Primer Testing Reference

This testing was done to try and rank primers by power (brisance).

Primer tester1.JPG (43461 bytes) This is the home made tester.  The shot is fired against a weight which in turn moves a pointer.  The pointer remains at the highest point of the shot.

Primer tester2.JPG (37043 bytes) This shows the pointer after a shot has been fired.  In this case, it was a Federal large rifle magnum

NOTE: This data is reference only.  This is on a DMS (don't mean squat) scale.  It is relative to this set of tests and this tester.  Take them with a grain of salt and as a guide only.  Most of the tests were of 100 or more primers.  A few were of 50 when limited amounts were available.

Ranked in order of power

Large Rifle = LR, Large Rifle Magnum = LRM, Large pistol =LP, 

Brand/type                Power Average            Range            Std. Dev

1 Fed Match GM215M        6.12               5.23-6.8               .351

2 Federal 215 LRM             5.69                5.2-6.5                .4437

3 CCI 250 LRM                  5.66               4.5-7.4                 .4832

4 Winchester WLRM          5.45                5.1-6.0                .2046

5 Remington 9 1/2 LRM      5.09                3.5-6.75              .6641

6 Winchester WLR              4.8                 4.1-6.0                .4300

7 Remington 9 1/2 LR          4.75               3.7-6.25              .5679

8 Fed Match GM210M         4.64               4.0-5.6                .3296

9 Federal 210 LR                  4.62               3.7-5.5               .3997

10 CCI BR2                         4.37               4.0-5.0               .2460

11 CCI 200 LR                     4.28               3.8-4.8               .3218

12 KVB 7 LR Russian           4.27               3.8-4.8               .2213

13 Rem 91/2 (30 yrs old)       4.16                3.8-4.8              .3427

Pistol primers

14 Rem LP                            4.47                3.2-5.6                .5171

15 KVB 45 LP Russian          3.89                3.3-4.2                .2232

16 CCI 300 LP                      3.18                2.7-3.5                .2406

17 Federal 150 LP                 3.11                2.6-3.5                .2090

18 Fed Match GM150M        3.05                2.6-3.7                .2299

This is a retype after losing the original web page.  I did not put in the individual comments.  Note the spreads.  The Rem's had some very wild shots high and low.  CCI BR2 and the Fed 's were the most even of the common ones.  The new Russian were very even, but this was a limited lot and they are not widely available.

Weighing Primers: I did some test weighing and found the bench rest had virtually no variations.  Of the others, there WAS a relation between weight and power.  Those extra heavy tended to be stronger, and light were weaker.

Firing pin strength also seems to be a definite factor. Stronger hit is probably more consistent.  This has been noted by some sharps shooters when they break a firing pin.  It will still fire, but they get fliers and open groups. 

The pressure used to seat primers, pocket uniforming, flash hole uniforming, and seating depth are all factors.  Keep them all the same.

Another thing that is not in this test, but I have noted, is using a newsprint wad over the primer.  This keeps grains of powder out of the flash hole.  It seems to even out the ignition by eliminating a variable (sometimes with grains in and sometimes without grains in, or a variety of combinations).




Welcome to CabineTree

CabineTree loading Products

CabineTree Wood Products

GMW Products