7-6.5 PRC

@Jackomason @Rockdoc173 following your progress...thanks for the info and keep us updated...as a side note if you haven't, check out the 7FCP. Basically an improved 7-6.5prc from the F class world designed around the 180 berger....just in case you want to tinker further.
Cheers
There's just one problem with any cartridge designed around the 180 Berger, there are no 180 Bergers! lol
 
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I'm getting pretty close. I've got my bolt face and supressor mount. All I need is to get my die and start testing.

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The barrel threaded on nice but the start to the threads was iffy. PVA Said that it was odd but shouldn't hurt anything. That's all I'll say about that. I know they would have fixed it if need be. They've been good to work with and I wouldn't hesitate to recommend them. Can't wait to see how the Osprey barrel shoots.
 
Man, I’ve been looking for something just like this! I’ve been wanting by to build a very accurate gong shooting rifle, and been floating between the hot 6mm’s , 6.5 variants, and 7mm variants, and been trying to avoid the overbore options.

This (IMO) fits perfectly to my spec. It could even be used in the fclass applications if ever needed… Only difference is I would hope to run this in a long action.

Can I ask, what size bolt face are you using?

And also, if I may, what reamer did you use?

Super excited now 😁😁

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Ps, every thought about improving the shoulders ?? My mind is running wild now…
 
Man, I’ve been looking for something just like this! I’ve been wanting by to build a very accurate gong shooting rifle, and been floating between the hot 6mm’s , 6.5 variants, and 7mm variants, and been trying to avoid the overbore options.



This (IMO) fits perfectly to my spec. It could even be used in the fclass applications if ever needed… Only difference is I would hope to run this in a long action.



Can I ask, what size bolt face are you using?



And also, if I may, what reamer did you use?



Super excited now 



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.

.

Ps, every thought about improving the shoulders ?? My mind is running wild now…
Bolt face is a standard magnum .535"

The reamer used on mine was from PVA and Josh has talked extensively about not sharing specifics because they are his own design and work. I trust he's flushed out the flaws and made a sweet reamer.

The 7mm PRC primal is Okrans improved version. Take that for what it is but he's made a complete reloading system around it and other 6.5 PRC variants.

I've got a match on Saturday but after that I should be able to get out shooting this thing. I'll keep this thread updated with what I find!
 
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Bolt face is a standard magnum .535"

The reamer used on mine was from PVA and Josh has talked extensively about not sharing specifics because they are his own design and work. I trust he's flushed out the flaws and made a sweet reamer.

The 7mm PRC primal is Okrans improved version. Take that for what it is but he's made a complete reloading system around it and other 6.5 PRC variants.

I've got a match on Saturday but after that I should be able to get out shooting this thing. I'll keep this thread updated with what I find!
Updates would be much appreciated!!

Do you think they would sell me the reamer? Or is it exclusively for their own chambering?

Alternatively, even reamer drawings that work for this build would work!
 
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Would it be appropriate to call the 7-6.5PRC the "7 Creedmag"? I really like what you guys are doing and think this caliber is the perfect balance of interior, exterior and terminal ballistics for the vast majority of hunters and target shooters. One day when Hornady release this as a factory round, pushing the 180ELDM at a modest 2750fps out of a 24" barrel, then I am all in! Wish you all the best with this project and hope this will inspire the folks at Hornady.
 
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I did one, a 7mm-6.5 PRC. Well, I guess the appropriate way to say it is "doing" one since the barreled-action has been at the Cerakote guy for like 5 months so I haven't fully put the rifle together yet! Mine was designed to use a SA (I had just traded for an Archimedes so I just switched the BF to 0.532 and off we went) but the bullet I originally wanted to run, the 190 Hybrid, was way to long. I switched to the 180 Hybrid and, while sitting a little deeper than I'd like, it's acceptable at just below the body/shoulder junction. I know, not ideal but it'll work. I'm also building a little stock of 166 ATips. They're of course lighter than we want to see in a SAUM-ish case, but they performed well in a 7mm-08 I had and out to a mile I think they'll do okay in this new gun. Plus, I can get them far more readily than the 180s. Actually, given the 2.95" OAL restriction of a binderless SA magazine, I pretty much think of this as a grownup 7mm-08, and I'm okay with that for now. I may sell this in the future and move to at least an XM so I can really get all the ability of the case. I may also do a single feed-only 190 Hybrid load but we'll just have to see.
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7mm-6.5 PRC: 180 Hybrid > 166 ATip > 7mm08 w/ 166 ATip

One of my core tenets in precision rifle is the brass. I like the concept of the 7/65 in part because Lapua is making brass, as are other good manufacturers. Hornady is still one of the only 6ARC suppliers I've been able to get brass from and I pretty much hate it. I'll be following this thread to see what direction other folks go with the 7mm-6.5 PRC concept
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And for those interested:
Action: Archimedes SA
Barrel: Krieger MTU 28" 8tw
Stock: Bravo w/ a bunch of goodies on it
Trigger: B&A TSP
Brake: ?
Scope: SB PMII in Badger rings
Dies: Whidden custom set based off the reamer print above
thanks for sharing this - was this the reamer you used in your chamber for this build??
 
