Primers can make a difference.

[Will.284]

I guess I'm dense. What did the OPs test results yield with many different variables and a coarse ladder?

Inquiring minds want to know.

For those of you using LR primers on mag cartridges…cool. I won't use them on large charge cartridges as I live where it's cold. Sometimes hunting season in MT can be way below zero. I'd prefer a consistent bang in those temps.

Good point FireFlyFishing . I'm in central Mt and it gets cool here to

 

[Will.284]

I think I'd give it a few more weeks if its your shooting shoulder

Yes it's the same shoulder but I was shooting in a little over a week . I heal quickly and it wasn't a full replacement. I'm getting a itchy trigger finger

 

[thomasbangs]

40 to 50 years ago I never gave primers that much thought, I used mostly Winchester because that's what I had and I was only loading for a few calibers. I have however discovered after all these years and loading for several rifle and pistol calibers that sometimes primers can make a difference. When I experiment I only change one variable at a time until I'm satisfied before changing anything else. Here are a couple things I have found out with my test results, over the years changing from Winchester primers to Remington 9 1/2 primers tightened groups in my 220 Swift when I was shooting, max or near max loads of IMR 4064 behind a 55 gr. bullet. Groups tightened when I switched from a WLR to a Federal 215 Magnum primer in a. 270 Winchester when shooting, max or near max loads of IMR 4350 behind a 130 gr. bullet also the Federal 215 shot a little better but not much when shooting max loads of H 4831 behind a 130 gr. bullet in same gun and caliber and the WLR had a little more velocity but not enough to matter. Remington 2 1/2 large pistol primers shoot better for me in several of my handguns with target loads including the 44 Magnum.

 

[asd9055]

In my limited experience, IMR7828 works great with CCI 200 in my 300WBY and 180TSX.
In another 300WBY, 180BT, IMR4350 with Rem 9 1/2 standard.
Yet two other, with RL22 and Fed215.
I think you have to match powder to primer. But like I said, limited experience.

 

[bluedog69]

I'm so confused......

 

[Louisiana Reloader]

Only difference is primers and yardage.
I like federal 215's but this combo seems to prefer the CCI 200's which is surprising with 90+ grains of powder.

I agree—very surprising with large (90+ grains of power) that regular large rifle primers would be used. I guess I've been living on the moon the last 31 years I have been reloading. I've always followed the loading book's recommendations for primers on large amounts of powder (large rifle magnum primers). But, if you can prove it on paper and a chronograph, it's hard to argue that. I have (2) 6.5 PRC's (SAKO & a Benelli) that I dearly love. All of the loading manuals have said use regular large rifle primers; however, Vihtavouri's load data uses a large rifle magnum primer—which I thought was interesting. Currently I am using Federal 210 large rifle match primers for all my 6.5 PRC loads and all has been well. But, I will say that the 6.5 PRC has the powder capacity that is kind of on the fence where you start to approach load charges where conventionally large rifle magnum primers are used. I've never tried large rifle magnum primers in my 6.5 PRC's and I doubt I will based on current results I am getting. However, Vihtavouri thinks it's a good idea. Interesting conversations here. Thanks

 

[Beluebow]

Primers can make a difference......I'm not convinced this test proves that.

 

[ButterBean]

It's a simple fact that there really is no NEED for a magnum primer. I often use a standard primer even in my wildcats on the 416 Rigby Improved case where loads run 120+ grains, never have issues until a ball powder comes into the mix, which usually isn't quite compressed at all and the primer blast blows through the powder column, a magnum primer provides more pressure which compresses the powder and stops it blowing through it. It is visible on the pressure trace as a rise then dip in start pressure using a standard primer, it goes away when a magnum is used.
I often switch between the 2 in standard cartridges too.

Cheers.

ShoNuff

 

[Hard H2O]

Sorry I was not clear. The only thing I changed was the primer. Even the brass was the same. First shot contained 91 grains and each subsequent shot contained one more grain.

With the large rifle primer there were no stiff bolt lift like with the magnum primers.

So you changed the primer, powder charge, and range. That is 3 variables.

Try 2 ten round groups with one powder charge, same range, and just the primer change.

 

[ARlife4me]

There's been post on the temperature and capacity on the primer subject. Temps below X w/ capacity above Y use magnum primers. Usually the powder type falls into those categories. I have rarely shot below 50°, unless it's been 5.56 ammo. Since I don't shoot in nor develop loads for freezing and below Temps I have 0 experience in that area.

 

[Fatcatbuster]

I must be missing something. The only change that I see is the primer. The first target indicates "200yds" the second target doesn't indicate distance. The velocity spread is about 40-50fps, not 200fps.

I've got to be missing something.

I'm going to try this with my 7PRC - it seems that a lot of guys are seeing good results with regular LR primers.

I've had to use LRP instead of a Magnum primer many times in 300 WM and many receipts calling for a mag primers in 30 cal,25 and 243. I've seen no difference.

 

[bluedog69]

There's been post on the temperature and capacity on the primer subject. Temps below X w/ capacity above Y use magnum primers. Usually the powder type falls into those categories. I have rarely shot below 50°, unless it's been 5.56 ammo. Since I don't shoot in nor develop loads for freezing and below Temps I have 0 experience in that area.

LUCKY!
Actually I will take our 0 - 45 F hunting weather here in MO and let you keep your
summer heat. I like 85 and under. Can tolerate up to about 95. Still slows me down when working.
100+ kicks my butt anymore.

 

[UCzO___]

So you changed the primer, powder charge, and range. That is 3 variables.

Try 2 ten round groups with one powder charge, same range, and just the primer change.

And same range trip, i.e. different days in you original test.

 

[Philward]

What is meant by 70° pocket and 60° pocket?