I went to the funshop today and all he had was magnum primers and said he had a hard time getting anything including powder. I bought all the LR primers and they are magnum. How much should I back my charge down? I am using an AR-10 and settled on 41.6 grns of 4895 in a Hornady case.
Re: RE: Magnum Primers
From the powder charge and gun you're using, I presume you're shooting a 308 Winchester.
I'm currently working on loads for a 308 Winchester handgun using IMR 4064 powder. Primers I've tried include Federal GM210M, Federal GM215M and CCI 250 primers (the latter two are magnum primers in case you didn't know). I did back off the load a couple of grains just to be sure but it turned out that the optimal load for all without excessive pressure was exactly the same and thus far the best accuracy has been with the CCI 250 primers.
This is in keeping with my prior experiences with medium to large capacity cartridge cases; no decease in powder charge is needed. Now, in smaller cases it's different. For instance, I tried CCI 250 primers in a 44 Remington Magnum and had to decrease the load of H110/Win. 296 by 1.5 to 2 grains.
From the powder charge and gun you're using, I presume you're shooting a 308 Winchester.
I'm currently working on loads for a 308 Winchester handgun using IMR 4064 powder. Primers I've tried include Federal GM210M, Federal GM215M and CCI 250 primers (the latter two are magnum primers in case you didn't know). I did back off the load a couple of grains just to be sure but it turned out that the optimal load for all without excessive pressure was exactly the same and thus far the best accuracy has been with the CCI 250 primers.
This is in keeping with my prior experiences with medium to large capacity cartridge cases; no decease in powder charge is needed. Now, in smaller cases it's different. For instance, I tried CCI 250 primers in a 44 Remington Magnum and had to decrease the load of H110/Win. 296 by 1.5 to 2 grains.
Re: RE: Magnum Primers
Spoke to a Federal rep not to long ago about the difference between regular and magnum primers. According to him the only difference is that the cup is made thicker on the magnum. The actual compound in the primer is the same. Don't know if this is the same for all manufacturers or not.
Spoke to a Federal rep not to long ago about the difference between regular and magnum primers. According to him the only difference is that the cup is made thicker on the magnum. The actual compound in the primer is the same. Don't know if this is the same for all manufacturers or not.
Re: RE: Magnum Primers
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: GhostFace</div><div class="ubbcode-body">Yes, I am using a .308 and thanks for your response. Magnum primers just burn a little hotter correct? So in theroy there shouldn't be a rise in pressure? </div></div>
There can be significant rises in pressure going form a regular primer to a magnum one.
http://www.snipershide.com/forum/ubbthre...234#Post1037234
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: GhostFace</div><div class="ubbcode-body">Yes, I am using a .308 and thanks for your response. Magnum primers just burn a little hotter correct? So in theroy there shouldn't be a rise in pressure? </div></div>
There can be significant rises in pressure going form a regular primer to a magnum one.
http://www.snipershide.com/forum/ubbthre...234#Post1037234
Re: RE: Magnum Primers
To go from regular to magnum primer, you may have to back off a few grains and start working up. This is for SAFETY and accuracy also. When the primer is too hot, it can throw off your accuracy as well.
To go from regular to magnum primer, you may have to back off a few grains and start working up. This is for SAFETY and accuracy also. When the primer is too hot, it can throw off your accuracy as well.
Re: RE: Magnum Primers
Remember if you are at the ceiling of your powder curve, then I would back off even more than a couple grains. It's always better be safe than sorry. Worse case scenario is you have to buy one more pound of powder to work up a new load.
Remember if you are at the ceiling of your powder curve, then I would back off even more than a couple grains. It's always better be safe than sorry. Worse case scenario is you have to buy one more pound of powder to work up a new load.
