Dr69er, Where is you?

Hello Fellas, Yes I'm still here...I'm sending out the Hornady 6.5 MPC dies as I somehow got a stuck case(and I used plenty of case lube) in the sizing die,thus no new load developement. Will have to wait for the new dies

I do plan to go out next weekend and restart load developement and a new HD Video range report...

Ron, the only thing I killed thus far was my budget

Thanks fellas and stay tuned...

P.S.

OH, when I talked SSK they quoted a max. COL of 2.240" for the 6.5 MPC...go figure.
My 6.5 AR-TCU round can go well  above 2.300" COL.

I was just pondering the idea of this cartridge and playing around with it on quickload. glad I found this thread. looks promising especially with the 107gr smk and H355 or Exterminator(the 6.5 tcu). In for more info.

Hello Garred8787, yes my ballistic program also shows H322 and Extermt'r as gtg powders for both the 6.5 MPC and 6.5 AR-TCU rounds.

I'll try to keep you guys updated...also, best results will be with bullet weights of 125grs and lighter (6.5 MPC)
and the 144 grs as max.(short/medium range, moderate velocity,super high BC) for the 6.5mm AR-TCU.

how is the feeding with the steep shoulder of the tcu? thats the only part that worries me.

Feeding is not much of a issue...since the angle of approach is nearly Identical to the parent 223 case and the larger bullet diameter lessen the distance from
the case neck to the case body,thus giving you a wedge affect.

The Lapua FMJBT 144 grain loads in the 6.5 AR-TCU w/ the 24' Bbl (1:8 twist)will average between 2,162fps - 2,298fps with a BC of .636 ! Pressure @ under 50K CUP.
Again, the main limiting factors are mag. length and case capacity.

Any new developments?

Hello Fellas, I promise some new HD Videos in 2 weeks or so...I been side tracked with a lot of family/work Issues and working a 1911 project as well.
So this has taken a lot of time away from the AR projects on the 6.5 MPC and 6.5 AR-TCU. I've been also frustrated by my 6X45mm AR project w/ short stroking
problems...oh well.


Thanks

OK Friends here are some HD Video Clips for your pleasure...Sorry the video was very rushed and was not able to convert to full HD.


The 6.5mm AR-TCU shot well, there were some tweeks made to the gasport and was able to do some chrono testing as well.

The loads tested were:

100gr.Nosler Ballistic Tips @ 2,460 fps.
120gr. Speer Hot-Cor Soft Points @ 2,280 fps
120gr. Nosler Ballistic Tips @ 2,222 fps

You may have noticed that the bolt did not lock back, this was do mainly to the fact that the loads were loaded a bit mild
and I did not want to open-up the gasport bigger than .096" .

Accuracy was MOA, I was very happy with the Pac-Nor Match barrel...

The other pieces were two Custom 1911's the first w/ the Blue Slide (Springfield) was a 9mm Parabellum.
The second (Stainless Slide) was a Custom 1911 .45 ACP w/ 200gr. +P Speer TMJ's going through the tube...S/L Match Barrel w/ Clark-Para cut.

The 45 ACP +P  loads were sizzling @ 1,050 to 1,080 fps.


http://www.youtube.com/watch?v=nT2hFEMeXMA

OK Friends, here is the original SSK load data I recieved w/ my new 6.5mm MPC AR Upper Kit.






My 6.5mm AR-TCU is nearly Identical to the MPC, however the AR-TCU has a approx. + 3 grain powder charge advantage (the computer
says 33.071 grains of H2O).

I fired my 16" MPC today.  Mostly functioned fine.  I had a few issues with the bolt holding open after the last round.  Load was 120 grain Sierra using 19.9gr 1680 powder.
his weekend, I will be trying 95 gr vmax with 22.9 gr 1680

I had the same issue with some of the lighter loads (and somewhat weak magazine springs) with the 6.5 AR-TCU round. It just a matter of some minor tweeking...

The 20" 6.5 MPC upper has not yet been tested and I had some Issues with the  SSK reloading (Hornady) dies which are now resolved...the rounds refused
to fully chamber...so now it seems everything is OK.

Hornady dies aren't the greatest.  I wish they used RCBS or Redding dies.  They were a lot of trouble to resize 223 brass.  Trimming would be a chore without my trimming machine.  Hopefully I can get it to function 100% and then get it sighted in

Found a very very good load for the MPC today.  Functioned flawlessly.  The recipe is as follows:

95gr Vmax
22.9gr 1680.

Cycled fine.  Bolt held open after magazine dump.  I am going to stick to this recipe.  It looked like it was grouping decent as well.  My red dot optic wiggled loose.  Had to break out the locktite, but ran out of ammo.  Try this recipe.  Works wonders!

Cool and interesting report, ( I just now saw this)
1 MOA is quite surprising considering that the structure of the round looks completely wrong

OK, the SSK MPC Upper has been shipped back...let's see how long this takes...lets hope JDJ does the right thing, fast.

My custom 6.5 AR-TCU has been running real sweet thus far and as the barrel is starting to break-in, I'm seeing higher velocities.
Just goes to show how things go when you do things yourself.

My goal is to safely run the 120-125 grain bullets in the 2,500-2,600 fps velocity range, and the 123gr. SMK to 2,450 + fps range.
So I'll be trying to squeeze every bit of the 33.072 gr. capacity out of that TCU case w/ the 24" match CM barrel.

I going to have to experiment w/ the different powders that work well for the 223 based cartridge case.