New JD Machine/JP Rifle build

[NoFail]

Oh for cryin' out loud!!!!! No I did not. Andreas Sorry for my ignorance, man.

[Andreas6.5AR]

Hi there NoFail... No problem what so ever.... I hope you have every bit as much luck with your build as mine... We have a great many components in common and it was a real toss up for me as to the stock, but since my intention was long range sniper unit I chose the PRS. The one I wanted was the one you picked, and I also looked at the JD hand guard and even requested from them if they could make me an adjustable gas block based upon their cool looking gas block with the rail... but never got a reply from them.  I am sure they get a lot of frivolous requests so I can't blame them. I think you should be very happy with the JD receiver/JP Rifles Low Mass enhanced bolt set... it is a pretty amazing combo. I intend to incorporate the a few of the things you have there in my next build too, like the Magpul UBR... I love that look for a Battle rifle. I would like to get the JD gas block and have a machine shop drill and tap for me to make it adjustable.

Where 140 grain is the light weight in 308 it is pretty heavy already for the 6.5, though it would be nice to see someone bring out some heavier spitzer types in 6.5 too (155gr to 160 gr... really get the BC up there). I have some Lapua 144 FMJ for reloading with already (amongst others). Just slowly getting all my reloading equipment lined up. While the 6.5 is more expensive I really wanted to try and get into some long range sniper type shooting as well, but didn't want to be having to put up with the kick of the 300 WSM or worse. The ballistics of the 6.5 Creedmoor can be almost identical to the 300 WSM and better wind bucking capability I believe. I love the 308... we used when I was in the militia in Canada in our FN C1 and C2s. (FALs). I loved that rifle too and would love to get another for old time sake. It is approaching 40 years since I was shooting those though. loved the wood hand guards on those, much more comfortable to hold in temperature extremes. A cool build would be with free float wood furniture on an AR platform IMHO.

I will keep an eye out on your post too to see how things are coming along for you.

Best of luck with it, it looks real sweet.

[Andreas6.5AR]

I would really like to take a moment to thank everyone, and especially Andrew for the contributions to making this site so great.... it made doing this build flawless and while challenging for a total newbie to this, still navigable without any troubles.

With out this site, I think there would have been many trials and tribulations in trying to piece things together.

THANKS EVERYONE FOR ALL THE HELP... directly and indirectly.

[Andreas6.5AR]

OK: the rear take down detent was just bothering me. I didn't see anything but a smooth hole, but to be honest I didn't remove the stock to check for a hole drilled and tapped and I wish I had, that was really silly of me... so I did the typical man thing: bought some tools, tapped the hole above the hand grip, cut back the spring, ground the cut edge, put it all back together, then decided to reread what you wrote, check the JD Tech website and see what you were talking about in your post... feeling like a bit of a sheepish idiot seeing the hole you were talking about right on their web site photography. In any case... Mission accomplished.

[NoFail]

Awe man why doesn't anyone ever believe me, all you needed to get was a 6-32 set screw bro :'( 

Oh well mission accomplished  <thumbsup>

[Andreas6.5AR]

Reloading for the 6.5 Creedmoor:

Great round but the loading from Hornady is a slower burning powder (H4350) and not the best choice for an AR based rifle.

With an 8 inch twist rate the heavier 6.5 mm rounds with high BCs are ideal for this rifle... and from initial looking over the selection the Lapua 144 grain FMJ Boat Tail with a quoted ballistic coefficient of 0.636 looks like a great bullet to work with. It is shorter than the HP from Berger (VLD and Hybrid) which are in the end too long for magazine feed when seated ~15 to 30 thousands off the lands. Sierra 142s would work as well as the Lapuas 139grain Scenars and 144gr FMJBts.

From a former 3 gun champion I was advised that IMR 4064 would be a very good choice for the AR format. I could not find any information on loads for this exact bullet and powder combination in this caliber so after a bit of cross referencing of sort of similar rounds I settled on starting out with 32.0 grains of powder and working up in 0.5 grain increments to 35.5 grains.

The adjustable gas port was opened an additional full two turns. I first shot some of 140gr Hornady A-Max rounds to confirm my scope setting and rifle operation... after three weeks of not shooting and being rushed and antsy my first grouping of 5 shots was abysmal at almost 2 MOA... the second grouping of 5 of the same was a bit better at about 1.2, all about the center (at 100 yards).

The 32.0 through 33.5 had issues cycling the action and also the shots were from about 1.5 to 1 inch average below center. The scatter was also bad, worst for the 32.0 grain.

At 34.0 grains I hit a sweet spot for grouping the shots at about 0.5 MOA for 5 shots, and the gun cycled fine but the shots were about 0.6 inches below the center.

