209 Primers

209 PRIMERS


I read an article by Toby Bridges, some time ago, regarding 209 Primers. No one seems to know exactly how 209 primers establish the strength of their primers. Some say it is based on the amount of HEAT generated and others say, NO it is the amount of FORCE that the fire from the primer exerts.

In any event, he did a test with a .32 cal Knight ML in which he tested several primers, shooting patched round ball out of the .32 rifles using JUST the primer and NO powder and chronographing the results:

Winchester 209ML 221 fps
Winchester triple 777 244 fps
Rem Kleen Bore 209ML 318 fps
Std Win 209A 336 fps
Std Rem #209 341 fps
Ceddite #209 347 fps
Federal 209A 381 fps

5 shot groups were fired and he threw out the slowest and the fastest and averaged the other three shots.

Despite the difference from slowest to fastest in his test, which was 160 fps; using just the primer itself to propel a .32 cal patched round ball, in shooting actual groups using 100 grain of Hogdon triple 777/fff’g powder behind a 250 grain saboted bullet, his greatest spread between the Winchester 209ML and Federal 209A was only 11 feet per second extreme spread.

As far as accuracy was concerned; his test using a Knight Disc Extreme .50 cal rifle with the 100 grains of 777/fffg and a 250 grain Barnes TMZ, ALL groups were between 1.25 and 1.75 inches. The hotter Federal 209A primer produced the MOST crud ring and the Win triple 777 primer the least.

The interesting thing to me and possibly to you as a reader, is the extreme velocity spread of only 11FPS between using (7) different 209 primers and the accuracy difference amongst all brands was a max of ½ inch at 100 yards. Most of us, including me cannot hold that well to notice ½ inch under field conditions anyway.

Perhaps another case of, “much fuss being made over little consequence”. If you are trying to work up the most accurate long range load possible from your smoke pole, then perhaps looking at which primer you use as one part of the equation would matter. You may also want to weigh your powder charges in addition to checking the volume of the load, and possibly weigh the saboted bullet on a scale etc.

See my writeup on accuracy tips for the Encore 209/50 for additional information.


Dan