Brand New to Reloading: 7PRC Load Development

[MurphyTX]

Hey all,

I’ve never reloaded and am looking to see what I can do in working up a load for my 7PRC. I’ve done a fair bit of reading but would really appreciate input from those with firsthand experience, especially loading for the Berger 195s.

Right now I’ve got:

• ~60 rounds of factory 175 ELD-X left (pre powder change so getting 2,915 out my 22” barrel)
• ~160 pieces of once-fired Hornady brass
• Access to a buddy’s press and reloading gear

I know Hornady brass might be a little soft and not as consistent as ADG/Peterson/Lapua, but I’d like to make the most of what I have before upgrading.

Reloading Plan

Here’s the process I’m planning to follow:

1. Deprime and clean the brass
2. Use a dummy round and comparator to find the lands, then back off 0.010-0.020” for initial seating
3. Run a powder charge workup to find a velocity node for best SD/ES across similar charges
4. Once I find a charge that looks good, I’ll fine-tune seating depth for accuracy

My main goal is low SDs and consistent accuracy at distance. I’m not trying to push speed, especially if it means burning out barrels and pressure signs, but I’m hoping to get at least 2800 out of my 22” barrel, which seems doable based on others’ 7 PRC load data. From what I’ve calculated, that’s the bottom end to keep the Berger 195s stable.

I’d also be open to the Berger 180s if they prove easier to tune, but I like the idea of running the heavier 195s in this caliber for the extra BC.

Powder Options

I’ve been looking at:

• H1000
• N560
• N565
• N570

It seems like:

• N565/N570 offer higher velocities due to the size of the powder and case capacity, but might be more temperature sensitive and tougher on barrels
• H1000 seems to be more temp stable and forgiving, even if slightly slower

Any input on how these powders behave with the 7 PRC, especially with Hornady brass, would be really helpful.

Dies

Haven’t bought dies yet. Do I need to jump into high-end dies to get .5 MOA or better, or will I be just fine with solid full-length sizing dies? Trying to keep it simple but not cut corners if it matters for consistency.

Primers

My plan was to run whatever large rifle magnum primers I can find are. Not sure if there’s stuff to watch out for from different brands, but figured there’s not much variation there just making sure I can ignite the powder.

Open to Suggestions

Totally open to any advice, this is my first time reloading. My buddy is helping me get set up, so I’m more focused on learning a repeatable, consistent process than squeezing out every last FPS. If you’ve got tips for brass prep, pressure signs to watch for in 7 PRC, or seating depth tricks, I’m all ears.


Thanks in advance for any guidance, excited to start tuning and see what this rifle can do!

 

[Maurygold]

Bc is relative to speed. The 180 hybrid 30-40 thou off lands is the easy button and where you should start. H1000 as well.

Dont chase speed on your reloads for a while. Go at least a grain under book max. Speed is way less important than consistency. Don’t chase speed it’s really not that important.

You can get by with Redding dies and make some good ammo

Good brass is critical. Reload those hornady one time to get a feel and then immediately upgrade

 

[Kaldor]

Id do a few loads on the Hornady brass just to get the hang of it all. Then look at buying nicer stuff, at least 300 pieces so you arent constantly sizing brass and will let you track firings a little easier. With brass being spendy, I would also look at annealing. Being able to extend brass life on brass that is minimum $1.50 a piece is a huge deal with will pay for itself over the lifespan of just a few hundred pieces. Once you have it on lockdown, bump your shoulder 2-3 thou, and with annealing, your brass will last a long time unless you abuse it.

Dont ignore faster burning powders like H4831SSC. They could function quite well, but powders like Retumbo and H1000 will be best for velocity and stability. Unless you are setup to handle N570 specifically? I dont recommend it. Its like metering road gravel, and its difficult to get anything better than +/- .04gr as the kernels can weigh .08gr each. I had to update from my ATv3 to the ATv4 to deal with it for my 300 PRC.

