Home Forums Reloading Big Game Rifles Rule of thumb for using magnum primers?

I always figured the use of magnum primers, was for large powder charges. In what charge territory do you start thinking about using a magnum primer. Would 61grs+ of R22 in a 280AI for example constitute using a magnum primer?

Forgive the newbie question, I never use magnum primers for anything. Even in my 338 I am only throwing charges in the 60's. Wondering if a magnum primer might offer some benefits.

thanks.

I was using magnum primers on my .338 RCM, when I realized that .338-06's, operating at almost exactly the same weight, were not. I tried out the standard primers, and found that they were more accurate at the same speed, with my .338 RCM.

The short version, I think, is that you have to try both approaches and figure out what's working for your specific cartridges and loads. And I think that's particularly true with loads that are "in the middle" of loads and designs.

FWIW...

Dennis

............This can get interesting.

But here are a few quotes from my 49th edition Lyman manual; page 56.

Quote........."Primer and firearm manufacturers have carefully worked out the nuances of primers and the reloader need not be concerned with specific differences so long as the correct size and type primer is used. The correct primer choice is listed in the data section for each specific cartridge."....Unquote

From page 57;

Quote....."The variations in primer sizes or types can create substantial variations in ballistic uniformity. For example: In one primer test, extreme velocity variation was an excellent 38 fps. With another brand primer, the extreme velocity variation was a poor 133 fps. Pressure comparisons for the same test loads showed spreads of as little as 3500 psi with the first primer and a very poor 9300 psi with the second primer.".....Unquote

Quote.......Nonetheless, it is not possible to state that one specific primer does a better job than another. A given primer might perform poorly with a specific load in one caliber, satisfactorily with a second load in another caliber and outstanding with a third load in still another caliber.".....Unquote

Quote........"The point is, that primer testing can be an important part of fine tuning any load.".......Unquote

For your 280AI or 338, you take whatever brand primer choices are listed, either L/R magnum or L/R non magnum for a specific charge weight and powder brand, chrony test for best ES uniformity and accuracy while looking for pressure signs when approaching maximum loadings.

Unless a specific cartridge "lists" and calls for the use of a L/R magnum primer across the board due to its larger case capacity, there is really nothing set in stone whereby you always have to use a L/R magnum primer.

Go by what primers "are listed",,,but also try different brands of primers to see what works best.

I start with Federal 215 Magnums for everything from .243 and up. Once I get the powder and bullet worked out I try different primers. Occasionally I end up with a non magnum primer because it gives better accuracy.

Accuracy is the final criteria.

have to agree with muledeer approach.if you live somewhere that gets really cold during hunting season you might want to check load performance of regular primers at lower temps.

Ed

I use magnum primers for cases that have belts. I use standard primers for everything else. I have tried switching to magnum primers in standard cases and never got any sort of enviable results so I stopped.
Some folks use magnums or standards for everything so as to simplify inventory but I've never had a problem with two boxes of primers on the shelf instead of one.

I've always equated the Magnum primers with the slower burning powders such as the 4350's 4831's etc. For everything else, I use standard primers
In my 375 H&H, for example, I use Remington 9 1/2's with RE15.

I've never found a need to use Mag primers , and I use ball powders in cold weather !

I'm still figuring out this whole primer thing (hadn't thought much about it before).

Seems to me like when in doubt (for standard cartridges) try the cooler primer first (Large Rifle) and see how it works. If all goes well, it will perform without increasing chamber pressures. If the accuracy suffers, go to a magnum primer to see what happens. If the rifle is getting inconsistent ignition, the accuracy difference between the two will show it, regardless of temps.

On another note, I've read that the Winchester WLR is the hottest LR primer you can get. Brian Pearce stated in an article about the .270 Win that Winchester used that primer for all standard cartridges, even in situations like a .270 Win with Winchester 780 ball powder.

I haven't tried WLRs yet, but that might be your ticket.

Years back,, a friend called, said accuracy in his Ruger 270 with RL22 was erratic,and velocity spreads were all over the map.I had not seen this at that point, but said, on a hunch,try a Fed 215.

