bad crony or bad load

[USMC 338]

My 25-06 loaded with 52gr 4831sc 115 NBT out of a 24'' barrel average speed 2820. Ive finaly found someone elce that has another crony to test the one i have . also i have to add 100FPS to exbal to get actual drops to 700 yards. (same with 338 lapua)THANKS

 

[specweldtom]

The velocity seems to me to be about 100 fps low, and exbal probably proves it. If you can find someone who has an Oehler 33 or 35, shoot through it and see. Try the Lapua through it too. Remember that the muzzle velocity will be a little higher than instrumental velocity because of the distance to the screens. Not much though. I just use the instrumental velocity and don't try to correct to M/V.

If this load groups, extracts cleanly, and has a good standard deviation, there isn't anything wrong with it.

Good shooting, Tom

 

[USMC 338]

thanks i will do that i think i know who has an oehler.

 

[.280Rem]

My 25-06 loaded with 52gr 4831sc 115 NBT out of a 24'' barrel average speed 2820. Ive finaly found someone elce that has another crony to test the one i have . also i have to add 100FPS to exbal to get actual drops to 700 yards. (same with 338 lapua)THANKS

You're about 100fps slower than the same powder charge with a 117 according to Hodgden's online data. Thats not at all unusual. 3050-3100 can be done with 120s. 3100+ should easily be doable with 115s in a 24". To check your chrony, simply run a known load of your from another gun over it. If its correct, then you simply need to add powder to get the velocity up where you want it. You should be able to run 3000+ easily with H4831 and not come near max pressure.