7-6.5 PRC

[rymart]

Other COAL measurements from my PVA Prefit barrel:

- 150 gr ELDX:
3.030” to-the-lands
0.080” jump at 2.950”

- 175 gr ELDX:
3.076” to-the-lands
0.126” jump at 2.950”

- 180 gr ELDM:
3.108” to-the-lands
0.158” jump at 2.950”

- 166 gr A-Tip:
3.082” to-the-lands
0.132” jump at 2.950”

The 166 A-Tips also shoot excellent in this rig with the 0.132” jump". My best 166 A-Tip load was 59.6 gr H4831 at 2975 fps.

 

[st1650]

Other COAL measurements from my PVA Prefit barrel:

- 150 gr ELDX:
3.030” to-the-lands
0.080” jump at 2.950”

- 175 gr ELDX:
3.076” to-the-lands
0.126” jump at 2.950”

- 180 gr ELDM:
3.108” to-the-lands
0.158” jump at 2.950”

- 166 gr A-Tip:
3.082” to-the-lands
0.132” jump at 2.950”

The 166 A-Tips also shoot excellent in this rig with the 0.132” jump". My best 166 A-Tip load was 59.6 gr H4831 at 2975 fps.

What would be your jump with the 162 eld-m ?

 

[ma smith]

My notes had calculation for Min COAL based on 7-6.5PRC of 1.7396 (base to shoulder/neck junction)

Min COAL for 184 hybrid is 3.09
Min COAL for 180 hybrid is 3.02

 

[wind gypsy]

So if the medium action is the best fit who makes them? From memory I have only seen one in a Defiance, are there others?

Lone Peak, Zermatt, BAT, stiller have medium action options as well

Tikka is my current darling in this application but that's always been hunting builds rather than f-class.

Still seems like a headache compared to 7 SAUM or 284..

 

[Good Boi]

I made a post about medium actions here:

Medium Actions

Invitation to discuss medium actions in general. Below are some of the notable traits traits I've seen: Lone Peak Integral picatinny rail and lug Lots of prefits Titanium option Nitride M-16 style extractor Zermatt Origin supports WTO and HLR lugs Integral lug on TL3, Ti3, & SR3...

www.snipershide.com

If you're looking to build for F Class exclusively then I'd suggest a Borden w/ the Borden bumps or a BAT.

 

[Cardboard Assassin]

Lone Peak, Zermatt, BAT, stiller have medium action options as well

Tikka is my current darling in this application but that's always been hunting builds rather than f-class.

Still seems like a headache compared to 7 SAUM or 284..

Thank you.

Lone Peak would probably be my choice from that line up.

What mags are people using in a medium action (not that it matter if single loading for F Class)?

 

[Cardboard Assassin]

It sounds like you are searching for the holy grail like everyone else, 284win performance with 180s from a SA, without the need to a crazy amount of brass prep.

I cant offer any advice but I hope you find an answer, as I would also like to know what it is.

Yeah, you're not wrong.

Its like the "Fast / Cheap / Good" equation where you only ever get too pick two of the three options......

For reference what barrel life does the 284 Win get? Or the 284 Shehane? (I am aware of the brass availability issues).

 

[4O6shootist]

Thank you.

Lone Peak would probably be my choice from that line up.

What mags are people using in a medium action (not that it matter if single loading for F Class)?

Hawkins makes a medium detach mag, wyatts makes bdl boxes.

 

[rymart]

So if the medium action is the best fit who makes them? From memory I have only seen one in a Defiance, are there others?

Pretty sure the Seekins Havak works as a medium action if used in their stock, bottom metal, and with their carbon-fiber magazines. They come with a spacer to use the action in a R700 footprint chassis with AICS mags.

 

[Cardboard Assassin]

Hmmm, which gets me thinking, if using a medium action what is out there for suitable chassis / stocks?

I'd imagine medium action limits your options for those?

I had a quick look on the MDT website and could only see one chassis for a medium action (ACC Premier for Defiance).

 

[4O6shootist]

Hmmm, which gets me thinking, if using a medium action what is out there for suitable chassis / stocks?

I'd imagine medium action limits your options for those?

I had a quick look on the MDT website and could only see one chassis for a medium action (ACC Premier for Defiance).

Since zermat, lone peak, defiance xm+, stiller all have same medium footprint, anyone worth buying has an inlet. Yeah chassis are limited, but xlr mdt make medium inlet.

 

[Good Boi]

XLR, MDT, MPA offer MA inlet chassis’. Foundation will be offering MA stocks soon.

