Magnum primers....results posted

Bigbubba

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So I am in the process of working up a load for a 308.

I have about 1500 CCI 250 magnum primers that I used to use in a 338 win mag which I do not have now.

So I am assuming I should be able to use these in a 308 load starting at the low end of the charts and slowly working up and looking for signs of pressure.

Any thoughts on this?

Thanks
 
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I worked on loads with mag primers for my 308, accuracy was better with regular primers. your rifle may be different. I would trade for regulars with someone looking for mag.
 
You are not going to explode your rifle.

Only way to find out how well they work is to try them.

A magnum primer from one manufacturer could be less intense than a regular from the next.

Only key is proper load work up.
 
I use magnum primers for everything, no matter what the book calls for.

Just work up you loads accordingly, like you would any time you change any component or purchase a new lot of components

Bench Rest rated primers tend to be hotter than the parameters for Standard primers. They're also more consistent from lot to lot. Consistence is a KEY ingredient to accuracy.

I have noticed some very significant differences between lots of the same brand of primers. Very significant differences between brands of primers as well.

I now stick to one brand of primers and they are all magnum primers, both large rifle, small rifle, large pistol and small pistol.

I find the consistency between the lots of same manufacturers is minimal for most purposes, other than match loads. Every manufacturer makes different grades of primers in North America.

My choice is CCI, mostly because they're the most available. I also buy flats of 5000 of every lot. I'm a bit anal about consistency.

Some folks cringe at the idea of using magnum primers for any reason. The choice is ultimately up to you.

I haven't had any rifle yet show a preference for Standard primers over Magnum primers.

I also find there is less temperature sensitivity under extreme cold conditions when using Magnum primers. Not my imagination at all. I've purposely loaded up 22-250, 243W, 223R, 308W, 6,5x55, 7x57, 30-06 and 338-06/338WM with the same powder charge but ten of each with Standard and Magnum primers, especially to shoot at -30C temps, to compare them to the same amount of rounds shot at +25C temps.

I used a Magnetospeed to measure velocities and all were tested from the bench, off rests on targets set at 100 yards.

The results were telling, in all but the 223R. Velocities were only slightly slower at -30C temps with MAGNUM PRIMERS. They were significantly lower and less accurate with STANDARD primers.

All of the rifles are personal rifles, chosen for accuracy. It's about the best I could do, without special equipment.

I have also tested a couple of these rifles with the same loads and primers at higher temps, 35C. I don't bother shooting when it gets hotter. The Magnum primers didn't produce much better velocities but I found accuracy was still more consistent.

OP, if you're going to get anal about accuracy, purchase specific BENCH REST PRIMERS, in the size you require. They are not quite as hot as Magnum primers, but they are definitely very consistent, accuracy wise and under temperature constraints.

Ganderite could likely go into a lot more detail than I've provided and the above results are my own, from my own Magnetospeed.

Remington primers are noted for being the hottest. Could be, but they're sometimes difficult to find and they're harder than most. Some people experience hangfires and misfires with them. They're usually fine in most off the shelf hunting rifles.
 
In a 308 cartridge if you are hunting it's fine and perhaps even advised to use magnum primers but not necessary . If it is for precision long range use regular primers as your sd and es will tend to be lower with them.Apparently IN a smaller cartridge the magnum primer tends to blow through the powder initially driving the bullet into the lands before the powder is ignited causing inconsistency. I don't know if this is true but I know even my 7mm saum is more accurate( consistent) with regular primers.It really becomes apparent at 1300 yards plus. In hunting season I use mag primers in many of my guns because of the colder temperatures.
 
Me Lawrd, I hear Mr. H. cussing...…………………………………...:sok2

Load five with magnums and five with your regular primers.
Set up two 100 yard targets and send'im down the range.

Post back your findings.
 
Me Lawrd, I hear Mr. H. cussing...…………………………………...:sok2

Load five with magnums and five with your regular primers.
Set up two 100 yard targets and send'im down the range.

Post back your findings.


Luke, I've run into a lot of hand loaders that are new to the process. Most of them, like most men, don't bother to get informed, read instructions, etc. We've all "bin there, done that."

Bruce was a good fellow and loved to shoot. He would have used H4831 in everything if he could have. His words, not mine.

Many hand loaders are terrified to do anything not listed in the manuals. IMHO, that is a good thing, simply because it keeps them within safe parameters.

