Midwest Powder 669

[95GTSpeedDemon]

Bought a jug on sale. it said it was similar to win supreme 780. i knew its more suited for magnums, but im trying in .243w & 6.5cm. loaded some test rounds based on data i scrounged. 780 should burn faster than H1000 but slower than H4831 is the general consensus i read. superformance is supposedly close in burn.

Fired test rounds, they are slower than i was expecting. So, trying to estimate new loads to work up is where im stuck.
22" 6.5CM, SL brass, 129gr Hornady spire point, 2.787 COAL, 44.1gr of mp669 was 2474fps
46.5gr 2545fps
20" .243w, SL brass, 100gr SP, 2.675 Coal, 45.7gr MP669, 2694 fps
108gr Berger Elite, 2.879 coal, 46.5gr, 2770 fps
108gr Berger Elite, 2.879 coal, 41.1 H4350, 2908 fps
if i OBT that data under superformance, is there any degree of accuracy of pressure its going to estimate with a higher charge?

 

[95GTSpeedDemon]

20" .243w

Powder Powder charge COAL ogive OAL Case FPS Projectile all used remington 9 1/2 primers MP669 45.8 2.675 SL 2694 100gr Soft Point MP669 46.5 2.879 2.259 SL 2770 108 Berger Elite MP669 47 2.879 2.257 SL 2771 108 Berger Elite MP669 47.5 2.879 2.257 SL 2838 108 Berger Elite MP669 48 2.879 2.257 SL 2879 108 Berger Elite MP669 48.5 2.879 2.257 SL 2878 108 Berger Elite MP669 49 2.879 2.257 SL 2850 108 Berger Elite MP669 50 2.879 2.257 SL 2909 108 Berger Elite 26" criterion .243w Match (longer throat than saami) Powder Type Powder charge COAL ogive OAL Case used FPS SD Projectile MP669 47​ 2.717​ 2.253​ SL NA 100gr SP MP669 47.5​ 2.717​ 2.253​ SL 2939​ 100gr SP MP669 48​ 2.717​ 2.253​ SL 2934​ 100gr SP MP669 48.5​ 2.717​ 2.253​ SL 2990​ 100gr SP MP669 49​ 2.717​ 2.253​ SL 2985​ 100gr SP MP669 49.5​ 2.717​ 2.253​ SL 3069​ 100gr SP MP669 50​ 2.717​ 2.253​ SL 3042​ 100gr SP MP669 47​ 2.915​ SL 2945​ 108gr Berger Elite MP669 47.5​ 2.915​ SL 2994​ 108gr Berger Elite MP669 48​ 2.915​ SL 2969​ 108gr Berger Elite MP669 48.5​ 2.915​ SL 3012​ 108gr Berger Elite MP669 49​ 2.915​ SL 3017​ 108gr Berger Elite MP669 50​ 2.7​ SL 3045​ 95gr Nosler BT 6.5 Creedmoor 22" Powder Type Powder charge Projectile FPS SD COAL Ogive Case used Primer MP669 44 129gr hornady spire point 2383-2474 2.787 2.258 SL Rem 9 1/2 MP669 46.5 129gr hornady spire point 2545 2.787 2.258 SL Rem 9 1/2 MP669 48 147 eldm 2517 2.898 2.26 SL Rem 9 1/2 MP669 50 147 eldm 2636 2.898 2.26 SL Rem 9 1/2

 

[fkimble@charter.net]

Notice in your post, the 108 grain bullet is going faster with less powder! That powder is designed for heavier bullets. Lighter bullets don't allow it to build sufficient pressure.

Frank

 

[95GTSpeedDemon]

I did notice that. Suprisingly the 26" shot the 100gr bullets tighter than the 108, by half. Im quite dissapointed there. I loaded some h4350 behind the 108s and ill ses how it does. If it doesnt shoot that well I'll be giving NSS/criterion a call.