I've noticed in past posts that some use Large rifle primers instead of magnum primers in their reloads of "magnum" calibers, for increased accuracy. The one that comes to mind most is using RL22 with both magnum and large rifle primers for the same caliber reloads. It seems to me that the use of "magnum" primers can't be related to a "magnum" caliber, but the powder.

So my questions are: What purpose do "magnum" primers serve, and when does one have to use them? Also, are there some powders which inherently don't require "magnum" primers?

I'm planning some reloading projects for my 7mmag and 35 whelan both involving RL22, and get puzzled when the "magnum"recipe calls for magnum primers, and the whelan's for large rifle primers!

Interesting observation......and you may be right.....

FWIW I am not totally sure there is ANY DIFFERENCE AT ALL in standard and magnum primers!!!!!

I have noticed a difference in only one situation. With a long case, like a .375 H&H, and using a medium/slow double base powder rather than a single base powder, I get much more consistant velocities with the magnum primer. I don't measure the velocity of every round I shoot at the range but I haven't noticed any problem at all with standard primers using single base powders in a shorter case like a .300 WinMag. I have never hunted with a large bore in sub-zero weather but if I were to use my 416 Rigby on polar bear with slow powders I would use magnum primers, just to be sure.

In the 7mag, I haven't noticed any difference between the magnums and lrp's. That's using alot of R22 and some very cold temps well below 0 degrees. These are CCI that I've been using and I'd assume that other primer types may act differently.

The magnum primer is supposed to be "hotter" and is thought to be needed to ignite large amounts of powder, especially ball powder. Some of the reload books reccomend using magnum primers with all ball powder loads. Again, they are thought to be an assist when hunting in extremely cold weather.
I try not to angst about it too much and just use Magnum primers in all belted cases and let it go at that.

Yup, it can get a bit confusing. Speer and some others recommend the use of Mag primers when using "Ball powders", they are supposed to be harder to ignite than the extuder powders. Some use mag primers when loading for a large cases that hold lots of powder.


I have never seen any load data on the 35 Whelen using R22. Seems a bit to slow for the Whelen. What manual did you find data for the 35 Whelan and R22?

when using large amounts of powder and certain types of power, use a magnum prime as your reloading manual lists. Some spherical (ball) powers are harder to start burning because of the coating used on the powders. A discontinued powder H450 i used in a 22-250 with cci mag primes would sometimes start the powder burning and then stop. When the bullets were pulled i could see how the powder started to burn ,but then just quit. Some times the metal cup of the primer is thicker for higher pressure rounds. I remember loading the wrong primer in 223. Federal at the time made 3 small rifle primes. Standard, mag, and one for rounds like the 22 hormet if i remember correctly. When the wrong primer was fired, the cup would blow out of some primers cutting a small hole into the bolt face. Always best to follow the reloading manual. I feel mag primers in all calibers work well, just when switching for std to mag. work up a new load as a mag primer can make more pressure.

Based on chronograph results, some std. primers are "hotter" than mag primers. I pretty much only use the mag primer for cases holding ,ore than 70gr of powder. Everythiung else starts out w/ a std. primer then I may try a good load w/ a mag primer to see if it shoots any better (usually not).

There is more poop to mag primers and usually with better buring of powder and accuracy in your firearm. I always use mag primes even in standard loads.Its said to start out a load using 10% less powder to start because the additiion power of the mag primes.

To add to obfuscationconfundiumdonknowupsetium...

One 30-30 load (W748, I think) called for a mag primer. If I'm not mistaken, that's a ball poweder too?

Rhyme? Reason? What fun would that be?

friar

One real difference is in my .358 404 IMP which can hold as much as 100gr. of 4350. With a number of powders( not 4350) I have corrected hang fires, Click bangs1by going from WLR to WLRM.

Changing to CCI MAG. primers did not cure the problem.Although this situation was more prevelant with ball powders, it did occure with Accurate 4064 and IMR 7383. roger

quote:

Originally posted by bartsche:
One real difference is in my .358 404 IMP which can hold as much as 100gr. of 4350. With a number of powders( not 4350) I have corrected hang fires, Click bangs1by going from WLR to WLRM.

