7 PRC

[Ranger188]

Good look at the different case sizes in the PRC line.

7mm PRC, Hornady's New 7mm - LoadDevelopment.com

We will firstly see Hornady brass for 7mm PRS cartidge, with factory loaded Hornady ammo also, and we are sure the other brass manufacturers like Alpha, ADG, Peterson and Lapua will follow with their own soon if we look at the 6.5 PRC and 300 PRC before it.

www.loaddevelopment.com

 

[c_bass16]

Been having a bit of a "debate" discuss over on the ole Facebook machine and I wanted to ask a question.

IS IT POSSIBLE to have a standard magnum bolt face cartridge that comes in at around 2.4" (shorter than the Rem Mag and LRM) and still has 83 to 85 gr of h20 capacity without doing something like an AI shoulder. Maybe a 35-36 shoulder for feeding.

TO ME, the 7mm PRC left a little performance on the table and FOR ME, the only reason to consider it, is 7mm LRM is hard to source, and people hate belts.

My Rem Mag is a match chamber with standard throat and it'll run circles around the published numbers of the 7PRC. I feel like in an effort to make it efficient, they made it too short and neutered it's potential.

 

[Orr89rocz]

Been having a bit of a "debate" discuss over on the ole Facebook machine and I wanted to ask a question.

IS IT POSSIBLE to have a standard magnum bolt face cartridge that comes in at around 2.4" (shorter than the Rem Mag and LRM) and still has 83 to 85 gr of h20 capacity without doing something like an AI shoulder. Maybe a 35-36 shoulder for feeding.

TO ME, the 7mm PRC left a little performance on the table and FOR ME, the only reason to consider it, is 7mm LRM is hard to source, and people hate belts.

My Rem Mag is a match chamber with standard throat and it'll run circles around the published numbers of the 7PRC. I feel like in an effort to make it efficient, they made it too short and neutered it's potential.

A stretched 7 wsm? By that point you are closing in on 28 nosler, or use the shorter 33 nosler case necked down? Its 2.46”

 

[B23]

My Rem Mag is a match chamber with standard throat and it'll run circles around the published numbers of the 7PRC. I feel like in an effort to make it efficient, they made it too short and neutered it's potential.

I'm not sure what you mean by "run circles around" Hornady's published 180 ELD-M ammo at 2975 from a 24in barrel is pretty good and unless someone is loading their 7mm Rem mag pretty hard, it's not going to do that much better in an equal length barrel.

I have a 7mm Blaser mag which has a tiny bit more case capacity than the 7 Rem mag and with a 26in barrel I'm shooting 180's 3088-3100 using 68.5gr RL26. My load is probably 3/4-ish gr. from being max. I don't see a 7 Rem mag doing any better, unless, you're using a longer barrel or you're running it harder. Yes, my Blaser is 100 +/- fps faster but I don't really consider that running circles around the 7 PRC, and, I'm also using a 26in barrel so mine at 24, the gap would be even closer.

 

[c_bass16]

A stretched 7 wsm? By that point you are closing in on 28 nosler, or use the shorter 33 nosler case necked down? Its 2.46”

The whole idea being that the 2.5 and 2.514 of the Rem Mag and LRM respectively...make loading 195gr bullets doable, but not ideal.

2.46 is better, as long as it wouldn't sacrifice neck length which I feel is important when holding super long bullets. (A reason I feel the 7saum is more desirable than the WSM)

My point would be case capacity slightly greater than LRM, even if only 1-2 gr...and slightly shorter...even if only .010 would be a very efficient cartridge for the 190 class bullet.

 

[c_bass16]

I'm not sure what you mean by "run circles around" Hornady's published 180 ELD-M ammo at 2975 from a 24in barrel is pretty good and unless someone is loading their 7mm Rem mag pretty hard, it's not going to do that much better in an equal length barrel.

You're right, I may have chosen my words poorly. It's not a fair comparison to look at factory loads compared to hand loads. That's my fault. However.
For 8 years now, I've been loading HBN coated 180 Hybrids at 3100 fps from a 24" barrel with RL33 (much more dense than RL26 and quite a bit more powder fits in the case comfortably)...and since then, I've seen a couple other people doing about as well, so it's not a fluke. It's just the powder selection. You're not going to get there with H1000 or RL26.

