Range Report Need some help with velocity predictions

[ReaperDriver]

HELP, I'm going 1K yd shooting in the AM and I'm trying to make up some ballistic cards. Anyone with QL that's willing to help out, I'd appreciate it. I know that's frowned upon, but I'm ordering QL next month for myself, I just don't have it yet.

I need the predicted velocity for
.308 WIN
20" factory Rem barrel
Lapua Brass (Empty wt - 177.4. w/ water: 234.8
Varget powder
Fed 210 primer
Temp 45F
Alt 4000' MSL

The three loads I need velocities for are:
45.0 Varget w/ 175 SMK, seated to 2.810
45.0 Varget w/ 178 AMAX seated to 2.860
47.8 Varget w 155 Palma (2155) SMK seated to 2.860

If you don't mind helping me late notice, please PM me your results. Thanks in advance.

 

[MitchAlsup]

Re: Need some help with velocity predictions

47.8 Varget w 155 Palma (2155) SMK seated to 2.860

Guestimate 2850-2875 fps, and pressure signs and not as accurate as you hoped for.

47.8 is for Win cases, 47.5-6 is for Lapua cases.

 

[ReaperDriver]

Re: Need some help with velocity predictions

Mitch, thanks. I shot the 47.8 load yesterday at 1k and the drops seemed to indicate the MV was in the mid to high 2700's out of my 20" barrel and no pressure signs. Accuracy seemed fine at 1K - it held the verticle very well but the wind seemed to push the 155's around a bit more than the 175 SMKs and 178 AMAXs I was shooting.

I ahd previously chrono'd the 47.8 varget load in Lapua brass at around 2740 (20") but they were seated at 2.875. This time I tried to go 2.860 and I noticed maybe a little faster velocities (20-30 fps) based just on actual vs calculated mils. Definitely not in the 2850 range with that short barrel. I wish!

 

[Grump]

Re: Need some help with velocity predictions

47.8 Varget w 155 Palma (2155) SMK seated to 2.860

I'm saying it looks more like 2,819 FPS and a bit more than 5KPSI over spec pressure.

Assumes standard bore, accurate reporting of input data, AND a lot of powder that matches what I have. Use at your own risk.

Check PM

 

[Grump]

Re: Need some help with velocity predictions

At 1K, your barometric pressure can make a difference. Cold and clear? That's NOT 29.92 corrected for elevation.