocity

If you really want to maximize things and go TOTAL OCD, you want to vary powder charges and seating depth AND crimp pressure. Oh and case manufacturer and primer. It's okay, you might only have about 20,000 combinations to maximize your load.

Yes, I am being very tongue in cheek. The recommendation to work on powder charge and then seating depth is the way to go. That said, depends on exactly what you are trying to achieve. Just finding your accuracy node for powder charge might just get you the accuracy you want. Tweaking seating depth and other components (other than maybe bullet selection from a generic FMJ to a match bullet) might take you from a 1MOA load to a .7MOA load or whatever. Might be what you want to chase. Might not be. Just depends on you. For me I don't have time to do that. Eventually I probably will. Especially once components are easier to source.

For me I am personally just chasing a safe, reasonably accurate load with the components I have. See what I get for accuracy and if it is good enough it is good enough. I haven't worked up .308 or .30-06 loads yet, but for >10gr loads I work it up .5gr at a time from starting to max. For <10gr I load .2gr at a time from starting to max. Especially since most loads aren't a nice even .5gr what I'll do is something like my .30 carbine loads, max was 14.7gr H110 (IIRC), so I started at 13gr, then 13.5, 14, 14.5 and then 14.7gr. Smaller jump to get to max so I am testing a load just slightly less than max first to make sure that looks good.

If I need better accuracy/consistency than what I saw, I'll go back and test with finer increments later. Like my CFE223 load for .223. I hadn't tested to max the first time out, but 25gr was a lot better than others, so I'll probably load 25gr, 25.2gr, 25.4gr, 25.6gr. Especially since a lot of what I've read is CFE223 really likes near max loads.

Pistol I am pretty much all shooting off hand for testing and for all my shooting unless I am trying to do something like snipe bowling pins at 50yds or something. So I don't really look at accuracy, unless something seems off. I just look at SD, ES and how sooty the cases are to figure out where I want my loads.

camobob said:

I've seen Eric Cortana discuss this relating to seating depth but it makes sense that velocity would work the same way. Ordinarily I'd be willing to test in 0.1g increments but with components being hard to find can I make it work in say 0.2 or 0.3g steps?

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OCW method uses 0.75% - 1% increments. For a 45 grain load, 0.75% is .33 grains. So a .3 or even .4 grain increment should work and not skip over any accuracy nodes.

I'm guessing that should see a node at about 45.7gr of RL15 behind a 150gr bullet. I'm extrapolating from my own experience and guidance from Dan Newberry's OCW docs. I usually shoot 175 SMKs with 44.2gr of 4064 in Norma brass. As usual, work up to this load while checking for pressure signs since it's near max.

Thanks!

I got it!
Before today Rifle reloading has nothing but equipment issues and learning experiences. I really appreciate being able to bounce this off you guys.
So....the answer was....neck tension.
I loaded a series of 5 loads with 4 of each. I varies the powder in o.4g increments from 45.4 to 47. When I was measuring the finished product I noticed some variation in COAL. I put a few long ones back in the press and the seating die pulled the bullets out. To make a very long story short, I ended up taking a few thousandths off the button in my FL sizing die to add some neck tension and redid all the ammo. This time COAL was good and at the range ES went from 85 yesterday to as low as 8 today. WooooHooooo...here's that chart:

Very good stuff!

Glad you figured it out. You should be able to adjust neck tension with the bullet seating die or crimp die.

Maybe its been a long day , but I'm not following. Mexk tension was the issue, how did you remedy it?

Measure cartridge base to ogvie for a more reliable seating depth guage

My sizing die has a button that sets the inside diameter of the neck. It's not adjustable so I just buffed a few thousandths off it. Now the neck is a little smaller and holds the bullet better. I think the bullet tends to stick to the seating die and that was causing differences in seating depth. With the extra tension, the seating is consistent so the ES is way down.
That's my theory anyway. I was never this anal with pistol loads.

Speed3 said:

Maybe its been a long day , but I'm not following. Mexk tension was the issue, how did you remedy it?

Measure cartridge base to ogvie for a more reliable seating depth guage

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Speed3 said:

Maybe its been a long day , but I'm not following. Mexk tension was the issue, how did you remedy it?

Measure cartridge base to ogvie for a more reliable seating depth guage

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I think he reduced the diameter of the expander ball, if I read that right.

dist1646 said:

I think he reduced the diameter of the expander ball, if I read that right.

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Thats probably it! Thanks for the clarity

A suggestion for you - Throw away the expander ball and buy a couple of mandrels for setting your neck tension. 21st Century Reloading and K&M both have them. The most consistent velocities will come at around 0.003” of neck tension. That is according to Precision Rifle Blog and Bryan Litz. The brass will want to spring back about .0005 - .001 after you size it, so to get .003 of neck tension (0.305 inside neck diameter), you typically need a 0.306 mandrel. The other advantage to using a mandrel is that it typically gives you very low neck runout, which helps your accuracy. Expander balls are notorious for introducing neck runout. Whenever I am loading new brass, I always trim them to the same length, and use a die and or mandrel to set them all to the same neck tension. New brass usually does not need to be run through a die, they just need the mandrel to set the neck tension. I know this sounds kind of nerdy and detailed, but if you want consistent velocity spreads, you need to start with the brass.
Varget is also the powder used by most competitors in .308 Winchester. If you can find it, I suggest trying it. Also CCI BR 2 primers.

Good luck.

I actually have a Lee collet neck sizing die that I've never used. It has a decapper so I would have to take that out to use it after the FL sizing/prime station.
Would that work or should I look at a new die?

camobob said:

I actually have a Lee collet neck sizing die that I've never used. It has a decapper so I would have to take that out to use it after the FL sizing/prime station.
Would that work or should I look at a new die?

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Depends on how far you want to chase the accuracy. For a factory gun, shooting 3/4 MOA with low ES I wouldn't go down the rabbit hole.

I've actually heard people using the Lee collet die and having good success with low run out. Its free, worth a shot.