Welcome to the wonderful world of reloading! I'm by no means an expert, but you won't blow anything up using a mag primer with a powder charge that is within the acceptable limits for your particular cartridge. You might get a little higher pressure because of the increase in the flame size from the mag primer, but at most you'll probably see some flattened primers or other signs of pressure. I've been known to use mag primers in my 7mm-08 and haven't seen any issues to speak of. In my larger capacity non-mag cartridges, like 9.3x62mm Mauser, I use magnum primers exclusively. Lots of powder to burn in the bigger cases. Either way, be safe, stay within the maximum load data for a powder/bullet combination, and you'll be fine. You may find (as you suggest), that your rifle prefers the specific combination that uses a magnum primer. Best of luck.

Deck

 

You don't need a magnum primer for Varget in the .22-250. A standard primer will work fine.

You can choose to use magnum primers in the 7mm Mag. Just work up your loads with them and there won't be any problems. Assuming you'll use something besides Varget for the 7 mag loads, it's a bit fast for that.

I have personally found that standard Winchester large rifle primers are adequate for use in several magnum cartridges of about that capacity, so I don't fool with magnum primers much. However some folks may find them helpful. In any case, I repeat the warning to work up your loads with them, and don't randomly substitute one for the other.

Good luck.

 

Welcome to one of the better shooting sites on the internet.

Magnum primers can be used when working up a load. Any time you change a component reduce your load and start back up in charge weights of powder. There is an almost zero chance of ending up in trouble doing that.

Using magnum primers is mostly when loading hard to light spherical powders (like H-380) or large cases full of any powder. A large rifle primer will work fine in your 22-250 with Varget. Just for what it's worth I use a large rifle primer (not magnum) in a H-380 load for my 22-250.

 

Thanks for the info. I do not even have the dies yet for the 7mm so I have no idea what powder I will use. I did a quick check when buying powder and saw that it had load builds for all the guns I have. I also have a 270 and I guess I was thinking that maybe I could use the same powder in all my guns.

The 7mm is for deer and usually inside of 150 which would be the longest shot so ultimate accuracy is not really paramount in that gun. Not that I would just sling a bullet at a deer and hope it hits something good but I do not think I need bullet holes touching accuracy for deer.

 

Looks to me you are going to need at least two different powders. The 7RM and .270 Win. have a lot of common powders but the 22-250 uses considerably faster powders.

 

I'd probably try H-4831 for the .270 and 7 RM.

 

Raptor5618,

I recommend you read this article on primers. It will make some things more clear.

 

That's a good article Nick, Thx!

I do have a question. I have loaded a lot of .30-06 rounds over the years with Win Magnum LR Primers. The powders used were mostly H414, IMR4350 and H4350 and some IMR 4064. Almost all the bullets have been 165s and 168s. Accuracy off a bench in three separate guns has ranged from 5/8" to 1.5" at 100 yards (so plenty good for hunting). My reasoning for the magnum primers is to maximize ignition in cold hunting conditions. Would I have been better off with simple LR primers? Are their any disadvantages to using the WMLR for these loads?

Full disclosure, I have also used CCI and Fed Match LR primers (to a lessor extent) as well, with no obvious change in accuracy.

 

That's a good article Nick, Thx!

+1. Thanks for posting.

 

Welcome Raptor. I have used both Varget and CCI250M (magnum) primers in my 22-250 loads, with varying success. It is true that you can notice a velocity and accuracy difference with magnum primers, but it's a variable that will take alot of reloads to bear out. Your two best bets and firsts for developing loads in your rifle will be powder and bullets. If Varget doesn;t work well on one 40gr bullet, for example, it may work fine on a different brand and type.

My best loads in my rifle, with varying makes and weights of bullets, come from IMR4064, IMR4007SSC, H380, and IMR4895, all with standard CCI200 and Winchester primers. The CCI magnum primers have yielded some good results with Berger 60gr Varmints and IMR4064. To say it again, the warning is to begin at starting loads and work back up when going from standard to magnum primers.

As long as you have plenty of standard primers on-hand, you shouldn;t have need for magnums, unless it's just to experiment. Good luck!

 

thanks

Thanks for all the good comments and suggestions. Amazing how much information I have gotten in only one day on this site. I will take a look at that article tomorrow. I will save those magnum primers for my other guns. For now I think the less variables the better. Being new to this I am not particularly very quick as I check list as I go through each step to insure I do not forget something. I also use two scales to make sure I have the charge just right. the beam scale got bumped a few times where it was not reacting properly but it became clear when I put the charge on the electronic scale. Not to mention the shell that I dropped and one that I dumped some powder out.

