In the Lyman book I use it calls for magnum primers when loading 158 gr 357, but some people say I dont need to use them. I guess one question is do I need to use them? If so does it matter what brand? The book is specific when using small pistol non magnum primers but generic when listing the magnum.
Magnum Primers
- Thread starter Danb6177
- Start date
In general whether a magnum primer is used it dependent on the powder used. Generally ball powders like H110/W296 among others are harder to ignite and need a magnum priers to get a good solid burn. I also used small rifle magnum primers with CFE223 because I get better SD/ES.
It can also be related to the case/powder volume relationship and a standard primer just did not have enough power to get all the powder lit. Lastly I have heard of magnum primers being used in very cold areas to help ensure ignition.
but if your manual says to use it its one of 2 reasons. 1, that's just the primer they used for testing. or 2 the load needs it.
CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.
I have substituted regular small rifle primers for small pistol magnum on more than a few times in 357 loads and it worked quite well, provided your guns firing pin has enough spring pressure to set it off.
This company did a test with 9mm a few years back comparing small pistol, small pistol magnum, and small rifle primers and found almost no difference in pressures generated.
https://www.youtube.com/watch?v=NGVRGsoOr6k
It can also be related to the case/powder volume relationship and a standard primer just did not have enough power to get all the powder lit. Lastly I have heard of magnum primers being used in very cold areas to help ensure ignition.
but if your manual says to use it its one of 2 reasons. 1, that's just the primer they used for testing. or 2 the load needs it.
CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.
I have substituted regular small rifle primers for small pistol magnum on more than a few times in 357 loads and it worked quite well, provided your guns firing pin has enough spring pressure to set it off.
This company did a test with 9mm a few years back comparing small pistol, small pistol magnum, and small rifle primers and found almost no difference in pressures generated.
https://www.youtube.com/watch?v=NGVRGsoOr6k
What powder are you using to load 357 Magnum , some slower and ball powders can need a magnum primer. Faster powders like Unique and accurate #5 do not need them .
Lyman may be listing Magnum Primers for all 357 magnum loads just to make it easy on themselves . Other loading manuals will indicate when and with what powders to use a magnum primer . I use data that is powder/primer specific .
You can substitute one brand of magnum primers for another brand ...
sometimes you have to and it isn't dangerous ... start Low and Work Up slowly to desired velocity .
Gary
Lyman may be listing Magnum Primers for all 357 magnum loads just to make it easy on themselves . Other loading manuals will indicate when and with what powders to use a magnum primer . I use data that is powder/primer specific .
You can substitute one brand of magnum primers for another brand ...
sometimes you have to and it isn't dangerous ... start Low and Work Up slowly to desired velocity .
Gary
Yes I think the magnums are due to the powder used. They recommend 2400 but also list
unique - acc#9
true blue - h-110
blue dot - imr-4227
acc #7 - N110
enforcer
The only one I found was the H110 But didt get it because the guy there said its more of a rifle powder. So I dunno. I used 231 for my 38 reloads with cci 500 primers
Whats a recommended powder for 357. I know that unique is on that list and I would have bought it. Someone did tell me that unique is very smokey for an indoor range tho
44caliberkid
New member
“the guy there…” is ignorant. H110 is a very common magnum pistol powder. I use it all the time for 44 and 357 magnum. In the olden days (70’s) I used a lot of 4227 and 2400, because that is what was commonly on the shelf. Then I added 296 to that list for quite awhile. I’ve been using H110 and 296 most of this millennium, but have played around with Enforcer and AA#9 the last couple years. I use Winchester primers which state, “FOR STANDARD AND MAGNUM LOADS”. I might ad, all my magnums are 6 inch barrels or longer.
SMH, H110 is a great magnum handgun powder for 357.
Its generally considered a slow pistol powder and works best with heavier bullets, in 357 mag, id say 158s and heavier.
H110 would be considered a very fast rifle powder and is generally used in rifle cases with very small case capacities or in specialty loads like subsonic 300 blackout where case capacity is significantly recused because to how far the bullet is pushed into the case, and a desire to limit velocity (subsonic)
Shadow9mm's post is spot-on. They usually are.
It's too bad the more potent primer has been named "magnum." The term has muddied the waters of the handloader's world - not that I can come up with a better name.
At any rate, as already discussed, it's mostly about the propellant used and whether or not it is an easily ignited propellant.
Now that we've covered the high level, let me give you 40 years of experience loading 357 magnum:
With W296 (or H110 - same propellant, different label), I always use a magnum primer.
Same with MP-300.
Same with HS-6 in revolver cartridges (because the cases are large), but I use a standard primer in semi-auto's (because the cases are small). In revolver cartridges especially, HS-6 likes to be stoked up real good to get a consistent burn. The magnum primer seems to help with that.