 

[Frank Green]

Yeah, you're not wrong.

Its like the "Fast / Cheap / Good" equation where you only ever get too pick two of the three options......

For reference what barrel life does the 284 Win get? Or the 284 Shehane? (I am aware of the brass availability issues).

284win in F open guys have gotten as much as 2k rounds out of a barrel. JJ's gun here has like 1800 rounds on it and the last time he shot with it he won the 1k match with it. Yes he's pulling the barrel and putting a new one on for next year.

 

[Good Boi]

How is that? Doesn’t 284 have about the same case capacity, use the same projectiles, and get similar or same velocities? If that’s the case, I’d think 7/6.5 PRC would get the same barrel life.

 

[4O6shootist]

How is that? Doesn’t 284 have about the same case capacity, use the same projectiles, and get similar or same velocities? If that’s the case, I’d think 7/6.5 PRC would get the same barrel life.

My thoughts exactly, straight 284 is 66.X gr capacity, 284 shehane is 69.5, adg 65prc is 69, so probably right there with shehane after necking up. I'd think between a straight 284(66gr) and 7saum(74gr) might have 15-20% barrel life difference between the two of ran at same chamber psi levels with same powders. So if a straight 284 will go 2k, a 7/65prc should go 1500 easy.

 

[Elite_KG]

I've seen 2800-2850 in a couple 22" 7 SAUMs with 0.200" freebore to load long with H1000. Could have eeked out a little more with RL26 i'm sure. I assume this is a pretty warm load, didn't push it till i had bad pressure signs.

I’ve back mine down to about 2,820 fps. I was as high as 2,880 fps, but didn’t like the bolt lift pressure. It was a little too hot for my liking.

 

[Cardboard Assassin]

284win in F open guys have gotten as much as 2k rounds out of a barrel. JJ's gun here has like 1800 rounds on it and the last time he shot with it he won the 1k match with it. Yes he's pulling the barrel and putting a new one on for next year.

I know the main issue is lack of brass availability for 284 but if that weren't a thing it seems to be a decent all rounder.

1) Straightforward Long Action (not medium which seems to have limited support, particularly with chassis / stocks)

2) Decent speeds (a little slower than the hot rod cartridges but pretty good)

3) WAY better barrel life

The advantages of the 6.5PRC case are obvious but it does have its share of compromises (particularly barrel life).

 

[4O6shootist]

What's the short barrel performance of this guy? Curious if it'll run over 2800fps with a 180 from a 22" pipe.

 

[beetroot]

I know the main issue is lack of brass availability for 284 but if that weren't a thing it seems to be a decent all rounder.

1) Straightforward Long Action (not medium which seems to have limited support, particularly with chassis / stocks)

2) Decent speeds (a little slower than the hot rod cartridges but pretty good)

3) WAY better barrel life

The advantages of the 6.5PRC case are obvious but it does have its share of compromises (particularly barrel life).

The fat 7mms are usually good for another 200fps over the 284win. If you are going for a long action the 284win is probably the best option for barrel life vs performance.
Lapua did start producing straight 284win brass, not sure what availability is now though.

The biggest advantage to the short mags is the short part IMO, if you want to stretch performance in a short action the 284win gets limited to 160ish grain bullets which is definitely a bummer.

I'd like to see a related rim 7mm cartridge that can run 180s at SA mag length. Wlit would be a little cucked compared to the short mags and straight 284win but would be an attractive option for pushing performance in a SA.
Likely not ever going to happen but dreams are free

 

[ma smith]

I'd like to see a related rim 7mm cartridge that can run 180s at SA mag length.

.585 bolt face and you are good

 

[beetroot]

.585 bolt face and you are good

Only if interchangeable bolt faces are available

 

[4O6shootist]

The fat 7mms are usually good for another 200fps over the 284win. If you are going for a long action the 284win is probably the best option for barrel life vs performance.
Lapua did start producing straight 284win brass, not sure what availability is now though.

The biggest advantage to the short mags is the short part IMO, if you want to stretch performance in a short action the 284win gets limited to 160ish grain bullets which is definitely a bummer.

I'd like to see a related rim 7mm cartridge that can run 180s at SA mag length. Wlit would be a little cucked compared to the short mags and straight 284win but would be an attractive option for pushing performance in a SA.
Likely not ever going to happen but dreams are free

Aren't the Sherman short mags designed for this purpose? Based on a shortened Saum, with long neck, and almost zero case taper and 40° shoulder. Designed to operate at stupid high psi, all in the name of "efficiency" lol.