At 34.5 things got worse again... wider and lower and for some reason the gun didn't cycle for 2 rounds. (Yes I am sure I did not mix up the rounds in the loading order, they were all labelled individually as i loaded them and seated the bullets one at a time).

35.0 and 35.5 grains cycled fine and I pulled a shot or two in each group otherwise 3 in each group of 5 were right on top of each other, and the shots were about back to center too (~0.2 inches low.... within experimental error I think). While not rigorous, I take this as a sign I am at approximately the same speed as the Hornady A-Max.

For all loadings there were no signs of pressure on the case (flattened primers, brass flow at the ejector etc.) I take it I still have some head room but I am very satisfied with the 35.5 grain powder charge for this bullet. The primer is CCI BR2 large primer. All in all I am very pleased with this Hornady brass.

Using reloaded ammunition for ARs is a dangerous game if you do not know what you are doing! It is very demanding and exacting to do it correctly. Shoulder bumping (for head spacing) brass sizing and neck sizing/trimming bullet seating depth are all critical. I seated the bullets about 15 thousandths off of the lands using a Stoney Point (Hornady) guage to determine the seating depth for each bullet.

I include this information here to help others to find a starting point if they are loading the 6.5 Creedmoor for an AR, because finding this kind of information is difficult for this round still.

I would really like to get a Chrony so I can do better at load development work. Maybe in about 3 weeks I can pick up a beta master.

[NoFail]

Sounds like you know what you are doing brother Andreas

[Andreas6.5AR]

Thanks No Fail

Trying my best here and listening to all the sound advice I can get. I got pretty scared about reloading because at the Fulton Armory website they almost beg people not to reload for auto-loaders offering videos and what info of what happens when it goes wrong.

I have to get caught up here on this site... Last I saw some people were still having issues with the P Mags and the JD receivers...

Makes me wonder if it may not the particular parts kit since I have no issues.

Also you once asked about how far open the gas valve was (sorry I was away from the rifle and range for 3 weeks and I measured it this week. I was about 8 turns from having it extracted fully (I think it was about 6 turns from bottoming out if I am not mistaken... working from memory and not notes here and I can't check again now as I out it away in secure storage at a friends place as I am heading to the Philippines for a couple of weeks).

You have been very active... lots of good advice and friendly postings... and at 168gr level already... cool. Guess I am not such a social type.

[Andreas6.5AR]

Well it is has been a year+ of gaining some experience and not nearly enough trigger time but I have had enjoyed the response to the rifle at the range with all kinds of comments ("oh man... look at that military porn", Can I shoot it?", "Could I please") and compliments even from ex-CIA equipment specialists and special ops guys... and my own daughter and friends who came down from Canada to visit.

 

Learning: Hornady Ammo is too hot for the standard DPMS bolt style (mine is a JP rifles bolt with the same 0.08" firing pin hole). The pressures in the cartridge will breach the primer and eventually the situation became dangerous. Will eventually buy the Armalite bolt carrier group with the firing pin hole being slightly smaller at 0.068 I believe. As these are not available I have purchased another JP bolt and some firing pins. The Hornady ammo (super accurate and I am sure is amazing in bolt guns, has the slower burning powder and occasionally even blows the entire primer out of the brass upon ejection. Perhaps the enhanced bolt group is too light or the Tubb flat wire spring not resistive enough or the buffer heavy enough. I do not have any problems with the IMR 4064 as it is faster burning and its impulse is quicker early in the firing cycle. 

 

Hand loading: Got wonderful results with 144 gr Lapua 6.5mm FMJBT (full metal jacket boat tail) loaded with IMR4064 powder. These bullets are shorter than the longer Sierra Match King 142 gr and considerably shorter than the 140 gr Berger VLD and VLD Hybrid, so they can be optimally seated for being close but still off the lands and easily fit the magazine. There is much discussion about the actual BC on these because Lapua quotes such a high BC value on these but I suspect they are not far off because the firing results and the reduced surface and density of the round. These will have amazing sectional density and penetrating power out of an AR308 platform. This loading It is pretty hot too (about 2720 fps) and the primers show some slight flow back, but accuracy is amazing so I am looking forward to loading up and doing some long range shooting.  

 

The barrel I purchased way back from Fulton Armory is amazing. My understanding is it is a Douglas barrel with an 8 inch twist. The chamber is just perfect as is the head spacing job that Fulton Armories did. I have reused the brass up to 4 times so far on reloading with no signs of issues at all. They come out of the rifle a bit banged up but dimensionally exceptionally close to unfired needing pretty easy resizing for the most part. I have lost a few cases to loose primer pockets though and a couple over banged up. I wish these barrels were still available (maybe Douglas will do custom barrels from their sight) I would like to build another 6.5 Creedmoor but in a carbine style. I just want to commonize the ammo.

 

Mom and daughter at the range with me and the subject rifle: