I notice that most of the reloading info I come across for the various Winchester short magnums specifies magnum primers of some type. I'm wondering--is that really necessary?
The reasons I wonder about this are several. First, although the case holds about 10 grains more than the .30-06 family (which I've reloaded for for decades and never used a magnum primer for any powder), the shorter case puts the whole charge closer to the flash hole. Second, from what I've been able to find out the WSM family doesn't necessarily require the slowest powders available. Most loads I've seen use powders no slower than the .270 likes (e.g., the 4831s, 4350s, RL 22s) and those ignite just fine with standard LR primers. Also, as a great generality, the standard primers tend to be more consistent in their ignition and yield lower peak chamber pressures.
Anyone have any experience to share on this? I'm about to start rolling some .270 and .300 WSMs for myself. Many thanks.
I have shot a 7mm WSM quite a bit with 215's and RL 22. That's a good combination. I tried the same load with CCI's Br2's and got 25 fps less velocity.
While the groups with the BR2's were not quite as good as those with the 215's it could just be some other variation that caused it. The bottom line is that the loads with the 215's really shoot and that's what I am going to stay with.
For some reason many of the loads with the 7mm WSM and 270 WSM started out with fast powders. Even in the quite new Sierra #5 they omitted RL 22 with the 140 gr bullet. If you look at that manual on the 7mm WSM 150 gr page you will see that RL 22 gives the highest velocity with about 67 grs of powder. That cartridge will take 71 grs of RL 22 with an 140 gr bullet as far as capacity goes. This is not a load but just a comment that all of the slow powders have not been tested yet in these very new cartridges.
I load 69 grs of RL 22 behind a 140 Sierra SPT and get 3250 fps out of a 24" barrel. This is a very accurate and consistant load and magnum primers are part of it.
quote:Originally posted by Fireform: I notice that most of the reloading info I come across for the various Winchester short magnums specifies magnum primers of some type. I'm wondering--is that really necessary?
No, magnum primers are not really necessary. Use whatever you have on hand. Some primers (usually "standard" force, but not always) will tend to exhibit better accuracy than others, but you'll just have to try a few different ones to determine if there is any accuracy advantage. Standard force primers will provide reliable and consistent ignition in the WSM case with any powder that is appropriate to it.
If you're one of those people who is jsut not comfortable unless you paid more than the other guy, then by all means go out and buy yourself a carton of "magnum" primers. Otherwise, leave a perfect situation alone.
Posts: 13257 | Location: Henly, TX, USA | Registered: 04 April 2001
Winchester large rifle magnum primers give about 40 fps more vel than CCI large rifle primers and less deviation in shot to shot velocity in my 7mm Rem SAUM.
Posts: 5 | Location: OK | Registered: 09 January 2003
Standard primers will work, but magnums will usually give better ignition and more uniform results. Slow burning powders are harder to get going and need a little more "spark" than the faster ones.
Posts: 345 | Location: Pittsburgh, PA, USA | Registered: 01 February 2001
quote:Originally posted by The Maz: Standard primers will work, but magnums will usually give better ignition and more uniform results. Slow burning powders are harder to get going and need a little more "spark" than the faster ones.
Yep, that's the standard line right out of the book. Now, Maz, do you have any evidence to support that statement?
Posts: 13257 | Location: Henly, TX, USA | Registered: 04 April 2001
Okay, for the 300 WSM, which I've been playing with, let's see what the various mfr's recommend: 1. W-W says "the 270, 7mm and 300 WSM's all use a Large Rifle Primer". 2. IMR shows Fed 215. 3. Alliant shows WLR. 4. Accurate Arms goes with WLR. 5. Hornady calls for WLRM. 6. Speer goes for CCI 200's/250's (wow!!). 7. Hodgdon = WLRM.
I'm too lazy to run back downstairs to get my other load manuals, but I know I saw Federal 210's and 210M's in at least one of them. I think you can pretty much use whatever you want. I've used WLR's and WLRM's in the 300 WSM so far, and really can't tell a difference.
R-WEST
Posts: 1483 | Location: Windber, PA | Registered: 24 January 2001
Many thanks for all the input. I have on hand WLRs and BR-2s that I use for everything, and it looks like I'll just keep using them. I have a pack or two of WLRMs in case I want to experiment.
I've loaded for the .300 WSM extensively. Magnum primers are not only unneccesary, they are undesirable. My testing with both H4350 and W760 powders indicates that the use of the WLRM boosts velocities about 10 fps over the standard WLR, but raises pressure signs drastically. A load that is perfectly safe with the WLR goes sticky and hard with a WLRM. The net effect is that higher velocities are possible with WLR primer, because a greater powder charge is possible.
I have seen this with 150, 180 and 200 grains bullets in the .300 WSM.
Kuduking is 100% correct about the using the standard rifle primer in the 300 WSM. I am on my second barrel on my 300 WSM that I shoot 600 and 1000 yard F class competition with. I tried everything in the first barrel and all the magnum primers gave was higher pressure and less accuracy, and great extreme spreads across the chrono. I verified it with the second barrel with the same results. With the short fat case at least in the 300 WSM I firmly believe a magnum primer is not desireable. In addition I know of two 1000 yd. benchrest shooters that are very competitive with their 300 WSM and one of them uses the WLR and the other uses the Federal 210M.
From the testing I have done and what the benchresters are shooting, the 4350 class of powders is what works best in the 300 WSM. Even with bullets of 200 to 210 grs. If you are going to shoot 175 to 180 gr. bullets dont over look Vithavouri N550.
Shoot Safe, Shoot Straight.........RiverRat
Posts: 413 | Location: Owensville, Indiana USA | Registered: 04 July 2001
Is it safe to assume that most of this advise is also applicable to my 300 RSAUM? I don't really know the specific differences in the case of a wsm vs rsaum, but I too have been wondering which primers to go with.
Posts: 119 | Location: Houston | Registered: 06 November 2003
mitchell, I guess I've got to load up some more 300SAUM's using BR or Fed 210Match's or even CCI-200's!!! I've been getting .6's out of a Renington BDL SS 300AUM using 57.0 gr of VARGET and CCI-250's!!! Reckon I could get it down in the .4's with standard primers?!!!!!!GHD
Posts: 2495 | Location: SW. VA | Registered: 29 July 2002
I tried some standard primers in my .458 and found accuracy to be a bit less than the magnums. In smaller cases I never really noticed anything much with IMR-type powders, but ball seems to like a magnum cap a little more.
So... I'm convinced, but YMMV.
Posts: 345 | Location: Pittsburgh, PA, USA | Registered: 01 February 2001
