115grain JHP .357 sig with blue dot.

[five.five-six]

I'm getting a new to me glock 23 in a week or so, It came with a .357 sig barrel and I'm working up a load for it. I have loaded .357 sig in the past and am aware of just how difficult and dangerous it can be. I have setup my 550B with a .357 sig toolhead including a lee factory crimp die and it crimps good!

right now, the components I have are blue dot, green dot several other wildly inappropriate powders and 115 grain JHPs I'm seeing recipes starting at 9.2 gr. and maxing out at 10.3 gr.blue dot for 124's will those be safe for 115's?

 

[sequins]

The general rule is that you use more powder for a lighter grain projectile and less for a heavier projectile. In this case whatever is recommended for 124 grain 9mm will likely be on the lighter side if loaded in 115gn.

That said, COAL plays a big part so if the 124 data is for a longer COAL it might be overpressure for a radically different projectile type at a different length.

 

[five.five-six]

Well, I’m building for the same COL but a lighter projectile should leave more space in the case and lower pressure. .....

 

[Hartkopf]

I’m a reloading newbie but I would be measuring and closely comparing your bullets bearing surface area and diameter to the bullets of the known load data. This would be the sort of thing that would bite me.

 

[Paul Toms]

I'm getting a new to me glock 23 in a week or so, It came with a .357 sig barrel and I'm working up a load for it. I have loaded .357 sig in the past and am aware of just how difficult and dangerous it can be. I have setup my 550B with a .357 sig toolhead including a lee factory crimp die and it crimps good!

right now, the components I have are blue dot, green dot several other wildly inappropriate powders and 115 grain JHPs I'm seeing recipes starting at 9.2 gr. and maxing out at 10.3 gr.blue dot for 124's will those be safe for 115's?

556,
9.2 to 10.3 will be completely safe with 115s in your pistol. Shoot them

 

[five.five-six]

The general rule is that you use more powder for a lighter grain projectile and less for a heavier projectile. In this case whatever is recommended for 124 grain 9mm will likely be on the lighter side if loaded in 115gn.

That said, COAL plays a big part so if the 124 data is for a longer COAL it might be overpressure for a radically different projectile type at a different length.

I think you’re on to something there.

I loaded up 50 115’s over 9.2 blue dot and it went poorly. At 15 yards my groups were like 4-5” The recoil and muzzle flash were spectacular, regardless of how I gripped my G23 I’d have to re-grip every round or two because it pretty much jumped out of my hand. that wasn’t too big of a deal because every 7-8 rounds I’d have to run a stoppage drill when the last case got stuck in the chamber.


I’ve never perforated a primer before but I think I did on a few of these.

 

[five.five-six]

 

[Craig28]

I think you’re on to something there.

I loaded up 50 115’s over 9.2 blue dot and it went poorly. At 15 yards my groups were like 4-5” The recoil and muzzle flash were spectacular, regardless of how I gripped my G23 I’d have to re-grip every round or two because it pretty much jumped out of my hand. that wasn’t too big of a deal because every 7-8 rounds I’d have to run a stoppage drill when the last case got stuck in the chamber.


I’ve never perforated a primer before but I think I did on a few of these.

View attachment 928394

What kind of wheather were you shooting in? I've heard blue dot can be temperature sensitive.

What was COAL and what primer were you using? I've ran 9.2 grains of blue dot behind a 125 speer in .38 super with no problems. I believe the sig can handle larger charges than the super can.

Any bulges/marks on the brass?

My hornady manual shows a max load of 10.8 grains for the 115 at 1350 fps. Hornady data is generally more on the conservative side.

 

[five.five-six]

I went to my bench and checked my notes and confirmed by throwing 10 charges from the tool head, my post was errant.

Charge was 10.2 +/- 0.1 Grain


I was shooting indoor nice 75 degree day

Primers were CCI standard SPP, I almost ran magnum but I’m glad I didn’t I understand they can increase pressure.