Answered my own question.

Took a 6.5 Creed brass and type S die.

Use a .284 mandrel and opened it up, Turned it, and ran it through the type S die with no bushing. The neck measured at .300".

The bushing for my .0135" thiccc necks is .308" so I'm guessing I'll be sending my die off or finding someone local to open it up.
 
It's been a slow start but I should be shooting this thing next week. I was just playing around at the bench and realized that I'm not sure that the factory redding type S will have enough clearance for the neck.

Did you have custom dies made, open up the shoulder, or was this a non-issue?
Sorry it's been a bit but to answer your question, yes I had a custom set made by Whidden based off the reamer print above. Easy button
 
Quick update for those interested.

When I actually started to develop a load, I ran into accuracy (really precision) issues. I couldn't get anything to group. I'm including some target scans for reference. I put five in a hand size group at a mile, but somehow I couldn't get the gun to group worth anything at 100 yards. The prevailing theory is that maybe there's something going on with the stock, though I completely tore the gun down to see if I could identify some funny business, no such luck. From the targets, you can see that at times it'll put three I n a hole, then throw flyers that wideln the group to 1.5". So, I bought a MPA chassis off a Hide member and changed it out. I have yet to shoot it since, probably Thursday or Friday.
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If that doesn't do it, my next suspect is the brass. The K&M tool I used to removed the doughnut from the inside was not very precise and I'm concerned that I / it introduced inconsistencies in the neck. I may open a fresh box of my Lapua 6.5 PRC brass stash and start over. The only way to address the doughnut consistently is turning the outside of the neck. I dont have the tool(s) for that operation and quite frankly don't really want to go down that hole at this point. So, either I invest in the neck turning tools, find someone to do it for me, or...wait for it...turn this puppy into a 7SAUM and save this 7/6.5prc project for another day. I have SAUM brass, a reamer, and very few patience left so we'll see. Also, I thought this would be closer to SAUM speeds than what it is. It's not a deal breaker, just a note. I've always said this is a 7mm-08 big brother and/or 7SAUM little brother. The jury is still as to which it favors more.

More to follow...
 
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Quick update for those interested.

When I actually started to develop a load, I ran into accuracy (really precision) issues. I couldn't get anything to group. I'm including some target scans for reference. I put five in a hand size group at a mile, but somehow I couldn't get the gun to group worth anything at 100 yards. The prevailing theory is that maybe there's something going on with the stock, though I completely tore the gun down to see if I could identify some funny business, no such luck. From the targets, you can see that at times it'll put three I n a hole, then throw flyers that wideln the group to 1.5". So, I bought a MPA chassis off a Hide member and changed it out. I have yet to shoot it since, probably Thursday or Friday.
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If that doesn't do it, my next suspect is the brass. The K&M tool I used to removed the doughnut from the inside was not very precise and I'm concerned that I / it introduced inconsistencies in the neck. I may open a fresh box of my Lapua 6.5 PRC brass stash and start over. The only way to address the doughnut consistently is turning the outside of the neck. I dont have the tool(s) for that operation and quite frankly don't really want to go down that hole at this point. So, either I invest in the neck turning tools, find someone to do it for me, or...wait for it...turn this puppy into a 7SAUM and save this 7/6.5prc project for another day. I have SAUM brass, a reamer, and very few patience left so we'll see. Also, I thought this would be closer to SAUM speeds than what it is. It's not a deal breaker, just a note. I've always said this is a 7mm-08 big brother and/or 7SAUM little brother. The jury is still as to which it favors more.

More to follow...
Have you tried another scope? Next thing to check is your striker assembly and spring to ensure consistent and reliable ignition.
 
I should also note that the targets above represent 3 bullets (166 ATips, 180 Hybrids, and 180 SMKs) and H4831SC. I have also tried N165 but I don't have any of those targets. Recommendation for the next powder to try? Just one condition, I have to be able to get it lol
 
N560 or N565 depending on what pressure signs vs. case capacity you observed with N165.

