I am considering a 6 mm PPC upper. Primarily for paper punching at long distances (700 yards max)
A few questions please:
a. Is it reliable in an AR15 format?
b. Is it inherently more accurate than a .223 upper?
c. What kind of magazines are required?

Regards ACK

Here's my take on the 6mm PPC ... mine has a 24" Olympic SUM barrel.

Reliable?  Yes.  I remember reading here of a guy shooting one full auto reliably.  However, mine only likes to feed ballistic tip type bullets.  I tried loading some exposed lead spitzer bullets... no luck feeding those.  I have never tried hollow points.  This doesn't matter to me... I only load polymer tipped bullets anyway.

Is the upper inherently more accurate?  I doubt it.  My plain jane 20" hbar is sub-moa with factory ammo.  My 6PPC will easily shoot sub 1/2 MOA.  I contribute this mostly to the fact I carefully reload 6PPC (Lapua brass).  I've never tried reloading .223... I bet I could tighten up the groups quite a bit.  In theory, the 6MM PPC is one of the most accurate rounds... it's supposedly capable of .1 MOA.

Which magazines?  7.62 x 39.  I use 10 round mags made by MWG.  They're plastic and look cheap but work great.  I've tried 7.62x39 mags from USA... save your money.

Any other questions?

Scot

This route might be just a little easier:  

www.6mmbr.citymaker.com/65Grendel.html

Thank you gentlemen.
So many choices.

6.8 SPC
6.5 Grendel
6 mm PPC

Decision decisions...

Best Regards

ACK

Quoted: <donning nomex suit> Quoted: 6.8 SPC 6.5 Grendel 6 mm PPC At least he has the order right </nomex suit>

Your claiming that for his intended purpose of "punching paper at long distances, 700 yards max" that the 6.8 is superior to the Grendel?    


Maybe this might help, just look at the drift and drop differences at 700 yards...  

www.65grendel.com/graphics/grendelballistics.pdf

 

Quoted: Quoted: Your claiming...<snipped> I made no claims. I made a funny remark to elicit your equally funny response.

Hilarious.  

I've got the 6mm ppc upper together now(Model 1 bull barrel)...though I haven't run any ammo through it.

A couple of questions are banging around in this gourd I use for a head,and I hope some of you can answer them.

First, the bolt for the 6mm ppc,has a thinner wall surrounding the base of the cartridge(where the lugs are)than the .223,as they use the same carrier system.It seems like the(6ppc) wouldn't take the pressure that the.223 would be able to....I hope I'm explaining this alright.The area I mean,is the bolt face.

Also the bolt for the 6ppc,which is a 762x39 bolt(I understand)doesn't slide as easily as the .223 bolt,in the same carrier.I'm wondering if this is normal,or if I have a slightly large bolt.If so,should I put some abrasive cleaner inside the carrier,and loosen up the bolt a little?If it's a dumb question,I'll just have to absorb the abuse.haven
Another question I have,is the distance that a 6ppc will be appropriately accurate.Everything I've read about the 6ppc round,says that it's extremly accurate out to 200 yards or so....but,with an 80 grain round,coming out of a barrel at around 2800 fps,wouldn't a 5-600 yard range be feasable,with acceptable accuracy,for the 6ppc round?possibly even longer?...it seems it would to me,but I'll be the first to admit that I'm no expert.

I have it set up in my Colt lower now,with a Rock River two stage trigger,but also have a single shot lower,that I'm going to put some kind of target trigger into.

Sorry the post is so long,but I'd sure appreciate any information and or advice on the subject.....thanks...Dave

I'll take a stab at answering your questions:

Don't worry about the bolt going into the carrier with some resistance.  While I'm no expert... new bolts / gas rings go in harder compared to a well shot b&c.  I would NOT introduce any sort of polishing compound, etc... that just seems bad.  I'm sure it will wear all by itself soon enough.

As far as pressure; the 7.62x39 is a high pressure round (50,000 cup according to Speer).  The .223 Rem is only slightly higher at 52,000 cup (again, out of my Speer manual).  I'm sure the 5.56 nato round is considerably higher but I don't have that info.  I can tell you from experience, you are not going to want to play around on the hot end of the spectrum anyway... you want to baby that expensive brass.  The more reloads per casing the better.

