300 Win Mag Load Data H1000 220 SMK

[Norseman1950]

I'm somewhat new to loading for the 300 win mag and I have some questions about the pressure signs I'm seeing. I'm loading on WCC 01 cases using Fed 215 M primers.

I don't seem to have any pressure signs such as extraction or sticky bolt problems but it seems that my average velocity peaked out when I went from 76.5 to 77.5. Since my av velocity isn't increasing am I getting close to my max or does this mean nothing?

Thanks.

75.5 H1000 AV 2787 Std Dev 19
76.5 H1000 AV 2839 Std Dev 18
77.5 H1000 AV 2840 Std Dev 16

 

[ChadTRG42]

Re: 300 Win Mag Load Data H1000 220 SMK

If the WCC cases are thicker than your standard 300WM cases (I think they are, but never measued), then you will reach pressure before you get to the "book" max. Typically, when you reach your max pressure, the velocity levels out, and doesn't yield an increase from the next charge up. With a full grain increase from 76.5 to 77.5, you should have seen a velocity increase. So, I think your pressure is there. Look for shiny spots on the case head (case stamping) from the ejector plunger, or around the edge of the rim on the case head. This will tell you if you have reached pressure. You can also measure the case web for increased expansion from case to case.

 

[Norseman1950]

Re: 300 Win Mag Load Data H1000 220 SMK

Thanks a lot for the reply. So based on the fact that I worked the load up at about 40 degrees should I keep to 76.5 and see how it goes this summer? I'm assuming on a 95 degree day the pressure will increase even though this seems to be a pretty stable powder when it comes to temperature.

 

[esorensen]

Re: 300 Win Mag Load Data H1000 220 SMK

I'm pretty sure this is the combo that the military just ordered millions of. I'm not sure of the recipe. Maybe do a search or someone else can chime in.

 

[jrob300]

Re: 300 Win Mag Load Data H1000 220 SMK

For those who get excited by such things...

MK248 Mod1 Specifications

Not sure you would WANT to duplicate this load. Nominal chamber pressure is 68,000 psi. Max. allowable pressure at temp. is 71,500 psi. SAAMI is 64,000 psi. I'm not sure I'd even want their once fired's.

John

btw... OP, why 220's? Military used them because they're more forgiving (tangent ogive) but we can tailor our loads to fit our rifles and the 208/210's will outperform the 220 at long range due to BC. Just curious.

 

[Norseman1950]

Re: 300 Win Mag Load Data H1000 220 SMK

Would like to go with a vld type like a 210 smk or maybe a 208 AMAX but my barrel is a schneider 1/12. Frankly, I'm surprised it stabilized the 220s. Anyone else have any luck shooting these longer bullets out of a 1/12 twist?

 

[Jerry R]

Re: 300 Win Mag Load Data H1000 220 SMK

I'm using a 208 AMAX in an 11.27" twist with no issues. Run it fast and you'll be fine.

 

[Driftwood]

Re: 300 Win Mag Load Data H1000 220 SMK

I called Hornady in reference to the 208 Amax. All the load data they had was based on a 1-12 twist rifle. I told him I had a 1-10 twist and he said "You may get better stability by slowing down the velocity". I asked if there was an issue with a 1-10 twist with a 300 WM and he replied "No it just that all our data comes from a 1-12 twist barrel" He suggested seating .005-010 of the lands for starters. He stated that the case volume would be more important than the seating depth. He suggested H4831 and IMR 7828SC for powders. He had no data on H1000 and suggested I call Hodgdon, which I did.

The man at Hodgdon was very friendly, but had no data on 208 Amax bullets. He suggested I use the data for the SMK220 as a guide with H1000. He didn't like the suggestion of IMR 7828SC, but thought the long cut version would be ok. He did suggest H4831 as a good powder for 210-220 grain bullets.

 

[jrob300]

Re: 300 Win Mag Load Data H1000 220 SMK

Shane,

To me this shows just how out of touch with their customers some of these companies are.

I'm sure you've read through threads here... everybody and their dog is using H1000 and 208 Amax's. And the US military is using H1000 in their Mk248 Mod1 load driving 220 SMK's. No load data? Seriously?

1:12 twist for a 300WM? I've never even *SEEN* a 1:12 in a WM. Wow!

For the most part, as far as I can tell, because I *have* called these guys (Hornady, Sierra, Nosler, Hodgdon) and talked to them enough, I could tell they were pretty much useless (the Sierra guys are pretty savvy about ballistics and SMK's, gotta give them that) and cater primarily to the hunting crowd. I know that Hornady sponsors Rob01 and other Tactical shooters, not sure how much information get's all the way back through to the phone support guys though.

Perhaps the ammunition and components end of the business is a little slow to respond to the "tactical" craze that has taken this country by storm.

John

 

[Driftwood]

Re: 300 Win Mag Load Data H1000 220 SMK

John,

I wasn't trying to sidetrack the thread, but I got the same impression as you did. The Hodgdon guy was actually pretty good, although I mentioned the military load and if you have ever "heard" deer in the headlights that is what I got. He said he didn't have any idea what the military was doing. It could have been he did know what the military was doing and wasn't about to tell some guy over the phone to try to duplicate it. The data I recieved from Hodgdon was the published data for the 220 SMK. Hodgdons Max load for the 220SMK is listed about 150fps slower than the specs for the M248 Mod 1 load. He did mention that H1000 is very temperture stable.

The Hornady rep sounded like he was reading from a computer and just looking up stuff...as if I hadn't already done that. He sounded bored and didn't really seem too enthused. I wasn't too impressed with the Hornady rep.

 

[jrob300]

Re: 300 Win Mag Load Data H1000 220 SMK

On the MK248 Mod1, to be fair, it's spec'd to 3.5" COAL and max. PSI of 71K, so I'd expect it to be a bit toasty! Frank said the MK13's they were shooting at RO were getting 2950'ish. Smokin'. It'll come real close to hanging with a nominal 208/H1000 load
(<span style="font-weight: bold">nominal</span>: means we can reuse the brass when we're done

)

Honestly, things are getting so specialized they almost need a Hunting, BR and Tactical/Precision LR choice on their Tech Support menu. Most of the guys I've talked to on these help desks sound like good ol' boys that sight in their rifle a week before huntin' season. Totally different world. The guy I talked to at Hornady a couple years ago asked me why I needed so many Amax's. He was flabbergasted that anyone would shoot over a 1000 rds. from a 300WM in one year.

Just imagine if it wasn't winter 6 mos. of the year here!

John

Apologies for the derail!