Large rifle std vs mag primer ?

[sean eady]

What difference would I see on an identical load of .308 using 150gn fmj 45grains of W748 and a CCI magnum primer (my current load) VS same load using standard CCI large rifle primers? Is there going to be a dramatic difference just switching primers?

 

[Ifishsum]

Probably not much - but conventional wisdom says that any time you change a load component, it's best to do some re-testing to be sure you're still safe. If you're near the maximum safe range for your rifle, the standard primers sometimes start showing pressure signs that you wouldn't see from magnum primers with a heavier cup. If you're already well behind max, it's probably not an issue. I would at least try loading and shooting a few prior to loading up several hundred that way.

 

[KansasSasquatch]

Some ball powders supposedly don't get consistent ignition when used with standard primers. But I have yet to use a ball powder for rifle loads so I can't say how much truth there is to that. If its true then it could cause you some issues.

 

[gamestalker]

I ran out of CCI-250's once and tried using the CCI-200's (standard) instead, but it was for a powder that recomended the 250's (mag) primers. Performance was very noticeably effected. I had what seemed like burning powder blowing back in my face and a large amount of powder debri in the barrel and brass. Over all, I ended up with a very dirty burn. Velocity and accuracy was erratic as well. RL22 was the powder I used for a 7mm RM application.

But going the other way, as in substituting magnum primers for a standard primer application would probably be OK, providing you do a complete new work up though.

GS

 

[Skyshot]

You should see some difference in very cold temps, as the mag primer has a little hotter burn. I don't know how much of a variance it would have though.

 

[JLDickmon]

so far, you're getting good advice..
if you are near max, you may want to back off 10% and work your way back up..

If you're at a starting load, they do tend to light large charges of spherical powders with more consistency.

 

[Patocazador]

Ball powders should use magnum primers as a rule. 748 is a Ball powder. The loads may all ignite with standard primers but you take a chance that the powder may not burn consistently.

 

[sean eady]

Thaks everyone for the input. I will just grab a pound of something to play with that will allow me to use up the 1000 regular large rifle primers I bought. Thanks again everyone.

 

[PCCUSNRET]

If you can find any, you might give Varget a try. One of the best powders I've found for the 308 and regular large primers work just fine.