Superperformance maybe an option. H1000 could work or could be a little slow or over on case capacity.

Burn rate chart:
 
I just shot 162 eld-x and IMR 4350. 49gr to 58c. 57gr was where compaction started and so did some pressure. That was 3040fps at 57gr. Again, 26" barrel at SA mag length 2.945"

It was only one shot each and actually just shot to find the neck diamiter of a fired case. I've got a guy willing to let me come over and we can open up the neck of the die.

I've got lots of powder and a few bullets. Will be testing soon... hopefully!
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Made some progress today! This project has been a lot less plug and play than I first had thought. With that said, I wouldn't change a thing. Found a great guy in my area that was happy to help me out. I brought my rifle with me while going out to his place to work on the 6.5 PRC die.

Last night I decided to load up 55gr of IMR 4350 under a 162 eldx. I chose this because it wasn't dangerous, had some speed and landed in a pretty tight group in my 100 yard ladder.

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We chucked the die up in his lathe and had it opened up in no time to .321" at the neck shoulder junction. Fired brass measured .319" with his micrometer.

We took our rifles out to 765 yards and had some fun. Shot some off the tripod and then I laid down and tried to see how this random load would shoot.

Needless to say I think this PVA barrel is very forgiving. 10/10 would recommend.

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Just eye balling it, looked like about 2.5" tall and less than 5" wide. I'll take it.
 
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I kinda get this over the saum for brass but it seems very close in performance to the 284win (which has decent brass availability) That’s a very good cartridge so not a bad thing I guess. The saum seems to fit the short action better though from my experience, or better yet the Sherman short.
 
Really the choice comes down to two factors.

Action length and brass availability/quality.

Like you said 284 win does better in a LA but also lapua just suspended production of 284 brass.

ADG Makes saum and sherman brass but the sherman brass costs just as much (maybe more) than the lapua 6.5 PRC brass. I haven't shot ADG so I can't speak to its quality.

The guy helping me out let me shoot his 284 win, the top three hits above my rifles group. It was pretty cool. Very similar.
 

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Makes sense, good cartridge just curious as there were a couple right around the performance. I have several in that range and decided to try out the 7-300prc as a larger jump up. But that is a good all around as the barrel will last longer.
 
First time out with the lapua brass and it didn't disappoint.

180 ELDM. N555
Loaded 50gr up to 59gr but didn't make it all the way.

These things are Loooong.
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No pressure signs at all but I stopped because I like my face. I was expecting to hit 2800fps and maybe 2825fps.

56.5 was at 2900fps.

Accuracy testing next.
 
Well, not all days are glorious days.
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Nothing all that exciting in this velocity range. But I took 55.7 out to distance just to see. These loads were 180 eldm and N555. This combo should have me around 2860~

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This is a 66% ipsc so about 12" wide. 675 yards.

The top shot was my sighter the next 8 were my group. About 1 MOA. Not ELR material...
 
First question: How many rounds do I need in the magazine with an overbore barrel burning magnum for hunting or elr?

If 3 rounds are enough a Blaser R8 is a short "223 micro action" that will handle 338LM, 375H&H and 500 Jeffery.
The R8 will handle anything from 22lr to 500 Jeffery.
Measure the distance from trigger to the muzzle and compare the R8 with any traditional bolt action. The R8 is about 4" "shorter" than a traditional long bolt action. The R8 can have a 26" barrel compared to a long bolt action with a 22" barrel when both rifles have the same OAL.

These barrel extentions cost app $250 and any barrel and caliber can be fitted to the R8:

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Here's a custom IBI carbon R8 barrel made with a barrel extention:

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Here's a R8 in 338LM. Notice the distance from trigger to chamber end of the barrel. The R8 is effectivly about 4" shorter than a traditional long bolt action

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Any idea where one could purchase a IBI barrel extension for a Blaser in the states?
 
I kinda get this over the saum for brass but it seems very close in performance to the 284win (which has decent brass availability) That’s a very good cartridge so not a bad thing I guess. The saum seems to fit the short action better though from my experience, or better yet the Sherman short.

Since the 6.5 prc had basically the same capacity as 6.5x284, the idea of this round seems weird to me as well. There's already an option that's well established out there where all the smiths have reamers, dies available, lapua/peterson brass.. I guess if you like to eff around with stuff but it seems like wasted effort to me.
 
