Who's built a 7-.300 PRC?

[Wannashootit]

I've got an itch to build a new 7mm ELR stick.
Have a .300 WSM, so a 7 WSM doesn't do anything for me. Want to stick with a regular magnum LA, so no .338 LM or .300 Norma.

I'm not a typical wildcatter, I don't turn necks, etc. and like to keep reloading easy. Could the 7-.300 be as simple as 7mm bushings in a .300 die without an intermediate step?

Who's been down this road already, and how did it work out?

 

[HOOFER]

I've got an itch to build a new 7mm ELR stick.
Have a .300 WSM, so a 7 WSM doesn't do anything for me. Want to stick with a regular magnum LA, so no .338 LM or .300 Norma.

I'm not a typical wildcatter, I don't turn necks, etc. and like to keep reloading easy. Could the 7-.300 be as simple as 7mm bushings in a .300 die without an intermediate step?

Who's been down this road already, and how did it work out?

7-300 win would be “easier”. And brass much more available.

300 win and 300 PRC are ballistic twins

Just doing a 7PRC would seem to make the most sense. For a LA magnum.

 

[Wannashootit]

Just doing a 7PRC would seem to make the most sense. For a LA magnum.

Thought about that first; the .300 PRC case has substantially larger capacity from what I'm seeing.

 

[HOOFER]

Thought about that first; the .300 PRC case has substantially larger capacity from what I'm seeing.

Defiantly does.

28 nosler and 7 rum also come to mind.

I’m a 7 STW whore myself. I think I’ll go 28 nosler once the barrels I have are smoked.

Prolly too fast for match use.

 

[Supersubes]

I think theres a thread here on the 7-300PRC. The availability of lapua brass makes it an easy choice. Id recommend sizing the neck down in two steps, they come out better that way. There are a handful of reamers out there. Pick the one that will allow no-turn.

 

[Wannashootit]

I’m a 7 STW whore myself.

Funny- thought about that one a couple of years ago- bought the reamer then backed out. Great hunting cartridge, but I've never heard of that one being as accurate as some others for ELR target.

I think theres a thread here on the 7-300PRC. The availability of lapua brass makes it an easy choice. Id recommend sizing the neck down in two steps, they come out better that way. There are a handful of reamers out there. Pick the one that will allow no-turn.

Thanks, I'll try a search. I'll email Manson on the reamer selection.

 

[TEUFEL820]

Look into the 28 Sherman Magnum. It's a 300 PRC case with the shoulder blown out and necked down.

 

[Supersubes]

I was wrong, there are 4-5 of them. This is the one I was thinking of.

7-300 PRC Initial Results - Winner

I'll be doing most updates on my FB page so feel free to follow there but I've also copied all the initial data below. https://m.facebook.com/story.php?story_fbid=2293458990932473&id=2028645630747145 Some of you may know that I had a reamer made to neck down the new 300PRC to 7mm to see what...

www.snipershide.com

 

[Wannashootit]

Look into the 28 Sherman Magnum. It's a 300 PRC case with the shoulder blown out and necked down.

Not for me. Too much work...and proprietary brass.

 

[Schw15]

I shoot a 7mm-300 win mag. I neck the brass down in one step in a bushing die. No issues ever and I don't neck turn. I think you should be fine there. Both of them are pretty easy since there's bushing dies and both offer lapua brass and adg. Just make sure the reamer allows for no neck turn.

 

[FuhQ]

I've got an itch to build a new 7mm ELR stick.
Have a .300 WSM, so a 7 WSM doesn't do anything for me. Want to stick with a regular magnum LA, so no .338 LM or .300 Norma.

I'm not a typical wildcatter, I don't turn necks, etc. and like to keep reloading easy. Could the 7-.300 be as simple as 7mm bushings in a .300 die without an intermediate step?

Who's been down this road already, and how did it work out?

You might as well build a 7mm-300 Wby, or a 7mm STW, or a 7mm RUM... That way you don't have to spend all the money on a custom reamer and custom dies, etc...

 

[Schw15]

You might as well build a 7mm-300 Wby, or a 7mm STW, or a 7mm RUM... That way you don't have to spend all the money on a custom reamer and custom dies, etc...

Dies are easy just have to buy 300 prc bushing dies and throw a 7mm bushing size in. A lot of smith's have the 7-300 prc reamers on hand the 7mm-300 win mag not to many but a few.

 

[Wannashootit]

I'm a smith- so it's easy street.
Didn't want a belted mag (which is why I went with the WSM instead of the WM.

Thanks for the input, gentlemen.

 

[psharon78]

If you didn't want the belt, I'd look at 28 Nosler, 7mm RUM, 7mm-300 PRC

 

[4O6shootist]

Ive got one. 22" rock creek 8tw carbin, terminus helios lite, alterra carbon hunter stock, just under 9# with a nx8 4-32x50. Running 195 bergers at 2990 with N570. The terminus shows pressure early, figured I'd get more out of it, but it shoots well, grain under pressure.

 

[Wannashootit]

Ive got one. 22" rock creek 8tw carbin, terminus helios lite, alterra carbon hunter stock, just under 9# with a nx8 4-32x50. Running 195 bergers at 2990 with N570. The terminus shows pressure early, figured I'd get more out of it, but it shoots well, grain under pressure.

