Need help with velocity swings

[ubet]

What the hell is going on here? Rifle is a colt 6920, the first two pictures, all cases fl sized, trimmed then loaded on a Dillon 650 charged with 23.1 cfe223 and all lc brass. The last screenshot, mixed head stamps, fl sized, not trimmed, crimped, 23grs re15, on a single stage. Bullets are 77gr nosler cc.

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[MtnCreek]

Do you trust the chronograph?

 

[FishDr]

Different brass prep, different brass, different length, different powder, etc, expect same result? I'm not sure what is the exact question. Your SD and spread looks pretty high, even in the given groups which are "same". Are you weighing charges or dropping on the 650? Sometimes technique can make a big difference if you are using the Dillon powder drop, as well as powder type. It's not extremely friendly to stick type powders but can be used with consistent techniques and a few mods. Just a guess.

 

[ubet]

Do you trust the chronograph?

It's my first chronograph, so I'm not sure

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[ubet]

Different brass prep, different brass, different length, different powder, etc, expect same result? I'm not sure what is the exact question. Your SD and spread looks pretty high, even in the given groups which are "same". Are you weighing charges or dropping on the 650? Sometimes technique can make a big difference if you are using the Dillon powder drop, as well as powder type. It's not extremely friendly to stick type powders but can be used with consistent techniques and a few mods. Just a guess.

With prepping the brass I was expecting the mv to have less swing as opposed to just loading it and going. I'm just dropping them with the 650 powder drop, I weigh about every tenth round. Each time they are right on the money.

My questions are, what can I do to get a more even mv and why would non prepped brass be more consistent?

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[MtnCreek]

It looks like you have more variables than just brass. You also changed powder and added a crimp, correct?

I tried CFE with 77/75 gr BTHP and didn't care for it in the two barrels I tried. It may work great for others.

Several years ago I was shooting with a new reloader that was getting single digit SD & ES over my CED chrony with 30-06 loaded with FMJ bullets. He crimped the piss out of them, deforming the bullets. I believe the excessive crimp was the reason for the great numbers (although the bullets were pretty much ruined).

My old CED millennium is very picky about lighting. It's good for getting an approx. velocity, but I wouldn't spend too much time chasing small SD's based on what it's showing. I would at least consider that the chrony numbers you're getting could be off.

 

[ubet]

I did change powder, the bullets with re15 were crimped the ones with cfe weren't. So I should try crimping then, you help even things out?

I want to buy a Labradar but it's way down on the list of needs vs cash.

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[MtnCreek]

I wouldn't crimp. But I do believe it has an effect on SD's.