[Brian Carlson]

I have been using the WLP primers in my 45 Colt. They were in a blue box and were copper colored. I bought more recently and they were in a white box and were silver colored. Can I use these silver ones with the exact same loads and expect the same accuracy, velocity and pressure? Thanks, Brian.

 

[Jack Monteith]

Hi, Brian:
   They should perform the same, but always back off at least 5% when you get a new batch of componets and work up. I haven't noticed any difference with the new WLP in my .45 ACP, but I'm loading light and I haven't had a chance to chronograph them. Primers are the one thing I buy by the 1000. Incidently, the white box primers are old stock. Winchester went to the blue box & copper shell last year or maybe in `99.

Bye
Jack

 

[James Gates]

I too noticed the change in the composition of both the large  and small pistol primers...After a couple of phone calls...I was told that the change was to increase the sensitivity of the primer. The old white box was first..then the blue box and nickle primers...then the blue box with copper primers. This seems to fit since I have examples of each. I was told that the new copper primer is 10% more sensitive to hammer fall. This may be factory BS and it is really a cost savings change for the factory???? I also was told that the primer mix and strength was the same. I would suggest that all watch their primer seating for any over stressing the copper primer until we can see if there is any difference.
Best Regards, James

 

[Longrifle7]

I purchased 7000 primers last fall, All were the newer Winchester primers.
   I didn't change any load data and just went to loading with the new primers.  I tested my old loads with the old primers with the new loads with the new primers, I didn't see any change with velocity but did notice my group size in my Ruger M77 VT .243 reduced.

 

[J Miller]

Since Win changed the primers I have used both versions interchangebly.  I notice no difference.  I have used them in standard and hot .45 Colt loads.  
The only thing I noticed was a difference in "feel" when seating the primers in a Lee hand priming tool.  They seem to require a bit more effort to seat them.