300 PRC Data

[croue]

I had a thread going on my first 300 PRC reloaing efforts. Took too much time off so can't post there. Will start new.

Tried 2 powders and 2 bullets today. Mostly focused on 190 gr Hornady CX bullets and H1000.
Did 2 small rounds of 212 gr Hornady ELD-X (factory seconds from Midway) and LRT.

Interesting results. This rifle really does run tight and HOT compared to Hodgdon's test barrels.

Having trouble adding pictures from my laptop.
Will email images to my phone and post next.

Stay tuned. Upshot - running 100 to 150 fps faster than expected. Getting super high velocities and I have to presume presssures are likely running high as well.

[croue]

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[Cowboy T]

Very interesting, indeed. A couple of questions.

1.) What are the respective barrel lengths, both Hodgdon's and yours?
2.) Are you seeing pressure signs?

[croue]

300 PRC Data

Hodgson uses 24? normally. And I double checked this was from a 24? test barrel.
My barrel is 26? So a little more speed maybe expected. But not that much I think?

The velocities had me watching closely. But nothing like I had before. Primers flattened - but with a large magnum they are always flattened.
No stiff bolt or difficulty extracting. Maybe a tiny bit at the real screamers. But never had to do more than just pull it back while still in the sled.

The 190 gr data was new Lapua brass that I sized for consistency and gauged. But no trimming was needed.

The 212 gr data was once-fired Hornady brass. Sized and gauged. No trimming was needed.

CCI magnum primers in all loads. I had primer piercings before with Winchester Std/magnum primers on this rifle before.

I?ll save those for my 270 which has no such issues at a very accurate load.

Edit: not firing pin piercings, ruptures actually with the Winchester primers before

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[croue]

Oh, and the extreme spreads started at 43 fps on the 78 gr H1000 and dropped to 23, 18, and 16 respectively as I increased the load. 4-5 shots each group.


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[Cowboy T]

True, they do. The degree of primer flattening would be what I would be looking pretty hard at. Any stiff bolt or similar, I'd back off a bit. Maybe your rifle simply has a really tight chamber, which, of course, would be a great thing for efficiency. You're getting more speed with less powder. Awww...I feel so sorry for you....

The extra 2" of barrel will make some difference, especially with magnums. But you already know that. I might expect maybe 100 ft/sec, so you're really not that out of line. Shooting my Superformance .30-06 loads out of a 22" Savage vs. a 24" Winchester 70 showed about about 80 ft/sec difference. And you're shooting a magnum cartridge with even more powder. So, actually, your differences do appear to make sense, especially with the 212gr bullet.

Your extreme spreads shrinking would corroborate these two ideas, the possibly tight chamber and the barrel length. Your rifle seems to like the warmer loads, at least with that powder.

Would you consider giving, say, some Reloder 25 a shot (so to speak), or are you pretty much set on H1000 (a fine powder, not knocking it)?

[croue]

Thanks cowboy. That?s good to hear.
After my bad experiences with the Winchester primer ruotures I was pretty nervous when I saw those velocities.

I don?t know that I want to push any higher. Those extreme spreads are excellent. Think I?ll look closer at 80-82 grains and really start dialing in an optimum load. That velocity will make for great ballistics!


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