Some people are so convinced that it all requires rocket science or some sort of magical alchemy, that they will only shoot factory loaded fodder. They are adamant that all hand loaders are playing Russian Roulette. Well, some are and they give the rest of us a bad name.

It's great when experienced and knowledgeable people chime in to help newbies out or even people that only load sparingly.

You and I, nowarningshot, Ganderite etc would feel deprived with only a pound of powder, one hundred bullets and one hundred primers. That's a good start to an afternoon of shooting for us.

Most hand loaders aren't at that level. They can't financially afford to be for one thing and there are constraints of time, available shooting areas etc.

Some are downright stingy and only load enough to "get them through the hunting season" without any sighters or practice rounds. Depends on how and where they hunt.

I used to wonder why the local gun shop carried the five and ten round boxes of Nitrex ammo. They do, because that's all many folks can afford.

I shake my head at how many people purchase part cans of powder, with four or five ounces in them at the gun shows. They go fast and are seldom at a good price. Same goes for partial boxes of bullets and primers. I often suggest that they mix those part cans of powder with any of the same type they have at home. You would think I was a Vampire, when they pull out their silver crosses and retreat in fear.

They just don't know what's safe and what isn't, other than what some mentor has told them, or they've read in a manual or online.

Bruce was bound and determined that using Magnum primers was strictly verboten, dangerous and horror of horrors OVER PRIMING. He was a pretty astute fellow though and a few years before he passed, we went on a couple of shooting sessions to the Salmon Arm range and the Lumby range. He deigned to try some of my hand loads in his 308Win. They shot a bit high for his sight settings but the group was much tighter than his hand loads were shooting. The powder charge in his loads was very close that in mine and the powder was the same. The only difference was he used Standard primers and I used CCI 250 Magnum primers.

He saw the light. As I said, he was very astute. Ganderite made a few comments here about the subject as well and that convinced him that he wasn't going to be injured or harm his rifle. Bruce still had thousands of Standard primers on hand, which he fully intended to use up and likely gave it a pretty good try before passing. I didn't see or hear much from him for the last six months or so. Usually we talked or emailed at least once per week. I miss those chats as well. I know you two spoke a lot and he spoke well of you.

Anyway, you CAN'T OVER PRIME, as long as you use proper hand loading techniques. With medium to large cases it's almost impossible. With small cases and fast powders, there might be some issues.

Just use some common sense and all will be well.
 
Thanks for all the input.

The ONLY reason I was planning to use them is because I HAVE them....and they need to get used.
I also used to use them in my .270 with 140 gr Hornady BTSP bullets and Win785 (? IIRC) powder?

Anyway, I shall use them up this year I hope....
 
as someone noted, magnums can vary greatly by brand. saw some flash photos which demonstrated this, as was noted, some mags can be someone elses lr.
 
Thanks for all the input.

The ONLY reason I was planning to use them is because I HAVE them....and they need to get used.
I also used to use them in my .270 with 140 gr Hornady BTSP bullets and Win785 (? IIRC) powder?

Anyway, I shall use them up this year I hope....

785 is a ball powder, right?

If so, a magnum primer is an excellent choice for it. Probably the best choice.

I have had ball powder loads fail to ignite until I switched to a hotter primer.

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in my .308 win.and .303 brit. with win.748 powder i had to use magnum primers .with standard primers i had a lot of misfire.
 
Using the Mag primers is a non-issue as long as you follow the safe procedures: as always start low and work up.
Ultimately your rifle & accuracy will tell you if it's working out or not.
 
The brisance of primers varies from brand to brand, and within a brand we expect that the brisance of their magnum primer will be more than the brisance of non magnum one. And that has been pointed out already.

However, there hasn't been any mention of testing to see if the primer is the ideal match for the load. Simply stated, unless you chronograph your loads, you will not know. Any ignition issues will show up on the chrono. I'm no ballistics expert, but I've used a chronograph to select the optimum primer for my 38/357 and other pistol ammunition. In pistols a change in primers can give you a big change in velocity, and obviously pressure.

Chrono testing is a bit of a chore, and is time consuming, but it is a very good tool.

Here's an interesting test: http://www.targetshooter.co.uk/?p=1471

Once you determine if it is safe to do so, let us know how your chrono testing went.
 
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