Magnum or Standard small rifle primers for 300 whisper?
 

Which should I be using for loads with W296 and AA1680. I have been using Federal standard small rifle, and seem to run into high pressures pretty quickly. Will magnum primers make any difference?

Any input would be appreciated.

I think all of JD Jones' data was done with Rem 7 1/2 primers which are standard small rifle primers. However, if I remember right Federal primers are the softest with Winchesters being the hardest.

I've used 7 1/2 Rem for all my reloading in the 300 Whisper. Didn't think I needed a hot spark for such a little case. When I did a lot of reloading for my 454's, Dick Casull told me he found the 7 1/2 Rem had the hardest cups, and the Fed 205 next in hardness. Use to really load them hot in the early days, constantly stretching the primer pockets, which I have also done as well with some 300 Whisper early load developments. I found the standard primers to be more consistent for me also, and thus better accuracy. Out of my 10" blue SSK 300 Whisper, I get 2000+fps with a Nosler 150 BT, and Rem 7 1/2 primer. A little on the warm side with H110. With the old W680, velocities are just slightly under 2000fps, but primers show a lot less pressure signs. Unless your really going to push it, I think standard primers is more than enough.

Standard for me as well.

FWIW,

Gentlemen,
My experience with primers in a side by side comparison is that CCI Small Rifle Magnum primers printed appx 3/4 in high and 1/4 in left through my bolt whisper.
Did the test for grins and really did not expect much and was surprised just a tad by the shift in POI.
The load was 7.5 gr. Accurate #7, 220gr. Sierra HPBT in once fired 221 Fireball cases.
With both "regular" CCI primers and the Magnumn varieties the groupings stayed a very acceptable .4" at 100 yards- that is about the best my aged eyes can hold a grouping.

Din NOT drag the Ohler chrono out for the test but the regular primers with that combo are right in the 1050 range through my 18 in. barrel -Gemtech suppressor - at 75 to 80 degrees.

That's it. Just a bit of near useless information for the masses.

Gary

Hardly! That sounds like a sweet load to try out! Thanks!

BTW, which gun and barrel maker are you using?

It is a custom made job on a Rem. XR action with a Lilja barrel cut to 18 inches, crowned, threaded for the "can" and a Jewell trigger set for appx 1 1/2 pounds.

Had a local gunsmith who has an excellent rep. around here build it for me and I could not be happier- he got it out on time(less than 3 months total and 2 of it was waiting for the barrel) Fair price and an overall nice guy.

Even had him build me a sweet 223 on another Rem 700 BDL action he had laying around (didn't even charge me for the action) used the barrel that came with the 223 XR (already paid for) used the Rem trigger set up(already paid for) and had him pillar bed it, crown the barrel and it too shoots far better than I can on most days.:smile: :smile:.

Gary