We chronographed together and compared the old loads to the new. It worked....velocity variation moved way down and accuracy dramatically improved. To that point, I had not seen the benefit of a mag primer in a standard case,though always used them in magnum hulls.

Since then I use standard primers in the 270 with H4831,but if I move to RL22, 7828,H1000,RL25, etc, in the 270, I use a Fed215.Further research found that the oldtimers using WW II H4831 in the 270 years back also used CCI250 mag primers.

Slower powders,charges over 60 grains,I would use mag primers and Fed 215's would be first at bat in a 280AI with RL22 and anything slower.

Interesting responses, to be sure.

I seldom use a magnum primer in a "standard" case unless using a real slow burning powder. A prime example is my 25-06, when shooting 115 to 120 grain bullets with IMR 7828, I always use a Fed 215M. For lighter bullets with IMR 4831 I just use a Fed 210.

All my magnums get a magnum primer, to be sure. EXCEPT, I did a lot of fooling around with RL 19 in my 338 Win Mag and found it gave better extreme spreads and better groups with standard primers versus magnum primer. (Regardless of brand, CCI, Fed, Rem, you pick one.)

And I just do not worry about the well spread advice about using magnum primers with ball powders, because I just do not use ball powders any more, PERIOD.

I use magum primers for all my magnum rifles, I use winchester mag primers when using powders with same burning rate as H4831 or slower, I use CCI mag primers for all the rest of my magnum loads.

I always use mag primers in mag cases. Then I try tweek'n the powder charge a little or play with seating depth to fine tune in the mags. The charges have always been over 60 grains no matter the case or caliber of center fire magnums.

Standard case capacity caliber get all forms of primers thrown in them. Be the primer a standard rifle, standard rifle match, or mag rifle primers. Primer is the easiest item to 'switch' and see if performance increases or tanks. The charges have always been under 60 grains in my standard capacity rounds.

Seems I read somewhere the fed 215 mag rifle primer was engineered to insure ignition of 60 grains of supposedly hard to ignite ball powder in the .300 weatherby....

There will be neither an advantage nor a disadvantage in your rifles with using magnum primers instead of large rifle primers. You will have no difficulty igniting the powder column in either your 25-06 or your 243 with standard primers. You may witness a pressure increase using magnum primers. If you opt to use them, remember to work up to ensure that you have no serious problems with pressure. I wouldn't anticipate major problems, but you will likely witness a measurable increase in velocity which translates out to increased pressure.

Let your load be your guide. When going from standard to magnum primers I have found it beneficial to decrease the charge some as pressure signs peak when going straight to a magnum primer. Personally, I use them very little. About my only use of them is in .300 Wby, .375, and .416. Also, I won't consider using one until trying standard primers from CCI, Federal, and Winchester. If what we would call a "standard" caliber load won't shoot with one of those 3 primers then it is probably best to look for another load.

Good thread. Nice to hear everybody else's thoughts on the subject of primers.

Worked up a ramshot hunter 30/06 load onetime useing remington 9 1/2 large rifle primers. Velocity spread was 140 fps with 12" 500 yd groups. Switched to Remington 9 1/2 M for a 25 fps spread and 3 inch 500 yd groups. Primer was the only change made.

Shod

In the 06, 270, 25-06, or 6mm-284 I use CCI 250 with 4350, RL 22, and 4831, and I use the CCI 200 with 3031 or 4064.

In the 22-250, 22-243AI, 30-30, or the 260, I use the CCI 250 with 4831, Magnum, RL22, or Retumbo, and I use the CCI 200 with 3031, 4064, RL15, or 4895.

I use only the CCI 250 in the 264 Win, 7 Rem mag, and the 7mm STW.

I tried the CCI 250 in the 340 Wea, but determined the Fed 215 worked better.

I changeover to magnums when the load reaches 70 grains.

1.) Large case capacity (70 gr +)

2.) Ball Powders (BL-C2, H414, H380 etc.)

3.) Slow powders (H870, H4831 etc.)

4.) cold weather

Any combination of the above. If you are using standard LRP in a magnum case and getting 5 shot groups that have 3 close and the other touching an inch away, could be ignition problems and try magnum primers.