A redesigned bolt would allow for higher pressures in the Grendel just look at the work AR15 Performance have done with their proprietary bolts with rounds like the 6.5 and 6mm BRX.  The 6mm BRX is pushing close to 243 velocities with 105 and 108 gr bullets.  AR15 Performance will build bolts and barrel extensions for the Grendel.

They make great stuff...but @ $100+ for the bolt it can get pricey...It unfortunately doesn't cure the other Issues that can effect the AR as we mentioned before...Boy do they make some great AR's !!!

I have had fabulous customer service from AR15precision.  I had some problems, and they wanted to look over the rifle.  When they had the rifle, they faced off the upper receiver because it was out of square.  Didn't even charge me for it.  They wanted to know what was causing my problems, and so they could learn and serve other people better. And they did it for free..  I like that.

That's what makes them so well respected, customer service and quality products is what makes them king in the AR world.

I am pretty interested in this type of thing.

––––-I'm interested in seeing how the 6.5PCC develops (you can read about it here). It promises performance a bit closer to Grendel spec because it is an improved design (which is why it requires fire forming) and boasts increased capacity over something like the 6.5MPC.––––- From another thread by Altair.

We may even get closer when we get PCC dies, because the dies I am using now are taking out the fireforming each time I re-size, so we have not shot a true 6.5 PCC case yet.

R 6.8 bolts stronger than 6.5 bolts?  What about necking 6.8 down to 6.5?

Course the case neck of 68 is kinda short so u would run into problems of COAL w/ long bullets...

How does arperformance make stronger bolts? Are they thicker lugd for a deeper barrel extension?

6.8 bolts, all else being equal, should be stronger than 6.5 bolts because the case head is smaller in 6.8, allowing there to be more material in the bolt.  As I understand it, that is why the Grendel has a lower max pressure in the AR platform.  The trouble with necking 6.8 to 6.5 is, as you pointed out, the longer bullets won't seat to magazine depth.  You could bump the shoulder back and trim but then you would have something like a Grendel with a lower case volume, so you wouldn't really gain much ground.  

The reason for the 6.5 PCC isn't because it has a larger case capacity than a Grendel (it doesn't) or higher pressure capability than a 6.8 (it doesn't) but rather because it uses very inexpensive brass to reach near Grendel performance using standardized .223 bolts and magazines.

As for the ARP Superbolts, I've been researching them (still haven't bought one) and the main design features that I've found that make them stronger is the radiused junction between the lugs and the bolt and added material around the cam pin hole.  Those are the two most common problem spots on the AR bolt.  I've read debates on whether the 9310 alloy is stronger than the standard C158 and people that know more about metal alloys than I do can't agree so as far as I can tell it's a wash.  I think the main improvements are in design, not material.

Altair,Correct on all counts...the 9310 "Carpenter" alloy is supposedly "stonger & more flexible" than the C158 or C86S alloys...It's the Improved Geometry that has added the Increased strength overall.

Altair, I am rather interested in this concept but I wish it didn't run into COAL limitations w/ the ideal 123 schenar.

I am sort of done with 556mm.  I am interested in one or two calibers for short action ARs.  I already have AR10s to fill the battle and...marksman rifle roles so I am not particularly interested in Grendle or 6.8.  I have a great interest in 300 blackout for launching 30 cal projos out of a 9" bbl for close range stuff.

I also have an interest in something that uses standard bolts and brass but that can launch a larger/heavier (than 5.56mm) projo w/ a high BC for some better long range performance.  The options would be .243, .257, or .264/6.5mm.  I can't find any of .257 bullets w/ BCs of over .5 yet, but there is a 105 gn berger .243 w/ a BC of .532.  Would that bullet load into a pmag w/ plenty of case capacity to run it up to over 2500fps out of a 16" barrel?  I bet there is some 223/243 wild catting already right?

Why is 6.5 the best bullet for this type of objective?  

Thanks.

With the .257 projectiles you are looking at a max of about 100gr bullets for use in a .223 based wildcat like the .25-223.  The .25-223 is trimmed to about 1.70" which gives you a bit more room than a .223 but even at that the 100gr bullets are just barely seatable to magazine length.  A 100gr SMK in .257 has a BC of .376 and they go down from there (other bullets like the 100gr Nosler BT have a higher BC and will seat to mag depth but encroach on case capacity too much).

Something a bit shorter, like the .25x40, will seat longer bullets but again, the powder capacity suffers.  According to Kurt, the .25x40 is laid out specifically for 100gr SMK and GK's and works very well for those bullets.

