Primer question

[Mbradley21]

Wondering if anyone has used standard large rifle primers in 300 win mag loads? Will be primarily loading for hunting so reliable ignition is more important than velocity. I will be using these In Colorado for 2nd and 3rd elk rifle so temperatures down to the teens at times. Anyone have any experience with this?

 

[Quant]

I think the general rule is to use magnum primers for any load greater than 65 grains. I am running low on magnum primers myself, so if I can’t buy anything before fall I will be trying LRs.

 

[Zappaman]

If using ball powder I'd want a mag primer. That said, OLD Winchester LR primers were plenty hot for any powder (I still have them for some loads I'll have to try mag primers on when I run out). If you have some of the old (white/red/orange packs) of Winchester primers load away. If you are using a stick powder, I think a standard LR primer will light your load fine otherwise. Could always load up a few and hit the range early when it's cooler out- find out

 

[Mbradley21]

Ya that’s sort of my issue right now. I have been able to find some large rifle primers on the secondary market for a fairly decent price but can’t find magnums anywhere. I will start working some loads up with some stick powders and just try and see what my gun likes. I appreciate the help!

 

[menhaden_man]

I'm in a similar pickle, have no LRMPs. I've shot about 100 rounds of various reloads (H4831sc and IMR4350) in my 7 RM in the past couple weeks using BR2s and not seeing any problems.

 

[Mbradley21]

Did you see your velocities suffer at all using the br2’s? Was the accuracy pretty comparable?

 

[menhaden_man]

Did you see your velocities suffer at all using the br2’s? Was the accuracy pretty comparable?

Sorry, never did see this question! The velocities are smoking hot - same with accuracy. I have three different loads (H4831, Returmbo, IMR4350) that are close to or above 3,000 fps with 168 VLDs and all under 0.5 MOA. That said, I've never had LRM to test since I bought this rifle so can't say if velocities are off. But I have some at 3,100 fps (IMR4350) and that's blazing quick.

 

[Zappaman]

I'd call it good with the more accurate of the three loads. .5 MOA is good enough for elk (or mastodons) at 500 yards with a 300.

 

[Sako300]

77.5 grains of h1000 with large rifle primers federal and 215 Berger hybrids. Most accurate load I shoot in 3 different 300 win mags. Velocity is still close to 2900 with 26 inch barrel