shooter177
CGN Regular
- Location
- Durham region
i have a 260 rem with a 26 inch broughten bbl i am shooting 123g lapuas in lapua brass with between 44.4 and 45g of h4350, does anyone have any idea how fast this load is? i dont have a cronny (yet) !
how fast am i going
- Thread starter shooter177
- Start date
Shoot at targets for every hundred yards to 500yrds or so. Calculate the required drop to equal the dialed drop to hit point of aim and you should have a good ballpark estimate on velocity.
JBM Ballistics is wonderful for this.
JBM Ballistics is wonderful for this.
hometownhero
CGN Ultra frequent flyer
- Location
- Toon Town, Sk
For sure they are cheap enough.
- Location
- Somewhere on the Hudson Bay Coast
With a cartridge length of 2.800", Quick Load suggest 44.5 of H-4350 is an over load that produces 2978 fps with 60,622 psi, (60191 psi is maximum) but 43.8 is OK and gives you 2965 with 59737 psi, 43.5 gives you 2946 fps with 58435 psi. Velocities are based on a 26" barrel. If you can seat your bullet out longer that effectively reduces pressure. With a cartridge OAL of 2.850", a 44.0 gr load is safe and gives you 2957 fps with 58683 psi.
Based on this information, I would check your fired brass for pressure signs and if you find them back off on the powder charge. Look for shiny extractor marks on the case head and check for web expansion beyond .001". As you'll note there is no velocity benefit worth the risk of dancing with dangerous pressure.
shooter177
CGN Regular
- Location
- Durham region
The owl I have is 2.82 and inwas starting to see pressure signs at 45, and that's why I asked, thanks this helps me! (croney is on it's way)
Pathfinder
CGN Ultra frequent flyer
- Location
- Northeast Ontario
An educated it would only be..I noticed Quickload does not always (or never) agree with my Chrony. As Boomer mentioned pressures can vary quite a bit depending on the Seating lenght , Chamber/throat / Barrel etc etc.
Pathfinder
CGN Ultra frequent flyer
- Location
- Northeast Ontario
Yeah I know, I use it as an add to a manual for odd-ball stuff...its really not to be mistaken for real life results....QL has no real idea of the actual internal Ballistics going on at your actual end.
- Location
- Somewhere on the Hudson Bay Coast
I agree, some stuff it predicts quite closely, other stuff not so much, and it can get you into trouble if you're not paying attention. IMHO it works best with middle of the road cartridges loaded with mid-weight bullets seated ahead of powder choices that are well balanced for the cartridge. It certainly doesn't take the place of real life load evaluation. As with any load prediction, you must be aware of lot to lot tolerances of all components.
