25 GT 10 twist

[806guns]

Morning everyone, I will be playing with a new build that I happened to think about. There is a guy i know running a 10 twist 25 creed shooting 70gr Blitzking at 4050fps as a night time varmint rig. It got the ideas running and I decided to run a 25 GT 1:10 24" #5 contour remage barrel. Running the same 70gr Blitzking, its about the same cost as a 6mm 70gr blitzking. Hoping to get 3600-3850 fps when it's all said and done. Will try vsrhet first and see but might need rl15.5. Looks like I should still be able to run up to a 110gr eldx or others. Going for efficient speed with this one just to be different.

 

[std7mag]

Interesting....

I have a 250 Savage with 24" sporter barrel (Savage Axis II action).
With a lowish charge of Alliant Varmint I'm getting 3,150 with the 75gr Sierra HP Varmint.

I think max velocity is listed close to 3,400fps.

Makes me wonder what pixie dust gets over 4,000fps from a 25CM.

 

[806guns]

 

[std7mag]

Wow!!!

Ok, color me a believer...

Your 25GT does sound interesting to me.

What kind of freebore are you looking at?

 

[806guns]

Wow!!!

Ok, color me a believer...

Data doesn't lie

 

[806guns]

Wow!!!

Ok, color me a believer...

Your 25GT does sound interesting to me.

What kind of freebore are you looking at?

First go around is a std freebore. .150 or. 180 didn't ask my barrel guy. Just for testing, if it works well I will get a customer reamer made with a shorter freebore.
Headstamped Alpha 25 GT brass
Bullets and barrel will be here on Thursday. Hope to test by next weekend.

 

[dk17hmr]

Midway has those 70s for $135/500 right now. I have been thinking about them for my 25-223 & 25-06AI. Currently shooting the 87gr TNT in both at 2850fps & 3740fps.

 

[806guns]

Midway has those 70s for $135/500 right now. I have been thinking about them for my 25-223 & 25-06AI. Currently shooting the 87gr TNT in both at 2850fps & 3740fps.

That's what I bought. Also have some 87gr tnt too

 

[STOMP442]

Should be a hammer. I run the 75gr Vmax out of a 24" 250 Savage and I am getting right at 3400fps with IMR 4064.

 

[Gabe22BR]

So if a 257 Weatherby shooting 70gr bullets can only achieve 3868fps w/ 80gr of powder

How’s a 34gr capacity case gonna get 4000 fps w/ 70gr bullets ??
Efficiency???

 

[806guns]

So if a 257 Weatherby shooting 70gr bullets can only achieve 3868fps w/ 80gr of powder

How’s a 34gr capacity case gonna get 4000 fps w/ 70gr bullets ??
Efficiency???

Sometimes its not all about case capacity. I'm shooting for 3800 fps in the GT

 

[shoot4fun]

So if a 257 Weatherby shooting 70gr bullets can only achieve 3868fps w/ 80gr of powder

How’s a 34gr capacity case gonna get 4000 fps w/ 70gr bullets ??
Efficiency???

I suspect the 257 WBY Mag is doing that within the pressure limits of the brass and action.
I also, knowing a bit about how IMR8208XBR can be crazy fast, suspect that 25GT load would test way over pressure. I have seen personally how that powder can ruin brass while seemingly showing zero pressure signs. No ejector marks, no flattened, pierced or blown out primers but the Lapua virgin brass wouldn't hold a primer and measuring the case heads with a blade micrometer showed excessive expansion.

 

[806guns]

I suspect the 257 WBY Mag is doing that within the pressure limits of the brass and action.
I also, knowing a bit about how IMR8208XBR can be crazy fast, suspect that 25GT load would test way over pressure. I have seen personally how that powder can ruin brass while seemingly showing zero pressure signs. No ejector marks, no flattened, pierced or blown out primers but the Lapua virgin brass wouldn't hold a primer and measuring the case heads with a blade micrometer showed excessive expansion.

I'm going to start with varget first and measure the case web for pressure signs first as you can really push the Alpha brass

 

[dk17hmr]

My 25-06AI will out run my Labradar with 75gr VMAX. I had a 257 bee at one time that would almost do it with an 85gr.....26" barrels

I'm curious what the GT will do

 

[806guns]

My 25-06AI will out run my Labradar with 75gr VMAX. I had a 257 bee at one time that would almost do it with an 85gr.....26" barrels

I'm curious what the GT will do

I have a buddy who will help running the 70gr in his 25-06 as well.

 

[806guns]

Just waiting on a barrel now. Hurry up Thursday!

 

[806guns]

Running numbers in GRT seems 3500-3600 may be pushing it. I will know more by Saturday for sure

 

[806guns]

All together. Just need to load some test rounds.

 

[806guns]

 

[806guns]

@urbanrifleman