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Since the 6.5 prc had basically the same capacity as 6.5x284, the idea of this round seems weird to me as well. There's already an option that's well established out there where all the smiths have reamers, dies available, lapua/peterson brass.. I guess if you like to eff around with stuff but it seems like wasted effort to me.
short versus long action?

how many cartridges are 'close to another well established' ... a lot
 
short versus long action?

how many cartridges are 'close to another well established' ... a lot
Not to be contrary, but this doesn't add up.

PRC is a saum derivative, dimensionally. IE, Its same as SAUM in terms of length.

This thing needs to do something better. Maybe it will shoot out of short barrels better?

How are the groups/SDs coming allong?
 
Not to be contrary, but this doesn't add up.

PRC is a saum derivative, dimensionally. IE, Its same as SAUM in terms of length.

This thing needs to do something better. Maybe it will shoot out of short barrels better?

How are the groups/SDs coming allong?
I was comparing 6.5PRC to 6.5-284 from the guy i quoted

But yeah PRC. SAUM. SS/SST/Max/Mega. 7RM. 7LRM. 7PRC. All roughly the same. Slightly different case lengths and action lengths...but not a whole lot

The 7mm variants of the 6.5PRC have one big thing. Brass. And a lot of it. From a bunch of manufacturers.
 
short versus long action?

how many cartridges are 'close to another well established' ... a lot

Fair. I skimmed the thread and saw people saying it is a compromise in SA but seems people are using it there. 6.5 PRC is already a stretch for a SA so I saw a 7 as being more so.

So it's a slightly smaller alternative to a SAUM in a short action where you can trade poor SAUM brass availability for poor reamer and die availability and additional brass prep.
 
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Fair. I skimmed the thread and saw people saying it is a compromise in SA but seems people are using it there. 6.5 PRC is already a stretch for a SA so I saw a 7 as being more so.

So it's a slightly smaller alternative to a SAUM in a short action where you can trade poor SAUM brass availability for poor reamer and die availability and additional brass prep.
yup. similar to the SS and SST sherman cartridges

i have no need for a long action, or even a medium action for a hunting gun. so cartridges like this make a lot of sense for 50-100fps loss
 
So it's a slightly smaller alternative to a SAUM in a short action ...
There is ZERO advantage to using simply necked-up PRC cases when seeking improved fitment with short action magazines. :oops: Hornday took the OAL-specific dimensions for 6.5 PRC directly from the 6.5 SAUM when it sent PRC to SAAMI. There are tons of comments to this effect on page 1 already. If I am mis-umnderstanding this, of course, please correct me.
 
There is ZERO advantage to using simply necked-up PRC cases when seeking improved fitment with short action magazines. :oops: Hornday took the OAL-specific dimensions for 6.5 PRC directly from the 6.5 SAUM when it sent PRC to SAAMI. There are tons of comments to this effect on page 1 already. If I am mis-umnderstanding this, of course, please correct me.
6.5PRC to SAUM yeah there's no difference on fitment, with the PRC having the shorter neck even

it's the SS and SST shermans that get you the (slightly) shorter case oal and a longer neck

the PRC gets you available brass
 
There is ZERO advantage to using simply necked-up PRC cases when seeking improved fitment with short action magazines. :oops: Hornday took the OAL-specific dimensions for 6.5 PRC directly from the 6.5 SAUM when it sent PRC to SAAMI. There are tons of comments to this effect on page 1 already. If I am mis-umnderstanding this, of course, please correct me.

I don't know if you're agreeing with me or if you read my post wrong and think by saying smaller i meant shorter (they are different words with different meanings). I'm guessing it's the latter based on prior posts claiming the prc is a SAUM derivative. It is not. It's a Ruger Compact Mag (RCM) derivative. They are not the same. SAUM is fatter with a rebated rim.

My post was simply comparing the compromises for 7 saum and 7/6.5 prc in a short action because in a med or long action 284 win is an easier choice vs 6.5-7 PRC due to almost identical case capacity.
 
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I don't know if you're agreeing with me or if you read my post wrong and think by saying smaller i meant shorter (they are different words with different meanings). I'm guessing it's the latter based on prior posts claiming the prc is a SAUM derivative. It is not. It's a Ruger Compact Mag (RCM) derivative. They are not the same. SAUM is fatter with a rebated rim.

My post was simply comparing the compromises for 7 saum and 7/6.5 prc in a short action because in a med or long action 284 win is an easier choice vs 6.5-7 PRC due to almost identical case capacity.
Yeah, were not disagreeing...I'm just trying to clarify for people what is going on. The PRC having width dimensions of X vs Y don't matter for COAL. For the COAL you need to look at the longitudinal dimensions (specifically to the shoulder, the angle, and base to the neck)

The longitudinal-dimensions of the PRC are lifted right off the GAP-4S. That part is what GA precision/George Gardner contributed to the 6.5 PRC cartridge design. The GAP 4-S is not a Ruger 375 or RCM, its derived from SAUM.
 
