Large Rilfe primers instead of large rifle magnum primers

gonzo63

New member
Rating - 0%
0   0   0
Hello everybody. I just got into reloading and have almost everything I need to start. My Lyman Reloading manual says to use large rifle primers for my win mag 300 but it calls for large rifle magnum primers for my 7mm Rem Mag. Problem is I have a thousand CCI large rifle primers and a 1000 CCI Large rifle BR2 primers. Had a hell of a time finding them and I can't find Large rifle Magnum primers ANYWHERE. My question is if I can use LR primers for my 300 win mag why the hell can't I use LR primers for my 7mm Rem Mag? Any help would be greatly appreciated.
 
for the most part you can interchange the primers .
the hotter primers help get large cases of powder up and burning . some say the mag rifle primers may also be made out of harder material , which may affect how a person reads pressure signs .

when you change a component , treat it as a all new round being built , and watch for signs of pressure and other anomalies
 
They also recommend magnum primers for spherical powders don't they, as those can be harder to ignite than stick powders?

OP do you have a chrono? That would allow you to monitor for extreme spread in your velocity to ensure you're getting consistent enough ignition.
 
OP - as mentioned above - usually the primer called for is related to the powder charge - what type of powder, how much of it and what temp will you be in when you want to fire it? Does not mean the other kind won't go "bang", but typically one works "better" than the other. At least until recently, ball type powders usually required magnum primers, regardless of which cartridge they were used in. Larger quantities of powder in a case usually benefit with more constant ignition with magnum primers. And magnum primer at least used to be found more useful when hunting in cold weather - like minus 20 C and colder. Some people develop loads using magnum primers for any kind of powder, for most any cartridge and use them in most any temperature - any loading that you developed with standard primers - you will need to back off several grains before substituting magnum primers - the extra "force" can be like adding several grains powder to the load - that might be a good thing or not a good thing for your purposes. But, I am sure that I have never read to always use magnum primers in this cartridge and never use magnum primers in that cartridge - I do not think it works that way ...

Just looking in the Hornady 9th Edition loading manual - all the loadings listed for 7mm Rem Mag and for 300 Win Mag call for Winchester WLRM primers - a magnum Large Rifle primer , in both cartridges, the cases are Hornady/Frontier cases. And the Lyman 50th Manual calls out as you report in your first Post above - but more specifically , not any "magnum" primer for 7mm Rem Mag - they called for Remington 9 1/2M primer, in Remington cases. For the 300 Win Mag, not just any standard Large Rifle primer - they used Winchester WLR - Winchester Large Rifle primer, in Winchester cases. Is what each company used for testing with their stuff - their manual reflects what they got for results - might be a guideline for you, what you might get with your stuff.
 
Last edited:
Thanks. It's pretty much Impossible to get the primers specifically recommended in the manual. Hard enough time getting powder and brass. I have Varget, H4350 and H4831 so I will use the appropriate powder and recipe and just work my way up with my loads. I have Sig 7mm Rem Mag brass coming. I am using Federal blue box brass for my 300WM that I've saved over the years all cleaned, inspected, de-primed, resized and cleaned and inspected again. I also am reloading my 7mm-08 using Hornady Whitetail brass I've saved. Bullets being used for 7mm 08 are Hornady Soft Point Bullets - .284 139g and Hornady ELD-X Bullets - .284 150gr which I also want to use with the 7mm Rem Mag. For the 300WM I'm using Hornady Soft Point Bullets - 150 grn, Sierra Bullets - .30 cal 180 gr. MatchKing HPBT and Barnes TTSX 180grn. Basically these are the components I have and spent countless days finding them so I don't want to wait for all the components specified in the manual because that day may never happen given the lack of reloading components available in Canada. So I'll start at the bottom end of the powder load and work my way up. Any other suggestions?
 
Since you already have primers, it might be easy for you to trade with someone for the primers you want. Easier than trying to buy some.
 
That's what I'll do. Work my way up with the powder loads.

I had previously posted an experience why that is a very prudent thing to do - an acquaintance in Calgary used a Start Load from Nosler website for 7mm STW using H1000 powder - is clearly a mis-print or clerical error that is repeated in the Nosler #9 book - the same loads are given for 175 grain bullets as for 160 grain bullets. His first hand loads, using 175 grain bullets, at what he was led to believe were Start loads - caused VERY tight bolt opening - what Nosler listed as a Start loading is / was higher amount of that powder than their previous published Max loadings. If he had jumped in near the Max loading, his bolt likely would be frozen shut tight, or worse. And, he was using different primers, different brand of cases and a different brand of bullet - none of which help to rely on the Nosler "recipe" to be a "safe" pressure - they reported what they got with their stuff - I think. Is no guarantee that you will get the same results with your stuff - in his case, using different primers, cases and bullets.

