270-300 Win Mag now feasible

[Big Jake Duke]

I had a 270 JDJ, an improved version of the 270 AI. Powder charges were near 70 grains. I liked it a lot. Like the AI I felt the powder capacity vs. bore diameter was near optimum.

It just seems the powder capacity vs. bore diameter in the 300 WM case would be a diminishing return with increased heat exponentially. Are you stuck on the .277's? Have you considered the 7mm Mashburn Super?

I looked at it, it is a great cartridge. I also shoot a 7mm STW.

It is just kind of cool that the optimum bullets for this caliber are finally made. Many of us drank the O'Connor kool aid and started with a 270. It is a lights out cartridge to around 500 yards, but the typical bullets offered let the cartridge down from its potential. The AI and JDJ helped but as im sure you found out that you need a bc at least in the 600's to deliver energy at long range in hunting conditions.

I think the 70-75 gr capacity on an action i already own and brass i can neck down from my stockpile are advantages i want to pursue.

 

[Big Jake Duke]

I'm not trying to pick on anyone, but the last I heard Berger said the 170 would be released after the 7mm 180's are caught up and the 195's are in good supply. Have things changed? After the extremely long wait on the 195's, I'm glad to hear about something else coming out.

They just released the 6.5 130's.

The 270 was brought up 2 years ago, but it is close now. In the mean time i can try the CUTTINGEDGE BULLETS 140s and Nosler 150 LRABS and the Matrix 165s. I have taken animals with all of them already ( the 130s in cutting edge).

Its just another project that keeps the dream alive until the fall.

 

[JARHEAD1371]

I'm looking at the 150's or 160's out of a 6.5 SAUM, looks like a good combo for deer sized targets. The 170 would be great out of a shortened and improved 28 Nosler. Now to wait for the GAP Tempest long action and decide on which caliber to build...

 

[300R]

I'm watching this with interest,I'm having a 27 nosler put together at the moment so they should be similar in performace,I have some 150 LRAB and 140 ceb on order.If berger gets the 170's out the door I think the 277 will come alive.
Keep us posted.

 

[300R]

Some food for thought for those considering a fast 270,all great options.
L to R:270 Dakota(NK down 7mm),27 Nosler(saami),26 Nosler,300wm.

 

[Big Jake Duke]

The Dakotas or a rum will have more power for sure. I made a 338 Sin from a 330 Dakota, but on this cartridge i wanted a more common brass, and one i already had hundreds of!

The barrel was delivered today from PacNor. I am sending it off tomorrow to de Nitrided. I should have it back in 10-14 days and then have the action installed.

 

[Big Jake Duke]

Here is the Barrel-now it is off to phoenix for nitriding!

 

[Big Jake Duke]

Barrel is at Controlled Thermal Tech in Phoenix and should be back to me in a week.

Then i have to bribe Gruning Precision to install the barrel in a timely fashion. I have found out that timely to me means light speed to a gunsmith and that timely to a gunsmith is glacial time to me..

 

[Big Jake Duke]

Thr barrel is back, i met with Jim Gruning today to screw on the barrel, set headspace and cerakote it. Now i am going to work on loads.

I have Matrix 165s and nosler 150 lrabs.

I am planning on trying imr7828 and h1000.

I have had great luck with imr4350 in 300 mag but i think it will be a little too fast for this cartridge.

Thoughts?

 

[Big Jake Duke]

Ok range report. I initially tried rl25,imr7828,h4831 and h1000 with the nosler 150gr lrab.

The best consistency was with the h1000. The other had higher pressure earlier. The h1000 put three shots within a half inch at 100yRxs, and the loads were 1 grain apart. 70-72 grs. Velocity was 3300 almost exactly.

The Matrix 165s i loaded with h1000 and i achieved 3200fps with a 3/8"group.

I am thinking of trying slower powders like retumbo or h869,870.

The velocity is there, i may yet get 3250-3300 on the 165s which is what i am hoping for.

 

[Big Jake Duke]

Some photos

 

[TXAoudadKlr]

Sounds like you got a winner. That's a lot of power out of a .270 Cal bore.

 

[Thumper1991]

Sounds cool. Whats the estimated barrel life gonna be on it? My son love .277 's. Will follow this one.

 

[Shane Lindsey]

If you talk to Marshall at Matrix he can do a special run of the 175 grainers if you order enough of them.

Would definitely be a strong candidate for this. I have an older 300 WM that you have given me an idea for. lightbulb