Primer's

[Greg Duerr]

Has anyone with a pet load switched primer brands just to see if going from a F205M to a BR-4 would make any noticeable Difference in Velocity or Group size. I have been using F205M in all my loads and just the other day switched to some Rem 71/2 in the 17 Remington just to see. For me its the Primer that seems to be last in line

 

[MagnumManiac]

Has anyone with a pet load switched primer brands just to see if going from a F205M to a BR-4 would make any noticeable Difference in Velocity or Group size. I have been using F205M in all my loads and just the other day switched to some Rem 71/2 in the 17 Remington just to see. For me its the Primer that seems to be last in line

I test the SAME loads with 3 different primers, sometimes 4 when I include Fed205M .
I haven't used ANY CCI primers in a long time, but did side by side testing with Fed205M, WSR & BR-4 a few years ago and the BR-4 were in the middle of the test.
In my 6.5x47 I tested Fed205M, WSR & WSRM Primers with the last load tested with the 142gr pill.
Of the 3 the WSRM was the most accurate.

In my 25-06, a WLRM is also the most accurate with RE25 powder.

To be honest, I always find one primer superior to the rest.

Cheers.

 

[Trnelson]

It totally depends on your rifle and load. When I develop a new load I always try a few different primers to measure how they effect group size and SD. Sometimes it will surprise you what actually works the best in your rig.

 

[Gunpoor]

I made up an accurate load for my 270Win using CCI #200 primers and H4831 and then tried the same load but switched to Win WLRP primers and the load showed extreme over-pressure signs and also was not accurate. Sometimes switching primers shows little or no difference but sometimes its a real deal breaker.

 

[Jud96]

When I was developing the load for my .308 Norma, I started with WLRM primers. I was having a tough time keeping ES under 30 and I tried fine tuning my powder charges and never could tighten it up. Loaded 5 rounds up with my previous best load but tried Fed 215s, ES went from in the 30s to 12 fps. I settled with the 215s lol

 

[g0rd0]

primers can and are your best friend and your worst enemy. I try to use CCI250's but every now and then I am stuck using something different. Every time you switch out a component you should back off and work up.
Point,, I recently loaded a batch using wlrm did not back down and at the range I noticed small pinholes burned out the sides of them (I fired 10, 8 of them where burnt). Took them home pulled the bullets reweighted the charges and replaced the primers with my usual cci's back to normal.
There is nothing wrong with the wlrm primers I just did not use the rule of start low and work up.
Primers are now more sensitive and LEE recommends that if you have an original auto prime stop using it and contact them. They also don't recommend using federal primers in their priming tools as federal are the most sensitive.
LEE second edition, chap5, pg64
new primer info for the original auto prime, auto prime2, pro 1000 and load master
all sizes of cci primers, win sm pistol and all Remington primers 100 to the tray
limit of only 20 in the tray for win lg pistol, win mag pistol and win mag rifle
only 10 to the tray for win lg rifle
and do not use fed primers

 

[Mikecr]

I pick a primer and load develop with that.
I would shoot a ladder & re-adjust powder for a different primer.
If I changed bullets, I would re-test seating and shoot a ladder to adjust powder for the different bullet.

Anything that changes pressure peak timing, takes you back to finding tune.
Primer changes are in no way a fine adjustment.
Powder is the fine adjustment to get back into tune.