OCW test White Oak AR15

[Pilotscrappy]

hey guys just looking for a little guidance/conformation on this ocw test I just shot on my ar 15
Load is 23-24.5 grains on 8208XBR
Lake city brass
69 SMK seated @2.250
Didn't have the chrono today so velocity is unknown for now.

Ar is 18" 1 in 7 twist white oak 223 wylde.

I've never done an ocw for an ar but looking at this target I think that 24.2 gr shot the flattest.
24.5 had the smallest group but there was more vertical difference.

So should I load more at 24.2 and start messing with bullet seating depth or should I keep exploring with charge weight ?

Any guidance appreciated

 

[Pilotscrappy]

Also I should add the groups that are circled with a sharpie were not part of this test.

 

[TheOfficeT-Rex]

Is 24.5gr max for pressure?

 

[Jordanwickham]

If 24.5 is max pressure I'd play in the 24 range. 23.9 and 24.2 had the least change. Means 24 is in the middle and safe from changes.

 

[Gustav7]

hey guys just looking for a little guidance/conformation on this ocw test I just shot on my ar 15
Load is 23-24.5 grains on 8208XBR
Lake city brass
69 SMK seated @2.250
Didn't have the chrono today so velocity is unknown for now.

Ar is 18" 1 in 7 twist white oak 223 wylde.

I've never done an ocw for an ar but looking at this target I think that 24.2 gr shot the flattest.
24.5 had the smallest group but there was more vertical difference.

So should I load more at 24.2 and start messing with bullet seating depth or should I keep exploring with charge weight ?

Any guidance appreciated

IF you're shooting this at 100yds, I wouldn't worry about what is shooting flattest or what has more vertical. Thats something I've always tested at 300+ yards, more like 500yds.

Someone may correct me if I'm wrong, but an OCW is not about velocity or group size, its about group position relative to POA. You're trying to find multiple charges that have the same basic POI at the center of their group, showing you that those charges produce similar harmonics and therefore similar POI's.

You would then load to the middle of that range of charges, giving you the most leeway with powder charge.

For my OCW with my AR using 8208 and 75gr HPBT's, I went from 22.9-24.0 spacing every 0.2gr. I found that 23.4-23.8 had the same POI. So I played around with 23.5 and 23.6gr.

Judging by your picture, I might play around with 23.9-24.5gr, or retry the OCW with 5 shot groups.

 

[Jordanwickham]

IF you're shooting this at 100yds, I wouldn't worry about what is shooting flattest or what has more vertical. Thats something I've always tested at 300+ yards, more like 500yds.

Someone may correct me if I'm wrong, but an OCW is not about velocity or group size, its about group position relative to POA. You're trying to find multiple charges that have the same basic POI at the center of their group, showing you that those charges produce similar harmonics and therefore similar POI's.

You would then load to the middle of that range of charges, giving you the most leeway with powder charge.

For my OCW with my AR using 8208 and 75gr HPBT's, I went from 22.9-24.0 spacing every 0.2gr. I found that 23.4-23.8 had the same POI. So I played around with 23.5 and 23.6gr.

Judging by your picture, I might play around with 23.9-24.5gr, or retry the OCW with 5 shot groups.

You are correct which I feel the OP had a fair grasp on since typically people would see 25 and think "oh there it is" because it's a tight group. But the OP noticed it's quite off from where the two previous charges were. You are also correct in between 23.9-24.5 being the OCW.

 

[Gustav7]

You are correct which I feel the OP had a fair grasp on since typically people would see 25 and think "oh there it is" because it's a tight group. But the OP noticed it's quite off from where the two previous charges were. You are also correct in between 23.9-24.5 being the OCW.

No disrespect meant to the OP.

Ok good, glad my OCW eyes are getting better lol.

 

[Jordanwickham]

No disrespect meant to the OP.

Ok good, glad my OCW eyes are getting better lol.

Oh sorry man didn't mean for that to come across as a call out or anything. Was more reassuring the OP that he was seeing what we were seeing.
And basically thanking him for not doing the typical shiney small group thing.
For the OP I would play around in 24. You could do a narrower OCW from 23.9-24.2 but I'm fairly certain that playing with seating on 24 will give you good results. I'd say you are probably 15-20k away from the seating node. Once you find that then I'd play with the Chrono on a 10 shot or take it to 300-500 and see how it holds as Gustav said then do a Chrono string.

 

[Pilotscrappy]

Thanks for replies guys looks like we were seeing the same thing.
Couple things ,those were in fact 5 shot groups shot @100 yards.

And yea I stopped at 24.5 for pressure signs
Imr actually says 23.8grains was max charge

 

[Gustav7]

Thanks for replies guys looks like we were seeing the same thing.
Couple things ,those were in fact 5 shot groups shot @100 yards.

And yea I stopped at 24.5 for pressure signs
Imr actually says 23.8grains was max charge

My B.

I worked up to 24.0gr with 75's in my rifle before I started seeing a few things that bothered me. I settled on 23.5gr with Hornady 75's.

Let us know how the rest of the development goes. Always interested to see more 8208/.223 development.