Primers? Probably CCI 250s or Fed GMM is the best route.

Dies? Just buy a set. Spendy dies do not magically make more accurate ammo. I like Hornady, because I like their seater with the sleeve, but I also own Reddings, Lyman, RCBS, and Lee. This is something you can always swap around later. The expensive dies just add more features, whether or not they are useful has to be determined by the user.

Berger 7mm 180s have been the standard for quite a while and there is a reason for it. They just work. Start there, then try other stuff.

 

[MurphyTX]

Thanks again for the input, it’s been really helpful getting started.

Ill go with the Berger 180s for now based on yalls feedback. I ran a few quick ballistic comparisons against the 195s at different velocities, and was surprised to see there wasn’t much wind drift difference out to 1,000. While I may shoot steel beyond that at some point, I don’t plan to hunt that far, and realistically I’m more likely to misread the wind than be limited by bullet choice.

I’ll be starting with H1000 and keeping charges below book max while I work up a load. My goal is low SDs and consistency so definitely not chasing velocity.

For dies, I’ve narrowed it down to:

• Hornady Match Grade Full Length Die Set
• RCBS MatchMaster Bushing Full Length Die Set
• Redding Type S Match Bushing Full Length Die Set

I know the RCBS and Redding sets require bushings, which aren’t included. At first I was leaning toward the Hornady for simplicity, but after reading more, I’m now leaning toward a bushing die setup. It seems like controlling neck tension directly becomes more valuable once you start annealing and get more consistent necks.

That brings me to a few questions I’d really appreciate some guidance on:

• How important is precise neck tension control when reloading?
• If I’m planning to anneal down the line, does that tip the scales in favor of bushing dies long-term?
• Is there a real-world downside to just using a full-length die vs a bushing die?

I’m trying to find the right balance between building good habits now and not overcomplicating things too early. My goal is repeatable precision, and I’m okay with a bit more complexity if it sets me up for success long term.

 

[Kaldor]

Ive done both. I use a bushing Hornady and Redding dies with SAC bushings, where I set the neck tension to be just a bit more than the bullet needs, so maybe set for 4 thou. But I use a mandrel to set the final inside diameter at 2 thou. Its easier to make something concentric by pushing the inside out than the outside in unless you are neck turning to make sure neck thicknesses are absolutely the same. Not gonna lie? Other than my 6 CM and 6 Grendel? Everything else I just use a full length sizing die with the expander ball removed, with 2thou neck tension set with a mandrel and accuracy is still better than I can shoot.

• How important is precise neck tension control when reloading?

Alot. Major contributor to low ES/SDs

• If I’m planning to anneal down the line, does that tip the scales in favor of bushing dies long-term?

No. Annealing does 2 things. Makes neck tension more consistent, and makes your brass live longer with less neck splits

• Is there a real-world downside to just using a full-length die vs a bushing die?

I dont think so. See my above statement

The rest of your plan looks solid. Use known working components and dont try to reinvent the wheel when youre first starting out. Berger 180s and H1000 is a great start.

Edit: If you are just getting into annealing? You dont need to buy an AMP. Alot of shooting titles and world championships have been and still are being won by guys with a flame annealer.

 

[Maurygold]

Thanks again for the input, it’s been really helpful getting started.

Ill go with the Berger 180s for now based on yalls feedback. I ran a few quick ballistic comparisons against the 195s at different velocities, and was surprised to see there wasn’t much wind drift difference out to 1,000. While I may shoot steel beyond that at some point, I don’t plan to hunt that far, and realistically I’m more likely to misread the wind than be limited by bullet choice.

I’ll be starting with H1000 and keeping charges below book max while I work up a load. My goal is low SDs and consistency so definitely not chasing velocity.