I think the .243 you are looking at would be the 6x45.  I've read you can use up to 100gr bullets in that cartridge but not all of them.  I suspect the really slick ones, like the Berger, will have an ogive that won't allow them to seat to magazine depth as well but it would be best to talk with someone who has a 6x45, I do not.  I do know that the 6x45 will have a bit less velocity potential than the .25's or 6.5's in similar weights because of the effect of bore size.  Generally if you keep the weight of the bullet and the case roughly the same the larger the bore the more velocity you can achieve.  The larger bore allows faster powders which allows you to get more efficiency out of the case capacity you are limited to.  Since the .25's get 2500-2600fps with 100gr bullets I'd expect to be in the ballpark of 2400-2500 from the 6x45 (these would be 16" barrels).

I'm sure there is a .243 (6mm) wildcat out there that is more what you are looking for.  Something like the 6.5 PCC with an improved design and more case capacity, but still based on the .223 case, that is short enough for the long slick bullets.  I'm just not personally aware of one.  Hopefully someone who is can chime in.

The reason the 6.5 is popular is because there is such a large number of projectiles designed for it with very good BC.  I think the popularity of the Grendel is why there are bullets as light as 123gr that have such good BC's and the 6.5 PCC takes advantage of that using the .223 case.  From what I've read and my personal experience the 6.5 is probably going to be the best at what you want, extending the range of the AR platform without getting away from the .223 parent case, but my experience and research into .243 wildcats is very limited so I may be missing something there.  You won't get high velocities (relatively speaking) because you can only do so much with a case the size of the .223, but you can get a solid performer.

Good luck and be careful.  Once you are infected with the wildcat strain of BRD it is twice as bad.

Any estimate on when dies will be available?

Thanks,
Gus

Last time I talked to the manufacturer he gave me a late April/May time frame...It's the long wait that's a killer for the custom dies...

I'll post up inquiring about the 243 wild cat cartridges.  I understand what u mean by the higher efficiency of the cartridges that are closer to straight walled.

Ur not kiddin about the shitty .257 bullet selection.  Theoretically that would be a better about attaining an ideal balance of capacity and COAL with slick bullets if there were in that diameter.

I heard the good selection of 6.5mm bullets has a lot to do w/ its historical popularity in N northern europe.

Tell me this: if one had some 300 blackout brass could it be sized into your cartridge?  

I like the idea of your cartridge, I just don't like the COAL issue, but is not that big of a deal and I tip my hat to you for finding such a good solution w/i the parameters.  Seems to me that the slick 243 might be enough shorter than the slick 6.5 to en able to have a farther forward shoulder and more case capacity to somewhat make up for reduction in efficiency and in the extra oomph you get with the 123 schenar.

...

All the 223 variants have pluses and minus to them, the 6mmx45 gives you more flex on BC, and slightly heaver bullets, 25 cal has some good bullets to pick from.  The 6.5, WOW look at the BC, and I'm watching how this develops, this one should trump the MPC(good work guys).  Starting at 7mm and 30 cal, I think the case capacity runs out, but some are doing good work with the 7mm.

The 300 Blackout steps in a different direction, it excels in subsonic mode, but still has some pop with the lighter 125's, I watching to see other work with the 110 gr loads, the BC of these bullets are lower than the 6.5, and they start slower.  A 125 Ballistic tip in a blackout is still good coyote medicine.

Your Blackout brass has been trimmed about 1/4 inch shorter than a 223 case.  You should be able to sell your Blackout brass, and buy more 223 brass.  My latest load for the Blackout is the 175gr OTM M118.  It's a pulled bullet, but it's working really good in the Blackout with a 9 inch barrel.

To you guys working this 6.5, Thanks, please keep sharing, many eyes are here :)

This is a very interesting development. I currently run a 6.8 from AR Performance. I have never liked the 5.56 for much more than cheap plinking, but the cost and the availability of brass, coupled with the high b.c. bullets, and the ability to still reach out a great deal further than the 5.56 makes this very desirable. I would love to see more results with 90-110gr bullets from a 16 inch barrel. Great work guys.

Thanks P-Wolf, the best velocitiies will be from 85gr. to 125gr pills and the barrel manufacturer kept a 16" barrel for himself which we will be tested as well.

So far testing has been very positive, the 18" barrel is getting 2,441 fps. w/ 120gr. Speer SPHC with non-fireformed brass and no pressure signs , using cheap Remington brass.
It seems to have at least  1.5grs. to 2.4grs of powder capacity available once the cases are fully fireformed.

Estimated maximum fireformed velocities for the light 85gr. bullets are in the 2,700fps range w/ a 16" bbl., 2,792fps. for the 18" bbl. and 2,898 fps for the 22" bbl.

