Adjusting load for magnum primer- UPDATE post #13

[Pauliedad]

UPDATE on post #13

Hi guys,

Been plugging away loading up 30-06 for my Garand. Had a thread going here about a week back and got all sorts of good guidance. The load I'm running with is 47gr IMR 4064under a Hornady 155 gr AMAX. COL of 3.215 and I ran low on my Winchester LRP stock. Decided to go with some CCI 250's I had. They are Magnum Primers as opposed to the Winchester. These are going into my Garand.

Ive seen some people say go down a grain although that may be more critical for pistol?

Any experiences with this you'd like to share?

Thanks.

[devster55]

I would go 1gr as long as you are not close to max and try that. I use mag primers if I am going to be hunting in below freezing temps. Just my 2 cents and work up your load with caution. I have talked with a few old timers that say they do not make a difference but I do not believe that. They are magnum for a reason. I would try 1 grain

[highpower790]

Considering the military loaded a 173gr projectile with IMR4895 I think your safe,but I would load it down especially for short range.
You can get buy with 42gr4064.Another thought could be to load one powder charge and change the bullet to suit your needs.

[Pauliedad]

Thanks.
I really just want to stay similar to what the 47 grains is doing. I'm so far under max with 47 that I'm confident the pressure isn't a problem with the mag primer. Much below 45.5 gr the groups opened up so I guess I'll go with 46 as previously suggested and see how that goes.
Still interested in any other opinions out there.

[highpower790]

Thanks.
I really just want to stay similar to what the 47 grains is doing. I'm so far under max with 47 that I'm confident the pressure isn't a problem with the mag primer. Much below 45.5 gr the groups opened up so I guess I'll go with 46 as previously suggested and see how that goes.
Still interested in any other opinions out there.

Chabot gun club had a M1 match at 200yds this last Sat,as a example I loaded the same 155amax with 42 IMR4895.Shooting on a SR target slow prone I shot 200/196.

[Pauliedad]

Nice.
I'm not far from Chabot but with kid's sports and weekend family time, weekend range time is pretty rare. Was it crowded?

[Divernhunter]

You will be fine with your original load and the mag primers.

[mjmagee67]

You will be fine with your original load and the mag primers.

Only if you are a grain or 2 or 3 below MAX, I would drop a few grains and work back up. don't use Mag primers unless you really need them. They can cause pressure spikes with powder that is easily ignited.

[highpower790]

Nice.
I'm not far from Chabot but with kid's sports and weekend family time, weekend range time is pretty rare. Was it crowded?

Only 12 shooters!would be nice to see more attend.There is a sticky for Chabots M1 and military bolt rifle matches.People read it,but if those who read actually showed we could have full relays of 15.

[highpower790]

Only if you are a grain or 2 or 3 below MAX, I would drop a few grains and work back up. don't use Mag primers unless you really need them. They can cause pressure spikes with powder that is easily ignited.

I respectfully disagree.With a near max load of 4064 and only a 155gr projectile he is safe. Considering the military loaded a 173gr bullet there is a 20gr difference in bullet weight alone ,this will allow for the difference of a magnum primer.
I too think a magnum primer is unnecessary, unless thats all op has for right now.

[LynnJr]

A primer is simply a tuning aid that is used to adjust the ignition of your load.
Find the node or center point of your powder window first.
Next you find the center point of your seating depth.
Next you chronograph the load and if your extreme spread is not good you swap out primers until it bottoms out.

[Pauliedad]

Appreciate all the input. 47 of IMR is far below max so I wasn't really concerned other than keeping the load similar.
Seems like a waste on those primers but that was all I had left and I'm not seeing 1000 rounds of 300 WinMag in my future so just wanting to use them up.
I'll take a look at that sticky and see if I can swing a weekend somewhere.

[Pauliedad]

Took out the Garand today and ran a few clips
(it's fun to say "clip" without fear) of both the CCI Magnum Primers and the Winchester LRP with 47 gr. of IMR 4064 under a 155 A-MAX and all went fine. Groups looked no different and I could not feel a difference. Woo Hoo!

[highpower790]

Took out the Garand today and ran a few clips
(it's fun to say "clip" without fear) of both the CCI Magnum Primers and the Winchester LRP with 47 gr. of IMR 4064 under a 155 A-MAX and all went fine. Groups looked no different and I could not feel a difference. Woo Hoo!

Now your all set for the Nov Chabot M1 match.

[sl0re10]

Took out the Garand today and ran a few clips
(it's fun to say "clip" without fear) of both the CCI Magnum Primers and the Winchester LRP with 47 gr. of IMR 4064 under a 155 A-MAX and all went fine. Groups looked no different and I could not feel a difference. Woo Hoo!

My Winchester large rifle primers say ok for magnum loads on the front. Whether this means they are magnum primers (re: close to the CCIs) I don't know. But for some reason they sell them as combo regular / magnum primers... supposedly ok for either task.