For dies, I’ve narrowed it down to:

• Hornady Match Grade Full Length Die Set
• RCBS MatchMaster Bushing Full Length Die Set
• Redding Type S Match Bushing Full Length Die Set

I know the RCBS and Redding sets require bushings, which aren’t included. At first I was leaning toward the Hornady for simplicity, but after reading more, I’m now leaning toward a bushing die setup. It seems like controlling neck tension directly becomes more valuable once you start annealing and get more consistent necks.

That brings me to a few questions I’d really appreciate some guidance on:

• How important is precise neck tension control when reloading?
• If I’m planning to anneal down the line, does that tip the scales in favor of bushing dies long-term?
• Is there a real-world downside to just using a full-length die vs a bushing die?

I’m trying to find the right balance between building good habits now and not overcomplicating things too early. My goal is repeatable precision, and I’m okay with a bit more complexity if it sets me up for success long term.

I only use bushing dies and it’s my rec to buy them. No downside to not. You’ll end up slightly overworking the brass or not having ideal tension otherwise.

To select a bushing measure the outside diameter of an assembled (ready to fire) case and subtract 3 thou. That’s the size bushing you need.

Don’t get caught up in the mandrel talk. You don’t need to do this or even consider it. I shoot 5-8 sd without ever touching one.

Annealing- you can easily get 2-4 firings from a case without ever annealing. (Not annealing for that many firings won’t ruin them either). Start simple and just ignore annealing you will do more harm than good trying to learn flame annealing while also learning reloading

 

[Kaldor]

I only use bushing dies and it’s my rec to buy them. No downside to not. You’ll end up slightly overworking the brass or not having ideal tension otherwise.

To select a bushing measure the outside diameter of an assembled (ready to fire) case and subtract 3 thou. That’s the size bushing you need.

Don’t get caught up in the mandrel talk. You don’t need to do this or even consider it. I shoot 5-8 sd without ever touching one.

Annealing- you can easily get 2-4 firings from a case without ever annealing. (Not annealing for that many firings won’t ruin them either). Start simple and just ignore annealing you will do more harm than good trying to learn flame annealing while also learning reloading

Alot of point here that really are not best practice anymore. It works, but its really the hard way. Ill say this: Consistency is king.

"I only use bushing dies and it’s my rec to buy them. No downside to not. You’ll end up slightly overworking the brass or not having ideal tension otherwise."
Not really. If you anneal every firing there is about zero chance of over working anything. I do use bushing dies, but I just messed with it as an experiment in conjunction with a mandrel.

"To select a bushing measure the outside diameter of an assembled (ready to fire) case and subtract 3 thou. That’s the size bushing you need."
True, but using a bushing is most effective when used with neck turned brass as its consistent.

"Don’t get caught up in the mandrel talk. You don’t need to do this or even consider it. I shoot 5-8 sd without ever touching one."
Mandrels make the ID of the neck concentric with the centerline of the brass. Bushings do not, unless you are neck turning. And what is really so hard about pushing mandrel thru a piece of brass? Consistency is king. Mandrels are consistent. Unturned neck ODs are not.

"Annealing- you can easily get 2-4 firings from a case without ever annealing. (Not annealing for that many firings won’t ruin them either). Start simple and just ignore annealing you will do more harm than good trying to learn flame annealing while also learning reloading"
True and false. Yes, you can get 4+ firings on brass, but with every firing and subsequent sizing you are work hardening the brass. This work hardening will cause neck splits and will cause inconsistent neck tension with spring back. And going to a smaller bushing to fight spring back only work hardens the case even more and accelerates failure. You seem to have a huge gripe with flame annealing. Honestly, I can teach someone how to anneal properly in about 5 minutes with a flame annealer like an Annealeez or AGS. Its not some rocket science mystical black art anymore. A bit of instruction, a dose of common sense and the right equipment makes it really quite trivial to do it correctly. For the record? I flame anneal at least 5000 cases per year. I used to use an Annealeez, but now use an AGS. Ive never melted or ruined a single piece of brass even when starting out.