Our next step in development other than more load testing w/ the lighter weight bullets (85,90,95,100grainers etc.) and then very high BC mid-weigths (100,107,108,110 grainers)
and finally the heavier (120,123,125 grainers) super BC bullets.

Then for just curisosity factor, heavy moderate velocity 140 grainers (since we have 1:8 twist barrels) to see the long range accuracy potential at moderate velocities in the
maximum estimated velocity range of 2,020fps to 2,300fps. depending barrel length and powders used...

ETA: Up next will be ballistic gel testing & pressure testing of various loads..

Here is a video of how easy it is to make a 6.5 PCC case.

Start with a .223 case, apply Imperial Sizing Wax, one pass threw the full length re-sizing die, pop it into the case trimmer, trim to 1.63", debur, and you are good to go. I wipe off the wax with a towel, then put them in the tumbler for a couple hours, and you are ready to load.

I am in the middle of framing my basement so my reloading bench is now the edge of a desk, until I get my Man Cave done.
Not the  best video, I had my cell phone attached to a tri-pod with rubber bands.

6.5 PCC case prep Vid

Never mind, saw the answer to this a few posts down.

Altair, you asked about using the 95gr. V-Max w/ the 6.5mm PCC w/ a 16" barrel...computer estimates are around 2,622fps... w/ certain powders.
Since we have thus far exceeded the computer modeling,you may yet have a chance to see 2,700fps for your 16" barrel.

The only thing that worries me about the 95 V-Max is like in the Grendel, people have had problems the bullet sticking to the rifling in the chamber...
lets hope once we try it everything goes well...

OK Guys, spoke to the reloading die manufacturer on Friday and looks like we will be on track for a late May delivery date...

Well, I posted up about a 6x45 w the 105g  .5+ bc bullets and they say you would also run in to coal issues unless you ran a HK mag or similar.  But if that's the case I don't see much benefit in shooting a 243 105g high bc bullet over a 273 123g high bc bullet.  It doesn't sound like you'd even get better velocity.    It seems weird though. What is the length of that 243 berger bullet and the 123gn 6.5 schenar?  One would think it was shorter, having similar porportions but thinner and shorter.

The whole hk mag thing isn't that big of a deal really. I have like 8 of rhem, I just have a lot more pmags.

My one question is can some of the shorter 6.5 bullets be loaded to a COAL to fit in a pmag?

yep, looks like this is the best option for a general purpose cartridge using the 556 brass, bolt, magazine in an AR for sure.  The grendle is better is certain respects, but I have 308's if I want to take the next step up...

The 105gr. 6mm Berger is 1.235" long.


The 6.5mm 123gr. Lapua Scenar is about 1.299" long w/ a BC of .547

The max. COL w/ The Pmag is about 2.275"

Velocity estimates are around 2,350fps. w/ barrel lengths in the 22"-24" range w/ the 123gr. Lapua.

We are currently using cheap C-Products mags and are getting around 2.280" or so COL's

So, jus wunderin, would some of the shorter bullets load out to < 2.275"or would the experimental loads be loaded to the same COAL of 2.280?  

Yes,correct...you want to load the bullet/rounds to maximum COL...thus achieving the most powder capacity...the shorter bullets are preferred as they give you
the best velocity...

Got out today and shot 120's with RL-10, it is too bulky of a powder for the small 223 case with the 120, with as much RL-10 as I could pack in, it only shot in the mid 2200's.  Loaded a few 100gr Hornady interlocks over H335, and worked them up to 2537fps, the groups got tighter as I worked up, no pressure signs at all.

I have to say I am amazed at how the BHW barrel is shooting, so far it is grouping no matter what load I throw at it, not that two shot groups are a real test, and I am shooting two, then back to the basement, load two a little hotter, and shoot two more so it does cool down between each two shot group.

So many more powders to try, so little time.

alright guys, I did some more research.  I see that there is the 6.5 TCU and the 6.5 MPC and the 6.5 whisper already which are the same basic concept of 6.5 bullets in 5.56 brass.  It looks like you guys were involved in some of these cartridges a few years ago.  

I read through the thread again but didn't see the argument for PCC over the TCU, MPC or 6.5 Whisper.  I suspect the whisper is made w/ a very short case for launching 140 gn bullets at subsonic velocities, so I understand the difference there, but what is the advantages and trade offs of PPC over the TCU or MPC.  

Thanks.

What is the latest fastest chrono data you have for different bullet weights out of different bullet lengths w/ fireformed brass and are these values likely to be representative of the performance you will get when you get when you get the proper dies in?

