Problems w/Norma ammo - need advice

[shogi]

The chrony is a Caldwell G2 w/Bluetooth. It isn't a fancy chrony but it is reliable. I always recharge the batteries before heading out. It was about 2pm on both days and fortunately both days were overcast when I shot.
I used the lighting feature on the G2 both times.
The distance I placed the chrony was about 12-15 feet away from the muzzle. I originally placed it about 7-8 feet (for the fouling shot) and it rocked pretty good so I placed it further.

 

[AkBirder300]

The one thing not queried was the chrony. What make, time of day when both series of shots were fired, distance from muzzle and did you replace the battery?

I'm thinking the same thing, I know I have gotten some really unexpected readings using a Caldwell before due to clouds, ambient light, etc. I'd try another round you have established data on through it or even better verify with a second device like a magnetospeed at the same time so you have two data sources.

 

[shogi]

Well, there is no one near me that I know who I can borrow their chrony (hopefully a better one). I will text a few guys at work that I think have one but that will take a bit of time. I figured a 10 shot string would give a broad data base. I think it did, it just didn't turn out they way I expected it to. It is a possibility that I had two boxes of crappy ammo and rest are fine despite them all coming from the same lot.
I will try to find another chrony to test with, as I still have 10 rounds each left. It wouldn't hurt.
I do trust my chrony though. I ensured that every shot was lined up with centre of the chrony (actually used my laser bore sight to make sure of it lol). Despite it being a middling chrony, I'm pretty sure it didn't fail me.

 

[shogi]

Oh, just in case it makes a difference, the G2 doesn't shoot up to sense the bullets, it shoots down. The ambient light isn't as much of an issue and hence it tends to be more reliable especially when the lighting feature is used.
Just wanted to clarify that if anyone wasn't familiar with Caldwells G2. Caldwell states that the accuracy is +\- 0.25%.

 

[Mike Matteson]

Variance of one grain is a lot to me. Your variance in velocity isn't that great being a difference of 1 gr of powder. The other is case volume? Did you measure volume in each case? Unless you are shooting over 500 yds then there maybe a problem. The long range shooter are under .1 of a grain. If I remember correctly the Prometheus Gen 11 is less than that. Somewhere around .04 gr difference or less per charge.

 

[shogi]

Variance of one grain is a lot to me. Your variance in velocity isn't that great being a difference of 1 gr of powder. The other is case volume? Did you measure volume in each case? Unless you are shooting over 500 yds then there maybe a problem. The long range shooter are under .1 of a grain. If I remember correctly the Prometheus Gen 11 is less than that. Somewhere around .04 gr difference or less per charge.

Matt, please read the previous comments from myself in order to gain the full picture, I think you have things confused.
I'm fairly certain I was clear in exactly the progression of how this all has unfolded.
At least I have been trying to be clear.
I'm not going to reiterate every step I made when it's already in my previous comments multiple times already.

 

[David Emerson]

If it was me I would use the brass after you weigh it to prove consistency. Then use new primers and powder and other bullets. Woodleigh , nosler partition, barnes triple shock. With the lead core I would use 200 grain bullets. Buff are big and thick. Sucks but at this point it is the best you can do. Resize the brass after you pull the bullets to reset the neck tension. I have a 308 norma and friends also have them. VERY accurate guns and not fussy.