To sum up? Mandrels are consistent. Annealing creates consistency. Good consistent reloading using good proven methods and equipment creates accurate ammo. Can you get good results with other methods? Sure can, but it can introduce a host of issues that you have to be aware of that honestly arent worth the potential problems.

 

[Maurygold]

Alot of point here that really are not best practice anymore. It works, but its really the hard way. Ill say this: Consistency is king.

"I only use bushing dies and it’s my rec to buy them. No downside to not. You’ll end up slightly overworking the brass or not having ideal tension otherwise."
Not really. If you anneal every firing there is about zero chance of over working anything. I do use bushing dies, but I just messed with it as an experiment in conjunction with a mandrel.

"To select a bushing measure the outside diameter of an assembled (ready to fire) case and subtract 3 thou. That’s the size bushing you need."
True, but using a bushing is most effective when used with neck turned brass as its consistent.

"Don’t get caught up in the mandrel talk. You don’t need to do this or even consider it. I shoot 5-8 sd without ever touching one."
Mandrels make the ID of the neck concentric with the centerline of the brass. Bushings do not, unless you are neck turning. And what is really so hard about pushing mandrel thru a piece of brass? Consistency is king. Mandrels are consistent. Unturned neck ODs are not.

"Annealing- you can easily get 2-4 firings from a case without ever annealing. (Not annealing for that many firings won’t ruin them either). Start simple and just ignore annealing you will do more harm than good trying to learn flame annealing while also learning reloading"
True and false. Yes, you can get 4+ firings on brass, but with every firing and subsequent sizing you are work hardening the brass. This work hardening will cause neck splits and will cause inconsistent neck tension with spring back. And going to a smaller bushing to fight spring back only work hardens the case even more and accelerates failure. You seem to have a huge gripe with flame annealing. Honestly, I can teach someone how to anneal properly in about 5 minutes with a flame annealer like an Annealeez or AGS. Its not some rocket science mystical black art anymore. A bit of instruction, a dose of common sense and the right equipment makes it really quite trivial to do it correctly. For the record? I flame anneal at least 5000 cases per year. I used to use an Annealeez, but now use an AGS. Ive never melted or ruined a single piece of brass even when starting out.

To sum up? Mandrels are consistent. Annealing creates consistency. Good consistent reloading using good proven methods and equipment creates accurate ammo. Can you get good results with other methods? Sure can, but it can introduce a host of issues that you have to be aware of that honestly arent worth the potential problems.

Mandrels are completely unnecessary and just add complexity and more room for error. Here’s my Garmin from 2 weeks ago on two different guns.




You don’t need to neck turn brass for bushings. (See chrono above)

Flame annealing is inconsistent - amp or nothing. Beginners don’t need to anneal and should learn basics.

 

[MurphyTX]

Thanks for the continued discussion, this has been really helpful to follow.

The idea of using a mandrel to true up the inside of the neck makes a lot of sense to me, especially from a consistency standpoint. But I’m still a little fuzzy on where exactly it fits into the process. From what I understand, you typically full-length size the case first (with a bushing die and no expander), and then run the mandrel in as a second step to set final neck tension from the inside out. I’ve also seen references to dies that let you run a mandrel inside the die itself, is that something different, or just a different way of running the mandrel?

I’m leaning toward getting set up to anneal eventually. Since I’ll be using Hornady brass for my first few firings and plan to upgrade brass later, I figure it’s a good opportunity to learn. If I lose a piece or ten early on, it’s not the end of the world. I’ve watched a few videos, and the biggest concern seems to be overheating or torching the brass. I’m hoping I can work up to consistent results by watching for correct color change or timing, whichever method is most reliable.

I also get the logic behind skipping the expander ball in the die to reduce runout. That makes sense. I’m just trying to wrap my head around how best to adapt the process to keep things simple, but consistent, especially as I get through these early batches and start layering in more control over neck tension.

Appreciate all the insight so far, this has been a great thread to learn from.

 

[Maurygold]

Thanks for the continued discussion, this has been really helpful to follow.

