Where to start?

[adamsredlines]

Looking at Hodgdon site for load data...they show max charge but not a min...so how do you decide how low to start?

220gr with CFE BLK

https://hodgdon.com/wp-content/uploads/2020/07/subsonic-data-final.pdf

 

[thor447]

Looking at load data for other Powders, including some others from Hodgdon, it appears that most start out around 1.5 to 1.7gr below max for the min. You might start in that area and start working your way up.

Having never loaded any .300 AAC myself, I'll defer to others who have gone through this exact process for that round.

 

[rickm]

I would make sure to check for a squib after every shot if you start lower

 

[adamsredlines]

Is that not standard practice to start under the max load?

 

[DRC458]

I've never loaded subsonic, so there may be some guidelines I am not at all familiar with. The old conventional wisdom was to start 10% below max and work up from there. But, dealing with such light charges that might be an issue. IDK. I would contact Hodgdon directly!


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[Rayce]

I would also look at a hornady reloading manual. They have quite a range of powders for specific loads. With the starting point to max charge.

 

[ignerntbend]

you could start from where you are, but that would be unheard of.

 

[MacFromOK]

you could start from where you are, but that would be unheard of.

Lol, some folks say ya can't get there from here...

 

[264killer]

they speculate some light charges detonate.

 

[MrChris]

From what I understand, you should be working your sub loads backwards. Starting high and working backwards from there.
Starting too low will leave you with an under pressured situation and a projectile that didn't leave the muzzle, which could be catastrophic on the next shot.
I am no expert, as I am just starting to load myself, but I have been reading alot on loading .300 BO and this has been the general consensus on subs from what I have read.