I have a 7mm Blaser mag which has a tiny bit more case capacity than the 7 Rem mag and with a 26in barrel I'm shooting 180's 3088-3100 using 68.5gr RL26. My load is probably 3/4-ish gr. from being max. I don't see a 7 Rem mag doing any better, unless, you're using a longer barrel or you're running it harder. Yes, my Blaser is 100 +/- fps faster but I don't really consider that running circles around the 7 PRC, and, I'm also using a 26in barrel so mine at 24, the gap would be even closer.

I hadn't considered the 7 Blaser, but at 2.35 with a reported 86gr of H20 capacity and a longer neck than the Rem Mag...that's about exactly what I was describing as "ideal". (more research suggests h20 is only around 76gr which makes it unlikely that it produces MORE velocity than the 7m Rem Mag)

For comparison though...I tested 190 Atips with RL33 in my 7RemMag and was at 3040 fps....and was at 3000 with 195 EOLs. If the H20 capacity is truely 4gr more in the blaser....that would make a perfect candidate for using the 190-195 class bullet with RL33.

 

[c_bass16]

If my numbers are off with the 7 Blaser, please educate me as I have very little knowledge o the cartridge.

 

[B23]

If my numbers are off with the 7 Blaser, please educate me as I have very little knowledge o the cartridge.

New brass, Norma as they're the only ones that make it, holds 83+/- gr. H20 My fired and FL sized cases hold 84 +/- H20. I mentioned, FL sized, because they'll hold more fired and unsized but to me that number is pointless.

RL33 is considerably bulkier, more similar to powders like Retumbo that take up a lot of space, than is RL26 so I'm surprised you can even get enough in the case, without a good amount of crunching, to get that kind of velocity, especially, since you mentioned your 7 Rem mag has a match reamer with a standard throat which means not a lot of freebore. But, the fact that you don't have a lot of freebore and you're shooting really long bullets very possibly means you're right at touching the lands or maybe even in to them which will spike up pressure leading to higher velocities.

Generally, powders like RL26, in cases of this size, produces the best velocities. The slower and bulkier powders like RL33, Retumbo, and N570, again in these size cases, are usually down on velocity because you run out of room in the case before you can get enough in there. The much bigger and overbore cases like the 7 RUM or 28 Nosler, where you have a lot more case capacity, is where those slower powders shine.

 

[c_bass16]

New brass, Norma as they're the only ones that make it, holds 83+/- gr. H20 My fired and FL sized cases hold 84 +/- H20. I mentioned, FL sized, because they'll hold more fired and unsized but to me that number is pointless.

RL33 is considerably bulkier, more similar to powders like Retumbo that take up a lot of space, than is RL26 so I'm surprised you can even get enough in the case, without a good amount of crunching, to get that kind of velocity, especially, since you mentioned your 7 Rem mag has a match reamer with a standard throat which means not a lot of freebore. But, the fact that you don't have a lot of freebore and you're shooting really long bullets very possibly means you're right at touching the lands or maybe even in to them which will spike up pressure leading to higher velocities.

Generally, powders like RL26, in cases of this size, produces the best velocities. The slower and bulkier powders like RL33, Retumbo, and N570, again in these size cases, are usually down on velocity because you run out of room in the case before you can get enough in there. The much bigger and overbore cases like the 7 RUM or 28 Nosler, where you have a lot more case capacity, is where those slower powders shine.

For the Blaser, that makes a sense. that's a nice (phenomenal) H20 cap for that case...it's no wonder you're getting such great numbers. I read folks doing a slight blow out and slight shorter neck to get that 68gr capacity that I read in a previous post...which makes it all that much more interesting.

As for my Rem Mag...I can only go off the loading I am and have been doing for nearly a decade. I'll have to dig out my old book to find out where my lands were on a new barrel, but I was most definitely not jamming. If I remember correctly...I was about .005 off when I started doing initial load work.

It is indeed a far more dense powder, but there is a reason I use it. IMO, it's the perfect mix of capacity and weight for the 180+ bullets. BUT, you're 100% right that it's too bulky and dense to use on anything less than 180 class bullet.
I tested 175s and 168s...and the numbers just don't jive. Not worth it, way to slow.
It did perform remarkable with the 190 and 195s as well, and I probably could have taken it even further with a slightly shorter case to pull some bullet out of the powder column.

The only reason I haven't rebarreled yet, is I've been waiting hoping wishing wanting a cartridge to grab that last little bit of performance out of a 180-184 class bullet. I thought it might be the LRM, but it doesn't seem to offer enough...and the 7-300 PRC might just be too much. At this point...it's just splitting hairs and I was hoping the 7 PRC would be a factory cartridge that would be right in the middle. But it's not.

