7mm PRC

[lash]

By the way, those rounds are loaded to 3.320 inches.

My gunsmith used a Manson reamer, the standard one they have off the shelf with a slightly different base diameter, and he did not add any additional free bore. My COAL for a 180ELD – M touching the lands is 3.330“.

Just an FYI, for anybody considering getting one of these spun up. That COAL puts the top of the boat tail right at the bottom of the neck for that bullet. I wouldn’t see a point of extending the free bore unless you were shooting a solid or a 190 class bullet that is longer.

I was just curious, as I’m also using a long action (cut de gras) and have a single metal mag for it. The mag works great and is tight with no rattling. Those MDT mags were not out when I put mine together. I’m shooting 190s also seated to a COAL of 3.435”.

And yes mine is throated a bit longer for their use.

ETA: in an MDT ACC LA chassis.

 

[AznTactical]

My 7 PRC is at the G'smith.
I touch the lands at the following COL values below:
-175 ELDX 3.260"
-180 ELDM 3.191"
-180 Berger Hybrid Target 3.373"
-190 A-tips 3.495"

All values are avg out of 5 measurements per bullet. Decided to borrow a friend's factory rounds of 175 ELDX and 180 ELDM and forced the bolt to close. As expected, bullet got stuck in chamber.

Used Hornady's OAL length gauge with their 7 PRC modified case AND Sinclair's OAL gauge with an actual used piece of brass and values are very close. Even had a fellow buddy measure to find out where my lands are to make sure I'm not going crazy.

 

[lash]

My 7 PRC is at the G'smith.
I touch the lands at the following COL values below:
-175 ELDX 3.260"
-180 ELDM 3.191"
-180 Berger Hybrid Target 3.373"
-190 A-tips 3.495"

All values are avg out of 5 measurements per bullet. Decided to borrow a friend's factory rounds of 175 ELDX and 180 ELDM and forced the bolt to close. As expected, bullet got stuck in chamber.

Used Hornady's OAL length gauge with their 7 PRC modified case AND Sinclair's OAL gauge with an actual used piece of brass and values are very close. Even had a fellow buddy measure to find out where my lands are to make sure I'm not going crazy.

Freebore a bit short eh?

 

[secondofangle2]

Is the smith extending the freebore?

 

[AznTactical]

Is the smith extending the freebore?

I don't know yet. Waiting on g'smith. Is it weird to have a very short COL when using X and Y bullets but yet COL is fairly normal when using bigger Z and A bullets? My PRS gun is 6BR and it has a short freebore for all 6mm bullets.

 

[4O6shootist]

I don't know yet. Waiting on g'smith. Is it weird to have a very short COL when using X and Y bullets but yet COL is fairly normal when using bigger Z and A bullets? My PRS gun is 6BR and it has a short freebore for all 6mm bullets.

Coal will be different for sure. Base to ogive should be pretty consistent between all the bullets, likely within 0.010"

 

[Ronws]

I agree with this IF that person doesn't have mags for their PRC yet. I bought 2 of those MDT mags to compliment my existing Accurate RUM/PRC 3.850 mags and had to remove material off the MDT's so they can latch properly.
-When the Accurate latches, the MDT's wouldn't latch.
-Adjusted the mag latch down on the XLR chassis so all mags latch but started having feeding issues with the Accurates.
-Went back to original latch position and removed material off the top of the MDT's. No problems.

And @secondofangle2

Update. I checked with technical services at MDT. That polymer mag will not work with my Oryx chassis, hence the use of the metal 5 rd mag for .300 WM.

I have not had a single feeding problem, by the way. And the feed lips are just right for single feed by hand.

 

[Slides]

I already had a heap of metal mags for 300winmag, 7PRC fed fine in LSSG2/Howa LA so far.

 

[Ronws]

I already had a heap of metal mags for 300winmag, 7PRC fed fine in LSSG2/Howa LA so far.

Yeah, at the Hornady site on their 7 mm PRC page, they mention that if you already have a 7 RM or .300 RM, you can simply re-barrel with the 7 PRC.

 

[secondofangle2]

Yeah, I spent a lot of money to shave weight off of my rig and couldn’t stomach adding 7 ounces for a magazine

 

[Slides]

Yeah, I spent a lot of money to shave weight off of my rig and couldn’t stomach adding 7 ounces for a magazine

Mine has a 32 inch full profile 1.25 barrel with a T4 on the front so magazine weight isn't a big concern .

 

[secondofangle2]

Most of my rifles are v heavy "crew served weapons". This is my very first "lightweight" hunting rig.

Related: My buddy has the factory Savage with titanium action and 20" Proof in MDT and is running a TBAC Ultra 7 and I thought it was going to thump with 180 grains. It was surprisingly pleasant to shoot. (I still haven't shot mine yet, which weighs in about a pound more than his.)

 

[Slides]

I had a Savage impulse big game in 7prc on order as I was happy with a predator in 308 but then got a dud barrel on a 6.5PRC elite precision, I didn't write the barrel serial and I don't think it made it onto the registration, I sent it for warranty with the Australian supplier and I'm 99% sure they sent it back with the same barrel as it developed the same peculiar carbon deposit near the muzzle and shot like shit when they sent it back to me. Most Savages have mad chatter the whole way down the barrel so that didn't bother me but I suspect the bore opened and was gas cutting projectiles or causing odd barrel exit behaviour.

Especially outside Northern Territory or the Caoe in Queensland where there are buffalo and scrub bulls, 7prc is probably the perfect cartridge for hunting in Australia as it should easily deal with any deer, pigs or camels here with good balistics without too much recoil.

I eventually try a Ruger M77 as I don't have a control round feed rifle yet.

 

[Ronws]

I had a Savage impulse big game in 7prc on order as I was happy with a predator in 308 but then got a dud barrel on a 6.5PRC elite precision, I didn't write the barrel serial and I don't think it made it onto the registration, I sent it for warranty with the Australian supplier and I'm 99% sure they sent it back with the same barrel as it developed the same peculiar carbon deposit near the muzzle and shot like shit when they sent it back to me. Most Savages have mad chatter the whole way down the barrel so that didn't bother me but I suspect the bore opened and was gas cutting projectiles or causing odd barrel exit behaviour.

Especially outside Northern Territory or the Caoe in Queensland where there are buffalo and scrub bulls, 7prc is probably the perfect cartridge for hunting in Australia as it should easily deal with any deer, pigs or camels here with good balistics without too much recoil.

I eventually try a Ruger M77 as I don't have a control round feed rifle yet.

So, it is more likely a case of putting bison on the barbecue than shrimp. Awesome.

 

[Slides]

Ours are Asiatic water buffalo as opposed to bison but similar sort of thing.

I think Australia has the largest wild camel population in the world too.

 

[Ronws]

Ours are Asiatic water buffalo as opposed to bison but similar sort of thing.

I think Australia has the largest wild camel population in the world too.

I did not know that. Cool.