7mm PRC

[Rio Precision Gunworks]

Anyone try monos? Tried a few different ones and no matter what I do they won’t get sub moa. They are usually 1.5 at least to 3. 160s and 168s with H1000, ADG, GM215M.

Monos can be finicky. Especially larger bullets. Since they don't conform to the barrel as easily as cup-core...if the particular bullet doesn't fit well with the bore size of the actual barrel, it can go haywire pretty easily.

That's the short version. There's much more to solids and how they interact with barrel than regular bullets.

 

[AZgeek]

Well I didn't cherry pick anything. Pulled my info from my actual testing results. Should anyone owning a MagnitoSpeed be raising hell with them for producing invalid or inaccurate data? SD is just one metric to evaluate in the pursuit of an accurate load, not the only one.

 

[Yankee88]

Smarter people than me on here but Maybe your tube needs to settle in? Maybe revisit the monos after you have 200-300 rounds on it. I’ve only heard second hand stories of guys talking about barrels being Jackal and Hyde’s of sorts until the 150-300 mark. Not talking about velocity but consistent groups. These couple guys were shooting magnums as well for what it’s worth.

You know it’s funny you mention that, the Jekyll and Hyde thing. Because I thought I had a load, good numbers small group. Went out and shot it, couldn’t hit the broadside of a Buck at 500 yards (literally). Went back to paper and it was all over the damn place.

 

[Yankee88]

Monos can be finicky. Especially larger bullets. Since they don't conform to the barrel as easily as cup-core...if the particular bullet doesn't fit well with the bore size of the actual barrel, it can go haywire pretty easily.

That's the short version. There's much more to solids and how they interact with barrel than regular bullets.

Well that’s the thing. I shoot solids in my 6.5 and 375 ct and load dev went as smooth as leadcore. This 7PRC has me wondering about the gun itself

 

[Rio Precision Gunworks]

Well I didn't cherry pick anything. Pulled my info from my actual testing results. Should anyone owning a MagnitoSpeed be raising hell with them for producing invalid or inaccurate data? SD is just one metric to evaluate in the pursuit of an accurate load, not the only one.

It's not magneto speed's fault. It's yours for not understanding how "Sample SD" works. Pretty common misunderstanding of how to use the numbers we get from a chrono.

You have to extrapolate the data you get from your chronograph into the correct and useable data.

 

[Rio Precision Gunworks]

Well that’s the thing. I shoot solids in my 6.5 and 375 ct and load dev went as smooth as leadcore. This 7PRC has me wondering about the gun itself

That's why some who are super serious about solids will get barrels air gauged and attempt to match up to bullet. It can be a headache trying to figure out what/why.

We've had several rifles that don't play as well with solids as we'd like. Its frustrating.

 

[TxLite]

Anyone try monos? Tried a few different ones and no matter what I do they won’t get sub moa. They are usually 1.5 at least to 3. 160s and 168s with H1000, ADG, GM215M.

What’s your jump? I usually have good luck at around 50thou or further. Though, I haven’t tried any in the 7prc.

 

[Rio Precision Gunworks]

Well I didn't cherry pick anything. Pulled my info from my actual testing results. Should anyone owning a MagnitoSpeed be raising hell with them for producing invalid or inaccurate data? SD is just one metric to evaluate in the pursuit of an accurate load, not the only one.

For example (just making up numbers that are common):

It's mathematically impossible to have a 5sd and a 15es. Your sample ES might be 15, but with a 5sd, your ES will be at least 30fps in the long run. And a very, very small amount of the time it will go up to 40fps and sometimes a bit more (provided that your sd is actual 5).

So, anytime anyone references an ES that is less than 6x their SD, they almost assuredly don't have the proper understanding of how to use the numbers from their chosen chronograph.


If we take your 2sd over 5 shots and extrapolate it properly, it's just as likely that your SD is 6fps that it is 2fps. Which would give you up to an ES of 36fps. And with sample sizes as small as 3 and 5 shots.....there's a very likely chance it will be higher than that.



When we choose not to properly extrapolate our Sample SD (ES is all but meaningless.....so much so that almost no one outside of the shooting industry cares about ES), we end up either wasting components or having a false sense of exactly what can/will happen over the life of a rifle/barrel.

 

[Ronws]

Smarter people than me on here but Maybe your tube needs to settle in? Maybe revisit the monos after you have 200-300 rounds on it. I’ve only heard second hand stories of guys talking about barrels being Jackal and Hyde’s of sorts until the 150-300 mark. Not talking about velocity but consistent groups. These couple guys were shooting magnums as well for what it’s worth.

I am the least likely to know, as well. Your comment about a barrel settling in between 150 - 300 rounds makes me wonder if it has to do with getting some copper in the barrel. I have read that it is best to remove just carbon but let the copper reside, providing a smoother surface for travel of the bullet down the barrel.

