Magnum Primers vs. Standard Primers

[muzzleblast525]

Loading for my 270 WSM, and had been shooting standard primers, getting okay groups, and have since gotten some magnum primers, and still geting okay groups.  Does it really matter?

[Lawdog]

muzzleblast525,

You'll get two schools of thought on this.  One is going to say it doesn't matter and the other will say it does.  I belong to the latter group.  It all depends on how large the powder charge is and what type of powder.  In my .27 WSM I am using magnum primers.  In fact in most all of my "magnum" cartridges I use the magnum primers even in my WSSM's because of the width of the powder column.  I want the hottest flash I can get to make sure of complete ignition.  So far it has proved out with closer more consistent groups.  Lawdog
 

[Lone Star]

MB525, I believe that you should use listed data as published, not make up your own rules, particularly on new cartridges like the .270 WSM.  Nosler #5 uses only magnum primers in their data, so does Hornady and Hodgdon.  If you use their published data, then you should use their primer type.

Just because you get "good groups" doesn't mean you're getting good performance.  You may be getting a wide velocity variation which will effect long range groups, and how the bullet performs.  Or, your muzzle velocity may be lower than you think it is.  All are reasons for using the primer types specified in the published data, but the greatest reason is safety - a hangfire caused by poor ignition in cold temperatures (while hunting for instance) could be bad news.   :cry:

.

[Redhawk1]

I always use the recommended primer from the reloading manuals.

[Chief Beel]

Just thought I would drop my thoughts in on this. My standard is to use standard primers on 22-250 up through say....the 7mm-08 Remimgton. All cartridges that I load with more that 50 grains of powder, particularly extruded powder, that are likely to be shot in weather below 40 degrees will always get magnum rifle primers. I experimented with this years back (probably 7 years) with a 270 winchester cartridge using a Weatherby Ultra lightweight and a Winchester M70 Classic, of course with 270 Winchester handloads. Both had cases fired once from Winchester. Both used equal charges of H4831 and H4350 for 130 gr Hornady SST in 130/140/150 grain.  The Winchester shot the first salvo with standard primers and the Wby with magnum primers. Both groups shot well and we had loaded six rounds each for each bullet so we swapped the bullets because the OAL was close enough to get a good test for accuracy. THe WBY shot first with the standard primers and then the Winchester shot with the Magnums. The grouping were almost identical with the exception that the magnum primed loads seemed to have the first two shots touching in a clover patter for both guns and the third was usually a flyer of about a half an inch and maybe up to 3/4 an inch. If there was any discernable pattern it would be that the older Winchester Model 70 really liked the magnum primers and it's groups shrank noticibly with all 3 bulletts and both powders. The Weatherby is finiky to this day but I continue to feed it 140gr SST, Winchester LRMP, Winchester Brass, and a measured dose of 59 grains of Hodgdon 4831, and she does what she's suppossed to do.

[shot1]

Which mag primers are you using? No two makes of primers have the same mix in them and one will be hotter than the other. The hottest mag primers are Federal. I have been hand loading for over 30 years and I can tell you that primers DO MAKE A DIFFERENCE. Any time you change a component in a load you need to back off on the powder and work back up.To really find out what is going on with a load you need to shoot it over a chrno. I am what you could call an accuracy nut. I try to get the best out of any firearm that I have. Here is what I do. From experience and research I use one of the best powders for the caliber. If it is on a 30-06 case or smaller I start out with a standard primer for stick powder and a mag primer with any ball powder. If it is a mag case I use a mag primer. I choose the bullet I want to use and I start low and work up the best accuracy with good velocity load I can. Then I back off the powder and switch to different make primers and work back up to see if the accuracy can be improved on. I sometimes end up with mag primers with stick powder in 30-06 and under size cases. My most accurate 25-06 load that I have used for years is 49 grs IMR 4350, CCI 250 mag primer, Rem case, 117 Sierra Pro Hunter and it does 3000 fps and I have killed well over 100 deer with this rifle from point blank to over 500 yards and I have never had to shoot one twice.   

[wncchester]

"...been shooting standard primers, getting okay groups, and have since gotten some magnum primers, and still geting okay groups.  Does it really matter?"

Not in your rig with that load.  ??

[carbineman]

For hunting rifle loads all I use are magnum primers. I usually hunt in cold weather so I'm set for anything that comes up.

Sometime back I read where a company did a test on all the LR American made primers and was ready to report on the findings and decided before they did they purchased more primers to test. They ended up scraping the test simply because with the new lot numbers of primers the rankings changed and with the second batch of primers including all the magnums, the CCI 200 standard primer was the hottest in the second test. The point is all the components of a different lot number are different.

I have purchased many years of Remington 9 1/2M primers and mainly use them for all my hunting loads, even with the little bit of extruded powder I have.

[Drilling Man]

  I ALWAYS go by the published loads in the loading manual from the bullet maker, of the bullet i'm using.  Doing so, i've NEVER had a problem in cold weather, and i've stayed in and hunted in below zero weather many times.

  Making up your own reloading rules, is a poor practise to get into.

  DM

[carbineman]

  I ALWAYS go by the published loads in the loading manual from the bullet maker, of the bullet i'm using.  Doing so, i've NEVER had a problem in cold weather, and i've stayed in and hunted in below zero weather many times.

  Making up your own reloading rules, is a poor practise to get into.