Changing to CCI MAG. primers did not cure the problem.Although this situation was more prevelant with ball powders, it did occure with Accurate 4064 and IMR 7383. roger

Roger...IIRC Saeed said he seeded a few grains of bullseye in the bottom of the (large) case and over the primer and solved the problem of hangfires as well. In essence a bit of a duplex load.

I have tried both large rifle and large magnum rifle primers in 357 Herrett, 308 Win., 30/06, .22-250 and .44 Magnum. In only one of these was there a clear difference in accuracy and that was in the case of the 357 Herrett with IMR 4227 which clearly preferred magnum primers.

quote:

Originally posted by vapodog:
Roger...IIRC Saeed said he seeded a few grains of bullseye in the bottom of the (large) case and over the primer and solved the problem of hangfires as well. In essence a bit of a duplex load.

I think this will work but I've always been a little reluctant as to where the fast powder might possision itself. I have also had some bad happenings with duplex loads. When the powder capacity really gets high we should have a different primer. The 50 cal Bmg does. roger

243, some time ago, Federal had some bad primers. The mix was wrong and they had a recall on them. Gas would escape around the primers and cut a circle on the bolt face.
It was something about the mix eating the primer cup if I remember.
It has been long corrected.

I am writing from memory, which at my age is risky, but Alliant recommends AGAINST magnum primers with its powders.

Magnum primers are often recommended, as mentioned above, with large cases and slow, ball powders.

In many applications I have found that magnum primers "blow" the group on what was a accurate load with standard primers.

I generally don't experiment with primers until the last thing, going with FC or Win Large Rifle primers to start out with. Kudude

I used some mag primers on a r22 load and got major over pressure blown primer and heavy extractor slot imprint on case head, Screw that!

I dont try different primers either, to improve groups. just winchester standard primers is all I have been useing.

quote:

Originally posted by bfrshooter:
243, some time ago, Federal had some bad primers. The mix was wrong and they had a recall on them. Gas would escape around the primers and cut a circle on the bolt face.
It was something about the mix eating the primer cup if I remember.
It has been long corrected.

I had bad cups in rem. primers before. The hole would appear on the edge of the prime, not near the hit of the firing pin and not gas leakage between primer and case. At one time federal made 3 small rifle primes, one for 22 hornet types. I loaded the wrong primer in 223 ammo.

There is definitely a difference in the ignition between the two.

I have worked up loads w/ Magnum primers and switched to stds just for kicks. The groups usually open up. Now, I'm sure more load developement would get the groups tuned again in some instances but, why bother, they cost the same price.

If it says Magnum on the case head, use a magnum primer, it certainly will not hurt anything. If you think a mag primer will cause your loads to be over pressured, you have too much powder to start w/ .

Many sources also recommend a magnum w/ ball powder even in the std carts.

Good Luck

Reloader

Just a thought on why large primers might give higher velocity in some loads. In a cartridge that benifits from a slow burning power could using a hotter primer ignit more power and you end up burning the powder faster?

I've also read that in light weight bullets and small calibers the magnum primers can start the bullet moving before the powder ignits. Not sure if that is true or how to test it.

Some of you may not like what I have to say but it needs to be said.

For all you CCI guys, wake up Rem, Win, and Fed. our head and shoulders better.

I only use CCI for pistol and plinker loads.

I read some of your posts I know you have limited reloading time when you say there is no differance between Mag vs Std. and that mag primers don't improve accuracy that is not always the case but they do in some Cal. with some powders I have seen huge improvements by switching to mag primers.

I have found that regular primers work very well in the loads I have worked up for my .300 Winny.
I just worked up a load that prints five shots under a inch at 100 yards with 83.1 grains of H4831sc and 125 Nosler BT's. I plan to try the load with mag, reg and BR primers next. I was suprized to get 125's to shoot this well and the max load shot the best.
This same rifle will shoot under an inch at 200 yards with 180 grain BT's.