Many use magnum primers with 2400 in 357 Mag (158's), but my tests (CCI 550) show that signs of high pressure begin with less charge weight and yield lower velocities. Besides, I get good, consistent burns with standard primers (CCI 500). So magnum primers are a "no" for me, using 2400. I tried them using 125gn bullets too, and canceled testing before completion due to lack of consistent performance. That was years ago, and I kind of wanted to re-run the test, but I'm out of 2400 and it may be years before it ever shows up on store shelves again. This makes me sad, btw.
I don't use magnum primers for any other propellant. I've used N310, N-100, AA#2, AA#5, AA#7, Bullseye, BE-86, Power Pistol, Unique, and W231 (& HP38 - same as W231, different label). And probably others that escape me at the moment.
It's too bad the more potent primer has been named "magnum." The term has muddied the waters of the handloader's world - not that I can come up with a better name.
At any rate, as already discussed, it's mostly about the propellant used and whether or not it is an easily ignited propellant.
Now that we've covered the high level, let me give you 40 years of experience loading 357 magnum:
With W296 (or H110 - same propellant, different label), I always use a magnum primer.
Same with MP-300.
Same with HS-6 in revolver cartridges (because the cases are large), but I use a standard primer in semi-auto's (because the cases are small). In revolver cartridges especially, HS-6 likes to be stoked up real good to get a consistent burn. The magnum primer seems to help with that.
Many use magnum primers with 2400 in 357 Mag (158's), but my tests (CCI 550) show that signs of high pressure begin with less charge weight and yield lower velocities. Besides, I get good, consistent burns with standard primers (CCI 500). So magnum primers are a "no" for me, using 2400. I tried them using 125gn bullets too, and canceled testing before completion due to lack of consistent performance. That was years ago, and I kind of wanted to re-run the test, but I'm out of 2400 and it may be years before it ever shows up on store shelves again. This makes me sad, btw.
I don't use magnum primers for any other propellant. I've used N310, N-100, AA#2, AA#5, AA#7, Bullseye, BE-86, Power Pistol, Unique, and W231 (& HP38 - same as W231, different label). And probably others that escape me at the moment.
Thanks. I’d like to get those primers hopefully I can find them. I’m going to a local reloading supply store today to see what they have
Met a very knowledgeable guy today at the reload supply store. He lead me in the direction of ACC.#9 powder and standard CCI 500 nickel plated primers for my 357 loads. Also he recommended lead bullets vs jacketed. For cost and also for some sort of wearing on the gun barrel. So I may do lead. The Lyman book doesnt have a 158 gr lead and they have 155 gr SWC # 358156. They also have 160 gr #358311. I may go with that one. I dont know anything about wadcutters
edit: Oh wait are those numbers for casing bullets? oof that wont work haha
edit: Oh wait are those numbers for casing bullets? oof that wont work haha
A few things to note. If your shooting led you many need a little extra flare in your case mouth to keep from shaving lead.
You may need gas checked bullets if you are pushing the loads hard.
In addition to the carbon and copper you will have lead buildup you will be cleaning out.
SWC style bullets are more likely to hang up going into the cylinder. I generally prefer more of a flat nose style bullet.
High quality lead can be just as expensive as jacketed. These are some nice wide flat nose I have shot before, geat bullet's and a good example of the wide flat nose style I prefer. https://www.montanabulletworks.com/product/357-180gr-wfn-gc/
Over all you will need to tweak your reloading technique a bit to go from jacketed to lead, but not by much. Give lead a try, its pretty cool.
Im sure the magnum primers can be used because thats what Lyman used in their testing, so thats obvious. But Lyman doesnt say what other primers can be used. Hence my inquiry. So Im not really trusting, Im gathering : )
But when a guy who owns a reloading supply store that has been reloading for decades says stuff about his craft Im going to pay attention to that as well.
SO gather this as well, Lyman Manual 1970, .357 data, the primer used was a Rem #5 1/2
Speer manuals list CCI primers
Hornady manuals generally list Federal primers.
The point here is that, just because one edition of one manual doesn't list a certain component, doesn't mean it can't be used, it just means that they didn't use that component in that edition's data.
H110 is a good MAGNUM pistol powder, work well in full house .357 loads because it was originally developed for use in the .30 Carbine case, with its 110 gr bullet. 2400 was also ORIGINALLY a rifle powder, used in the .22 Hornet.
Both powders, while having different characteristics, were made for use in cartridges where you are lighting off somewhere between 10 and 20(ish) grains of powder in a normal full charge. Small rifle cases and large pistol cases with volumes in that range are where they are good choices for full house loads. Of the two, 2400 is more "flexible", H110 gets a bit squirrely if loaded to less than it thinks it needs to be.
Sure, pay attention, its might be something worthwhile. BUT, also keep in mind that the guy is running a store, and might simply be pushing what he wants to sell. Either is possible.