Hodgdon H335 in .308/7.62 load data??

[wogpotter]

**PLEASE DO NOT MAKE THIS A 7.62MM/.308 WIN DIFFERENCES THREAD**

I've read all the posts & made my decision so you won't change my opinion anyway & I'm looking for actual hard data from those that have reloaded those cases using H335 powder.
Thank you in advance.

OK on topic (for now)

I'm getting set up to reload a batch of 7.62mm brass (LC04) with 150 gr bullets, this load will be used in a semi-auto EBR. So I start checking reloading manuals for the H335, which I'm not familiar with & I find an odd inconsistency in the data within the same manual! Now I'm familiar with differing data manual-to-manual & I'm ready for that. BUT I find that using the Hodgdon powders data sheet from manual #26 in the ".308 Winchester Match Loads (7.62mmNATO)" section I'm supposed to be using MORE powder in a "GI case" than in a "Winchester case", but this is reversed in the "regular load data tables"

The data lists as:
From the regular load pages.
41.0Gr for 2619fps @ 42,600CUP to 44.0Gr for 2787 fps @ 51,200CUP.

From the ".308 Winchester Match Loads (7.62mmNATO)" section:
with Winchester brass
43.0gr for2619 fps@43,800cup to 45.0gr for 2806 fps@47,500cup

BUT!!!
"Using GI cases"
42.0gr for 2589fps to 44.0gr for 2728fps@47,000cup.


See my problem?
Within the one section the reduce by a grain for military brass is holding true, but looking at the "regular" pages it's reversed you load MORE in "GI cases"! What am I missing here

[Unclenick]

See my problem?

Well, no, not really. Winchester has about 2.7 grains more water capacity than Lake City. Hence the 43 gr vs. 42 gr match starting loads. Some brass, like IMI, is even heavier and smaller inside than Lake City, and that accounts for the 41 grain starting load in the regular data. No load data can be expected to be safe in all cases at maximum. That's why starting loads exist. You work up from there to where your case in your gun says "stop". Why the standard data doesn't make it to 45 grains, I don't know.

[Poodleshooter]

Weigh some Lake City 7.62 cases. Weigh some Winchester, Remington,Federal,etc commercial cases. They will vary in weight and case capacity. They may even overlap in their case capacity,especially if you have multiple years of LC brass. Your LC brass is not the same as the manuals brass,and probably the Winchester isn't either. That's why they give starting loads and not just a single "load this" value.
Don't worry so much. Pick any of those starting loads and work up slowly watching for pressure signs. Load manuals are guidelines,based on averages. There's plenty of safety margin built in to their loads to ensure that you aren't blowing op rod pieces down the firing line.

[wogpotter]

Oh I understand the variables of brass well.
I just thought it interesting as it contradicts the old "Drop the charge weight by a full grain for MilSurp brass" rule of thumb.

I only know one reloader whose motto is "Don't worry, be happy!" they call him "Lefty the one-eyed"

[NWPilgrim]

wogpotter,

I understand your surprise at the data in the same manual, versus the old adage. I found this out a couple of years ago too. Weighing cases I have found that Federal and Fiocchi are some of the heaviest in .223 whereas LC, Remington, Winchester, PMC are all about the same.

My theory is that perhaps in the past military ammo was made thicker than commercial, but in recent times many of the commercial firms supply both military and commercial. And many foreign makers also supply military and commercial. Perhaps they are using the same cases now for both and we don't have that clear demarcation between the two uses.

[Dave R]

Speer No. 13 used milspec brass to develop their loads. So they say no need to back off for milsurp brass. They max at 46gr. of H335 for 150gr. bullets. But my experience is they are the "hottest" of the manuals. Just checked their website and they don't go over 44gr. there.