I have been working on a new .45 load since I was able to stop by the Xtreme bullets plant and pick up some nice plated bullets recently.  I have always wondered what difference the LP or SP brass made on the loads, so I ran some across the chronograph last week to find out.  The results are below.  Everything was loaded on a Lee Pro1000 all I changed was the priming setup and settled on an in-between OAL after testing my LP loads.  It was -2* when I tested the LP loads, but I kept the magazines in the truck until I was ready for them.  The SP loads were tested when it was about 2 above, the ammo was kept in the truck then as well.  All of the numbers are from a CED ProChrono Digital.  I also shot a couple of other loads just to have somewhat of a baseline since this is the first time I've checked my pistol rounds.

My conclusion, SP or LP doesn't matter much for this load although I prefer LP.



Zero 180gr. HP - 1.120"
9.2 Gr. AA#5
Rem LP Primers

959   AVG977
1030  ES108
984   SD39
973
933
987
1031
923


Hornady Critical Defense

882   AVG889
887   ES143
879   SD47
864
1004
862
880
861

Xtreme 230gr. RN - 1.230"
6.0 Gr. Unique
Rem LP Primers

797   AVG787
764   ES65
787   SD20
804
819
788
787
754

Xtreme 230gr. RN - 1.240"
6.0 Gr. Unique
Rem LP Primers

754   AVG764
814   ES99
715   SD28
748
773
768
779
767

Xtreme 230gr. RN - 1.235"
6.0 Gr. Unique
Rem LP Primers

850   AVG795
826   ES78
785   SD30
772
785
778
773

Xtreme 230gr. RN - 1.235"
6.0 Gr. Unique
Rem SP Primers

775   AVG794
789   ES67
769   SD22
812
836
809
787
781

Xtreme 230gr. RN - 1.235"
6.0 Gr. Unique
Rem SP Primers

764   AVG790
725   ES111
836   SD36
808
804
773
783
828

Hornady Critical Defense

1024
890
900
873

I have done this and played with FC brass(LP) and other brands whose flash hole was smaller than the FC cases.  It really doesn,t seem to make any difference, even when using several different powders, velocity is really close.   Interestingly, accuracy differences did show up on paper.  The edge seemed to go the small primer cases, a small edge, but it was a fun few days shooting and testing.  I'm over it now  :)

nice job

In the past I've always just sorted the brass, loaded it then tossed it all in an ammo can and never paid attention to the primer size when shooting it.  For shooting steel and paper at the range it definitely doesn't make a difference.  My wife and I shot our first USPSA match a few weeks ago, and we are planning on doing it again in Jan. so I figured while I'm working up a new load I might as well be a little more exacting about it and use the chronograph.  At least now I know that I can shoot the SP brass at matches in the winter where I'll probably lose the brass in the snow, and not have to worry about it being any different velocity wise from the normal LP loads.  

On a side note, I was surprised by how well the Lee powder measure on the Pro1000 worked with Unique.  It's the first time I've used a flake powder in there and every load out of the 20 or 30 that I checked was +/- 0.1 gr.  In the 500 rounds that I loaded over a couple of evenings last week, I never had to stop to fix a jam or hang up of any kind on the press.