For various reasons what you propose to do is about "best" - for us home hand loaders, it appears that muzzle velocity (allowing for barrel length differences) is about the best surrogate for pressure that we have. If they got 3,000 fps with XYZ powder, at ###X psi pressure, and you get 3,100 fps with XYZ powder, you did so with higher pressure, regardless how many grains that you or they used. Perhaps is why it was posted on CGN to do your pressure series at least 0.5 grain past what the manual lists - you may or may not get to the velocity they did - you might get there sooner than they did, or later. But, if you are like me - want to know where the Max line is - even if the most accurate loading is somewhere less than that.
 
I tried CCI200 standard large rifle primers against CCI250 magnums in a 7mm Rem Mag

I tested IMR 7977, IMR 4831, RL22, RL23 and H4831sc, in winter (-15c), spring (+13c) and summer (+29c). On average, the CCI200 gave 18% smaller standard deviation than the magnum primer. In winter, the standard primer was 40% better for SD. Go figure

You're fine to use the CCI200, not sure on the BR2 but they'd be worth a try
 
Couple good points above. Start low and work up. I would add that recent loading manuals give lawyer approved powder charges. Often if you look at a manual, by the same source, but years earlier, the older numbers can be several grains larger charge weights. There are many telltale signs your loads are getting frisky such as, difficult bolt lift/extraction, ejector marks on the head of the brass, or cratering or flattening primers.

The bullets you listed were mostly premium hunting bullets, except one was match?
 
OP - an example of "working up" a loading. I have a new-to-me 22-250 rifle. New W-W brass. Fed 210M primers. Speer #1035 52 grain Hollow Point "Varmint". A correspondent advises real good luck with IMR 3031 powder, and I have some on hand. Speer manual lists 32.0 grains as Minimum and 36.0 grains as Maximum, using Remington cases and CCI 200 primers for this powder. So my intention is to load 2 each and do a pressure series - 32.0, 33.0, 34.0, 34.5, 35.0, 35.5, 36.0 and 36.5 grains. So 16 rounds. Could be fired off into a ditch - not too concerned at this point about most accurate loading - I want to find where is Max, in my stuff, if it is there. If my bolt is going to "freeze up" or worse, I want to "feel" that coming with lesser loadings. There might be a more "scientific" way to find the most accurate loading - I will likely back off 0.5 grain from any pressure signs (if I get some?) and try 5 round or 10 rounds groups. Once I find something "good enough", that will likely be my loading to use. No doubt at some point I will use the MagnetoSpeed to get a velocity reading or three - to see. I am not terribly interested in wringing out the last fps from this rifle and bullet. But I do want it to be able to hit a crow in a tree or in a pasture - at 200 yards - like my last 22-250 could.

For this start, I will likely use the COAL length as given for this bullet by Speer - 2.350", after I confirm that does give me some amount of "jump" in this chamber - most manuals, I think, show you how to do that. Afterwards, if the magazine allows - I might play with more or less "jump" to see if that makes a difference on the groups that I shoot. The rifle's receiver recoil lug has been epoxy bedded, and the barrel is free floating - I have received a Leupold 6-18x40 scope to install, yet.

I also note that the Sierra V manual lists IMR 3031 with their 52 grain HPBT MatchKing bullets - using Federal cases and Fed 210M primers - they Start at 30.1 grains and go to 32.9 grains. Neither Hornady 9th nor Nosler 9th list IMR 3031 powder with their 52 grain bullets. To be seen what I get with this rifle and my components. I am pretty much convinced that loading manuals are reports what they got with their guns and their components, when they ran them on their pressure testing machines. I do not have any of that - I don't have a pressure testing machine, and they did not use my rifle or my components, so is not likely the results would be identical.
 
Last edited:
... I will use the appropriate powder and recipe and just work my way up with my loads.... I don't want to wait for all the components specified in the manual because that day may never happen given the lack of reloading components available in Canada. So I'll start at the bottom end of the powder load and work my way up. Any other suggestions?

You're on the right track I think.

I find that of all the different choices with reloading, standard vs. magnum primers is one of the least important. There are some cases where it is very important. But generally not, for the reloading that I do. Either it's enough primer, or it's not, and your chrono data and other observations should be pretty clear on that.

Not sure on the specifics, but you should look closely at the intended impact velocity range for those .284 bullets that you're planning to use for both 7-08 and 7mm RM. If it's good for one, it's probably less good for the other. Too fast or too slow is a real problem for hunting bullets.
 
I’m new to reloading to, only a year and a half in, I’ve been using only federal 215 so far in 30-06 and 9.3x62 and plan on trying CCI version soon! I did reload some 7x57r with the 215 and hope it is all good! Up here during hunting season we rarely have hot weather and mostly cool to cold to really cold weather and I got told that magnum primers are the way to go!
 
Back
Top Bottom