Large Primers vs Magnum Primers?

[thaHooligan]

Im wondering if I can use some Winchester magnum primers instead of regular large rifle primers for reloading my 308? I did a google search and got mixed results, some people say its ok and to use a little less powder and some say not to use them. Im asking because I cant find any large rifle primers right now, but I have found some Winchester magnum primers. Have any of you guys used the magnums over the regular?

 

[dennishoddy]

You can use the magnum primers. Just back off the powder charge a tad and watch for pressure signs on the way back up.

 

[Calamity Jake]

^^^^^What he said

 

[thaHooligan]

You can use the magnum primers. Just back off the powder charge a tad and watch for pressure signs on the way back up.

For scientific purposes, just how much is "a tad"?

 

[MR.T.]

If interested,
I'll do some horse trading with ya.
I'll go in for 1000 large rifle primers for 1000 small pistol primers.

 

[dennishoddy]

For scientific purposes, just how much is "a tad"?

One grain. Move back up in tenths of a grain. Sorry, should have been more specific.

 

[thaHooligan]

If interested,
I'll do some horse trading with ya.
I'll go in for 1000 large rifle primers for 1000 small pistol primers.

Dang I'm not sure how we'd do that, looks like your 3hrs away from me...

 

[easy]

Well, that would depend on how badly you want them, wouldn't it?

 

[MR.T.]

Dang I'm not sure how we'd do that, looks like your 3hrs away from me...

Yeah, 3 hours is quite a trip. Which direction from me.
I do plan on going to Piedmont either this weekend or next weekend, & I'll be going to Gotebo for rifle deer hunting season

 

[swampratt]

I have found with ball powders tha primer change from magnum to regular primer makes a big difference 50-100 fps.
But with stick powder I did not see that much difference.
That was in .223.

Read this for .308.
https://www.snipershide.com/shooting/threads/velocity-differences-from-brass-and-primer.6970191/


I have found different accuracy with a primer change in .308 and 30-06 but velocity with Varget or IMR4064 was not changed enough to justify a change to my load.

I get more velocity change from changing to a different brand of brass.
Winchester vs Lapua.
I do have different powder amounts for those cases.