The idea of using a mandrel to true up the inside of the neck makes a lot of sense to me, especially from a consistency standpoint. But I’m still a little fuzzy on where exactly it fits into the process. From what I understand, you typically full-length size the case first (with a bushing die and no expander), and then run the mandrel in as a second step to set final neck tension from the inside out. I’ve also seen references to dies that let you run a mandrel inside the die itself, is that something different, or just a different way of running the mandrel?

I’m leaning toward getting set up to anneal eventually. Since I’ll be using Hornady brass for my first few firings and plan to upgrade brass later, I figure it’s a good opportunity to learn. If I lose a piece or ten early on, it’s not the end of the world. I’ve watched a few videos, and the biggest concern seems to be overheating or torching the brass. I’m hoping I can work up to consistent results by watching for correct color change or timing, whichever method is most reliable.

I also get the logic behind skipping the expander ball in the die to reduce runout. That makes sense. I’m just trying to wrap my head around how best to adapt the process to keep things simple, but consistent, especially as I get through these early batches and start layering in more control over neck tension.

Appreciate all the insight so far, this has been a great thread to learn from.

Just start with the expander (I shot every round above with an expander - I own a mandrel). later on you can play with Mandrels if you get bored but it’s completely unnecessary.

Only $300+ dies have a mandrel function built in and it’s not a true mandrel so you don’t have to worry about those.

You should eventually anneal. Just get some good groups and learn first then add it in. It’s not critical to learning to reload.

 

[Kaldor]

Thanks for the continued discussion, this has been really helpful to follow.

The idea of using a mandrel to true up the inside of the neck makes a lot of sense to me, especially from a consistency standpoint. But I’m still a little fuzzy on where exactly it fits into the process. From what I understand, you typically full-length size the case first (with a bushing die and no expander), and then run the mandrel in as a second step to set final neck tension from the inside out. I’ve also seen references to dies that let you run a mandrel inside the die itself, is that something different, or just a different way of running the mandrel?

I’m leaning toward getting set up to anneal eventually. Since I’ll be using Hornady brass for my first few firings and plan to upgrade brass later, I figure it’s a good opportunity to learn. If I lose a piece or ten early on, it’s not the end of the world. I’ve watched a few videos, and the biggest concern seems to be overheating or torching the brass. I’m hoping I can work up to consistent results by watching for correct color change or timing, whichever method is most reliable.

I also get the logic behind skipping the expander ball in the die to reduce runout. That makes sense. I’m just trying to wrap my head around how best to adapt the process to keep things simple, but consistent, especially as I get through these early batches and start layering in more control over neck tension.

Appreciate all the insight so far, this has been a great thread to learn from.

Ive used a full length and a very close fitting bushing dies with no expander ball with my mandrel. On annealed brass? It does not seem to make a difference in my experience. You are correct on process, size and then mandrel. Yes, its an extra step. Dont sweat run out too much to be quite honest. Very few people are good enough shots to be able to shoot difference between a 0 and 5 thou runout.

Annealing becomes alot more appealing when the brass starts costing $1.50 a pop or more. If you buy 300 pieces for $500, spending $300 for a flame annealer that will double or triple the lifespan of the brass is a no brainer. Youre correct on process here too. Figure out your process on the cheap Hornady brass, and then move on once you have increased your knowledge. My advice to people is to skip the Tempilaq. Instead, turn the lights off, point the torch right at the neck shoulder junction, keep the dwell time fairly short at the start, and slowly increase the time in flame until it just starts to glow, and then back it off just a little bit. The reason you start with short dwell time is to avoid melting a case. You can always pick up an under annealed case and run it again. Brass has a wide range for annealing, in laymans terms, its hard to eff it up. Cortina proved that with a Benchsource flame annealer a few years ago before the AMP was even a thing, and if you wanted to anneal with induction, the best choice was to buy an Annie. I let mine just start to glow, and drop it from the flame, and it works fine even it it may be a little excessive.