Also, do you have any computer modeling for 90-110gn loads out of 8-10 barrels?  I would be interested to see how it compares to 300 blackout for similar barrel lenghts & bullet weights. Though the blackout will have the advantage as being more thermally efficient in this application w/ the bigger bore diameter, I wonder how close the two might be.

Well it all comes down basically to case capacity...all are .223 Based...

6.5 Whisper, Max. Case Capacity 23.8grs. Designed for the AR,Short Range,SBR,Suppressed
6.5 MPC, Max Case Capacity 27.6grs. Designed for the AR,Intermediate,SBR,Suppressed
6.5 TCU, Max. Case Capacity 33.07grs. Fireformed (Not Designed for the AR Platform) Sharp 40 Degree Shoulder,Designed for 2.500"+ COL

6.5 PCC, Max Case Capacity 33.02grs. Fireformed and Designed for the AR Platform,Improved Case Design and Max Capacity from Parent Case.

Right now, we are getting 2,441fps. w/ the 120gr. Speer HotCor's w/ the 18" Bbl.
and 2,537fps. w/ more room still in the case w/ the 100gr. Hornady Interbond SP w/ the same 18" Bbl.
All are from non fireformed cases...once fireformed they will have at least 2-3 grain extra capacity...

We do plan to have a 16" test barrel in for testing in a few weeks...
Next week we will have the 22" barrel in for testing...

We will also be trying lighter weight bullets in 85,90,95,100,107,108,110 grains...as well as the following powders: AA1680,RL-7,H322,AA2460 .

No shit...

For comparison, BA's Grendel ballistic charts, w/ a 120 nosler, are showing 2450 fps out of a 16" tube and 2520 fps out of a 19.5"...  That's pretty damn good!  When will you be able to repeat tests w/ fireformed brass and w/ the scenars???  How much case capacity would you loose shooting the scenars as compared to the 120gn speer?

I know the 6x45 and the 6.5 SMK have been futilely suggested to .mil as cost effective improvements in the arsenal from 5.56 but this is much better indeed!  Prolly never happen though, it is hard to turn that ship around  Hell, if this is as promising as it seems I suspect that it could go big time eventually...

Looks like next weekend we will do some fireformed load testing,provided the dies we are using size the cases to the proper diameter...which we believe it will.
If the dies don't size to the correct diameter,then we will have to wait till the original 6.5mm PCC custom dies are delivered sometime in late May.

Then you will likely see at least 50-100 fps added to velocities from the 2,441fps. 120gr. Speer and to the 2,537 fps. 100gr. Hornady Interlock SP's loads.

Estimates for the 16" Bbl w/ the 123 Lapua Scenar are in the range of 2,248 fps. and 2,369 w/ the 22" Bbl. with a avg. loaded case capacity 24.2 grs. of powder.

Don't hold your breath if you looking for the DOD to make any changes that make sense...especially under Obama rule...

I was just wondering if you had tried this cartridge loaded in 30 round mags yet.  With the different case taper I was curious if there was any stacking issues.

I know the 7.62x40 doesn't stack properly in a 30 round P-Mag since it is a constant curve.  The improved design, with less case taper, doesn't stack the same as .223 so the 7.62x40 seems to work much better in my 20 round P-Mags which have straight bodies.

Have you noticed the same thing with the 6.5 PCC?

When I tried it with my 6.5mm AR-TCU varient I allways loaded it w/ 28 rounds and it functioned flawless w/ the HK 416 Mags.

So, I don't see any Issues w/ the 6.5mm PCC...but your right it can cause problems w/ stacking...

Next up for load trials are the light to medium weight 6.5mm bullets shown below:

From L to R :

Sie 100gr. Varminter(.930")...Nosler 100gr.Partition(.960")...Hornady 95gr.V-Max(1.025")...Nosler 100gr. BT(1.082")...Barnes 100gr.TTSX(1.155")...Barnes 110gr.Solid Sptzr.(1.300")



The order in  the picture was not correct, V-Max(Red Tip) then the Barnes TTSX(Blue Tip) then the Nosler BT(Brown Tip)...

The issue may be just because I'm using Pmags which have a constant curve and a true anti-tilt follower.  Since the follower cannot tilt it can't self adjust to the different stack geometry of the improved case.  If you try a 30 round Pmag let us know if it does turn out to be an issue.  They are my preferred magazine.

We plan to test w/ the 30 round Pmag as well...fingers crossed....

Has anyone tried thoose new Euro Spec? Pmags yet ?

Good news, looks like this comming weeked Paul will be ready with my 22" bbl. build/upper unit.  

So will some of the fireformed loads if the dies we are using sizes the cases properly, so we can't wait till then !  

