Loading 7PRC with 168 LRX and using Hodgdon data for H1000. 60-66 grn listed.
This gun loves this bullet loaded by choice ammunition. So I measured the BTO for the choice ammo and set that as my seating depth for my hand loads. It’s about 0.2 deeper than the jam indicated by using the Hornady tool.
64 gns gave me wonderful accuracy, right online with what choice was giving me but moderately slower than choice and significantly slower than what the data on the website says I should be getting. So i tried 66.
Velocity better obviously. But notice something strange. About 40% of the rounds would be about 6 thou longer than what the seating depth was supposed to be. This was solved by this running them through the seating die a second time. Accuracy suffered a little bit although not much.
So was going to just stay with 64 since it seems to be consistent both in terms of accuracy and not giving me troubles with seating depth
Then Barnes publishes its data for that round this week and instead of maxing out at 66, they max out at a little over 69 and do note that it is a compressed load.
So what the heck, I tried loading just a few rounds at 67 just to see what would happen. Now, instead of just a few rounds being long all of them are. And instead of being only 0.006 long, they are 0.025 long. Furthermore, a second run through the seating diet doesn’t actually make any improvement. I had to adjust the micrometer in order to get them to the appropriate depth.
Just for the heck of it also I decided to load a few more at 64 and they seated perfectly fine with no inconsistencies.
Is this what one sees when one starts with powder compression? I thought maybe it was an issue with my die but since it went back normal with going back down to 64 that makes me not believe that that’s not the culprit.
Anyone shoot with compressed loads? Are they to be avoided?
Should i lengthen COAL to what Barnes lists and see what happens?
If 64 grains is grouping at 100, 300, 600 yards, meaning you can shoot them at distance to test, that is a good load.
If you have a chronograph, then look at the SDs, ESs, and if those are good at 64, along with downrange results, that is a good load.
If it meets your velocity, and subsequent energy requirements downrange, then that is a good load.
Unless you need the extra velocity, your rifle may be telling you what it likes.
Over the years in reloading, if I loaded rounds that were at close to or max loads, when I put them away for a while, and the copper would tarnish or turn a darker color, when I took them out again, I could see an original shiny color band just above the neck; maybe 5-10 thousandths, where the bullet had crept out over time. I accredited that to the internal pressure from the compressed powder, and the neck tension I was using in seating. The combination of those two seemed to allow the bullet to flex outwards after seating. Just a thought on what I have seen.
If the compressed loads shoot well, without pressure, then you can use them. But, this a good example of why working up in loads on powder charges is a good thing, so we can see changes as they occur and make a decision. Compressed loads can be fine, just not a good place to start. Sounds to me like you worked it up the right way.
John
I don’t know your barrel length, but with a 24’ you probably are pushing 2800-2025 at 64, maybe 2850ish with a 26". Kind of defeats the purpose of a 7 PRC if you wanted more than what a 7 Rem Mag will do with the same bullet.
Choice doesn’t list a barrel length, that I saw for testing.
Good luck.
JV
What a confounding round, Hodgen’s manual shows 66 for the max, does not list it as compressed. I will try and load 5 this week and see what results I get. I am going to try the COAL in the chart.
Guys, it would be another powder, but the 7828 was designed specifically for the 7 rem mag; and the case capacities for both rounds is very close. Using 62.4 to get you close to what the h1000 is doing at almost 3.6 grains more, might be a course of action. Pressure for both is a match. Just a thought.
Maybe that’s what the C in PRC actually stands for.
Curious to see what you get with your results. Barnes definitely loads shorter than Hodgdon, and Choice even shorter.
I’m tempted to try adjusting that to see what happens with compression as well as group size. On the other hand, part of me just wants to say I’m done with this and not go through another bottle of powder and several boxes of bullets again.
My rifle is slow no matter what data you look at with the 168 lrx. Maybe it’s just a slow rifle. So I tested it with Federal 175 eldx. Most people are getting 2950 or so out of 22 in barrels with that round. Me, 2780.
But then I try Fed 155 Terminal Ascent and end up getting box velocity if not faster.
Carter, from what I have “read”, the federal ammo is doing much better than the hornady in producing as published or higher velocities with good SD/ES. I am looking for a box of the 155s to try in my 7 rem mag.
Yeah, I’ve heard / read that too. But it doesn’t seem to be true with their eldx load in my particular rifle, but is true with the terminal ascent. I wish I could find some of the 170 terminal ascent to try.
