6.5 PRC load development

[Choid]

So, I got some of the new Lapua brass, and looking to run 144 LHRTs at 3050 or so, I loaded up rounds from 54.5 to 58 grains of Rl26 at 2.945 OAL. Surprisingly, even at 58 grains and 3125 fps, there was absolutely no sign of pressure. Brass looked identical to 54.5 grains, no heavy bolt lift at all. I am wondering how far I should push this. I don't think I am gaining much by going faster than I am now, but was wondering if anybody was running 145 class bullets at screaming speeds, and how it was going for them. Also, wondering what charge weights people are using with this weight bullet. Thanks in advance.

 

[Graycliff]

Sounds like you're getting some real good speeds.
How's the Lapua brass looking? I'm waiting on 3 boxes myself

 

[Choid]

It looks great, very consistent weight. I didn't check case capacity, figuring I'd just start with a medium load and look for pressure. Only downside I ever see in Lapua brass is that a small percentage have less neck tension than others out of the box. This is not different in that way.

 

[Graycliff]

The good news. When I switched from Remington 260 brass to Lapua, the Lapua neck walls were thicker than standard. Hopefully this isn’t the case with the prc.
I’ll be paying attention to your results. Thanks

 

[Choid]

I will have more data to share tomorrow, though it might just be velocity data as I jacked up my back today and might just load and get my wife to shoot. Her groups are suspect.

 

[Dthomas3523]

Haven’t run this combo before. Just be aware, no pressure signs does not always equal not high pressure.

 

[Choid]

Haven’t run this combo before. Just be aware, no pressure signs does not always equal not high pressure.

Copy that. It is within pressure per Quickload as well, so it seems like a pretty fair bet. My plan is to end up somewhere around 3075-3100 fps, so lower than I got to today.

 

[nn8734]

Copy that. It is within pressure per Quickload as well, so it seems like a pretty fair bet. My plan is to end up somewhere around 3075-3100 fps, so lower than I got to today.

use a 1” micrometer to measure your case body diameter just above the extractor grove of each test round before and after firing. Any expansion beyond your pre-fired measurement greater than .0005” indicates you’ve crossed the threshold into over pressure territory. Brass prob would look unremarkable until expansion is greater than .001.

 

[Supersubes]

Where’d you get the brass? Good score, lots of people are chomping at the bit for that stuff.

 

[Choid]

Where’d you get the brass? Good score, lots of people are chomping at the bit for that stuff.

Whidden. I've had good luck finding hard to find brass there.

 

[Choid]

I think I am going to end up really close to 56.8 grains, which is below book max on the 143 ELDx, and the 144s should be slightly lower pressure all else equal, but within 1000 PSI. Knowing all the kerfuffle about SDs, I will say that the load has shown not to suck, lol, but hasn't been rigorously tested enough to know whether it is the shit. OAL determined by mag length, so it is what it is, but it seems to shoot just a little better than factory did in that rifle, which was already really good. Casehead expansion was less than factory, but that has always been hit or miss for me as a measurement, and that maybe because of my abilities to measure. Will update more as time goes on.

 

[Choid]

So, necks are pretty thick on this brass. Loaded rounds measure .2945, which is a bit more than factory Hornady does. Enough to be slightly outside of what I would say my normal experience with loaded 6.5mm rounds is. Measured brass thickness with a ball micrometer and it is .01475, which corresponds to the loaded round measurement. SAAMI says .297 max for neck diameter, and it functions great in my chamber, so no biggie. FWIW, the barrel is a Bartlein heavy palma 1/8 chambered by Altus. 26 inches. STFU suppressor on it.

Did end up at 56.8 grains of Re26. Giving me 3098, which is almost identical to what I got in the same barrel with factory 143. SD for 17 rounds was 7.7, which is just fine by me. Then I had some chrono troubles, so no more data.

 

[Hookman]

Following for info - I have a Seekins Havak in 6.5 PRC but I haven't started reloading for it yet. Looking to learn what you guys find.