 

[AZgeek]

For example (just making up numbers that are common):

It's mathematically impossible to have a 5sd and a 15es. Your sample ES might be 15, but with a 5sd, your ES will be at least 30fps in the long run. And a very, very small amount of the time it will go up to 40fps and sometimes a bit more (provided that your sd is actual 5).

So, anytime anyone references an ES that is less than 6x their SD, they almost assuredly don't have the proper understanding of how to use the numbers from their chosen chronograph.


If we take your 2sd over 5 shots and extrapolate it properly, it's just as likely that your SD is 6fps that it is 2fps. Which would give you up to an ES of 36fps. And with sample sizes as small as 3 and 5 shots.....there's a very likely chance it will be higher than that.



When we choose not to properly extrapolate our Sample SD (ES is all but meaningless.....so much so that almost no one outside of the shooting industry cares about ES), we end up either wasting components or having a false sense of exactly what can/will happen over the life of a rifle/barrel.

Fair enough. Time to do some manual math and evaluation of these two statistics during barrel cooling. Since I can't drink a beer at the range, this will keep me busy!

 

[Yankee88]

What’s your jump? I usually have good luck at around 50thou or further. Though, I haven’t tried any in the 7prc.

Started at lands. Then jammed. Then 005 off, then 020, then 025, then 030. Driving me nuts. Haven’t tried that far off yet though

 

[TxLite]

Started at lands. Then jammed. Then 005 off, then 020, then 025, then 030. Driving me nuts. Haven’t tried that far off yet though

I usually start at 50 for monos and have always had great luck

 

[FuhQ]

Well I didn't cherry pick anything. Pulled my info from my actual testing results. Should anyone owning a MagnitoSpeed be raising hell with them for producing invalid or inaccurate data? SD is just one metric to evaluate in the pursuit of an accurate load, not the only one.

Exactly... I made one run of 3 shots through that rifle, and that was it. And my drops in my dope-chart are perfect, too. I didn't cherry-pick a damn thing. I didn't shoot several different sets and pick that one to show. That would be disingenuous. I shot 3 shots, that's what the chrono spit out. But I'm not going to argue with someone over this. They can believe whatever they want to believe.

 

[DEWD_STUFF]

I am the least likely to know, as well. Your comment about a barrel settling in between 150 - 300 rounds makes me wonder if it has to do with getting some copper in the barrel. I have read that it is best to remove just carbon but let the copper reside, providing a smoother surface for travel of the bullet down the barrel.

Primal rights YouTube channel also talks about this a little bit.

 

[AZgeek]

It's not magneto speed's fault. It's yours for not understanding how "Sample SD" works. Pretty common misunderstanding of how to use the numbers we get from a chrono.

You have to extrapolate the data you get from your chronograph into the correct and useable data

Sure my fault. I should have paid more attention to the statistical definition section when I read the manual 10 years ago. Nothing on their web site that I could find regarding definitions. Just checked.

 

[Yankee88]

Ok let’s get this started because there ain’t shit out there and this was an absolute headache to load for;

Surgeon 1086 LA
Proof carbon 24” 1:8 w/ 419 Hellfire
MDT HNT 26
TT Diamond
Mason reamer

69.4 - H1000
FED GM215M
ADG Brass (fired, bumped .003)
160gr McGuire Copper Rose Solid
-.020
SAC dies
Zero press

The flier was 100% me. Was shooting a 2 stage 308 waiting for this to cool down, then jumped back on the gun which has a single TT diamond at about 1.5 lbs. I was definitely not settled as I started to pull the “slack”

560 yard group in red circle on 2/3 ipsc (11x16)

Hopefully this is helpful for someone.

 

[DEWD_STUFF]

Ok let’s get this started because there ain’t shit out there and this was an absolute headache to load for;

Surgeon 1086 LA
Proof carbon 24” 1:8 w/ 419 Hellfire
MDT HNT 26
TT Diamond
Mason reamer

69.4 - H1000
FED GM215M
ADG Brass (fired, bumped .003)
160gr McGuire Copper Rose Solid
-.020
SAC dies
Zero press

View attachment 8256001



View attachment 8256002
The flier was 100% me. Was shooting a 2 stage 308 waiting for this to cool down, then jumped back on the gun which has a single TT diamond at about 1.5 lbs. I was definitely not settled as I started to pull the “slack”
View attachment 8256004
560 yard group in red circle on 2/3 ipsc (11x16)

Hopefully this is helpful for someone.

What aspect of the load combo do you think made it a pain? Bullet, barrel, powder?

 

[Yankee88]

What aspect of the load combo do you think made it a pain? Bullet, barrel, powder?