 

When I throw a charge, I weigh it first on the electronic scale. I have a couple of them, but the one I use most is a little $40 Hornady scale. It serves only as an initial first check - these things are too fickle to be trusted. If the charge is off, it goes back to the Lee scale where it gets trickled up to the correct weight.

I trust the beam scale and it serves as my final check whenever there's a discrepancy.

These will help if you reload in stages:

 

I have the same electronic scale. I do it the other way, I trickle up to the full charge on the balance scale and then check on the electric. The balance scale sometimes seems to hang up so I end up sort of starting all over. But I go back and forth until both agree. I probably check more than I need to but I think the more practice I get at making sure the load is exact the sooner I will have it down. I have some blocks and plan on making some out of wood that I have.

 

Bird Dog II,

The military runs magnum priming for better low temperature ignition, I am told, but if you Look at Denton Bramwell's test freezing primers, it doesn't actually appear to be necessary. Your best bet will be to develop the load to the same velocity with each kind of primer (if you get a different velocity at all), then run them side-by-side in cold weather and see how they shoot. Your chronograph won't likely work below the freezing point, but look for group sizes being different and run some at 300 yards or more, if you can. I would alternating from one kind to the other on two targets and see if the group sizes differ or the average POI centers differently.

 

Raptor,

Many folks have gotten into reloading, thinking they'd save some money on the ammo they shoot, only to find that they just shoot a whole lot more, they just spend a bit less for each load! Fortunately, you also get the joy of a wonderful hobby and the invaluable experience of sending more shots downrange. In business acumen, that is a clear "win-win"!

As far as magnum primers and their use is concerned, I read a book by Wayne Van Zwoll many years ago where he performed a series of test on various loads. The only conclusion he was able to reach is that you just can't predict what a given type of primer will do until you shoot the dern things. He found loads that gave lower velocity readings with magnum primers than they did with standard and in some situations, he had better standard deviation, in very cold conditions, from standard primers, versus magnum. No rhyme or reason to it.

With that said, I have a personal conviction that if you are using a powder that is very slow for the application at hand, especially if you have a lot of powder in a tall column, the load books seem to call for a magnum primer. Good examples would be under the slowest pistol powders, like H110 and large doses of 4831 in a 7RM. I'm sure the even bigger RUM cases also benefit from such.

Yours truly loaded 100 rounds of 30 Carbine one time with small pistol primers, instead of the small rifle primers that are universally called for in such loads. Since I tend to stick with middling charges in just about any semi-auto rifle, I felt courageous enough to test fire a few of those cases. I sorta expected misfires or poor cycling of the action. At the very least I figured there would be some blow-back of gases from the case not sealing well. Only thing is, none of that happened. I pulled the trigger and 10 out of 10 went bang. I checked the first 5 for signs of a problem and there just wasn't one. Every single cartridge I loaded with the wrong primer fired just fine. I don't tell this story to encourage anyone to ignore the load recipes in their manuals, but to illustrate that you just don't know until you shoot 'em.

Bottom line: Don't make reloading decisions based on what some guy read or wrote in an online forum or article. Don't take MY word for any of the above. Trust the ballisticians who write reloading books and the websites for reloading/bullet companies.

 

I have decided that I will save those primers for where it is indicated. There are enough variables as it is without tossing that into the ring. I bought those primers before I had even purchased a single piece of equipment. Kind of like starting out my commitment to reload. The discussion was about a load that was not working out as they had hoped and there was at least one post where they had gotten better performance by switching to magnum primers. I saw them in the store and picked them up, a box of 50 is not all that much but I felt like I finally started. Since that day I have not come across that post again nor any discussion about improving the accuracy of a 22-250 by using magnum primers.

Maybe I will out of curiosity load a few lower load bullets with magnums and see if there is a difference but I think my time would be better spent with match grade primers. Again, I have no plans on going that route either.

My friend who is really into reloading and has been for a long time said about the same thing. Said it is not really cheaper because you are going to shoot a whole lot more. I have a background in accounting and based upon the cost of all the equipment I already bought, plan to buy do not even realize I will buy at this point it will take an awful lot of bullets to get to break-even against factory loads. Maybe I will do that calculation just for kicks. And based on how often I shot factory loads well I would never hit that point because at this time of year I would never fire my gun and now I cannot wait to get to the range.