Primer power

[rockrat]

SR primers have a thicker cup than SP primers. IIRC, WW primers were fairly stout, but what pressures are you going to run in your loads? SR primers should be good to 223 levels (50K psi) and your SRM were good to at least 60K as they have a thicker cup than the SR primers. In my 353 Casull, I use sr primers unless I am nearing top loads, then I will use the srm. I am talking about rem 7 1/2, wolf srm or cci 450's. BR-4's also if I had any. CCI 41's were designed for 5.56 Nato stuff, but don't know if the 353 has enough to set those off. They might be the same as 450's or might be a bit tougher.
Now, I have read that the older ww sr primers in the white box had thicker cups than the blue box version and were OK for 5.56 nato spec ammo, but the blue box primer should be limited to 223 pressure levels. Over at accurateshooters, they have a pretty good discussion on primers and what primer should be used for what ammo.

[murf205]

The 223 loads are at normal 223 pressures. No ignition problems there but the accuracy improved measurably with the CCI 450's. However the load that particular rifle likes is older lot BL-c2. and 69 gr Sierra's. The 454 is loaded pretty much on the top with 290 and 300 gr boolits and I since I use a Magneto speed chrono, I wont be able to clock those. However I will take the advice to do my own testing and try both primer types when I get some more SR magnum primers.
I just received an answer from a Hodgdon Powder tech that stated that the small rifle primer was more than adequate for a 454 with H110/296. I imagine the bad experiences I had with H110 and standard primers are the reason for my concerns with regards to primer choice, but the memory if pounding a 158 gr Speer and cleaning out a charge of unburnt powder still linger!

[a danl]

i would question the milisec's when the photo's were snapped

[murf205]

Absolutely, we don't know the equipment used or the operator. That flame doesn't last long.