Help with 9mm load

[DG23]

It’s silly to want to run up your 9mm loads to pressure anyway.


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Much more safe / forgiving with the slower powders.

[mRad]

Much more safe / forgiving with the slower powders.

I prefer sport pistol or N320; I’ll run it up to power factor with the bullet then tune based on the sights and recoil.


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[kerplode]

What sorts of pressure signs should I be looking for?

There are no reliable "pressure signs" for pistol cartridges. Hell, "pressure signs" are not really all that reliable for rifles either. By the time you're flattening/cratering primers etc, you're way over.

Buy a chronograph and measure velocity instead...It's a much more accurate indicator.

And as others have mentioned, you really can't just interchange data for bullets of the same weight. Always work up.

[chamber143]

There are no reliable "pressure signs" for pistol cartridges. Hell, "pressure signs" are not really all that reliable for rifles either. By the time you're flattening/cratering primers etc, you're way over.

Buy a chronograph and measure velocity instead...It's a much more accurate indicator.

And as others have mentioned, you really can't just interchange data for bullets of the same weight. Always work up.

I have a chrono. I get what you guys are saying, I am not sure I am being clear. The minimum and maximum are almost identical as well as velocities for 15 different powders except for the hs6 and it’s a large variance. I will build up as I always do as I don’t like getting near max but what makes the hs6 so different in these two bullets when every other powder for these two bullets is almost identical.


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[gaijin]

I would hazard a guess that one of the two bullets has more bearing surface, which increases chamber pressure.
One of them may be larger in diameter as well; .355”/.356”/.357”.

[wil]

Straight wall pistol brass does not 'read' like rifle brass will. You are better off reading tea leaves to determine over pressure.

Want to prove it to yourself? Trim a piece of 9mm brass a tiny bit short and then fire it with a known to be 'safe' loading and inspect the primer / brass. Compare to the same loading fired with brass that actually fits the chamber properly and chime back in...

Mouse fart loadings will flatten the hell out of primers in my 460 Rowland chamber IF the brass is short. (Think 45ACP brass fired in a longer 460 chamber)

Seeing as how most 9mm brass is going to be a tiny bit 'short' anyway and mixed brass will likely be all over the map in length - Visual 'signs' of pressure are very unlikely to be the same from one piece of brass to the next even if the loading / charge weight remains exactly the same.

Don't just take my word for it - Trim you down a few pieces of brass and give it a go for yourself.

Ummm.......no. inspecting your brass and trimming it a proper length, which is part & parcel to proper reloading procedures, you'll find pressure signs are accurate and consistent.

Also known safe loads are determined with brass properly trimmed and sized, not a screw-up on reloading procedures or a lack of attention to detail in regards proper procedures. Brass trimmed short is a screw-up and of course it will raise pressure, it is a given amount of gas pressure within a specified volume, reduce the volume and pressure goes up, this is in accordance with the laws of physics.

Neither have I found 9mm brass to be 'short' as you put it. Why would factories deliberately put out ammunition that does not conform to specs? They dont.

As for reading pressure signs on brass, my experience does not agree with your opinion. Pressure within brass is pressure within brass, it behaves the same owing to it's actions are determined by the laws of physic. There are external physical manifestations such as the ones I mentioned.
And brass improperly prepared, ie: a screw-up which according to your logic is a valid argument, will show higher pressure signs, an indication a reloader should be paying attention to.

[DG23]

Ummm.......no. inspecting your brass and trimming it a proper length, which is part & parcel to proper reloading procedures, you'll find pressure signs are accurate and consistent.

Also known safe loads are determined with brass properly trimmed and sized, not a screw-up on reloading procedures or a lack of attention to detail in regards proper procedures. Brass trimmed short is a screw-up and of course it will raise pressure, it is a given amount of gas pressure within a specified volume, reduce the volume and pressure goes up, this is in accordance with the laws of physics.

Neither have I found 9mm brass to be 'short' as you put it. Why would factories deliberately put out ammunition that does not conform to specs? They dont.

You just showed how smart you really are not...

Chime back in with your 9mm chamber length measurements and follow up with your brass lengths.

Hint: Factory new 9mm brass is going to be short so that it fits anything...

Also - Short brass does not do squat for chamber pressure OR your internal volume of the brass if the COAL remains the same.

You got a lot more learning about reloading to do before giving anyone advice. LOL!

Gave me a good laugh this morning thinking about you (attempting to) trim 9mm brass 'as part & parcel to proper reloading procedures'.

[mRad]

Lol trimming 9mm brass.


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[wil]

You just showed how smart you really are not...

Chime back in with your 9mm chamber length measurements and follow up with your brass lengths.

Hint: Factory new 9mm brass is going to be short so that it fits anything...

Also - Short brass does not do squat for chamber pressure OR your internal volume of the brass if the COAL remains the same.

You got a lot more learning about reloading to do before giving anyone advice. LOL!

Gave me a good laugh this morning thinking about you (attempting to) trim 9mm brass 'as part & parcel to proper reloading procedures'.

per speer reloading manual number 11 pg 386: brass length specified 0.754"

per hornady reloading manual 4th edition pg 543: 0.754"

As for case length and pressure, you should read about the laws of physics and thermodynamics in regards to pressure and volume, you'll learn something.......judging from the arrogant attitude displayed by your posting and the outright ignorance contained regarding what you've posted I have my doubts about that however I will offer you to read and learn.

[DG23]

per speer reloading manual number 11 pg 386: brass length specified 0.754"

per hornady reloading manual 4th edition pg 543: 0.754"

As for case length and pressure, you should read about the laws of physics and thermodynamics in regards to pressure and volume, you'll learn something.......judging from the arrogant attitude displayed by your posting and the outright ignorance contained regarding what you've posted I have my doubts about that however I will offer you to read and learn.

An example:



Both rounds here (not 9mm rounds obviously) are loaded to a COAL of 1.230 (tip of the bullet to the base of the brass), and both have the same exact bullet seated in them. For the sake of this discussion there is zero difference in the case capacity below the bullets in those rounds. If I use the same exact weight of powder charge in each the pressure produced will be nearly the same providing they are fired in the same chamber. The piece of 'short' brass is not going to somehow make the same exact (weight of) powder charge generate more pressure just because there is less brass up top holding the bullet in place. If fired over a chronograph they are going to be pretty much the same speed.

Your case length has nothing to do with your case capacity if the COAL (and bullet) is the same.

When firing both of those rounds (same exact everything with the exception of the case length) in the same chamber - The primers will NOT look the same after lighting them off.

Your tea leaves would be telling you stuff that was simply not true...



Agree with you that Speer 11 is a good book to have around.