First batch of reloads with Lee press at the range today

Very nice writeup, Duke.

PowPow said:

Very nice writeup, Duke.

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Well Thank You Sir! Always a bunch of guys here on MDS who like to try to help the newer folks in learning the reloading craft. Benefits all of us.

Uncle Duke said:

Sounds like you have a pretty sound plan in developing your load with your mentioned component combination.......

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Thank you for validating my plan the good advice and information. It might be a couple weeks before I get back to the range, but I'll post the results here.

I bought a pound of Hodgdon HS6 at Cabelas the other day on the advice of the people there but I can't find any reloading data on it with the plated bullets that I'm using. Hodgdon site only lists it with a 124 GR. BERB HBRN TP which is a Berry's plated bullet but it's hollow back and the plated bullets I have are not. Would the data be the same?

BULLET WEIGHT - 124 GR. BERB HBRN TP
MANUFACTURER - Hodgdon
POWDER - HS-6
BULLET DIAM. - .356"
C.O.L. - 1.150"

STARTING LOADS
GRS. VEL.(FT/S) PRESS.
6.0 1,016 28,200 PSI

MAXIMUM LOADS
GRS. VEL.(FT/S) PRESS.
6.6 1116 32,400 PS

strat56 said:

Thank you for validating my plan the good advice and information. It might be a couple weeks before I get back to the range, but I'll post the results here.

I bought a pound of Hodgdon HS6 at Cabelas the other day on the advice of the people there but I can't find any reloading data on it with the plated bullets that I'm using. Hodgdon site only lists it with a 124 GR. BERB HBRN TP which is a Berry's plated bullet but it's hollow back and the plated bullets I have are not. Would the data be the same?

BULLET WEIGHT - 124 GR. BERB HBRN TP
MANUFACTURER - Hodgdon
POWDER - HS-6
BULLET DIAM. - .356"
C.O.L. - 1.150"

STARTING LOADS
GRS. VEL.(FT/S) PRESS.
6.0 1,016 28,200 PSI

MAXIMUM LOADS
GRS. VEL.(FT/S) PRESS.
6.6 1116 32,400 PS

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You sir ask a very good and a very common question.

You'll encounter a number of instances where you'll want or need to switch components, either because of what you might have available on hand to load, or because of what you might only be able to obtain. Now some component switches are far more significant than others. But you can generally make changes when it comes to bullets of the same weight and the same general construction characteristics, in this case a 124 grain round nose plated bullet. Your base won't matter so much here. But bear in mind that there's a very definite rule in play here. That is, when a manufacturer publishes load data, they are publishing data for the exact combination they list. And you, because of your proposed change, won't now have the exact combination they list. So when you change from the published components, and you know that "the same" has now been changed by you to "similar", you want to start a new load workup.

Understand that when you make changes from industry published loads, you by definition introduce variables. The question then becomes, well, just how much difference will my change make? You have the same weight of 124 grains, which is good and what you want, and you have the same construction, which is a plated bullet, which is also what you want given the data you propose to use, with plated being an important consideration. Your base is different. The correct answer here to "so how much difference will my change make, even though I have my components being pretty similar?" The correct answer is "I don't know exactly." Why? Because you don't in fact know exactly, and because neither does anybody else know exactly, short of having access to a ballistics lab.

Your work around is to keep your components as close as possible to the listed load data. Ok, you've now done that. Your next step is to then build in a safety factor. Your working rule of thumb then becomes to back off maximum charge weight by 10%, and then work your load up from there. Most importantly as you go along, REMEMBER TO FORGET about what your charge weight might have been with a DIFFERENT 124 grain bullet. IT'S THIS NEW BULLET you're interested in safely developing a load for. When is your new bullet load a good and safe load in your pistol? When you do the research work and the bench work and the range work to be able to say it is! That's when.

In your example above, load a few rounds at 6.0, then 6.1, then 6.2 etc. Make your assessments as you fire each of your incremental increases.

Good Luck! Let us know how you make out.

Good write up above. I agree completely. To answer the question more directly; Most cartridge charges are designed to fill a significant portion of the case. In the horizontal ( ready to fire) position, the powder covers the flash holes and is burned from base to mouth. If the case volume increases significantly, whether that be by reducing the seating depth ( making a longer cartridge and more void space in the case) or by introducing a projectile with a hollow base, there is a risk that the flash hole will become exposed to the horizontal surface of the powder. The primer flashes across all the powder and it detonates rather than burning. The pressure spikes and there is a risk of damage to firearm and fingers. I do not wish to alarm you, but the effect was not intuitive to me until someone explained it. That's why there are minimum as well as maximum charges.

If I look at Berry's 9mm plated hollow base bullets, I see that the following load data is included:

The bullet profile is longer but the weight remains the same and you can load these bullets using any published load data for a jacketed bullet as long as it is the same weight bullet.
SAAMI MAX COL = 1.169"
Can withstand velocities up to 1500 fps.
https://www.berrysmfg.com/item/bp-9mm-356-115gr-hbrn-tp

They have given a cartridge overall length which establishes the total case volume, and instructed to use any available loading data for a plated bullet the same weight.