 

[wind gypsy]

My thoughts exactly, straight 284 is 66.X gr capacity, 284 shehane is 69.5, adg 65prc is 69, so probably right there with shehane after necking up. I'd think between a straight 284(66gr) and 7saum(74gr) might have 15-20% barrel life difference between the two of ran at same chamber psi levels with same powders. So if a straight 284 will go 2k, a 7/65prc should go 1500 easy.

Exactly. I've seen @Frank Green mention paltry barrel life of the PRCs a few places so I'm curious why the PRC would get half the barrel life of a case that is very similar.

 

[wind gypsy]

What's the short barrel performance of this guy? Curious if it'll run over 2800fps with a 180 from a 22" pipe.

Just based off of 7 SAUM i'm sure you could get there with a stout load of RL26.

 

[ma smith]

Exactly. I've seen @Frank Green mention paltry barrel life of the PRCs a few places so I'm curious why the PRC would get half the barrel life of a case that is very similar.

I wonder how much of it has to do with using nitro powders, like VV 5 series.

 

[Cardboard Assassin]

Any version of a 7 Short mag in F class and about 800 rounds is it. Same as 7Rem. Short mag or the 270wsm/300wsm necked to 7mm. My buddy John's 7/270wsm he's running his 180gr bullets at 3170fps. Barrels are junk around 800 and change for him. Your not getting a 1k rounds out of this caliber on a F open gun normally. Now on a hunting rifle or a casual target rifle where your not getting it smoking hot.... you can easily get more life out of it.

We've got 3 new barrels we are putting on our own rifles.... All BB material. Yes it should help.

If it's taking you 300 rounds to settle on a load.... that seems like a lot? At least in my opinion.

My chamber of the 7/6.5PRC is pretty close to the Wheeler chamber. Throat is like .015" difference and the freebore diameter is slightly different but like I said.... they are pretty close.

I was thinking more about fire forming cases (300 has been what I typically need to get through multi day matches) if I go with a variant that needs fire forming (ie 7FCP).

 

[Frank Green]

Exactly. I've seen @Frank Green mention paltry barrel life of the PRCs a few places so I'm curious why the PRC would get half the barrel life of a case that is very similar.

I would hope the 7/6.5PRC is easier on the barrels than the other 7 mags. Just not enough data out there for me to say we have good numbers.

Another reason for the ammunition test barrel.

 

[Frank Green]

I wonder how much of it has to do with using nitro powders, like VV 5 series.

Double based powders are harder on the barrels. That is known. The double base powder have a higher flame temp. I try and stay away from the double base powders.

 

[Good Boi]

Frank, is this test barrel thing for someone like Hornady to come out with a 7/6.5 PRC like cartridge?

 

[Frank Green]

Frank, is this test barrel thing for someone like Hornady to come out with a 7/6.5 PRC like cartridge?

As of right now the test barrel is for those involved to get real world pressure and velocity data.

I put the question forward about the possibility of it becoming a Saami standard but it doesn’t look like it as of right now.

Will see where this goes next year. My hope is yes but it’s just hope right now.

 

[beetroot]

Double based powders are harder on the barrels. That is known. The double base powder have a higher flame temp. I try and stay away from the double base powders.

Has your testing shown that certain powders have a notable effect on barrel life?

It's commonly said that Varget is a it of a barrel burner whereas H1000 is meant to be a lot kinder.

 

[ma smith]

F-class john is reporting comp loads as high as
~57.5gr of VV 555, ~compressed load~, with 180 Hybrid

 

[Good Boi]

Frank, any interest in trying to get Sherman to SAAMI approve his loads? ADG making his 40 degree shoulder brass makes it seem like a good contender with this cartridge. Sadly, people tend to ridicule it as a non option based on extreme best case scenario extreme loads advertised by him. I think his cartridges with more moderate loads sound great.

 

[wind gypsy]

Frank, any interest in trying to get Sherman to SAAMI approve his loads? ADG making his 40 degree shoulder brass makes it seem like a good contender with this cartridge. Sadly, people tend to ridicule it as a non option based on extreme best case scenario extreme loads advertised by him. I think his cartridges with more moderate loads sound great.

Wouldn't getting his cartridges SAAMI approved just expose the reality of how high pressures need to be to get to his advertised #'s? Doesn't really seem like something he'd be interested in.

