7mm PRC is here. SAAMI specs out

[7.62 Gunner]

Oct 14 update with the rest of my testing on the new RCC brass, 67.2-68.4grs of R26


Ok got to the range this morning with the new 7mm PRC, 24.5 inch 1-8 twist #2 contour 5R Benchmark barrel.
New RCC Brass, Reloder 26, federal 215M primers, 175gr Berger Elite Hunters, COAL 3.337"

First 6 shots 63.0grs for zeroing/cleaning between shots, 2882/2861/2869/2855/error/2848

All 3 shot groups to follow

63.0- 2828/2822/2828 same hole
63.5- 2856/2849/2856 .48"
64.0- 2884/2895/2912 .57"
64.5- 2929/2946/2938 .97"
65.0- 2941/2945/2945 2.0"
65.5- OOPS. 2.0"
66.0-3011/3025/3027 1.75"
66.5- error/3033/3027 1.35"
67.0- 3095/3101/3106 .95" No pressure signs
67.2- 3115 - 1 shot
67.4- 3124 - 1 shot
67.5- 3112/3112/3111 .67" group , muzzle jump
67.6- 3116 1 shot
67.8- 3134 1 shot
68.0- 3126/3136/3127 .9" group, noticeable Muzzle Jump
68.2- 3148
68.4- leakage around primer, slight ejector mark, considerable recoil/muzzle jump. I stopped here, I figure as quigley257 found 68.0grs would be max for new RCC brass/R26/175gr Bergers, please start lower and work up.

Overall I thought it was pretty good velocity for a 24.5 inch barrel, it was a pleasure to shoot.

Hey I'm curious what the case capacity is on virgin and fired brass.
Could you fill a few with H20 and report back?

 

[Weatherby Fan]

Hey I'm curious what the case capacity is on virgin and fired brass.
Could you fill a few with H20 and report back?

75.3 virgin brass
78.4 once fired

 

[7.62 Gunner]

75.3 virgin brass
78.4 once fired

Really? That's basically a saum,
I thought the capacity was supposed to be in the low 80s..
Be careful you're rocking loads that are max in a custom throated 7 wsm

 

[Weatherby Fan]

Really? That's basically a saum,
I thought the capacity was supposed to be in the low 80s..
Be careful you're rocking loads that are max in a custom throated 7 wsm

This is RCC brass and it's quite heavy, I'm sure the internal volume will be more for Hornady or Peterson brass.

 

[vancewalker007]

Meanwhile I have hornady 7LRM and 6.5LRM brass with over 20 firings on it, and still going strong.

You're a good brass shepherd. I likely have some with way over 10 uses but I have too many rifles to keep good count. If a primer pocket goes, toss it.

 

[codyadams]

Oct 14 update with the rest of my testing on the new RCC brass, 67.2-68.4grs of R26


Ok got to the range this morning with the new 7mm PRC, 24.5 inch 1-8 twist #2 contour 5R Benchmark barrel.
New RCC Brass, Reloder 26, federal 215M primers, 175gr Berger Elite Hunters, COAL 3.337"

First 6 shots 63.0grs for zeroing/cleaning between shots, 2882/2861/2869/2855/error/2848

All 3 shot groups to follow

63.0- 2828/2822/2828 same hole
63.5- 2856/2849/2856 .48"
64.0- 2884/2895/2912 .57"
64.5- 2929/2946/2938 .97"
65.0- 2941/2945/2945 2.0"
65.5- OOPS. 2.0"
66.0-3011/3025/3027 1.75"
66.5- error/3033/3027 1.35"
67.0- 3095/3101/3106 .95" No pressure signs
67.2- 3115 - 1 shot
67.4- 3124 - 1 shot
67.5- 3112/3112/3111 .67" group , muzzle jump
67.6- 3116 1 shot
67.8- 3134 1 shot
68.0- 3126/3136/3127 .9" group, noticeable Muzzle Jump
68.2- 3148
68.4- leakage around primer, slight ejector mark, considerable recoil/muzzle jump. I stopped here, I figure as quigley257 found 68.0grs would be max for new RCC brass/R26/175gr Bergers, please start lower and work up.

Overall I thought it was pretty good velocity for a 24.5 inch barrel, it was a pleasure to shoot.

In my opinion, for what little it may be worth, calling .4 grains below a leaking primer on virgin brass as "max" is way too high pressure. Your a coon hair away from blowing virgin primer pockets, I would go down way more than that.

But to each his own!

