Velocity variation from different primer brands

[regor]

What kind of velocity variations have folks seen when switching to different brands of the same primer type?  

 

I just finished re-doing my 9 Major load since I finished all my Everglades bullets and am switching to Montana Gold. I also decided to switch primers since I have 6k Winchester spp vs 1500 Fiocchi and don't want to have to re-do the load in a couple months. First test was much too fast, so I lowered the load and out of curiosity loaded up some with Fiocchi primers and some with Winchester. My friend had his chrono at the range as well so I shot over both of them and they were consistently about 10fps apart. I was quite surprised to find that the same load with Fiocchi primers was ~40fps slower than the Winchester and had much higher SD. Both made power factor, but the Fiocchi ones barely squeaked over. Curious if this is normal when switching primer brands for the same type or if one of the two I was using is known to be under/overpowered. 

[4n2t0]

I'm not sure about major but in minor I can see a spread of ~10 fps difference amongst all primer brands.

Edited January 20, 2021 by 4n2t0

[Farmer]

Have seen broader variations than that but have also seen where a slower one produced much lower ES too. Lot’s-O-Variables. 

[MikeyScuba]

These aren't my pics, Ganderite over at Canadiangunutz shot rounds that only had primers in them at night.  You can clearly see the difference between brands

https://www.canadiangunnutz.com/forum/showthread.php/1819206-Primer-Choice?highlight=primer

 

 

[BillChunn]

The link you posted requires a username and password to access.  Can you identify what primer is associated with each of the pictures?  That would help a bunch.

 

BC

[MikeyScuba]

It's a 4 page + thread.  Just set up an account, don't have to be Canadian to join!