I am assuming that I'm not the only one who reloads center-fire that is having problems buying components. I have checked with Cabela's and a few of the local gun shops to get more small rifle primers to no avail. I do have a generous supply of powder, primers, and bullets etc. for pistol and large rifle, but felt fortunate to find and settle on some magnum small rifle primers. My Hornady reloading book says to reduce the powder when using magnum primers, but the recipes do not give clues as to how much. I have never felt the need to use magnum primers before, and do not have any experience doing so, so my question is, do any of you have any input on the subject? I usually back off of the max load a couple of grains anyhow, to reduce case length growth and longevity. Thanks!
The conventional wisdom is to rework your loads (start low and move up, watching for pressure signs as you go) when switching from normal to magnum primers. There's not a good reason to bypass the due diligence afforded by checking that the combination isn't pushing pressure.
That said, I know several who have done so and not one has ever adjusted a loading (their magnum-primed loads performed identically to the non-magnum counterparts). Note that while some are shooting 223/556, most of those experiences are loading pistol rounds.
If you know where your round's velocity works best in your rifle I would work back up to that point with a minimum number of rounds fired (1-3) at each rung of the ladder (you're shooting to verify lack of excessive pressure, not necessarily for group size) and if possible use a chrono to check that velocities haven't shifted. Once at your prior load, I would fire for a group to see if performance (group size) has degraded. If you invalidate the hypothesis that both loads perform closely, you may have to restart load development.
Just my two cents.
There is a huge difference regarding the temperature that is expected when used. For example, I have 7mm magnum rounds that I have loaded for cold weather use _only_ that use magnum primers. I likewise have hot weather rounds in 7 mm magnum that are loaded with regular primers, intentionally. They are not consistent in cold weather, below 35 degrees. But, they have been worked up and tested in 95 -98 degree weather, and are safe. They are very consistent in hot weather, about 1.5 MOA, which is my limit with a sling. My cold weather rounds are likewise about 1.5 MOA in accuracy. I am careful not to mix the two.
I learned this when I fired some 7mm magnum loads with magnum primers in hot Florida summer weather and saw signs of over pressure with flattened primers. Did more research, and now have hunting loads for Cold weather and for Hot weather. I mark HOT WEATHER ONLY, or COLD WEATHER ONLY, ON my magnum rifle reloads. I document all batches of reloads in a bound theme notebook. I can look at any box of reloads, look at the batch number, and lookup the exact recipe, date, process, etc., that I used. Even the time in the tumbler is recorded for the brass.
â€"Gary
I've shot magnum primers (CCI 450) with my then-normal load, which was a common service rifle load (24.0 gr Varget under a Sierra 77 or 80 Match King). Conventional wisdom is to back off 10% of your normal load and look for pressure signs, but you might actually see less flattening of primers with magnum primers, if they have a heavier cup like the CCI 450 vs. 400. One of my friends says he saw a change in velocity and POI after switching to magnum primers.
As usual, nothing I say here constitutes advice or recommendation, and any load is given for illustrative purposes only.
On a related topic: What are folks' experiences / recommendations when switching brands of primers within the same type? E.g., CCI Small rifle to Federal Small rifle.
I've always used CCIs - I live in Idaho, they are made here, so usually easy availability, and I've had exactly one fail in thousands and thousands used. I've got enough for my anticipated needs up until the winter, but I don't see much on the shelves when I walk through Sportsman's or my LGS, so maybe I should think ahead...
Hey Tim, I've been reloading for years and have used several different makes of primers for several different calibers, and have never noticed any difference. I've never used magnum primers however, and I'm not a bench shooter, or an accomplished shooter for that matter, so probably wouldn't notice something different unless it was blatant.
The other responses have covered it.
If a shooter's current load were pushing the envelope for the last bit of velocity I'd say start over for safety. If your loads are more moderate then I'd probably start a couple grains down from current and load one or two cases every .3 grains or so up to my current charge and fire them looking for high pressure indicators like excessive velocity, flat primers or cratered firing pin indents.
Based on those results I'd pick my charges to do accuracy testing with (usually 3 or 4 charges at .2 grain increments where I'd load 5 or 10 rounds of each).
This would be my procedure for changing brands or to magnum from standard.
I'm not going to wear a barrel out but I'll do a little cautious testing.
Swapping primers among vendors for rifles and pistols, at least between non-magnum primers, is generally always safe. But, switching between non-magnum and magnum primers is not always safe. It depends on environmental conditions, too, as mentioned previously. Magnum primers are, however, often recommended for very cold weather round reliability. Standard primers may not be reliable in extremely cold weather.
I reload for shotgun, too. There, you never, ever, swap out _any_ components between vendors. Not even primers. Shotgun components are not swappable, EVER. Shotguns operate with much less margins than rifles and pistols. The reloading books are to be followed EXACTLY for shotgun loads.
Resurrecting this thread.
I actually found some primers, and a pound of IMR 4064, the other day at one of the sporting goods stores here in Alaska.
The primers were CCI 400 small rifle: $6.00 for a pack of 100. Limit was 2 packs. I spent $12.00.
The powder went home with me too. It was a reasonable $33.
After buying the items I felt a bit vexxed. As I was walking out to the truck, I felt practically elated. Then I thought, why am I feeling so happy about buying something that shouldn't be this hard to find?
A sign of the times I guess.
In Liberty,
Gus
I hear you Gus. Its like you just scored a touch down in the last few seconds of the game. Its weird. I know. Crazy world.