6.5 MPC

Trg42,
No offense taken.

Yeah I can understand why some would think it's another "perfect" AR round, but all in all it's not.
The main reason I find it suitable is I can shoot heavier, high BC bullets through an AR, while using .223 brass. :D
With that said I can gain more down range muzzle energy (1600 ft/lbs at the muzzle +\-) and if I can get a good enough velocity ( which won't be hard) these rounds will remain supersonic to 1000 yards.
 
Looks like it could be a pretty promising caliber for the AR-15 platform. Are you doing maximum loads to get the highest velocities and because its so new how do you know what those maximum loads are is it a trial and error and look for signs of too much pressure? I am ignorant when it comes to reloading:confused: Thanks for sharing your project!
 
Looks like it could be a pretty promising caliber for the AR-15 platform. Are you doing maximum loads to get the highest velocities and because its so new how do you know what those maximum loads are is it a trial and error and look for signs of too much pressure? I am ignorant when it comes to reloading Thanks for sharing your project!
Click to expand...

Only time will tell how well it performs, but from the far and few that already own one, they already love it.

Actually these are not maximum loads. They are moderate. I believe some guys are getting another .9 grains of AA1680 without any over pressure signs.

I spoke with JD Jones about maximum loads, and he said the load data he gives to his customers is not maximum and safe.
Usually when pressure becomes and issue you will get split cases and flattened or blown primers.
So far, I have not experienced any of this.
 
So, what is the difference in this round and the TCU cases? I suppose this one works better in an AR? I don't know much about gas operated rifles, so just asking. It just looks really similar to the TCUs.
 
Bigautomatic,
The difference is the case. I believe the TCU cases are fire formed and the 6.5 MPC does not require fire forming.
I hate fire forming. I tried converting AK brass to 6.5 Grendel and it was a pain.
But an advantage of fire forming is larger case capacity.
 
Wow, what a hectic week it has been. I hope none of you have been drooling as you wait over my range results? Long story short, I was without my car this weekend, so I did not get a chance to test ballistics and accuracy. The good news is I have my car and God willing if my chronograph works tomorrow, I can test my reloads for velocity.
Pictures to follow-I have been waiting on range data before my review goes to youtube.
 
Last edited:
Alright I finally chrono'd my reloads.
Here is my load:
22.0gr 1680
CCI 400
100gr AMAX
OAL 2.253

Chrono 10 feet in front of muzzle

Velocity average
2,622

According to my ballistic calculator this will get me 1525 ft/lbs at the muzzle.
This gives me close to a 300 ft/lb increase over MK262 out of my 5.56 upper.

Accuracy was holding within 2 MOA as I wasn't trying to put bullets trough the same hole.

All in all I am satisfied.
 
would love to see some targets if you ever do a ladder work up for groups. I have a AR receiver waiting on a new barrel sitting in the safe.
 
I think this round deserves to be revisited since my Initial testing a few years
back (although the testing was limited to mostly Speer 120gr. SSP's and 100gr. Nosler BT's).

Also, the MPC round really calls for relatively fast rifle powders like RE-7,
H4198, AA1680 and similar powders which at the time of testing were
hard to come by...

I have a 20" SSK Complete upper that has been sitting around and It is
calling for some range-time...

The best projectile weight range seems to be between 85grs. to 107grs.
with some shorter 120gr. pills that should work fine...

When last tested the 6.5mm MPC did do quite good in terms of accuracy
out of It's 20" Mid-Gas Bbl. with It's 5R Rifling and 1:8 Twist Rate.

For those Interested here is the original SSK Load Data Sheets for the 6.5mm MPC:

SSK65MPC2OF2.jpg
[/URL][/IMG]

SSK65MPC1OF2.jpg
[/URL][/IMG]

I realize this is a old thread but I think It deserves to be revisited...


Thanks.
 
Hopefully will be doing some load development using AA1680, RE-7, and H4198 powders...But will
likely stick to AA1680 since that powder does so well with .223 based wildcats 6mm and larger.

Have to look to see what pills are available so I can get things rolling, I am curious to see what the
95gr. Controlled Chaos round will do in the 6.5mm PMC.

The 6.5mm MPC should do best with projectiles weights from 85grs. to 107grs. and a limited amount
of 120gr. pills that are not long for caliber...


Here are the details of the projectile in question:

Brass jacket, air core projectile designed to progressively fragment
for sporting use in rifles.

Caliber: 0.264
Bullet Weight (gr): 95
Length (in): 1.125
BC (G1): 0.374
Minimum Twist Rate: 1:9
Velocity (fps): 2,000-4,200

LD%20CC%20264%2095gr_zpsa95gevqp.png
[/URL][/IMG]
 
doofus47:

Both copper and brass based projectiles behave in a similar way, as they
both have similar atomic weight(s). The Barnes TTSX being copper based
has a slightly higher atomic weight than the brass based LD CC projectile.

In testing with the 6.5mm PCC round (which is like a bigger brother to the
6.5mm MPC) both the TTSX and the LD CC did not do as well as conventional
lead core with copper jacketed rounds...this was due to a few factors:

>The test rifle barrels had polygonal bores (with a 1:8 twist, although the twist
rate was optimal and had nothing to due with the substandard performance).

>Cooper and Brass have a much higher heat expansion ratio than Lead...

>As a result of the above factors velocity and accuracy suffered due to a
Improper gas seal between the projectile (lower end/base) and the bore
rifling...

Interestingly, this was less of a Issue with longer barreled (24") versions with
the same loads, likely due to the longer time (and higher heat generation) the
projectile had...


But in the case of the 6.5mm MPC barrel that Issue should not be a factor in
testing as the 6.5 MPC barrel has a 1:8 twist and 5R rifled bore.

We will see once we do some field testing with the 6.5 MPC round again...

Thanks.
 
You must log in or register to reply here.
Back
Top