One of the things I've found is that Winchester's WLR primers are hotter than some other companies' mag primers (CCI definitely). The Win Mag primer, WLRM, if not definitely needed for ignition will blow the groups. A recent test of new primers showed the WLRM beat the Federal Mag Primer for brisance; the first time this has happened. I've been a user of mag primers for years in "all cases with magnum on the base." Found out I don't need it in about half the loads. Of course, my standard primer is the Win WLR. Just my 3,000 Zimbabwe Dollars worth (US 2 cents).

I have always used CCI primers. Not sure why they are just what I used. I started useing Federal small rifle primers for my AR15 loads because a store I deal with had several thousand of them for $15 a thousand and I am cheap. I am on my last 100 and will probably go back to CCI for them also. I just never felt the need to try different brands of primers.

My cousin and I use a lot of WLRMs. In fact he uses nothing but them. I guess he has just been fortunate having seemingly not sufferd in the accuracy department.

Two of his rifles a 34 year old Ruger .257 varmint and a new 22-250 Ruger varmint will shoot 10 shots at 100 yds you could cover with a nickle and some times a dime. He also does well with a 36 yr.old .270 Ruger hunting weight that shoots better than MOA.

Just for my knowledge , can anyone quantify the accuracy degradation they have experienced going from WLRs to WLRMs? roger

I have been reloading since 1973. Started with .308 Win and went to .300 Winny. Over the years since then I have loaded dozens of chamberings, used all available powders and primers. My thing is super accuracy with Standard and Magnum rifles for hunts at home for Deer,Colorado for Deer and Elk, Alaska for Caribou-Brown Bear-Wolfe, Alberta for Wolfe, Africa only one trip for Buffalo and plains game. Many thousands of rounds fired until ten years ago when I started shooting regularly three days a week and 3000 plus rounds per year testing my rifles and loads and many others for buddies. After confusing myself for years about primers and trying to decide on the best one for the chambering be it Standard or Magnum I could count on the Federal primers be most accurate. I now use all Federal Match primers, and yes I have heard the arguments for the nonmatch and the extra expense, but I don't mind the extra couple of bucks per 1000 to shoot the Match primers, so you fellows shoot what you want and so will I. ----- I start out shooting what the test rifles shot in the Manuals give, whether it is Magnum or Non Magnum and go from there. Normaly anything above 70 grains of powder get Magnum primers. One exception is my .300 Winny which shoots one hole groups with the 210M primer, when I go to the 215M my group goes to 1-2 inchs. Well that is what I do for primers, for what it is worth. I will say the only hang fire I ever had was when I failed to put powder in the case, and this after possibly 50 thousand rounds loaded and fired. Good shooting.

quote:

Originally posted by Westernmassman:

I'm planning some reloading projects for my 7mmag and 35 whelan both involving RL22, and get puzzled when the "magnum"recipe calls for magnum primers, and the whelan's for large rifle primers!

I've been using Federal Match primers in a 7mm magnum for quite awhile, have not noticed any problems with ignition or group sizes. Powders are the usual stuff, HS4831 and IMR 7828, somehow didn't like the feel of recoil using RL22 and laid that aside.

Am I full of beans, setting myself up for problems in cold weather? Things seem to be okay, working at least down to 10 degrees F.

I ran a test using 338.06 and a full case of W760.The three primers I have CCI200,CCI250,and WLR.The most consistant velocity(ignition) was the WLR,the magnum primers made no difference in velocity.The next batch lot # could change,because the last batch of WLR I had was threw one outragous flyer out of every ten shots. What I am trying to say,I think this is a batch to batch thing.

quote:

What I am trying to say,I think this is a batch to batch thing.

And me thinks that is part of it. roger

Working in a test tunnel, I've seen the differences in primer brisance, lot numbers (batch), and brands. Some powders and grain quantities need, no, demand magnum primers. Yes I do try different primers, but they are usually the last thing I change. Have found that seating depth makes a bigger change... except for flyers.

Rule of thumb. Use magnum primers when burning over 65 grains of powder no matter what the powder is. If you use magnum primers in place of large rifle it will increase chamber presures.