Reloading 300 Win Mag

[smokey3]

I'm working on a load with h4350 with Sierra 150 GK and Fed 210M primers (getting low on magnum primers). Let you know what I come up with. My rifle is very accurate with imr 4350 and 150 NBT.

I get better ES and SD with the 210M rather than the 215M. You will possibly have the same experience. Also, my barrel likes the 180 BT and AB, using same load data.

 

[badthirtyone]

I get better ES and SD with the 210M rather than the 215M. You will possibly have the same experience. Also, my barrel likes the 180 BT and AB, using same load data.

I have seen this as a common theme on several threads here. I have had a little bit of exposure to the science behind it and why that seems to be true.

It just seems like it would be counterintuitive, but I have heard repeatedly that it works.

I'm going to have to try it.

 

[smokey3]

I have seen this as a common theme on several threads here. I have had a little bit of exposure to the science behind it and why that seems to be true.

It just seems like it would be counterintuitive, but I have heard repeatedly that it works.

I'm going to have to try it.

The 300WM was originally developed around 1963 and it was with the standard primers at first. I believe that the magnum primers came about a few years later. Any way, either can be used successfully.

 

[ThrdKllr]

Glad to hear that. I've got a good many standard primers but I'll save the magnums for the RL26 I have.

 

[CApighunter]

Since H1000 is scarce now, I've been playing with RL26 and so far I'm impressed with both accuracy and speed. 2950 with a 215 from a 23 inch barrel.

 

[ThrdKllr]

Haven't done much load work with the way components availability have been. Been buying a few bullets every now and then when I find what I want in stock but powder and primers are nearly nonexistent.

 

[BPollard]

Graf and Sons sells the Peterson 300 WM Long brass, this will cure that problem before you run into it. Go to Peterson's website and Ben Peterson explains all you need to know about this version and remember they manufacture both long and standard versions and both are available on Graf's website. I have the long version from them and it is great brass. With that being said, I have reloaded 7 MM and 300 WM for years and have never had any issues with either one. Watch your pressure signs and do not overwork the brass and you should be fine.

Yeah just watch your brass , keep count of how many times you reloaded it size it correctly and you shouldn't have any problems. Just for curiosity what do you plans on loadIn?

 

[longrangebob]

Yes, Larry Willis' Collet die is the answer for "swelling" just in front of the Belt .. in any of the Belted Magnums developed from the 375 H.&H.... I used it more on my 358 STA ... the case was designed to "headspace" off the belt - not the shoulder ... I have had good success with 4350, N204, RL22, 4831sc in my particular rifles

 

[EE_Reloader]

I'm loading 200 grain and maybe 220 grain eldx's. I have new, blue bag, Winchester brass, federal large magnum primers and I'm probably going to use H4350. Wish I had waited for the Peterson brass now.

 

[Greyfox]

I have never had an issue bumping the should in my belted cartridges I use Reading FL dyes and like Norma brass for my 300WM.

 

[Huggy]

Graf and Sons sells the Peterson 300 WM Long brass, this will cure that problem before you run into it. Go to Peterson's website and Ben Peterson explains all you need to know about this version and remember they manufacture both long and standard versions and both are available on Graf's website. I have the long version from them and it is great brass. With that being said, I have reloaded 7 MM and 300 WM for years and have never had any issues with either one. Watch your pressure signs and do not overwork the brass and you should be fine.

I've been waiting for a coons age for Graf's to get the Peterson Long brass in stock. Seems to be as scarce as hens teeth.
I went to the Peterson site, thinking I'd buy from the manufacturer and you get directed back to Graf's, so I assume they are the exclusive distributor for Peterson. Sigh.
I'm really keen to try the Peterson cases but thankful I'm not held up for reloading for lack of other cases, all of which have given me good service.
Still, the heart ❤ wants what the heart ❤ wants, eh? LOL

 

[Steves1911]

I full length size bumping shoulder .002 on all my belted mags. Primer pockets loosing up is only issue I have had. Hornady brass is the worst at this im lucky to get 4 reloads on them before they need scrapped. I've found that mine does best with 200gr and heavier bullets.

 

[Ol' Red]

I'm loading 200 grain and maybe 220 grain eldx's. I have new, blue bag, Winchester brass, federal large magnum primers and I'm probably going to use H4350. Wish I had waited for the Peterson brass now.

I just tossed about 100 Winchester cases in .300 Win Mag. I had over 20 reloads on each. The primer pockets started to get loose. My chamber is tight, so never really had stretching issues. At least you have brass to get started. Enjoy and be safe.

 

[EE_Reloader]

Huggy, you are right about wanting what I want. I run Lapua brass for my 6.5 Creedmoor and it shoots really well. I was hoping to do the same with this project but I was bummed that Lapua doesn't sell brass for 300 WM at least not yet. Ol'Red thanks for that info. It at least let's me know I didn't completely fail to get decent brass.