SST shermans that get you the (slightly) shorter case oal and a longer neck
Cheers, were on the same page. The "tactical" sherman rpushes the shoulder back to get you the COAL benefits. The PRC doesn't relocate the in relation to the SAUM, so they have the same COALs if using the same bullets.
 
Cheers, were on the same page. The "tactical" sherman rpushes the shoulder back to get you the COAL benefits. The PRC doesn't relocate the in relation to the SAUM, so they have the same COALs if using the same bullets.
the SST is just 30 degree shoulder not 40 of the SS. theyre both VERY marginally shorter COAL than the SAUM/PRC. same COAL between SS and SST

even the Sherman cartridges run roughly the same COAL as the PRC/SAUM but with longer necks, sharper shoulders, and less case tape. better bullet position in the case, which is why they 'trend' to be a wee bit faster. they also have more available brass/dies/reamers than SAUM most of the time...minus the /B reamer stuff that's about all caught up anyways
 
Yeah, were not disagreeing...I'm just trying to clarify for people what is going on. The PRC having width dimensions of X vs Y don't matter for COAL. For the COAL you need to look at the longitudinal dimensions (specifically to the shoulder, the angle, and base to the neck)
@b6graham and I were discussing relevance of the 7-6.5 PRC when its the same capacity as a 284. You're clarifying things that were not confused.
The longitudinal-dimensions of the PRC are lifted right off the GAP-4S. That part is what GA precision/George Gardner contributed to the 6.5 PRC cartridge design. The GAP 4-S is not a Ruger 375 or RCM, its derived from SAUM.

I said the PRC is not a derivative of the SAUM (or gap 4s) because it isn't, it's from the RCM case.

Having the same COAL dimensions is a factor of the magazines they are designed to work with. Of course they are the same because they are very similar cartridges for similar use cases. IIRC the 6.5 RCM (PRC) was what George wanted from the beginning but the SAUM case was more readily available so thats the route he went until Hornady was on board with the PRC.
 
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The 6.5 PRC was designed to "blueprint" the 140 hybrid. You can see the SAUM and PRC... are within identical with production toleratnces of ± .001. This is because the GAP 4s was designed to blueprint the 140 hybrid properly.

You will note that RCM doesn't blueprint the 140 hybrid properly, its 4-5 thou over.

Moving to 7MM...equivalent shape/BC bullets are LONGER in relation to larger diameters.

So, there's no way to make "good" 7MM bullets fit since you only had .001 cleance on the 6.5s

Cheers.
 
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Got my “28 TAC” (7-6.5 PRC with variation in some specs; especially freebore) reamer in. Now then barreled action will go to the smith next week:

- Big Horn TL3 Medium
- 22” Bartlein 14 Carbon Fiber,
-Left Hand / Gain Twist
- Manners LRH Black and Blue, high gloss

Once back it will be pillar bedding and custom Cerakote on everything but the action. Yes, the Black and Blue LRH will get overlay Cerakote graphics to complement the base color. Gotta cover the “purple” that is mixed in.


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*Note - pictures with LP Fuzion medium action. I sold it for the TL3 so I can replace bolt faces later if desired.

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First time out with the lapua brass and it didn't disappoint.

180 ELDM. N555
Loaded 50gr up to 59gr but didn't make it all the way.

These things are Loooong.
View attachment 8087689
View attachment 8087694

No pressure signs at all but I stopped because I like my face. I was expecting to hit 2800fps and maybe 2825fps.

56.5 was at 2900fps.

Accuracy testing next.
Are these loads at SA mag length or are the 180s too long?
 
I’m in the process of obtaining some reamer prints for the 7x6.5.

This cartridge already has a lot of variants and improvements. Something I found very interesting was on an Eric Cortina video where he was saying that the original version of this cartridge was producing clickers, and therefore his 7 prcw (Alex wheeler design) has an improvement with a slightly larger 0.200” line diameter.

I thought this was very interesting, and wondered if anybody here has a reamer print of this spec?
 
JGS Reamers knows the dimensions to change that addresses the clicker and stuck case issue.

I worked with Alex in developing my prints specifics.
Thanks for the reply. Hope im not breaking any group rules here, but would you or Alex be willing to share or sell me the prints with this improvement? I’m outside of the USA, so ordering reamers and shipping to me is quite a big deal?