 

[Good Boi]

Wouldn't getting his cartridges SAAMI approved just expose the reality of how high pressures need to be to get to his advertised #'s? Doesn't really seem like something he'd be interested

Why does 7 PRC have faster velocity than 7/6.5 PRC? More case volume and different powder. You can’t argue that a 7 Max can’t out perform 7/6.5 PRC in velocity based on the same principle, just don’t load it as hot as Sherman suggests.

 

[wind gypsy]

Why does 7 PRC have faster velocity than 7/6.5 PRC? More case volume and different powder. You can’t argue that a 7 Max can’t out perform 7/6.5 PRC in velocity based on the same principle, just don’t load it as hot as Sherman suggests.

Of course. But I don’t see why hed be incentivized to have SAAMI prove he’s been selling high pressure more than “efficiency”.

 

[Cardboard Assassin]

I spoke with local gun smith last week and he explained that 7PRCW / 7FCP was fine in a short action the only issue being if you need to remove a live round for any reason the bolt wouldn't go back far enough to do so (need to remove the bolt to get the extra clearance which isn't a big deal anyway for the odd time when you find yourself in that situation).

This build would be a dedicated F Class rifle anyways so that wouldn't be an issue and that being the case I wouldn't be constrained by mag length for COAL or freebore / doughnut purposes.

On the other hand I can get Lapua 284 Win brass and could simply go the tried & proven route.

To do that I would need to pick up a long action and suitable stock (with the 7MM options I could simply get a barrel spun up for my Terminus Zeus QC and switch between that and my 223 training barrel - very easy and lower cost).

Decisions decisions......

 

[Elite_KG]

I’ve posted earlier that I run my 7-6.5 PRC (28 TAC) in a medium action. I modified a 6.5 PRC-AW print to load out to medium action length with room for throat erosion if I needed/wanted to be close or on the lands.

I posted some actual loaded lengths previously in this thread.

 

[Cardboard Assassin]

I’ve posted earlier that I run my 7-6.5 PRC (28 TAC) in a medium action. I modified a 6.5 PRC-AW print to load out to medium action length with room for throat erosion if I needed/wanted to be close or on the lands.

I posted some actual loaded lengths previously in this thread.

It seems medium action is the sweet spot for this round.

Has anyone tried 7-6.5PRC in a long action or is that just silly? I have zero experience with long actions but if it worked it would have more options moving forward.

For me I can go three routes, the fast / easy option is to get a barrel spun up for my Terminus Zeus QC short action (I'd need a bolt too). I could swap between this barrel and the regular 223 barrel that normally lives on there and in a reasonably short time and minimal expense I could be up and running. Advantages also include getting lots of trigger time on this rig as the 223 setup is my practice rig. One possible downside is that the chassis is a KRG Bravo with enclosed forend and while I love it in the 223 configuration I dont know how good it would be as a F Class rig and whether it would be a good partner for the 7-6.5PRC barrel.

Option two is a new build. Thinking out loud this would ideally be something like a non short action (medium or long) in a full on F Class stock (the Manners has caught my eye). This would be quite a bit more involved and more expensive to boot.

Option three is build something that is already a known performer like a 284, brass availability was one of the reasons that drove some folks to look for alternatives but that isn't an issue in my neck of the woods (Canada) - seems there is a good selection here (Lapua). Of course this would be a full build too so in that respect it is a wash with the 7-6.5PRC. One potential upside is barrel life, from what I have read 284s get 2000 rounds comfortably out of a barrel (whereas the 7-6.5PRC has been quoted as being as low as 800 rounds but there is some debate around how accurate that is).

 

[Frank Green]

Shipped the pressure test barrel down to Hornady last week. Should be shipping loaded ammo to them next week sometime.

Later, Frank

 

[Jackomason]

I had thought hornady had already tested the 7mm in the 6.5 PRC case? What's the purpose of this latest test?

 

[Frank Green]

I had thought hornady had already tested the 7mm in the 6.5 PRC case? What's the purpose of this latest test?

To my knowledge no it has not.

Hornady intentionally (I'm thinking outside the box here) made the 7PRC round/case different so you cannot by accident chamber a 7mm round into a 6.5PRC chamber for safety reasons. So a 7/6.5PRC again to my knowledge was never tested. You hear it over and over again where a guy got a 300BO round chambered into a 5.56 gun and other similar rounds and bad things happen.

