45/70 and Large Magnum Rifle Primers

[Chas.]

My "normal" 45/70 load is a 405gr. LFN, 31gr H4198 (trapdoor load from Hodgdon manual), and CCI-200 a Large Rifle primer.  Today, while inventoring what I had/needed, I noticed somehow I had gotten a box of CCI-250 Large Magnum Rifle primers.  What will be the expected effect if I use these rather than the CCI-200 primers?

[Lloyd Smale]

probably not much. Maybe a tad more pressure and velocity. I usually try mag primers in most of my 4570 loads. In many cases theyve given me better accuracy. Especially with compressed loads of slower powders and when using ball powders.

[Ranger J]

I regularly use mag primers in some trapdoor loads with powders that does not fill the case well or will give hangfires if the powder in not in the right position.  An example of this is trapdoor loads of RE #7.  Using the mag primer insures proper ignition all the time.  In trapdoor loads use of mag primers will not cause any real trouble.

RJ