H335

[Collateral]

My components
55 gr soft point flat base and FMJ boat tail, both cannelured
Mixed stamp 223 brass, trimmed to .750
CCI 400 primers
Putting a slight crimp on

18 inch barrel, NATO chamber, 1:8 twist, rifle gas is what they will be going through

I start loading something new near the specified minimum and slowly work my way up. I check the speed and accuracy of each load until I either get the tightest grouping, or get to the danger zone. If a slower loading proves more accurate, then that is where I stop. If I get to the danger zone without finding the accuracy I expect then it is time to try something else.
Accuracy is not always the hottest loading but it can often be found near the published Max load which, as you will discover, changes from manufacturer to manufacturer. The bullet maker says one thing and the powder maker says another. They each use test barrels whose chambers and barrel length varies from one to another.
Since my goal is an accurate (and cheap) loading, speed is a secondary concern. However, if you are shooting near the min load you may be surprised at the change in accuracy by bumping up a grain or two in powder.
24.5 grains may end up being perfect for you but try going a grain or two both under and over that.

My standard, 223 loading for my two 16" barreled .223 chambered EBRs -

55 grn FMJBT (bulk)
25.5 grn H335
2.24 OAL

I have loaded some 52 grn Hornady HPBT at 26 grns H335 that have been both speedy and accurate.
I am working on a load for some 62 SPBT for a 'hunting load' but haven't fired enough to find a winning combination as yet.

 

[AMProducts]

I usually load 25grs of SMP735 (H335) behind my 55gr bullets, usually come out of a 16" barrel at about 2950FPS all day long, and will do 3100fps in a 24" bolt action. My loading overall length is 2.245" (+/- .004") and my trim length is 1.745". I usually stick with the same load when loading 52gr SMK's (my coyote load). For pig hunting I use a 55gr Barnes TSX with 23gr.

My loads are a bit conservative, but I shoot in a pretty wide variety of places, so my ammo needs to handle everything from 0F all the way up to 110F and still deliver safe performance.

 

[Darkker]

Never heard of SMP735,
But H335 is the canister version of WC844

http://www.thegunzone.com/556prop.html
http://www.gd-ots.com/ballpowder_military.html

 

[bballer182]

I would take pretty much everything AMP says as gospel when I comes to loading commercially and by hand... ;-)

 

[AMProducts]

I don't think WC844 is H335, or at least I havn't tested it. I realize WC844 is the call out for loading M193 and IIRC M855, the data is in TM 43-0001-27.

I usually buy drums of SMP735 (never ordered it as an H-number) After a bit of consternation at first and several pounds of commercially purchased H335, as near as I could tell they were the exact same thing. First starting with middle of the road 23gr of SMP735 vs H335 behind the same lot of bullets, in the same lot of factory new brass and then working up to max loading. Even went so far as to find someone with a kistler transducer. If there is any difference I'm not aware of it, for chamber pressure and velocity they are grain for grain the same.

It's entirely possible there is a deterrent, geometry, flash reducer, copper fouling reducer, or other "difference" between the two, but for the sake of putting powder into a cartridge and having it go bang and the bullet hit the same place, that's where it stands.

Yes, I've read all of the literature from GD-OTS (SMP, Expro), ATK (NRE), as well as bugged people I know at ADI (Thales), and while the literature is pretty scant on SMP735 (even if you call SMP, they give you the lawyer response). I could call and harass hodgdon, but that would mean talking to them in friendly tones, which is something I'm somewhat averse to do over the last few years when they decided to screw commercial manufacturers and most of the public along with them.

Interestingly, I have a binder full of data for an SMP-556 to which I've found no other references to anywhere. I think it lists a few other powders some familiar (OBP-242 aka titegroup) and another SMP numbered powder for loading .308 (number isn't in my head because I use IMR3031 for .30cal oddly, I think it was SMP762) I'll check my notes when I get home.