What prompted this? The 7/6.5PRC is like the hottest round in F class. There is no hard/good baseline load data out there. You read different forums/threads and shooters loads are all over the place. I've seen guys using the same powder and bullet and you see one guy running 52gr as a max load another guy saying I'm running that at 57gr etc... It's all over the place. Now add in last Nov at a big F class match a shooter blew up a gun. My opinion is they had a round loaded with pistol powder or something like that.

So I contacted Hornady and asked as they've helped us with stuff and we've helped them with stuff similar to this. That if we made a p&v barrel and I supplied all the loads with all the lot numbers etc... would they do the testing? They said yes sure. So we made the barrel at n/c along with the ammo being loaded.

Even Sierra said this was a good thing for the community. So they donated bullets. I reached out to Berger as well and donataed some powder and bullets as well and Hornady donated brass, and bullets on top of they are doing all the testing at n/c.

 

[Jackomason]

That's awesome!

I'm almost sure that I heard the Hornady guys talking about it on their podcast either about the 6.5 PRC or the 7 PRC, likely the latter. I think they were in a different mindset when developing the 7 PRC so that's an understandable but disappointing oversight.

Either way, I'm glad you're putting in the work! Just make sure they let you name it before pushing it as some sort of novelty! 7mm ARC doesn't quite seem right haha.

 

[beetroot]

To my knowledge no it has not.

Hornady intentionally (I'm thinking outside the box here) made the 7PRC round/case different so you cannot by accident chamber a 7mm round into a 6.5PRC chamber for safety reasons. So a 7/6.5PRC again to my knowledge was never tested. You hear it over and over again where a guy got a 300BO round chambered into a 5.56 gun and other similar rounds and bad things happen.

What prompted this? The 7/6.5PRC is like the hottest round in F class. There is no hard/good baseline load data out there. You read different forums/threads and shooters loads are all over the place. I've seen guys using the same powder and bullet and you see one guy running 52gr as a max load another guy saying I'm running that at 57gr etc... It's all over the place. Now add in last Nov at a big F class match a shooter blew up a gun. My opinion is they had a round loaded with pistol powder or something like that.

So I contacted Hornady and asked as they've helped us with stuff and we've helped them with stuff similar to this. That if we made a p&v barrel and I supplied all the loads with all the lot numbers etc... would they do the testing? They said yes sure. So we made the barrel at n/c along with the ammo being loaded.

Even Sierra said this was a good thing for the community. So they donated bullets. I reached out to Berger as well and donataed some powder and bullets as well and Hornady donated brass, and bullets on top of they are doing all the testing at n/c.

Being that F class is driving this, I'm guessing loads will be longer than SA length?

 

[nrspence]

Being that F class is driving this, I'm guessing loads will be longer than SA length?

Being that F class is driving this, I'm guessing loads will be longer than SA length?

For sure, most F class shooters are using the 180 hybrid. The 162 eldm in a medium action length would be awesome.

 

[Frank Green]

Being that F class is driving this, I'm guessing loads will be longer than SA length?

Right now all my measurements.... OAL are coming in at right around 3.100" or even a tad longer.

So no they will not work thru a SA.

Same issue with the original 284W. It was meant for a SA gun but when longer heavier bullets came along and guys wanting to get the most out of them... they had to throat/seat them out longer... so this will not work thru a SA gun either unless your willing to live with a bullet deep in the case and you giving up some velocity.

 

[Frank Green]

Being that F class is driving this, I'm guessing loads will be longer than SA length?

Attached is my reamer print with ref to bullets and some seating depths/oal.

 

[Frank Green]

I had thought hornady had already tested the 7mm in the 6.5 PRC case? What's the purpose of this latest test?

Thought about it some more... if they did we never made them a test barrel.

Second... when I asked the ballistic lab guys about running the test... if they had done it they would've told me and shared the data with me.

So no it has not been done.

 

[Bergerblaster]

Any idea of how fast the 168’s would shoot out of a 24” with the 7PRCW? Based on my calculations the 168 would fit perfectly in a short action.

 

[Frank Green]

Any idea of how fast the 168’s would shoot out of a 24” with the 7PRCW? Based on my calculations the 168 would fit perfectly in a short action.

If I had to put a close guess on a 162/168gr bullet mag fed out of a 24" barreled gun... I don't know why you couldn't hit or knock on 2800fps.

In the F class guns with 30" to 32" barrels guys are basically pushing the 180gr type bullets in the 2900fps + range. Some over 3000.

But... that's why the ammunition test barrel we made and the testing that is going to get done.... nobody knows what the actual pressure this stuff is running at.