Question: Which primers are better?
Answer: It depends.........on a LOT of stuff.
A buddy and I were shooting 357SM revolvers in competition. I ordered the guns from the manufacturor and they were consecutive serial numbers. Since the guns were on the way, we put in an order for our components. We had the same lot of brass, same lot of powder, and same lot of cast bullets....he cast the bullets. We buy in bulk so all of the components were the same....except the primers. I was using Remington 7 1/2 SR primers. He was using WSR primers. We both worked up loads and got a load that shot well in our own revolver. We ended up going to the range on the same day and compared notes. His load chronographed within 50 fps of mine. His load of powder was a full 3.0 grains more than mine. Again, the only difference was the primer.
I shoot another competition pistol using H335 powder. I worked up my load and was getting a good 1" consistent 10 shot group at 100 yards. Primers were on sale, but they were a different brand than what i normally use. I decided to try different primers to see if any difference in the accuracy. 3 different primers, same load, same gun. Three distinct groups at 100 yards. 1.5", 1.0", and one .5" group with one flier that opened it up to about .75". Those primers were Federal 205M, Remington 7 1/2, and WSR. I immediately knew I wasn't going to buy the Federal primers that were on sale for this specific load. I also found out my cheaper WSR primers gave a better group than the Rem 7 1/2s that I had been using.
My buddy has been using WLP primers and H4227 in his 41 mag. He couldn't find any WLP primers so he picked up some CCI LP Mag primers. He worked back up to his load and powder charge is same with either primer. Go figure.
I have a load for my 7x30 waters using WW748 powder. I was using Rem 9 1/2 primers and have 5 shots under MOA out to 200 meters. I was out of the 9 1/2 primers, but did have a carton of the 9 1/2M primers. I am well under Max book load so shouldn't make a lot of difference, right? Flattened primers and groups near 3" at 100 yards. BIG mistake on my part.
You can pull up 4 reloading manuals and likely get 4 opinions on powder/primer combos for specific bullet weights. You will likely have several full grain differences in Max book loads for same bullet weight. Now add humidity differences, elevation differences, temperature differences and other factor that effect ignition and pressures and you will be hard pressed to achieve the same results as any one of the books.
Too many variables. You have to work up your load for your gun. You can use the books as a resource, but that is ALL they are....a resource to help get you started. You have to work with your reloading until you find the powder/primer/brass/bullet combination that works in YOUR gun.
Good luck and stay SAFE!!
Steve
