7mm PRC

[Korhil78]

did the 162's still have enough in the neck and wasn't too far away from the rifling?

Thanks

Yes, they were just fine.

 

[cajun]

did the 162's still have enough in the neck and wasn't too far away from the rifling?

Thanks

When Hornady designed the prc the throat geometry is such that you dont have to be in or near the lands to get good accuracy. They did this to accommodate guys shooting factory rifles with mag length restrictions and shooting factory ammo. The old adage you had to be near the lands to get accuracy is not really true. I have a 7 mag jumping .100 and it's shooting sub moa.

 

[KsKevin]

When Hornady designed the prc the throat geometry is such that you dont have to be in or near the lands to get good accuracy. They did this to accommodate guys shooting factory rifles with mag length restrictions and shooting factory ammo. The old adage you had to be near the lands to get accuracy is not really true. I have a 7 mag jumping .100 and it's shooting sub moa.

What's unique in how they did the throat geometry. Isn't it a pretty standard approach with Fn at 0.2845" and a 1'30 throat angle into the lands or is there more to it?

 

[blvette75]

Mossberg Patriot
7MM PRC
175 ELD-X bullet
Asiatic water buffalo ~1k pounds
1 shot and it flopped over after taking a single step.
Old Army buddy and I were chasing one today in Texas.View attachment 503095

The last one I help chase required 7 x 180 grain core-lockts to the point of the shoulder to bring it down and even then I used a 357 magnum at powder burn distance to finally dispatch it.

Amazingly tough critters and this picture does not do the size of this thing any justice sadly.

Approximate lbs for the big fellow?

 

[blvette75]

I watched - well listened as I was hanging sheetrock - the video again and did not hear Randy mention anything about 7mm Rem Mag factory gun twist rates vs. the 1:8 of the PRC. I expect that when Randy builds a gun, he designs it with purpose, and those would include faster twist rate barrels in his 7mms. He knows his stuff for sure. But I can't recall him discussing that. Maybe I missed it.

The heavier and longer high BC bullets out of a typical factory PRC rifle, which most non-handloaders would have access to, will be more accurate (stable) and maintain more velocity down-range for proper expansion at distances beyond that of the lighter factory projectiles out of the 7mm Rem Mag. Fuss free.

As a handloader, I like the beltless case of the PRC, allowing me to headspace off the shoulder. I also like the 30 degree shoulder and longer neck, which maintains more burn in the case rather than the barrel throat (with the right powders). I could assume that will lead to longer barrel life - not just better long range accuracy of my handloads. Working up a handload that was on par with the Hornady factory ammo was one of the easiest workups I have ever done. Had I had more than one and a half weeks to develop loads and practice for my elk hunting trip, I would not have used the factory cartridges.

I didn't get the PRC for anything other than its adequacy as an interesting all-around big game cartridge which filled a gap in my moderate to long range lineup. I like it quite a bit. The 7mm Rem Mag is ... well ...." awedinarwee".
View attachment 509564

Well said was hopeful, my daughter could shoot this caliber/rifle as an upgrade over the 6.5 Creedmoor.

 

[cajun]

What's unique in how they did the throat geometry. Isn't it a pretty standard approach with Fn at 0.2845" and a 1'30 throat angle into the lands or is there more to it?

The 7 mag has a 3 deg throat angle and shorter freebore. Same thing with the 300 win mag. The guys at hornady talked about this in a podcast.

 

[Mcranch]

I thought freebore was at .2846? Please correct me. I have wondered since the saami dimensions came out is if they had also tried a 35 degree shoulder, and what difference that would have done for capacity and mv? I'm still figuring and refiguring on reamer to spec?

 

[cajun]

I thought freebore was at .2846? Please correct me. I have wondered since the saami dimensions came out is if they had also tried a 35 degree shoulder, and what difference that would have done for capacity and mv? I'm still figuring and refiguring on reamer to spec?

I think the .2846 is the diameter at that point. You have to subtract the lengths listed below the diagram to calculate freebore.

 

[Mcranch]

I think the .2846 is the diameter at that point. You have to subtract the lengths listed below the diagram to calculate freebore.

Yes, in refreshing my memory I'm thinking it is at .233 freebore. The neck diameter is at .2846. Thanks. Looking at other configurations some are spacing out the neck at .250. Not being to well versed in these dimension reasons as to why some believe that having a wider neck I would gladly like for someone to clarify. To myself it seems that a tighter neck chamber would keep the cartridge more aligned/centered.

 

[cajun]

Yes, in refreshing my memory I'm thinking it is at .233 freebore. The neck diameter is at .2846. Thanks. Looking at other configurations some are spacing out the neck at .250. Not being to well versed in these dimension reasons as to why some believe that having a wider neck I would gladly like for someone to clarify. To myself it seems that a tighter neck chamber would keep the cartridge more aligned/centered.

.2846 is the throat diameter. The neck diameter is .318. Tight necks do help but you dont see that in hunting rifles usually. With a tight neck chamber you may have to turn your necks for clearance. For example a loaded 7mm bullet in nosler brass runs .310. That gives you .004 clearance per side.

 

[Pilsner]

Approximate lbs for the big fellow?

As stated above it was well over 1k pounds.
Let me see if I can get a closer guess.
I took half the meat and after butchering and packaging I got ~220# of bone-in meat.
So call it 500# of meat total.
Usual yield is 33% or so of live weight.
So the critter was somewhere in the 1200-1500# range.

That is if you meant the buffalo. My hunting partner in the picture is around 220#.

 

[richardmac37]

I think and it may have already been stated. The 7mm prc is the gun industry answer to short throating the 7mms of the past. The thing I like about is being able to seat the bullets out further. I have only shot hornady 180 match and the 175 precision hunters. Neither reached the advertised velocity in a remington 700 lrh 26in 1-8 twist barrel. I will be reloading here pretty soon after Christmas to try and achieve the velocities that have been claimed. Regardless it's all personal preference shoot what you want I aint buying it for you.
Semper Fi, Merry Christmas and Happy New Year to you all.

 

[HalfMileKiller]

I'm averaging 3010 fps with a SD of 8.9 using 79.5 grains of LRT and a 175 grain ELDX out of a 24" Preferred 7 PRC barrel with no pressure signs.

 

[richhymas]

I think and it may have already been stated. The 7mm prc is the gun industry answer to short throating the 7mms of the past. The thing I like about is being able to seat the bullets out further. I have only shot hornady 180 match and the 175 precision hunters. Neither reached the advertised velocity in a remington 700 lrh 26in 1-8 twist barrel. I will be reloading here pretty soon after Christmas to try and achieve the velocities that have been claimed. Regardless it's all personal preference shoot what you want I aint buying it for you.
Semper Fi, Merry Christmas and Happy New Year to you all.

I agree with all. Mine were over 200 FPS below advertised for both the 175 and 180 factory offerings in a ruger American go wild. I'm hoping the barrel will speed up after a couple hundred rounds but I'm doubtful it will speed up more than 100 FPS. All that being said, I'm still happy with the rifle and cartridge.