Magnum primers in 308

[mao0720]

Do I need to reduce my powder charge if I use magnum large rifle primers in my 308 win load?

 

[Johnboy]

Rule of thumb YES,the other way around NO

 

[L.Sherm]

Always reduce powder charge to be safe when switching primers if your getting close to max you will probably over pressure, especially switching to a mag. primer.

 

[amlevin]

Pretty much the same rule applies here as for other component changes. "Change a component, re-work up the load".

 

[mao0720]

How much should I back off? 1 Grain? More? Im running 44gr Varget, no where near max.

 

[bigedp51]

Why are you using a magnum primer with Varget a single base powder?

Normally a magnum primers is used with double base ball powders because of the deterrent coatings.

Any time you change any component you reduce by 10% and work up again.

How much should I back off? 1 Grain? More? Im running 44gr Varget, no where near max.

You haven't stated your bullet weight.

 

[mao0720]

I'm shooting 168 gr bullets. The only reason I may use them is because they are the only large rifle primer available locally right now.

 

[amlevin]

Any time you change any component you reduce by 10% and work up again.

Even if a 10% reduction would reduce the load below published minimum or starting load for that powder???

 

[bigedp51]

Any time you change any component you reduce by 10% and work up again.

Even if a 10% reduction would reduce the load below published minimum or starting load for that powder???

The manuals give you a reduction percentage, it may be only 5% and I was over charging the OP to pay for my mis-typing fee.

 

[Gunracer]

Even if a 10% reduction would reduce the load below published minimum or starting load for that powder???

I would also like to hear the answer to this one. I may have to start using magnum primers. Reducing by 10% is over 5.5 grains in a 7 Shehane.

 

[brokeasajoke]

I have been using CCI magnum in large rifle applications for years on all hunting ammo because I was given 5k of them. Of course I worked up the loads.

 

[AJC]

Just make a small ladder. Two rounds per or even 3 just to check for pressure. No big deal...

 

[HTSmith]

How much should I back off? 1 Grain? More? Im running 44gr Varget, no where near max.

Dropping back 1 grain is what I did. Ended up about 0.5 Gr less than the standard primer. Have to shoot what you can get these days

 

[kiwijohn]

!/2 a grain is about average MOIWYW