  DM

To each his own, but I've already ran into a pressure signs with one of "my rifles" with the starting load in a manual with the listed components. I ran into this with a .308 loading in the Barnes manual and BL-C2 propellant.  I've also noticed that some starting loads in the older manuals are above the highest charge weight in newer manuals. In a 7mmSTW rifle we stuck the bolt fairly tight with the starting load with H870 propellant. Again to each his own, but I don't make a practise of using the words ALWAYS and NEVER when it comes to reloading. I use a chronograph, a caliper, and a micrometer to do my testing. Wish I owned pressure testing equipment but I don't so I'll rely on what is safe for "my rifles" and you can ALWAYS follow the book and NEVER run into a problem AS OF YET!!

[Grumulkin]

I rarely use the primer recommended in reloading manuals since hardly any recommend the match primers I use.  I also routinely try different primers in the various loads I work up.  Sometimes there is a significant accuracy advantage with magnum primers in the smaller cartridges (357 Herrett for instance) and most of the time it makes little difference.  For larger cartridges like the 300 Weatherby on up, I always use magnum primers but I use regular Federal 210M cartridges for my 7mm Remington Magnum RL-22 load.

As far as "always" goes, if possible, I always compare data from 2 or 3 or even more sources to come up with a common sense starting load.  To date, I've never shot a starting load that gave me excess pressure except in one case where the starting powder charge I used was actually a little too low.

By the way, in my opinion, the loads in the older Barnes manual were pretty hot.

[Drilling Man]

I rarely use the primer recommended in reloading manuals since hardly any recommend the match primers I use.  I also routinely try different primers in the various loads I work up.  Sometimes there is a significant accuracy advantage with magnum primers in the smaller cartridges (357 Herrett for instance) and most of the time it makes little difference.  For larger cartridges like the 300 Weatherby on up, I always use magnum primers but I use regular Federal 210M cartridges for my 7mm Remington Magnum RL-22 load.

As far as "always" goes, if possible, I always compare data from 2 or 3 or even more sources to come up with a common sense starting load.  To date, I've never shot a starting load that gave me excess pressure except in one case where the starting powder charge I used was actually a little too low.

By the way, in my opinion, the loads in the older Barnes manual were pretty hot.

  I always compare loads between manuals too, and i've been loading for long enough (40+ years) to recognize a load that doesn't sound right.  I've also noticed the older Barns manuals were on the HOT side.

  DM

[carbineman]

I rarely use the primer recommended in reloading manuals since hardly any recommend the match primers I use.  I also routinely try different primers in the various loads I work up.  Sometimes there is a significant accuracy advantage with magnum primers in the smaller cartridges (357 Herrett for instance) and most of the time it makes little difference.  For larger cartridges like the 300 Weatherby on up, I always use magnum primers but I use regular Federal 210M cartridges for my 7mm Remington Magnum RL-22 load.

As far as "always" goes, if possible, I always compare data from 2 or 3 or even more sources to come up with a common sense starting load.  To date, I've never shot a starting load that gave me excess pressure except in one case where the starting powder charge I used was actually a little too low.

By the way, in my opinion, the loads in the older Barnes manual were pretty hot.

  I always compare loads between manuals too, and i've been loading for long enough (40+ years) to recognize a load that doesn't sound right.  I've also noticed the older Barns manuals were on the HOT side.

  DM

Being that I've only reloaded for 33 years, my youthful exuberance has probably shown during this thread, and I'll just add this to the OP's question of whether magnum primers matter in his 270 WSM vs. standard primers. I'd say if you are checking for pressure signs along your progression of loading increments you should be alright. Can things go wrong? Sure they can, but things can go wrong while following the book as well. Each one of your rifles is a separate entity that you must figure out. No two chambers are exactly alike, no two lots of powder, primers, or bullets or brass cases for that matter are alike. I had some 30-30 cases headstamped WW Super that were 13 grains different in weight than those headstamped Winchester. So by checking for pressure signs along the way, you should be alright. Be Safe and Good Shooting!

[charles p]

I think I'd stick with magnum primers when loads contain that much powder.

I do not use magnum with ball powder in 308 and 7mm-08. 

[I make oil]

I was at a local shop recently and wanted to buy primers to load for my 7-30 Waters.  The owner only had Magnum primers.  I told him I wanted standard and he insisted that it didn't matter.  I am not as experienced as many of you guy's and thought to myself, "The manual (Layman) called for standard primers I am going to use standard primers!"  There are no other local shops that carry reloading supplies so I had to pay a DOT charge to order then online.  Could I have used the Magnum primers?   

[carbineman]

I was at a local shop recently and wanted to buy primers to load for my 7-30 Waters.  The owner only had Magnum primers.  I told him I wanted standard and he insisted that it didn't matter.  I am not as experienced as many of you guy's and thought to myself, "The manual (Layman) called for standard primers I am going to use standard primers!"  There are no other local shops that carry reloading supplies so I had to pay a DOT charge to order then online.  Could I have used the Magnum primers?   

You got what you wanted, so everything worked out for you regardless of what a bunch of old guys say here on a forum. When you introduce a "different" component into your already established load one usually drops the propellant charge amount and works up again. The haz mat fee you paid kept you humming along without having to work up a new load. Sometimes though a different lot number of the same component can produce different results. If you are not at the "top" of the powder charge density in the book you got your load out of, it shouldn't matter. If everything worked out correctly, as my dad would say, you done good.

[gypsyman]

In a Sierra manual they mentioned that it was fine to use mag. primers in place of standard, just start the loading process out at the bottom of the powder charge, and work your way up as usual.
I've heard more story's about trouble using std. primers with hard to ignite powders or large capacity cases. Seems the primer will get the powder started, but because it's not a complete ignition, the burn will spike, creating more pressure than if a mag. primer was used. gypsyman