 

[Weatherby Fan]

In my opinion, for what little it may be worth, calling .4 grains below a leaking primer on virgin brass as "max" is way too high pressure. Your a coon hair away from blowing virgin primer pockets, I would go down way more than that.

But to each his own!

Yes I thought about that as well, I also find the RCC brass different as it doesn't appear to show pressure signs like normal brass.
I used guidelines from another chap that used 68.0 as his max as well, of course once fired brass may be max 1-2 or 3 grs below that as well, not to mention every rifle will be different, only thing that doesn't change is the limit of max pressure.
Looking forward to more info later this month from Hornady.

 

[codyadams]

Yes I thought about that as well, I also find the RCC brass different as it doesn't appear to show pressure signs like normal brass.
I used guidelines from another chap that used 68.0 as his max as well, of course once fired brass may be max 1-2 or 3 grs below that as well.

For sure, it does seem to not be showing typical pressure signs as early, probably really strong brass. I had that same thing with Peterson brass in a 28" .338 Norma mag and Stiller TAC 338 action, doing a pressure work up with Retumbo & 300 Bergers, I had them going 2975 and no ejector mark or even shadow on the case head. I knew it had to be way high, so I stopped my work up. Settled on a load going 2825 that shot very well. Did it with Peterson .270 brass too, my final loads were WAY below where I saw initial pressure signs. Tough brass can make it harder to see the pressure signs for sure

 

[VLD Pilot]

Sure, and SAUM's with 10gr less capacity (or even less) get 3100fps too according to some around here…

"nO pReShEr!"

lol

Never had either so can't say.

 

[orkan]

You're a good brass shepherd.

It's not like I love having slow velocities. However, I do love to shoot very small. It's a simple fact which most have not realized, that when you push brass to a certain point, it's firing to firing consistency is lost. When I say lost, I mean permanently lost. It can't be recovered once it's gone.

It is the second most common reason why guys are constantly chasing a tenth to 2 tenths of a mil around on their rifles zero.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

 

[VLD Pilot]

It's not like I love having slow velocities. However, I do love to shoot very small. It's a simple fact which most have not realized, that when you push brass to a certain point, it's firing to firing consistency is lost. When I say lost, I mean permanently lost. It can't be recovered once it's gone.

It is the second most common reason why guys are constantly chasing a tenth to 2 tenths of a mil around on their rifles zero.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

Let's face it, accuracy is king. Really how much is gained by 75-100 fps in anything except bragging rights ? For me another half MOA on the turret means nothing. As a hunter, the animal won't notice that difference.

 

[vancewalker007]

firing to firing consistency is lost. When I say lost, I mean permanently lost. It can't be recovered o

Let's face it, accuracy is king. Really how much is gained by 75-100 fps in anything except bragging rights ? For me another half MOA on the turret means nothing. As a hunter, the animal won't notice that difference.

All true, you should go for a blend of usable velocity and great accuracy. Especially when you're hunt Coues deer where a lot of shots are over 500 yards on a small target in rough country. The fast 7s work great especially when you can get 1/2 MOA accuracy regularly and you can then get the great Berger flop and drop.

 

[orkan]

All true, you should go for a blend of usable velocity and great accuracy. Especially when you're hunt Coues deer where a lot of shots are over 500 yards on a small target in rough country. The fast 7s work great especially when you can get 1/2 MOA accuracy regularly and you can then get the great Berger flop and drop.

The proper way to increase performance is to go with a bigger/different cartridge... not try to push a cartridge beyond its practical design limit.


-----------
Follow on Instagram
Subscribe on YouTube
Amazon Affiliate

 

[VLD Pilot]

All true, you should go for a blend of usable velocity and great accuracy. Especially when you're hunt Coues deer where a lot of shots are over 500 yards on a small target in rough country. The fast 7s work great especially when you can get 1/2 MOA accuracy regularly and you can then get the great Berger flop and drop.

We all have different ideas of which cartridge we prefer for various animals. I prefer a smaller .257/264 for antelope, Coues deer or that size animal. Flat shooting and plenty for the longest ranges. Antelope typically are killed beyond 500 yards for me. Out to 800+ usually. Coues not so much. Whitetail deer vary depending on where I'm hunting. In state, out to 450-600 max usually. Same rifles. 7s are great for Mulies out west and big whitetails but the 6.5s work as well. I find myself using my 284 for anything I need a 7mm for. Kinda prefer it over the magnum 7s anymore. Beyond that it's a bigger 30 or 338. Accuracy in the end means the most over velocity.