All three of those. Started with a 168gr and it just didn’t want to shoot it. Maybe with a different powder it would have, but I only have what I have and you know how getting powder is. It was brought to my attention that it was probably a stability issue, so dropped down to next weight class of bullet. Again, maybe changing powder would have helped what was going on but I don’t know.

Also tried playing with seating depths a little and pushed them in .050. Didn’t really see much of an improvement over the recommended .020 from McGuire bullets.

Tried 160 grain lazers and it hated those. Every group would have 2 fliers at about 2-3 moa.

Tried changing primers too, and at first it looked like cci 250s would shoot, but compared to multiple groups and mv numbers the feds were a smidge better.

 

[Schmo]

I saw N560 referred to once. What was the consensus on that?

 

[Hondo1]

Has anyone tried Retumbo? If so how were your results? I’ve been using H1000 but can’t seem to get my SD below ten.

 

[lash]

Has anyone tried Retumbo? If so how were your results? I’ve been using H1000 but can’t seem to get my SD below ten.

It depends on what weight projectiles you want to push. Retumbo will work for heavies, like 190 class. For lighter, try something else. H4831SC seems to get good results and velocity with lighter class clads and solids.

Here’s an Informative article that gives some good insights on powders, even though it’s not complete:

Reloading for 7 PRC - Hawkins Precision

Reloading 7 PRC - Learn how six different powders work in Hornady's new 7 PRC. Powders include H1000, N565, H4831SC, RL23, and Retumbo.

hawkinsprecision.com

 

[Death dealer]

Didn’t have time to search everything but can anyone with QuickLoad help me out? Waiting on my copy to arrive. I built an 18” 7 PRC that I will run suppressed. Looking for a powder than o can achieve 100% burn rate with while running 175 Berger elite hunter bullets.

 

[dankcincy]

I've seen a few different dies mentioned throughout this thread.
What have you all figured out is best to go with?

 

[Jperk0278]

Bighorn TL3
24” Proof CF - 220 rounds so far

180gr VLD Hunters
CCI 250
66.8 gr RL26
2,950 fps

3/8 to 5/8 moa very consistently- 5 shots

 

[TxLite]

Anybody having luck with N570? I’ve got 11lb of it for a rifle I ended up selling. Berger load data shows it adding ~100 fps over H1000 with 180’s.

 

[Rio Precision Gunworks]

Anybody having luck with N570? I’ve got 11lb of it for a rifle I ended up selling. Berger load data shows it adding ~100 fps over H1000 with 180’s.

Haven't messed with 570 yet. But 165 and 565 work well. So, I'd expect 570 to be similar.

 

[nick338]

I don't think you can get enough 570 in the case to take advantage of it. 565 is great in a 300 WSM which is very close to the capacity of the 7 PRC, and Quickload did not provide suitable numbers with 570 as a powder to try. I ran into the same problem with H1000. Was able to get good accuracy, but could not fill the case to get any speed with a heavy bullet.

 

[4O6shootist]

I don't think you can get enough 570 in the case to take advantage of it. 565 is great in a 300 WSM which is very close to the capacity of the 7 PRC, and Quickload did not provide suitable numbers with 570 as a powder to try. I ran into the same problem with H1000. Was able to get good accuracy, but could not fill the case to get any speed with a heavy bullet.

Oh I bet you can. N570 out runs all other powders in the 65prc with heavies, similar case capacity to bore ration. N570 does wonders in a 7mag, and it only holds a few more grains.

 

[nick338]

Oh I bet you can. N570 out runs all other powders in the 65prc with heavies, similar case capacity to bore ration. N570 does wonders in a 7mag, and it only holds a few more grains.

Well I'll give it a try when my new reamer arrives. I was running a 22" barrel so maybe that had something to do with it.

 

[TylerN]

What about n568 with heavies? N568 with 190gr LRHT's is where I'm thinking of starting when my barrel gets finished. On paper it sounds like a good combo, anyone have experience with that combo?

 

[Rio Precision Gunworks]

N568 is more or less short cut N570. I'd expect it to do well. We have some on the way for some 300nm ammo. Will probably try it in 7prc. But I wouldn't expect it to perform poorly.

 

[Bevo]

What about n568 with heavies? N568 with 190gr LRHT's is where I'm thinking of starting when my barrel gets finished. On paper it sounds like a good combo, anyone have experience with that combo?

I am going to try N568 and H1000. RL26 is what I want to test with but can't find any.

Mostly 175 bergers, but also have some 195s I'm going to mess with.

 

[ma smith]

N568 is more or less short cut N570. I'd expect it to do well.

From what I was reading, characterizing N568 may take a while longer. It apparently isn't all that close to n570 in enery density.

 

[Rio Precision Gunworks]

From what I was reading, characterizing N568 may take a while longer. It apparently isn't all that close to n570 in enery density.

It's been out for about three years now. Book max are within 50fps for most things. Obviously it's not going to be exactly N570 short or it would be labeled that way.