Finally, I see no reason why the 6mm PPC wouldn't group well at longer distances.  I've never shot over 200 yards with mine... but if it's sub MOA at 200, why not farther?  BTW, this is a fairly flat shooting cartridge.  You can reload those 80 grainers to 3100 fps (in mine, anyway) with no signs of excess pressure.

Scot

I appreciate the replies.

I'll have to learn as I go,but it always helps to hear from the voice of experience.

Even though it may sound like I'll tend to hotrod the loads up for distance,I have no intention of pushing the envelope of pressure on the AR bolt.As I stated in an earlier post on this subject,I'm ugly enough,without have an AR bolt planted permanently in my grill.

The 6mm ppc is an interesting project,and I'm anxious to see how she shoots.This weekend looks like a washout down at the Manatee range,so I'll probably go gun showing instead,and pick up more parts for the dreaded AR disease that I have.

As soon as I get this thing going,I'll post the results.....first is going to be trying to get it to run on semi-auto,with the 762x39 magazines running from my Colt lower,then I'll shoot the single shot lower(it's almost all together now)..and see what happens....again..thanks for your time....Dave


oh yeah..one other thing...I was reading that a 6ppc,is a legal deer hunting round in the area I'll be hunting....that's another reason I wanted to step up to a larger round.The 6.8 spc,or Grendal would have been a better choice,but I mostly punch paper....thus the 6ppc.h.gif

hat

Quoted: Be careful, WalkerTexasRanger is going to post that link to the ballistics charts again...

Sometimes the truth hurts.  

Quoted: ....I'm not stating that the 6ppc is the best for deer,I'm just stating that it's legal...and may be a more accurate round than the other two...If I can do my part in the shooting process...maybe he'll go easy on me...

The 6PPC dominates short range BR competition, yet it hardly figures into long range BR competition.  Why?  Ballistics of the bullets commonly used.  

Most common 6PPC bullets used are 66-68 grain flat base bullets.  They have low BCs and do not perform well at long range in windy conditions.  The 6BR is even considered to be a marginal performer at 600+ yards unless conditions are good.  This is with a minimum 88 grain, most commonly a 105-107 grain bullet with a high BC.  Try bucking the wind at 600 with a low BC bullet and you will struggle to say the least.  

So, you might say, well for the longer ranges I will drop a Sierra 107 into the 6PPC case and give it a whirl.  Your velocity will be an issue due to the reduced case capacity if you plan on using this out of the magazine.  This would work, yep.  Is there a better solution, IMO yep, the Grendel.  

Why?  First, more case capacity than a 6PPC, about 2 grains IIRC.  If you want to shoot the heavier bullets with high BCs, you can with no problems.  Second,  the Grendel functions much better than the PPC out of the AR platfrom.  There is less shoulder to impair feeding, and the feedramps (i.e. the custom barrel extension) are designed to work specifically with the cartridge.  Not to mention the Grendel parts should becoming more available.  Once guys like Randall get set up, parts should become less and less of an issue.  

Keep in mind, the Grendel is basically a 6.5PPC. Obviously, the case is necked up and the shoulder is also blown forward to increase case capacity.  Also. the taper has been slightly changed to help with feeding in gas guns.  However, the parent cardridge is not changed significantly.  Most importantly, the inherent accuracy of the PPC is maintained.  

With my Grendel bolt guns I have gotten the following groups:

200 yards - 5 shots


600 yards - 5 shots:



Different bullets, yep.  A Hornady 95 VMax at 200, and a Norma 130 VLD at 600.  Again, out of bolt guns and not ARs.  I did the whole bolt gun thing to prove to myself what the true accuracy potential of the cartridge is, and I am satisfied.  

IMO, that is the real beauty of the Grendel.  A very wide range of bullets based on your intended purpose.  Use the 95VMax for the short range stuff, and use the 130s for long range stuff - all out of the same upper and brass case.  I dont think the 6PPC has quite that versitility.  

Don't get me wrong, if I was building a pure short range 100-200 yard bench gun, it would be a 6PPC.  But, that is not what you ask about.....    