Speaking of dies, the die manufacturer emailed me and said the dies are going to the heat treating vendor for
heat treatment the first week of April. So, we may also get the die sets back a little sooner than expected !

I/we have pre-ordered a dozen of Full Length dies sets, those of you who have emailed us with solid Interest/or gave us a
deposit will be getting this 6.5mm PCC widcat baby first...So it only leaves us with 10 sets to work with as one set is of
course will be set aside for myself and one for Paul. I had to pre-pay for the dozen sets so you can tell Its not a cheap proposal.

So in a nutshell, the best is yet to come w/ the full boat fireformed loads getting ready to punch some paper and
some big Hogs hopefully very soon, we are eagerly awaiting the 22" bbl. velocity and accuracy results, as we were
very satisfied w/ the 18" bbl. thus far with non-fireformed loads !

We are also trying to get the pressure testing as well as the ballistic gel done as soon as we can, provided our budget
allows as it, as its quite a expensive endevore.  

We are expecting in the neiborhood of 2,541 fps. w/ the 120gr. Speer load and 2,637 fps. w/ the 100gr. Hornady load
based on the actual results w/ the 18" bbl. Paul has done so far...Stay tuned everyone.

OH, there will be a extra bonus for everyone in about two or three weeks, Paul get that HD camera ready !

Paul, you should be getting that package by this Wednesday...give me a buzz if you get a chance...

Can't wait for the pr0n!!

Finally got Doc's 22" Patriot together, took it to the bench to take some pics, and shoot, and the bottom fell out, if the rain ever quits I will be able to shoot and see what she will do. In the mean time here is some gun-porn.

Thanks Paul, everything looks great,,,Waiting for your excellent range report soon...Glad everyone is OK after that Tornado scare in your area.

Looks like more bad weather for me too, just in time for the next weekend in my Catskills mountains runaway...40's w/ heavy rain...AAAAAHHHHHH

40's and rain ain't all bad if it is just you and your Bride going.

Yeah, seems like in the recent months the weather has become just crazy...Let me check the calender again...

Played with some 1680 today, and the 120gn Speer HC, shooting the 22 and 18" Patriot side by side, with the same load, I knew the 1680 was a little fast for the 22'' but was wanting to try it in my 18'', and wanted to see what difference the 4 extra inches would make.

After sighting in the 22'', I shot two on the upper left with the 22'', then two on the upper right with the 18'', hit the basement added .2gr more, shot the bottom left with the 22, and the bottom right with the 18''.

The 18 can be pushed harder, no pressure signs at all. The 22'' is a different story, the .2gr more the primer was starting to flatten. I was going to work the 18'' up further, but the rain started again.

Got 2418 fps with the 18, I hope to get past 2450 fps with the 1680, but we will see.

I had plenty of room left in the case, the 1680 will be a good powder for the 144gr lapua. Yea I know, the 144 is pushing it with this small of a case, but with a BC of .636 whatever speed and energy it gets, it will retain for a long ways.

Paul thanks for your help w/ this wildcat project...The results so far are just wonderfull.

Some of you may be wondering why the difference in accuracy w/ the exact same load...

A) Pressure difference between the 22" and the 18" using a faster powder...
B) The 22" Bbl. has a 4 pound single stage trigger w/ no bipod and the 18" has 3.25 pound dual stage trigger which the
    man behind the trigger is used to having...
C) The 22" Bbl.is just starting to be broken-in,only a few rounds down the tube thus far.

Seems the Speer 120gr. HotCor is the go to bullet thus far in terms of accuracy and velocity...Good work man !

Just ordered a box (last one in stock) of 6.5mm Lapua 144gr. FMJBT w/ a .636 BC today...It will be sent out Paul for testing w/ the 6.5 PCC wildcat round
and will hopefully give us reasonable ballistics out of the small but efficient 6.5 PCC case.

It will likely do best w/ some of the faster powders like: AA1680, RL-7, H4198,and H322...

We are quite happy thus far w/ the accuracy and velocity of the 6.5mm PCC round.

I have been searching all morning for 123gr, and 144gr Lapua with no luck, did the place you got the 144, have the 123 scenar?

I don't get the value of these odd calibers - or wildcats.

I have 5.56, 6.8, 7.62 x 39 and even 7.62 x 54r

6.5 G = I already made my decision and went with the 6.8
300 BO = doesn't offer much the 6.8 doesn't offer

Maybe a few years ago, I'd opt for something different, but now I have all I need - EXCEPT a large thumper, say a 450 BM or 458 SOCOM or maybe a .308

Again - I don't see the value . . . just my opinion.