Primers can make a difference.

[WYO300RUM]

Only primer test I've done was a couple years ago. Was a 6.5 PRC. RL23. 124 Hammers. ADG cases. I chronographed 10 shots each with CCI BR2 and
Fed 210 M. The Fed's were way lower SD and ES. The late and good friend and LRH member Rhett Crider told me so. He was correct. God Bless him. About 2 months ago I did a test with 300 WM. RL26. 180 Hammer. Fed 215M. 4 Shots each with Norma case and with ADG case. The ADG was half the size group. There was no wind

 

[WYO300RUM]

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

I've tried both Fed 215M and 210M in 6.5 PRC. The 210M seemed to shoot a little tighter. I'd have to look at notes to see if I chronoed the 215M"s. I've stuck with the 210M for last 4 years.

 

[xsn10s]

Only primer test I've done was a couple years ago. Was a 6.5 PRC. RL23. 124 Hammers. ADG cases. I chronographed 10 shots each with CCI BR2 and
Fed 210 M. The Fed's were way lower SD and ES. The late and good friend and LRH member Rhett Crider told me so. He was correct. God Bless him. About 2 months ago I did a test with 300 WM. RL26. 180 Hammer. Fed 215M. 4 Shots each with Norma case and with ADG case. The ADG was half the size group. There was no wind

I found that my groups were more accurate using Fed 210M and 215M. My SD/ ES were lower also. This was years ago when I used an Oehler Ballistics Lab for pressure/ accuracy testing.

 

[lancetkenyon]

Personally, with a 91+ grain charge weight, I wouldn't even consider LR primers. Anything over 60-64gr is an automatic LRM primer for me.

You could, however, try CCI250, Rem 9 1/2Mag, Fed Champion 215, or Win LRM.

 

[JustMe2]

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.

With due respect, if you haven't seen a change, you are not doing a thorough test. Changing the brand of primers, changing match and non-match primers, and most definitely changing large rifle to magnum rifle primers will cause a change.

Will all these different primers ignite the powder? Yes, most of the time ALL the powder will ignite, not always, but just because the cartridge went boom, doesn't mean you will "see no difference."

Using magnum primers will cause pressure to increase faster and usually require you to reduce your powder charge. Magnum primers will cause pressure signs to appear faster. The powder is burning faster because a magnum primer has more energy to ignite the powder column than a non-magnum primer.

A magnum primer will help ignition in extremely cold conditions, like -40F because it has more energy to ignite frozen powder. That's pure physics. It takes more energy to bring frozen water up to the boiling point than the energy it takes to bring luke warm water up to the boiling point.

Group size will be affected by changing primer types because all primers differ on the amount of energy they produce. Even the non-magnum primers within one manufacturer will change your group size, velocities, SD, ES, etc.

Can you get a magnum cartridge to fire using non-magnum primers? Yes, but are you using a high-speed camera and other instruments to see if all the powder is being burnt inside the barrel and thus contributing to velocity? Maybe you are ejecting a lot of unburned powder out the end of your barrel thus wasting powder and efficiency and increasing muzzle flash. Unburnt powder also contributes to faster barrel fouling, more cleaning, and faster barrel wear because the next bullet fired is grinding that unburnt powder into your barrel just like sandpaper.

Yes, primers make a difference.

 

[xsn10s]

Personally, with a 91+ grain charge weight, I wouldn't even consider LR primers. Anything over 60-64gr is an automatic LRM primer for me.

You could, however, try CCI250, Rem 9 1/2Mag, Fed Champion 215, or Win LRM.

Yup I agree Lance. I should of said that in my post. I even start thinking of using magnum primers when I get into the 70 gr or more with ball powders. Since we live in colder climates during hunting season.

 

[KNOTFERSAIL]

This one time at reloading camp I stuffed LPP In my 300rum with 92gr H1000, lowest ES ever.

Try it out you might like the results.

 

[birddog 68]

I've had better results using federal 215's than 210's in the 7-08 with ball powder (W760)

 

[RichCoyle]

The yardage change too, correct? The first group was shot at 200 yds and second was at 100 yds. Why not do both groups at the same distance?

This rifle has fired multiple sub 1" groups at 300 yards. I was concerned the bullet holes would be too close together to make any since of if I fired them at 100 yards. When I saw the shotgun like pattern on the 200 yard group I was not concerned about firing the next load at 100 yards. I'm old and excel at lazy, so I didn't walk out to the 200 yard targets.

 

[RichCoyle]

LOL ok so change the powder weight for each shot. And then for the second group change the distance, powder charge for each shot, and primer. LOL good luck.

Everything was the same except for the range distance. I even used the same brass for both sessions.

 

[Hard H2O]

I'm pretty sure he was doing a load work up with Hammers

But for a subject that says "Primers can make a difference" not sure how the test and data supports that.

Still if he meant to compare the effects of the different primers he needed to isolate the primers and not have the variance in the powder charge. You essentially have a sample size of one in ten different rounds.

Need a larger sample size of one load to compare against a larger sample size of another load. Or at least have a larger sample of each of 5 loads in each of the two primers.

If you take one load, one shot with one primer and the same load, one shot with a different primer you learn nothing. Too much chance for shooter error.

One primer with 5 different powder charges had:
3693 fps
3699 fps
3764 fps
3925 fps

The other primer with 5 different loads had:
3647 fps
3659 fps
3712 fps
3748 fps
3871 fps

A bit over 200 fps from lowest to highest with each primer.

Not sure what one can extrapolate from the data other than one would need more data.

 

[xsn10s]

Everything was the same except for the range distance. I even used the same brass for both sessions.

You increased the powder weight for each shot. And then you changed the distance, the primer, as well as the powder charge for each shot on the second group.

 

[RichCoyle]

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

The weather was cold so I put the rounds in my pocket. I used an infrared thermometer to measure the temps.

 

[xsn10s]

The weather was cold so I put the rounds in my pocket. I used an infrared thermometer to measure the temps.

Well add another variable. Temperature.