 

[FURMAN]

You're right, I may have chosen my words poorly. It's not a fair comparison to look at factory loads compared to hand loads. That's my fault. However.
For 8 years now, I've been loading HBN coated 180 Hybrids at 3100 fps from a 24" barrel with RL33 (much more dense than RL26 and quite a bit more powder fits in the case comfortably)...and since then, I've seen a couple other people doing about as well, so it's not a fluke. It's just the powder selection. You're not going to get there with H1000 or RL26.


I hadn't considered the 7 Blaser, but at 2.35 with a reported 86gr of H20 capacity and a longer neck than the Rem Mag...that's about exactly what I was describing as "ideal". (more research suggests h20 is only around 76gr which makes it unlikely that it produces MORE velocity than the 7m Rem Mag)

For comparison though...I tested 190 Atips with RL33 in my 7RemMag and was at 3040 fps....and was at 3000 with 195 EOLs. If the H20 capacity is truely 4gr more in the blaser....that would make a perfect candidate for using the 190-195 class bullet with RL33.

You are choosing a very specific set of components to try to prove(just demonstrating you don't understand physics) one cartridge is better than another which is running mildly to work in thousands of rifles. The fact is the 7 PRC has 83 grains of H20 water capacity and the 7 rem mag has 84-86 depending on brass brand. The Rem Mag WILL NOT outrun the PRC if both have factory throats. The 7 rem mag is pretty limited with its SAAMI throat. In custom form you will not be able to see the difference between the two when the same components are used.

If you blew the walls out a few thousandths and went with a 40 degree shoulder you may gain 3 grains H20. So you would be at LRM capacity. I am guessing many PRC threads will get hijacked just like this one. If you want to discuss a new wildcat why not start your own thread? If you built a 7-300WM using ADG brass you will be in the 91-92 grains of H20 which sounds like where you want to be. It is very easy with a set of bushing dies. I have been there and I personally feel the 7PRC, Blaser, WSM case is perfect compromise between the accuracy of the SAUM and the speed of larger overbore cartridges.

 

[Alex Wheeler]

 

[Orr89rocz]

The rem mag loaded right seems very good, if you are doing 3000-3100 with 180-190 bullets that isnt far off what i seen posted for the 28 nosler and it’s substantially bigger. Im building the nosler and was hoping for more separation from the rem mag stuff, mine will be a 28” barrel so i should see some numbers

 

[762 ULTRAMAGA]

You are choosing a very specific set of components to try to prove(just demonstrating you don't understand physics) one cartridge is better than another which is running mildly to work in thousands of rifles. The fact is the 7 PRC has 83 grains of H20 water capacity

Where are you getting the 83 grain capacity number from Mr. Physics?
What I'm seeing is it's somewhere between 76-78 grains H20?

 

[FURMAN]

Where are you getting the 83 grain capacity number from Mr. Physics?
What I'm seeing is it's somewhere between 76-78 grains H20?

Measuring. Brass. Hornady.

 

[Tarmacshooter]

Measuring. Brass. Hornady.

Ok, you just lost all credibility!

 

[Alex Wheeler]

Where are you getting the 83 grain capacity number from Mr. Physics?
What I'm seeing is it's somewhere between 76-78 grains H20?

Furman made the video I posted above. He has the stuff in his hands.

 

[762 ULTRAMAGA]

Furman made the video I posted above. He has the stuff in his hands.

Uh huh
Just checking cuz I've heard all kinds of numbers mostly in the 70s, 83 grains is actually pretty good.

 

[2thdk]

Is 83gn h2o with virgin brass or fired brass that is not resized?

 

[Fuj]

Uh huh
Just checking cuz I've heard all kinds of numbers mostly in the 70s, 83 grains is actually pretty good.

A little confusing since there are 2 different PRC cases. If the 6.5
PRC is necked up to 7mm, that case would only be in the low 70's
and that would be a stretch. Published case capacity of the 6.5 PRC
is only about 68 grs, and the 7mm Sherman Surpassing that. I do
believe the case in question would be the necked down 300 PRC
and would be in the 80's.....

 

[FURMAN]

Is 83gn h2o with virgin brass or fired brass that is not resized?

Once fired not sized. All of my listed sizes on the net are this way. Ive checked sizing typically lose .2 grains.