     

SOLD....hey...I

Quoted: SOLD.......hey...I'm easy...I have three unloved empty ar uppers staring me in the face.....so I'll just end this torture,but building a 6.8 spc...AND...and grendal....since reading ballistics before hand..i've wanted a grendal anyway..

In the great AR15.COM tradition - ALWAYS GET BOTH!!!!!!!  

It's the American way....I'm glad you and Randall  talked me into it.h.gif

By the way,where is the best place to get a Grendal barrel?Probably not top dollar,but a reasonably good barrel.

The 6.8 barrel is on the way,along with the mags,bolt group and magazines.(maybe the 6ppc rounds will run from these mags?)

Quoted: Quoted: By the way,where is the best place to get a Grendal barrel?Probably not top dollar,but a reasonably good barrel. From my conversations with Alexander Arms while setting up my agreement, you will NOT be able to buy an AR-15 Barrel, only a complete upper. I can build you a complete upper with any parts you specify as long as they meet the quality and function checks.

Same sad stuff as 300 whisper - I think it holds back the future of any cartridge when you try to limit the sources...  - reminds me of Beta vs VHS policy stuff

It sure seems that way.

If the Grendal is as good a round as it seems,it will fight its way into the open..Every new thing starts like this...once it's accepted....more will be made...the prices will come down....that's why I'm still waiting to pick up on the new flat screen tv's....hdtv...and all that crap....Grendals will either loosen up,or go away.

From my conversations with Alexander Arms while setting up my agreement, you will NOT be able to buy an AR-15 Barrel, only a complete upper.

Do you know if that applies across the board? Parts will be available later on right (as in after shot, assuming a coulpe big name manufacturers pick up the Grendel)?

I really want a Grendel but I need to be able to build exactly what I want, with spare parts available too.

Quoted: You won't see big name manufacturer's picking up the Grendel without SAAMI approval and US based manufacturers offering ammo first.  Of course this will never happen because ....

I wouldn't be so sure about that, lets bring this back up after Shot  

AA is not a member of SAAMI, so not sure how they could get the round submitted unless they had a member do so on their behalf.  The cartridge is in the CIP process currently, so this should suffice in lieu of SAAMI, and if I understand correctly, they share data.

Grendel reamers are currently available to the public: www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=329990

There is nothing, no IP rights, trademarks, etc to prevent an individual from making thier own Grendel upper.  What the law is designed to prevent is another business from profiting from AAs IP.  You can build your own, for personal use, with no issue.  Randall, for example, cannot build and sell Grendel products without a license from AA.  This would be in infringement on AAs IP.  

Main thing to remember here, is that the Grendel is more than just a different barrel for the AR, it is more of a system.  Gas port sizes are different from 5.56, extractors are different, a custom barrel extension is required (5.56 barrel extension will not feed properly), the ejection port on the upper receiver must be enlarged, specific bolt, & specific magazine.  

You could, of course, purchase a reamer from Midway, purchase a 6.5 caliber barrel, chamber and install.  You will have to get the gas port size right, your rifle will not feed 100% without the Grendel barrel extension, your cases may or may not eject all the time, and you would be using a standard Colt 7.62x39 bolt vs a Grendel Carpenter 158 steel bolt designed for the higher bolt thrust of the Grendel.

Could you make it work, sure.  Is it worth the effort, maybe to some, not for most.  With folks like Randall working towards licenses, and with AA also introducing a 16" chrome moly chrome lined barrel model for +/- $595, is it really worth the trouble?  

I have no problem paying for a complete upper.The hang up has been price...I've not seen a grendal upper for 595$...I'll check into the prices...all pricing I've seen has been over eight hundred dollars.

I believe you,when you talk about the special parts to make the grendal run.I've run into a little of that in putting together this 6ppc.

Speaking of the special steel bolt to handle the Grendals thrust....that begs the question as to why not a special steel bolt for the 7.62x39 bolt for the AR carrier?...the lugs on the bolt on the 7.62x39 bolt,look like they are riding on a thin wall of steel to me...and are,compared to the .223 bolt...as I've stated in another post.

I understand about the different pressures,and having to watch your pressures...but it seems like a beefed up bolt for the 6mm and 7.62,would be in order....I'd buy one.

