Thread: What a difference a primer makes !

Thought i'd post the results of when i changed from using a standard cci 200 primer to a Federal 215 magnum primer in my Tikka 7 rem mag.
The powder i've been using is IMR8133, it was a new powder that came out a few years ago but has since been discontinued. I've had good results with it and have got enough for a fews years yet.
Using the 162gr ELDX my load was a book max charge of 75.5gr of 8133 and a cci 200 primer in Sako cases which gave me 2950 fps from my 22 inch barrel.
Until recently i had not been able to put any rounds over a crony, but just worked out my drops at various ranges out to 700 yd and using 2950 fps in my app that matched my drops perfectly . Using a crony recently confirmed my mv of 2950 but with a few wild fluctuations like 2920 or 2970 etc, hmm thats a not ideal i thought so apart from looking at my reloading process and trying to be more consistent etc i loaded a few rounds with a Federal 215 primer that i had bought awhile back when primers were hard to find. i used the same load but knowing my rifle i was confident there was a bit of room for a bit more mv and of course pressure .
Using a Garmin crony i got an xtra 50fps so cracking the 3000fps mark, fired 7 shots in total and apart from one were pretty consistent i think.
2995
3008
2996
3019*
3001
2999
3000
With my 22 inch barrel i thought that's right up there, first 3 shots about .5 inch group but with a hot barrel and operator error 5 shots went just over an inch. I let the barrel cool down completely then fired another 2 shots in same hole which is normal for me and this gun. I can usually get 2 shots touching but never quite get 3.

With that one shot that went 3019 i am sure i could feel a slight resistance when opening the bolt compared to the other rounds fired so i might drop back .5 grain or so in the interests of case life etc. Still be good mv but more reliable for hunting.

This is the load data i used to work up my load which used a magnum primer.