.338 LM velocity

[DaveV]

I have recently worked up a load for my AR30, but have no access to a chrono. Could one of you give me a ball park velocity to work with so I can work with some JBM charts. Thanks!!

.338 Lapua Magum
250 gr. Sierra Match King
87.5 gr. Reloader 22
Lapua brass
CCI Mag. Rifle primer
3.740 C.O.A.L.
0.002 neck tension

Armalite AR30
26” barrel

 

[ChrisGarrett]

Re: .338 LM velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DaveV</div><div class="ubbcode-body">I have recently worked up a load for my AR30, but have no access to a chrono. Could one of you give me a ball park velocity to work with so I can work with some JBM charts. Thanks!!

.338 Lapua Magum
250 gr. Sierra Match King
87.5 gr. Reloader 22
Lapua brass
CCI Mag. Rifle primer
3.740 C.O.A.L.
0.002 neck tension

Armalite AR30
26” barrel
</div></div>

Just a wild ass guess here, as I have no way knowing, but I'll say:

2825-2850 fps.

Chris

 

[DaveV]

Re: .338 LM velocity

Thanks Chris!

 

[mattmcg]

Re: .338 LM velocity

DaveV, with the data you've given, Quickload estimates 2885fps with the 26" barrel at 60.5K psi pressure at the 3.740" COAL.

BTW, not a bad guess Chris!

 

[DaveV]

Re: .338 LM velocity

You guys are awesome! This is exactly what I was looking for. Thanks!!!

 

[ChrisGarrett]

Re: .338 LM velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hazardus</div><div class="ubbcode-body">DaveV, with the data you've given, Quickload estimates 2885fps with the 26" barrel at 60.5K psi pressure at the 3.740" COAL.

BTW, not a bad guess Chris! </div></div>

Ha!

It was late and I wasn't going to go searching through my chrono data books, but I use VV165, VV170 and my go to powder for the 250s at 1k yds is ~85.5-87 grs of H-4831sc.

To be honest, RL-22 is a bit slower and 87.5 is a bit more, so I was actually thinking my guess was a bit low. I do shoot a TRG-42, with a 27.15" tube, so I get a few FPS more, but 2885 fps seems more in line with the parameters, upon further reflection.

I probably should have gone 2850-2875. I've loaded to over 3000 fps, but I generally stick with the more moderate loadings to save my throat. 1022 yds (my max in SoFla) is just a lazy lob for the 338LM.

Why load hot if you don't have to?

Chris

 

[DaveV]

Re: .338 LM velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">Why load hot if you don't have to?</div></div>

My thoughts exactly! I have a great node at 91 gr. but I'm not looking forward to re-barreling anytime soon.

Thanks again, Chris. And good guess!