Quoted: I have no problem paying for a complete upper.The hang up has been price...I've not seen a grendal upper for 595$...I'll check into the prices...all pricing I've seen has been over eight hundred dollars. I believe you,when you talk about the special parts to make the grendal run.I've run into a little of that in putting together this 6ppc. Speaking of the special steel bolt to handle the Grendals thrust....that begs the question as to why not a special steel bolt for the 7.62x39 bolt for the AR carrier?...the lugs on the bolt on the 7.62x39 bolt,look like they are riding on a thin wall of steel to me...and are,compared to the .223 bolt...as I've stated in another post. I understand about the different pressures,and having to watch your pressures...but it seems like a beefed up bolt for the 6mm and 7.62,would be in order....I'd buy one.

You will just have to wait another week for the $595 uppers.  They are to be formally announced at SHOT.  Probably be a couple of months til they reach the market though..  

Agree on the bolts.  Seems there might be an extra market for the Carpenter 158 bolts used by the Grendel just as replacements for the standard Colt 7.62x39 bolts already out there.  Obviously, the current Colt bolts work, and will work in the Grendel, but the extra strength just can't be a bad thing....  

if you use a colt 7.62 bolt, where can you get an extractor to use?

Quoted: if you use a colt 7.62 bolt, where can you get an extractor to use?

AA has them custom made - probably the only source.  

The rim of the case is thicker then a standard 7.62x39 case and hence the need for the custom extractor.  Same as the ejection port, will a standard work, probably, but probably not 100%.  I have never tried a 7.62 bolt as all the Grendel uppers I have shot have been complete AAs.  This is what Bill has posted over at the Grendel site.  

I would be curious to know what the rim thickness is on a 7.62x39 case though, to see just how much difference there actually is between the two.    

Here is Bills post from www.65Grendel.com :  

"Compatability of the parts sort of depends what model you are working from.

All Grendels use a reciever with an enlarged ejection port. This is nominally 0.050" taller but the outside frame dimensions remain the same to ensure the port door fits. The rail dimensions and rail height are standard. Depending upon the manufacturer and where they are on the tolerance some existing recievers may work and some may not. For example I have an AO upper that the brass case will not fit through the port.

The receiver parts are standard
The carrier is standard
The charging handle is standard

The bolt and extractor are specific to caliber. The extractor may be replaced with a 223 unit but needs some simple mods and may not be totally reliable. All other bolt parts are common. Remember that you are dealing with a larger case so springs must be the best you can buy. I use chrome silicon for the factory rifles.

Now we get to the messy bit. All the stainless barrels set for accuracy, essentially the premium grade stuff, use a 0.906" gas block journal. Gas tubes are standard, being either A2 or mid length. Where the barrel has a flash hider this is a 3/4-28 RH The heavier profile breach to muzzle prevents whip and allows for better heat sink capability.

The new carbine barrels that are being launched for SHOT next year use a 0.750" gas block journal. The muzzle thread for these is 9/16-24 RH. The typical 1/2-28 thread was stretching the rifling at the muzzle and accuracy was all over. 9/16-24 was chosen as the next standard size and it allows most brakes/flash hiders to be drilled out and rethreaded.

Obviously the barrel extension is specific to the Grendel as are the magazines.

I have been toying about with the idea of offering parts kits for the build it youself junkies, but when you look at detail at what you really save, the answer is the carrier, the charging handle, the delta assembly and the gas tube. I feel that the current approach of building a $550 carbine with a chrome lined barrel will allow people to tear down these to make any changes they need (little detail, I intend to fix the front sight with parallel dowel pins so that they can be removed without huge effort). It also ensures that the receiver/carrier group/barrel work in harmony for any future build.

And for those who shout that they know all this, a little fact you may not: 1 degree of alignment error on the reciever index position will knock the front sight out of square and cause intermitent function problems depending upon it being a clockwise or anticlockwise error. 3 degrees and your gun will close but never open again.

Bill Alexander"

sorry, i meant an extractor that would work with the grendel. I wonder if filing a bit at a time to fit the thicker case would work...it  may be worth a try since getting replacement parts seems to be only a dream at this point...