But you'll get similar velocities.

 

[4O6shootist]

What about n568 with heavies? N568 with 190gr LRHT's is where I'm thinking of starting when my barrel gets finished. On paper it sounds like a good combo, anyone have experience with that combo?

N568 is weird. Was advertised as short cut N570 but has way less energy. I tested it in a wildcat 257 similar to a Weatherby, and 300 norma. It would generate velocity similar to Retumbo and H1000, but required 2.5 to 3.5 more grains powder to do it, very high case fill though. It's not a high energy powder like N565 and N570.

 

[DEWD_STUFF]

First 50 rounds down the barrel today. Instead of typing too much below is a photo of target with some details.

Of note a little more than half of the factory 175 ELDX I put through it had noticeable stiff bolt lift. Lot number in the photo. I still have 2 more boxes of it.

I have a jug of IMR4831 sitting around that I picked up during the Covid era and a 100 gm215 primers from a diff lot I need to burn off. Figured good use of the primers, and powder to get a firing on all the ADG brass I have and get the barrel broke in/sped up.

Plan of attack is shoot all the factory 175’s I l have left and the remainder of the IMR4831 and gm215 primers, check velocity to see if barrel has sped up and then start a load work up with H1000 and H4831sc.

 

[Matt Moxness]

First 50 rounds down the barrel today. Instead of typing too much below is a photo of target with some details.

Of note a little more than half of the factory 175 ELDX I put through it had noticeable stiff bolt lift. Lot number in the photo. I still have 2 more boxes of it.

I have a jug of IMR4831 sitting around that I picked up during the Covid era and a 100 gm215 primers from a diff lot I need to burn off. Figured good use of the primers, and powder to get a firing on all the ADG brass I have and get the barrel broke in/sped up.

Plan of attack is shoot all the factory 175’s I l have left and the remainder of the IMR4831 and gm215 primers, check velocity to see if barrel has sped up and then start a load work up with H1000 and H4831sc.

I had pressure issues with some of my first factory loads also. The ELDM loads in particular. Check out the 7mm cartridge guide on long range only or on YouTube. My favorite load is with H4831SC. Good luck!

 

[AznTactical]

Time to play the bushing game. What are you using? .310? .311? .312?

 

[ForgeValley]

Time to play the bushing game. What are you using? .310? .311? .312?

Depends. How much neck tension do you want and what's the neck thickness on your brass? I generally like .002 neck tension and my ADG brass thickness is right at .015 so I mostly use a 0.310.

 

[DEWD_STUFF]

Time to play the bushing game. What are you using? .310? .311? .312?

My virgin ADG brass necks came in avg measuring .3095. Using a KM .0020 BT mandrel it pushed it out to .312. loaded 180eld measuring .313. I ordered a KM .0030 BT mandrel.

 

[TxLite]

Following up with my N570 results.

18” barrel, 2820fps with a 180 hybrid.

 

[Gtscotty]

I finally got my Tikka 300 WSM converted over with a 19" Carbon six 7mm PRC barrel and took it out for the first 20 or so shots.

I shot some 180gr ELD Factory which turned out pretty slow, then shot spreads with 162gr ELDx, 168gr LRX and 175gr ELDx and Staball HD.

 

[Boss Gobbler]

Following up with my N570 results.

18” barrel, 2820fps with a 180 hybrid.

I like the looks of that. I hope I can find some N570 to try when I get my 18inch 7 PRC in a few months.

 

[ForgeValley]

I like the looks of that. I hope I can find some N570 to try when I get my 18inch 7 PRC in a few months.

You searched for N570 | Powder Valley

www.powdervalley.com

 

[lash]

I probably should have reread the thread, but has anyone tried N165 for 7PRC?

 

[Matt Moxness]

What made you decide on an 18 inch barrel? That will be beautiful to carry or shoot from the stand!

 

[TxLite]

What made you decide on an 18 inch barrel? That will be beautiful to carry or shoot from the stand!

That’s the exact reason haha

24” + suppressor gets old quick. At my altitude (400’) and a MV of 2820 the Berger hybrid is expanding out to ~850 yards, which is further than I intend to shoot game.

 

[Matt Moxness]

That’s the exact reason haha

24” + suppressor gets old quick. At my altitude (400’) and a MV of 2820 the Berger hybrid is expanding out to ~850 yards, which is further than I intend to shoot game.

Hot Damn----Send some targets when you get shooting!

 

[axarob44]

Unknown Munitions has Peterson brass 7PRC in stock. Just a heads up.

 

[BravoSector1]

I've got my new hunting rig in hand and plan to shoot factory 175 ELD-X to break it in and then start reloading. I see a couple guys mention the 162 ELD-X. I'm curious to see what velocities your getting with this round. It may be a good all-around hunting round for Idaho. Barrel length is 24".