OCW question: switching bullets but using same weight bullet?
- Thread starter ChrisBCS
- Start date
I would at least test the load before depending on it to work. Maybe load 20 and see how it does
I bet you will be alright though.
I bet you will be alright though.
Yep you'll need to work it up again for the new bullets.
There's a very good chance the OCW for both will be different.
There's a very good chance the OCW for both will be different.
I've done this several times but rather than make up a bunch of different loads I just try one load on either side of my previously "good" load. For my rifle I find that 175 gr SMK's 175 gr Nosler Custom Comps, and 178 gr A-max shoot so well using the same load I don't even bother adjusting anymore. I find that different cases make more change than the change among these three bullets -------- in my rifle.
On the surface I would say your OCW powder charge should be GTG and only variation in seating depth should be revisited.
But, I have seen rifle barrels do some really unexplainable things when even slight changes were made to ammo.
Deadshot2 advice makes sense.
But, I have seen rifle barrels do some really unexplainable things when even slight changes were made to ammo.
Deadshot2 advice makes sense.
The HPBT can be a little finicky with seating depth as the ogive is a little steeper. I can not imaging the load being more than a grain different than your amax load, but I doubt the load will be the same. I guess you will find out soon enough.
Shape of the bullets and BCs are different, so you don't really know what's going to happen. Might be the same, might be very different, so it's better to test and find out for sure. If you don't want to spend a lot of effort on a complete new test, you can always try a minimalistic version centered around your previous optimum charge weight. It should tell you whether you're in the right ballpark.
I developed a OCW load for my rifle using 42.7 grains of 4064 using a moly coated 178 AMAX and Hornady match brass. I then switched to 178 HPBT using the same charge weight and the load was dead nuts on. The HPBT has less surface bearing than the AMAX too but it didn't change nothing but the POI is different even factory ammo using that bullet. I think you will be good but like mentioned earlier I would load 20 or so to test out before you start turning out hundreds of rounds....
I've found that heavier barrels or those with Muzzle Brakes added tend to be less sensitive to charge weight changes. I feel that on my rifle at least, this gives me more latitude in bullet selection, provided the main parameters are similar (bearing surface and weight) without any noticeable change in accuracy. Perhaps if I'm trying for One Hole Groups but not if I'm just going for an "X".
Yes. But what's the big deal. In a few rounds, you'll know where the new node is for your new projectile.
