Velocity

[Malazan]

I just got back from the range today, where I was Chronographing my loads. I shot 30 rds and this is what I came up with.


25.1 RL-10x
39 SBK
Rem 7 1/2
Hornady Case
Ogive: 1.860
COAL: 2.335

My average Velocity was 3931 FPS

That is 200 FPS more than the Sierra load manual states for this load. What Gives?

For what it's worth, my 32 V-max with 25.5 of RL-10x were going at 4124 FPS, that's about 200 FPS over the published data also

[Kingcrawler]

I'm shooting 24.8 gr. Of 10x with the 39 bk and getting 3850 fps out of a 28 inch encore barrel .

[Joe O]

Not unusual.A few factors will change the FPS that much.Brass,capacity and neck tention.Chamber and barrel.Powdwe from different lots.

[Jim White]

I've seen where;

- Sun light vs over cast;
- How high, low and centered the bullets fly over the sensors;
- Elevation;
- Environmental conditions;
- Distance from the muzzle to the chronograph;
- Any blast or other effects upon the chronograph.

There are probably others but these have skewed my numbers thru the years, not to mention the load itself.

[204cat]

barrel length and temp.

[Fred_C_Dobbs]

Let me guess. It's a Shooting Chrony.