9mm 147gn Reload Velocity

[treillw]

Shooting 150 grain hardcast out of a sig xmacro with 3.1" barrel. What's the max velocity people usually get the 147 grain class bullets to run at? Reloading book says 1000 fps. Underwood claims 1100 fps.

What is a generally safe velocity and how do you safely work up to it for your gun?

Thanks!

 

[BrBa]

A lot will depend on your choice of powder, and also how willing you are to push the envelope. I don't know of any boutique ammo companies that manufacture their own powders, so we all have access to the same off-the-shelf components they do. If a company claims to achieve higher velocities than published max. loads, it's because they are loading to higher max. average pressures. New guns are tested with proof loads of course, but who wants to shoot proof loads in any of their guns on a regular basis?

Accurate #7, Ramshot Silhouette, Alliant Power Pistol and BE-86 typically show up as providing the highest velocities for 9mm up to SAAMI +P (38500 psi) max. average pressures with 147 gr bullets. Most are in the 1000-1050 fps range, but the test barrels used are usually 4" or longer.

Unless you have one of those universal receivers which can accurately measure pressures, the only way to do it safely is to start roughly 10% lower than published max. loads and work up at a pace you feel is safe. The 10% reduction from published max. loads is due to lot-to-lot variations in powder burn rates.

Of course the easiest and safest way to get more velocity at the same pressure is to use a longer barrel.

 

[treillw]

A lot will depend on your choice of powder, and also how willing you are to push the envelope. I don't know of any boutique ammo companies that manufacture their own powders, so we all have access to the same off-the-shelf components they do. If a company claims to achieve higher velocities than published max. loads, it's because they are loading to higher max. average pressures. New guns are tested with proof loads of course, but who wants to shoot proof loads in any of their guns on a regular basis?

Accurate #7, Ramshot Silhouette, Alliant Power Pistol and BE-86 typically show up as providing the highest velocities for 9mm up to SAAMI +P (38500 psi) max. average pressures with 147 gr bullets. Most are in the 1000-1050 fps range, but the test barrels used are usually 4" or longer.

Unless you have one of those universal receivers which can accurately measure pressures, the only way to do it safely is to start roughly 10% lower than published max. loads and work up at a pace you feel is safe. The 10% reduction from published max. loads is due to lot-to-lot variations in powder burn rates.

Of course the easiest and safest way to get more velocity at the same pressure is to use a longer barrel.

Thank you. How do you know when you're reaching the unsafe point. I know how to do it in a bolt gun, but not a pistol or AR.

 

[BrBa]

Honestly I couldn't tell you, as I don't push the limits with any of my pistol cartridges. My way of thinking is if you need more power than you'll get from a published max. load, then it's time to switch to a more powerful cartridge, especially if you're shooting a semi-auto. Revolvers, especially all steel Rugers, you can certainly lean on those if you want. I've loaded some .357 Mag up to @ CIP published max = very unpleasant, huge fireball, accuracy was for shit. Not doing that again.

Back to your original question, I'll also add that I've never had much luck with heavy 9mm bullets (147 gr or more) in short barrels like your Sig. Accuracy tends to be much better with 124 gr in those barrels. 4" or longer and things will tighten up quite a bit with the 147s, better velocity too.