Well, still got a complete upper in the 6.5mm MPC caliber sitting around and though it would be a good Idea to
revisit this nearly forgotten development from SSK and JD Jones...

Since we got a good supply of .223/5.56mm brass and now have more powders that should be right in the
wheelhouse of this round...

There also have been newer projectiles developed in the 6.5mm/.264 caliber since the 6.5 MPC was released
which also helps to give new life to this round...

Below is the original SSK load data sheets for the 6.5 MPC cartridge:


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The list of rifle powders that should work well in the .223/5.56 based 6.5 MPC round are as follows (approx. order of burn rate):

> IMR-4227
> H-4227
> IMR-SR-4759
> AA-5744
> AA-1680
> Norma N-200
> Alliant REL-7
> IMR-4198
> H-4198
> VV-N120
> H-322
> AA-2015BR
>Alliant REL-10X
> VV-N133
> H-BenchMark
> H-335
> Ramshot X-Term.
> AA-2230

Naturally, the high density spherical or "ball" powders and very fine extruded powders are going to work best limited case capacity
of the 6.5 MPC round...

These newer Alliant Rifle Powders should also be very useful (although confirmation with Alliant is still pending) in order of approx. burn rate:

> Powder Pro 300 MP (this may be a bit to fast for some loads as it is designed for magnum pistol cartridges).
> Powder Pro-1200 R (this powder has worked well for the .277 Wolverine round by MDWS, thanks Mark !)
> Powder Pro-Varmint
> AR-Comp (this may be a bit to slow for this round).


Below is a very current burn rate chart courtesy of Hodgdon:

https://www.hodgdon.com/PDF/Burn%20Rates%20-%202015-2016.pdf


Below is one of the projectiles that may be a good starting point (although a bit long for caliber), the LD CC 95gr. monolithic:

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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



Since the 6.5mm MPC upper has a 20" M/L, 1:8 Twist, 5R (bore) Stainless Steel barrel it should have no Issues handling
monolithic pills like the LD CC and Barnes TSX/TTSX pills.

Once everything gets tuned-in it should make a fine and lightweight Childrens/Ladies rifle...

Thanks and stay tuned.

I can't wait to see how your project progresses.

advntrjnky

It has proven to be a accurate round during Initial testing...and now with newer and more available
powders, projectiles, and Internal ballistic calculator(s) It deserves to be revisited.

Awaiting my new version (v 3.9) of QL ballistic program, as I somehow lost my original program disc
and now have the upgrade disc that won't work w/o the original program disc...

Had my hard drive crash and burn on both of my laptops (so much for the antivirus program) and thus
had to have the new QL program sent to me...

But anyway should be out and about in two weeks putting the 6.5 MPC to work with the faster powders
that it was designed for...

Thanks.

How do these stack in the standard mags?  Do they need a slight de-rib or can you fit them OK with proper ogive placement?

advntrjnky

They should stack correctly in a 30 round 5.56mm magazine Including the Pmags,
unless you load them with a very long COL, I tried this same procedure in a Pmag
and it ran fine feeding from the Pmag (It maxes out at 2.269" COL) even when
loaded longer, but I did have to trim the polymer tips of the projectiles...and it still
fed fine from the magazine.