Primers recommendations for 300 Win Mag

jakes10mm

Well-Known Member
Joined
Nov 7, 2010
Messages
65
Location
Pennsylvania
I'm developing loads for a new Remington 300 Win Mag and have tested Reloder 22 and IMR4350 so far. I picked up some H1000 to trial next. For bullets, I've tried Speer 180gr SP, Berger 190gr Hunting VLD and Berger 210gr Hunting VLD bullets. All seem to be capable of 1/2MOA accuracy. I did some brief chrono work and had very favorable results. My questions to the group is primer choice. I've received conflicting views on Magnum versus Large Rifle primers for this cartridge. My loads so far have been with Winchester Large Magnum primers. I did slip in a couple rounds with Winchester Large Rifle primers to compare velocities across the chrono. These Large Primer rounds gained about 35fps over the same loads with mag primers. At the recommendation of a local gun dealer and avid magnum shooter, I picked up some Federal 215 primers to trial. Recommendations?
 
I'm developing loads for a new Remington 300 Win Mag and have tested Reloder 22 and IMR4350 so far. I picked up some H1000 to trial next. For bullets, I've tried Speer 180gr SP, Berger 190gr Hunting VLD and Berger 210gr Hunting VLD bullets. All seem to be capable of 1/2MOA accuracy. I did some brief chrono work and had very favorable results. My questions to the group is primer choice. I've received conflicting views on Magnum versus Large Rifle primers for this cartridge. My loads so far have been with Winchester Large Magnum primers. I did slip in a couple rounds with Winchester Large Rifle primers to compare velocities across the chrono. These Large Primer rounds gained about 35fps over the same loads with mag primers. At the recommendation of a local gun dealer and avid magnum shooter, I picked up some Federal 215 primers to trial. Recommendations?
currently I use the CCI BR2 and H1000 behing a 185g VLD 3030 FPS hope it helps
 
My testing to date:
Berger 190, RE 22 (74.0gr), Win Mag Primers - 3072 fps
Berger 210, RE 22 (71.2gr), Win Mag Primers - 2918 fps
Hornady 180 SST, RE 22 (75.6gr), Win Mag Primer - 3118 fps
Hornady 180 SST, RE 22(75.6gr), Win Lg Rifle Primer - 3128 fps
Hornady 180 SST, IMR4350 (70.0gr), Win Mag Primer - 3033 fps

I made an error on my Lg Rifle vs Mag primers. It was only a 10 fps bump with the Lg Rifle powder....should have know better than trust my memory.
 
Nothing but 215's and other mag caps here, but I hunt in sub-zero conditions and anything over 50 grains or so of powder gets a mag cap unless it pukes accuracy wise with it. The only larger rifle I don't use a mag primer with a full power load in is my 338; with 250 sierras and rl19 the accuracy is poor unless I go to a 210.
 
I've used standard primers (RWS5341) for 200 grain bullets in 30 caliber magnums and got about 1/2 MOA accuracy at 1000 with good velocity numbers. Tried all the large magnum ones made and none shot as accurate as standard primers.

But nowadays, the Wolff primers from Russia seem to be the favorite in long range centerfire competition.
 
If its a magnum its loaded with a mag primer in this house. Out of the mag primers ive probably had my best luck with Fed match mags for grouping. I also use alot of standard 215m and cci mag. both are quite a bit hotter primer then the ww primers.
 
In my 300 Win Mag

Fed 210 Match and CCI BR2
H1000
210gr and 220 gr
FC case

Rem 700 Tactical 5R with 26"
300 Win Mag

Better spread than with Magnum primers
 
I only use Federal Gold Medal Match 215Ms and 210s. Take the rest of your primers and sell 'em
 
Any time you get up near 70gr of powder it's a good idea to use a magnum primer, especially with slow powders like H1000. Of course not all primers are created equal so if you get a complete and smooth burn using a Win WLR primer then that's what you should use. (but I would test all the magnum primers I could find first)
 
My go to primer for my 300WM's, or any load over 60 gr of powder has been Fed215M's, but I have yet to see any difference in ES, velocity, or cold temperature performance compared to the "non-match" 215's. My current load is 210 Berger VLD/LRAB's, with 79gr Retumbo, Norma brass,Fed215M/215, 2904FPS, ES 10FPS, .25-.5MOA.
 
Warning! This thread is more than 11 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Recent Posts

Top