300 Win Mag primer mag or std?

[Paddywagon]

I have been reloading for many years now and am now starting to reload 300 win mag for the first time. It has been my experience that some cartridges do well with mag primers and some do not. I was wondering what the consensus is here for primers on the 300. I will be using RL22. Thank you!

 

[nuclear_shooter]

300 win mag absolutely requires a magnum primers, at least that's what all the reloading books I've seen say. It should help give you a consistent ignition of that large powder charge.

 

[ZLBubba]

I have heard some people say that they like regular large rifle primers for 300WM. However, I only use magnum primers for my big boomers and haven't had any accuracy/inconsistency issues. YMMV

 

[Paddywagon]

I appreciate the input on this. One cartridge that I load a bit of is 45-70 and I have found that my performance is better with lg rifle on some and mag on other powders. 30-06 is like it as well. I will experiment with both but am always looking for good wisdom on new loads. Tends to cut the learning time a bit!

 

[17874]

Stick with magnum primers on any case with a large capacity.

 

[pawprint2]

I would suggest you try both, one will undoubtedly give better results (accuracy wise). It is really the only way to tell-primer testing is the most overlooked step in load development.

 

[JB02]

Definitely a magnum primer with a slow burning powder in a large case.

 

[DroidSniper]

I had good luck with BR2's under a lot of H1000. when it was cold i would get some ES but decent Groups. If you are in a warm climate you should be ok. If not i'd use CCI 250's.

 

[George63]

I found R22 especially tough to ignite - no doubt magnum primers for that combo

 

[hessian]

My best load in the 300 mag Sendero is 74.7 of 3100 and a 9 1/2 primer. 180 NOSLER BT. Never tried mag primers.