7-6.5PRC accuracy nodes

[marchx]

From what I hear 7-6.5prc is more difficult to tune than .284win. It is supposed to have narrow accuracy window and hence finicky.

First time I heard this from guys preparing to European F-class championships earlier this year. Recently I heard this from a US colleague.
So, what does it take to make it shoot tiny groups?

 

[WeatherbyFan]

From what I hear 7-6.5prc is more difficult to tune than .284win. It is supposed to have narrow accuracy window and hence finicky.

First time I heard this from guys preparing to European F-class championships earlier this year. Recently I heard this from a US colleague.
So, what does it take to make it shoot tiny groups?

Well I’m no F-class shooter but 57.7grs of N555/210M primers/175gr Berger Elite Hunters necked up Lapua 6.5 PRC brass and I found it very easy to find a consistent accurate load with this cartridge.
My last 50 rounds ran 2895-2901 fps, pretty good ES for basic handloader.
This is out of a 26 inch Benchmark Barrel.

 

[Elwood]

I think it’s the same as any magnum cartridge, run it fast and you will have a narrow window, run it slower and that window becomes much larger.
I’m only on my first 6.5-7 PRC barrel but I’m doing OK with it, 180 Hybrids at 2910 fps.

 

[Lance21]

mine runs very well at this speed.

 

[Jim Ziegler]

Just from what I've run with it, it seems with an 8.5 twist barrel and N555 and !80 Hybrids 2875 is my target speed. If you're running a 9 twist you can run it a tad faster.

 

[Tangent]

What sort of barrel length would you need for a 180gr at 2850?

 

[Lance21]

What sort of barrel length would you need for a 180gr at 2850?

I run the 183 smk at 2840 through a 30 inch 8.5 twist Brux. 53.4 gr H4350/cci200/Lapua brass.

 

[FeMan]

What sort of barrel length would you need for a 180gr at 2850?

Based on the pressure data I have seen posted, it looks like you would want a 29-inch barrel or longer to comfortably hit 2850 with N555.

 

[Sandstorm]

I run a 30 inch and shoot the 180 Berger @ 2877 ( Tiny small tight holes ) in a 9 twist Brux.
It Hammers quite well..as well as my Shehane.

 

[gmr4]

Im still new to 7 PRCW but haven’t found it to be all that tough to tune. N555, Berger Hybrid 180, AGD brass CCI 200. 56.8 gr get me about 2900 and it shots good. 57 Gr is 2920+ and it shoots great. The Berger 180 Hybrid is the easy tune button I believe.

 

[Jim Ziegler]

Playing with seating depth today

 

[marchx]

Playing with seating depth today

How far off the lands?

 

[Fire Dog]

AND the winner is…… 2.415
Your results may vary and this example is for display purposes only…

All kidding aside that is looking as though you have nailed it and perhaps only a little tuning in the powder weight may render that elusive “0” group.

 

[Jim Ziegler]

How far off the lands?

12 thousandths into the lands

 

[stymie12000]

Here is my powder test with H4350. Probably a little over pressure but it shoots great at 2920fps.

This was tested with Berger 180 .010 off of lands. 100 yards.

I'd say there is a decent tune window between 53.5 and 54.very little POI change.

 

[marchx]

Here is my powder test with H4350. Probably a little over pressure but it shoots great at 2920fps.

This was tested with Berger 180 .010 off of lands. 100 yards.

I'd say there is a decent tune window between 53.5 and 54.very little POI change. View attachment 1619297

great evidence! that's looking almost like my 6BR load development.