Lyman's 49th Edition and the use of magnum or standard large rifle primers?

[MCMXI]

I notice that Lyman doesn't specify which primers were used for the loads that it lists. For example, for .300 WSM loads where it lists the barrel, twist rate, action, bullets, primers etc, it simply states "primers: magnum and standard large rifle" or words to that effect. I'm working up hunting loads for my .300 WSM using a Hornady InterLock 150gr bullet and IMR 4895 and have both magnum and standard large rifle primers and was wondering which would work best. With no guidance from Lyman I figured I'd ask here.

I've been shooting 168gr bullets using Reloder 22 with magnum primers. I use standard primers and Reloder 15 (or 4895) for my .308 but I'll be using about 50% more powder in the .300 WSM. Reloder 22 is a slow powder compared to IMR 4895 so my intuition tells me that a faster powder would work fine with standard primers even though there's 50% more of it in this case (no pun intended). Any thoughts?

In general, how do you decide whether to use a standard or magnum rifle primer?

Thanks.

 

[NCsmitty]

My rule on standard or magnum primer selection is to use magnum primers with spherical (ball) powders and standard primers with extruded (stick) powders.
Ball powders are usually more difficult to ignite, hence the use of magnum primers with their hotter and more intense flame front.
They may also be useful in large capacity cases with any type of powder, but proper workup is warranted for safe loads.
A little research will determine the type of powder that you are using.
Never switch primers in developed maximum loads. Always drop powder charges back at least 5% if doing so.


NCsmitty

 

[dakotasin]

my criteria for when to use magnum cartridges is powder capacity or powder type. ball powders get magnum, and any charge of 60 or more grains gets magnum primers. the gray area for me is -06 based cartridges. 30-06, 35 whelen, 338-06 get standard primers, while 270, and 25-06 get magnums...

 

[loadedround]

I just checked the current Speer #14 Manual since I don't load the 300 WSM. This manual lists both CCI 200 and 250 primers for their load developement. However neither of the powders you mentioned are shown for use with a 150 gr bullet, possibly because of the powder's burn rate. However Speer does show a load for Rel 19 with a CCI 200 primer(std). I realize this does not answer your question, but I posted this information as a reference for you.

 

[MCMXI]

magnum primers with spherical (ball) powders and standard primers with extruded (stick) powders .... [magnum] useful in large capacity cases with any type of powder

my criteria for when to use magnum cartridges is powder capacity or powder type. ball powders get magnum, and any charge of 60 or more grains gets magnum primers.

IMR 4895 is an extruded powder but I suppose the question is whether or not the .300 WSM case can be considered to be "large capacity". The max load listed for IMR 4895 is 60.5gr so it's right on the edge of your (dakotasin) 60+ grains criterion. I have a lot more magnum large rifle primers than standard large rifle primers [strike]and since I'm going to be up around 60.0gr I think I'll use magnum[/strike] but given the speed of IMR 4895 I'm going to use standard primers. I would bet that Lyman used standard primers for the 150gr and 168gr bullet loads listed and probably used magnum primers for the 180gr, 190gr and 200gr bullet loads listed.

neither of the powders you mentioned are shown for use with a 150 gr bullet, possibly because of the powder's burn rate.

Hodgdon lists Varget, IMR 4895, H4895, H380 and even Trail Boss loads for the .300 WSM with a 150gr bullet but thanks for the concern. The maximum pressure listed for 60.5gr of IMR 4895 is 62,300 psi. The maximum pressure listed by Lyman for the "accuracy load" using VV N160 and a 150gr JS is 62,800 psi. Lyman and Hodgdon both used 24" barrels with a 1:10 twist rate so I'm not concerned about using 4895. I haven't tried any loads yet so I can't say if the faster powders work well or not.

 

[dakotasin]

fwiw... my 300 wsm runs on mag primers.

also, a component of when i use magnum has something to do w/ my climate. during hunting season, it gets cold outside, and i've done deer hunts in sub-zero many times... so, i do sometimes run a hotter-than-necessary primer because i do not want any issues whatsoever when it is time to knock some ice off a monster buck/bull.

if it were me (and it isn't) developing another 300 wsm load, i would start and end development w/ a magnum primer, regardless of powder used.

my daughter's 300 wsm runs a light load of h-4895 behind a 130 grain hornady, and her load features a magnum primer.

good luck!

 

[MCMXI]

if it were me (and it isn't) developing another 300 wsm load, i would start and end development w/ a magnum primer, regardless of powder used ... my daughter's 300 wsm runs a light load of h-4895 behind a 130 grain hornady, and her load features a magnum primer.

dakotasin, thanks for the help ... the .300 WSM is more versatile than many realize. You make an excellent point about cold weather applications. Since I'll be working up this load in warm weather, a magnum primer would result in the highest possible pressures, so if I ever find myself in a colder climate, the load wouldn't need to be reduced. Magnum primers it is then!

How does your daughter like her .300 WSM?

 

[dakotasin]

i'm a fan of the 300 wsm. i find it suitable for whatever i want to do. for me, and all out performance, i think the 300 win mag is tough to beat and is my preference for a hard core hunting rifle, but the 300 wsm is a great cartridge and i think it loads down easier than a 300 win mag.

my daughter is left handed, so for her birthday last year i got her a lefty savage 300 wsm because i felt it would provide maximum versatility, and when loaded to full honk would be adequate for elk (my 300 wsm is a win m70 right handed). she is 9 now, and shoots the rifle pretty well. her load runs a 130 hornady at about 2500 f/s. felt recoil is about that of a sporter 22-250. this will be her first year hunting, and i stipulated she needed to put 200 rounds downrange before she could hunt w/ me, and her groups at 200 needed to be smaller than 6". she exceeded that easily, so this year we'll be harassing deer around the farm. she's excited and nervous. we'll take it slow and see how she does. however, being 9, she does not understand all the differences in rifles and chamberings, and couldn't care less about performance. she just wants to try deer hunting. she doesn't understand why people get all worked up at the range when she breaks out her rifle and they find out the chambering. all she knows is "cross hairs, trigger, breathing, bang!". i enjoy the "innocent" side of this type of shooting versus the endless caliber and performance debates so many gunnies get into!