25 Creedmoor

[sierracharlie338]

Feeling blessed living at 6k and hunting mostly from 5k - 9k.

Quit rubbing it in pal! I did just spend the weekend at 5500-8800 and it made me hate Houston that much more. . .

 

[Marbles]

I would go 7, in part because I like short barrels, so lower velocity, and in part because I've seen density altitudes of -5000 where I am.

My incoming 6 creed is a 7 twist for that reason.

 

[B23]

Berger stability calculator. 2800mv 135 Berger hybrid, 8tw is marginally stable at 1.4, 7.5tw is 1.61 full stable. 134 eldm are even longer than the Berger.
View attachment 977697View attachment 977698

I forget and assume everyone is higher then sea level. My home is right at 2K and I'm shooting them quite a bit faster not that it really matters since velocity doesn't really change it all that much.

 

[nm.otter]

I've seen density altitudes of -5000 where I am.

Wow.

I'll trade you this dewpoint (in April, dry bulb mid-50s):

 

[Marbles]

Wow.

I'll trade you this dewpoint (in April, dry bulb mid-50s):

View attachment 977782

That is pretty dry, I had to go back and look, my temps were about -12 with a dew point of about -2. DA -5268.

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[khuber84]

A lil too much twist is a far better problem to deal with than not enough!

 

[The Guide]

Any conclusions on the best brass? I see Alpha SRP, Peterson LRP and SRP, and Hornady brass available. I plan on using these loads in all weather conditions including below zero. Any concerns with SRP cases in below zero weather? I see that the 22 GT SRP Alpha brass claims to have a 0.080 flash hole to initiate good ignition in cold weather (as stated on the GA Precision website). Is this the same for all Alpha SRP brass?

Jay

 

[Marbles]

Any conclusions on the best brass? I see Alpha SRP, Peterson LRP and SRP, and Hornady brass available. I plan on using these loads in all weather conditions including below zero. Any concerns with SRP cases in below zero weather? I see that the 22 GT SRP Alpha brass claims to have a 0.080 flash hole to initiate good ignition in cold weather (as stated on the GA Precision website). Is this the same for all Alpha SRP brass?

Jay

I would avoid SRP for cold weather use. That is based on others reporting problems and hang fires, not personal experience.

 

[nm.otter]

I have seen quite a few reports of cold weather issues with SRP in Creedmoor cases -- unsurprising given that the original design was based around LRP.

6mm GT was designed for SRP. I figured the shorter case length might have been part of what made that work -- didn't even know LRP was an option for GT cases.

 

[The Guide]

I would avoid SRP for cold weather use. That is based on others reporting problems and hang fires, not personal experience.

This is my concern with the SRP since I do hunt and shoot as low as -20⁰ at times. Even though it might just be a cow elk hunt or coyotes at night, I would be highly agitated to have my rifle not spit fire upon request after putting in the effort to get the shot.

Jay