Help me with my velocities

[ubet]

So I went and ran two different loads through a carbine this morning. 14.5” barrel, 16.1” including muzzle break. The 77gr smk load when I did load development was 3/4 moa at 700 in a ladder/ocw test, the loads were 23.9, 24.1, 24.3 I settled on the 24.1. The other load is a 62gr hpbt Hornady at 23.9. I know the sd and es is high, I loaded these on a 650. My question I guess is, are these fast enough? I was fairly happy with the 62s but the 77s seemed slow. They were 10 shot tests



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[mRad]

If you’re shooting 3/4 MOA at 700 yards with a 14.5”, you don’t need to worry about it.

My 14.5” gets 2550 with my 77 gr load, my 16 gets 2750with it.

ES and SD would indicate out of tune load and it’s time to adjust there; usually it’s seating depth…but I had a hard time believing it’s worth chasing if you’re 3/4 MOA at 700.


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[JimmyB62]

If you were able to shoot 3/4 moa at 700 yards then there is likely something wrong with your chrono. A 122 es would mean about an 18” vertical spread at 700 yards which is well outside of 3/4 moa. Can you borrow another chronograph and confirm results? Maybe I’m just not understanding which isn’t uncommon for me these days.

[ubet]

I’m not getting it either. My chrono is a fairly new magnetospeed v3. For my bolt gun I show this screenshot. I haven’t taken this ar out too 700 since I built the load. But might have the target somewhere.


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[mRad]

I’m not getting it either. My chrono is a fairly new magnetospeed v3. For my bolt gun I show this screenshot. I haven’t taken this ar out too 700 since I built the load. But might have the target somewhere.


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If you haven’t taken it to 700 yet, why did you say it was shooting 3/4 at 700?


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[ubet]

If you haven’t taken it to 700 yet, why did you say it was shooting 3/4 at 700?


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Since I built the load. I shot it at 700 when I built it.


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[mRad]

Since I built the load. I shot it at 700 when I built it.


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And what’s wrong with the load you were using then? That’s great accuracy for an AR at 700.


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[ubet]

And what’s wrong with the load you were using then? That’s great accuracy for an AR at 700.


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The 77s are the same load. I don’t know why my velocity is so wanky I guess. What’s a normal es and sd for an ar with 77s? I just loaded those I didn’t weigh every load. Dumped the cases out of a jug, the 1000 top brass jug and went to loading.


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[mRad]

ES and SD can be a result of poor processes, inconsistencies in components, being on the edge of a node, or even chronograph equipment failure.

Believe it or not, even a weakening hammer spring can cause inconsistent velocity.

With 100 FPS ES, it would be really hard to attain 3/4 MOA vertical at 700 yards.


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[ubet]

It’s all cci 41, cfe223 powder, crimped, seated just below mag length with a Redding comp seating die. The cases for the 77s were lc brass from top brass.


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