Wouldn't have expected that velocity from a 22" barrel, interesting benchmark- thanks*

 

[4O6shootist]

Wouldn't have expected that velocity from a 22" barrel, interesting benchmark- thanks*

Standard powders like H1000 or Retumbo were 60-80fps slower before pressure. Looked back through my data. N570 Topped out at 3100(bolt lift) with 190LRHT, but accuracy is at 2970-3000. 195s shot there, and at 2920fps with N570. N565 with 190s made it to 3040fps before psi signs, shot well at 3000 fps. This chamber has a 535 diameter at 200 line, similar to AW spec prc reamers to prevent clickers and get adequate case sizing. Saami is 533 at 200 line. I have a very long freebore as all I planned to shoot were berger 184, 190 and 195.

 

[Schw15]

Standard powders like H1000 or Retumbo were 60-80fps slower before pressure. Looked back through my data. N570 Topped out at 3100(bolt lift) with 190LRHT, but accuracy is at 2970-3000. 195s shot there, and at 2920fps with N570. N565 with 190s made it to 3040fps before psi signs, shot well at 3000 fps. This chamber has a 535 diameter at 200 line, similar to AW spec prc reamers to prevent clickers and get adequate case sizing. Saami is 533 at 200 line. I have a very long freebore as all I planned to shoot were berger 184, 190 and 195.

What was your load with n565 and 190 berger? I'm thinking about doing one since the sale at pva. What's barrel life looking like?

 

[4O6shootist]

What was your load with n565 and 190 berger? I'm thinking about doing one since the sale at pva. What's barrel life looking like?

Barrel life I'm unsure of, 270 rounds on it. Its a light hunting rifle. 77gr N565 for 3000fps with 190lrht jumping 25k from a 22" rock creek 8tw carbon barrel.

 

[Schw15]

That is impressive wow

Barrel life I'm unsure of, 270 rounds on it. Its a light hunting rifle. 77gr N565 for 3000fps with 190lrht jumping 25k from a 22" rock creek 8tw carbon barrel.

 

[bodhisafa]

Barrel life I'm unsure of, 270 rounds on it. Its a light hunting rifle. 77gr N565 for 3000fps with 190lrht jumping 25k from a 22" rock creek 8tw carbon barrel.
View attachment 8000958View attachment 8000959

How much case fill do you have at 77grains?

 

[Rob01]

If you are looking to do a 7mm and want to save some money then look at the PVA sale now. @bohem Josh put a post up about them but worth a look if thinking 7mm.

7mm Over-run Blowout Sale - All Actions

[email protected]

patriotvalleyarms.com

 

[bodhisafa]

Is that price the barrel and chamber job together?

 

[Rob01]

Is that price the barrel and chamber job together?

Yeah that’s a prefit. Not just a blank.

 

[bodhisafa]

Yeah that’s a prefit. Not just a blank.

How long these barrels?

 

[4O6shootist]

How much case fill do you have at 77grains?

Id say 95%? 565 is pretty bulky, down around body/shoulder junction. Freebore is around 0.240

 

[Rob01]

How long these barrels?

Says 26” max.

 

[trophyhunter]

Since you have a 300wsm, stepping up into a 338-300wsm is easy.

I’m having a barrel spun for my AX short action. Chunking 250’s at 2700 seems fun

I know Red Beards Gun Works had built a few 7-300prc, @morganlamprecht might be able to tell you about his.

 

[Wannashootit]

What's barrel life looking like?

If 1,500 is avg for the .300, I'm not expecting more than around 1K or so with the overbore. I'm sure there's a few out there that have been built which have hit that by now or getting close...

 

[4O6shootist]

Barrel life is subject to rate of fire, and powder energy/flame temp. H1000 or Retumbo vs N565 or N570, will be 15% less barrel life. 28 Noslers might get 800-900 accurate rounds if you treat them nice with cooler powders. Run blowtorch powder and 600-800rd is more likely. Case capacity of a 7/300 water weight is right at 96gr with adg brass, 28N is 103. There will likely be little difference.

 

[Earnhardt]

Since you have a 300wsm, stepping up into a 338-300wsm is easy.

I’m having a barrel spun for my AX short action. Chunking 250’s at 2700 seems fun

I know Red Beards Gun Works had built a few 7-300prc, @morganlamprecht might be able to tell you about his.

With the 338 WSM, 160 TTSX’s at 3300 fps is fun also…

 

[Dirty D]

I’m patiently waiting for 7PRC brass to come available and I’m genuinely surprised that no one has mentioned the 7 LRM as an option.

THE BIRTH OF THE GUNWERKS 7LRM

This article originally appeared in the Premiere Issue of Long Range Magazine

www.gunwerks.com

 

[4O6shootist]

I’m patiently waiting for 7PRC brass to come available and I’m genuinely surprised that no one has mentioned the 7 LRM as an option.

THE BIRTH OF THE GUNWERKS 7LRM

This article originally appeared in the Premiere Issue of Long Range Magazine

www.gunwerks.com

I'm building on them as well. Smith has had all the parts for several months, he's a busy man unfortunately!