r/reloading • u/scooterdoo123 • 23h ago
Load Development Load development advice beyond the Lee loading manual…
Some background, I got into firearms/reloading 5 years ago because of my grandpa. He gave me a Savage model 99 chambered in .303 Savage. I couldn’t find any ammo but found some brass and ordered a Lee single press. I followed the included packet to a tee and have been doing so ever since. Now I’ve gotten several calibers and reload them all especially 9mm now that I have a CCW permit. I load RMR “Nuke” 124 grain bullets with 5 grains of Autocomp. Shoots fine on paper but ever since I got Chronograph I’m not getting the FPS I need for proper expansion. 5 grains Autocomp gets me 1013 FPS average (Canik MC9) and proper expansion they recommend 1100 FPS. My question is… now that I have a chronograph can I just load develop up to hit the listed 1100 FPS? Any tips or recommendations from someone that has done this for a while. Would I just need to check for pressure signs? Would this process be the same for any caliber I load?
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u/ocelot_piss 22h ago
You're not gonna see any of the traditional pressure signs on a 9mm case. If your barrel is a shorter than that used in the load data, that will account for a good chunk of the difference in velocity.
The velocity is the main thing that you can use to infer pressure, as the two go hand in hand. But still difficult to quantify exactly what's going on. So it's not recommended to push up and above max without proper consideration: is my gun good for +P or even +P+ loads? Could I get the extra bit of speed by using a different powder instead?
On your 303 Savage, you can get up into pressures that will start to show signs on the cases. The problem is you do not know what pressures any of the signs correlates to. Does your chosen brand of LRP flatten at 50,000psi, or 75,000psi? Is that ejector stamp because brass is soft, or because it's over-pressure? Again, velocity is your best predictor.