Magnum primer suggestions for 300 win

[rsmithsr]

did you work loads each time or just swap primers.
just swapping primers is not much of a "test".

I tested several mag primers compare to my go to CCI BR2. The BR2 was the smallest group at 200 yards hands down.

 

[Highvoltage]

It's a factory 700 24" barrel. It shoots lights out with this combo at both 70 (3030) and 72.1 (3140) ( both under book max jumping 80 thou). Both loads produce 1/2 moa loads at 200 and ironically 30'/ sec for 3 round groups . I've read those type chronographs can be troublesome.

 

[montana west]

look at the nosler data I belive that 77 grains on Reloader22 with the 165 and a fed 215 primer will do the trick.. IMR 4350 is to fast for the 300 winchester ... be sure to check the data though I think 77 gr is not the max but it will sure give you the velocity you want.. example winchester uses wxr powder for the 300 and reington uses 7828 .. or powders of the same burning rate.. and wxr is reloader 22..

 

[skipglo]

I've been working up a load in my 300 win using h4350 and 165 accubonds. I've been using Winchester large magnum primers ( nosler load data) And it seems like no matter what I do whether groups are 1/4 moa or 2 moa extreme spreads hover in the 30 ft per sec. I'm using hornady 1x fires brass and full length sizing. What are your thoughts on a different primer to reduce spreads. Any and all advice is welcomed.

Fed 215

 

[ILVTOHT]

I've been working up a load in my 300 win using h4350 and 165 accubonds. I've been using Winchester large magnum primers ( nosler load data) And it seems like no matter what I do whether groups are 1/4 moa or 2 moa extreme spreads hover in the 30 ft per sec. I'm using hornady 1x fires brass and full length sizing. What are your thoughts on a different primer to reduce spreads. Any and all advice is welcomed.

Federal gold magnum match has worked the best for me for over 20 years.

Nosler 168 Accubond Long Range with Reloader 26 @ 80grains gives me 3265fps with an ES of 5 from my 24" barrel.

 

[Highvoltage]

Wow that's bringing the mail! I think I'm gonna try the 215m and see how it goes. It will be a few weeks before I get time to shoot again. Thanks for all the good advice

 

[Tulsa Reiner]

I've been working up a load in my 300 win using h4350 and 165 accubonds. I've been using Winchester large magnum primers ( nosler load data) And it seems like no matter what I do whether groups are 1/4 moa or 2 moa extreme spreads hover in the 30 ft per sec. I'm using hornady 1x fires brass and full length sizing. What are your thoughts on a different primer to reduce spreads. Any and all advice is welcomed.

Is your rifle a 300 Win Mag, or 308 Win? Referring to it as "300 Win" is unusual, and most of the replies are assuming you mean 300 Win Mag.

 

[Reloader222]

High exstreme spread is caused by inconsistent components. For a start you must weigh your cases in groups, then only use those that you have the most of in one group. You need to trim them all to the same length, debur case mouths and anneal at least after every 3 shots. You could also debur the flash hole with something like the Lyman flash hole deburring tool. If the extreme spread is still high, try change to CCI BR2 or Federal Match primers.

 

[Highvoltage]

300 Winchester magnum. All cases are trimmed to exact length, I weighed them last night and they were within 1 gr. I Ream the flash holes, uniform the pockets, chamfer and deburr. I'm pretty good at prepping but I don't have a neck turning tool or annealer and again the chronograph might be some of the problem too. I don't have access to shoot beyond 300 yds so shooting at longer ranges to verify vertical isn't possible. Again appreciate all the comments. Best wishes

 

[Axl]

300 Winchester magnum. All cases are trimmed to exact length, I weighed them last night and they were within 1 gr. I Ream the flash holes, uniform the pockets, chamfer and deburr. I'm pretty good at prepping but I don't have a neck turning tool or annealer and again the chronograph might be some of the problem too. I don't have access to shoot beyond 300 yds so shooting at longer ranges to verify vertical isn't possible. Again appreciate all the comments. Best wishes

If you are shooting 300 yards, your ES is not going to be a significant problem, if you are happy with how it shoots run with it. As far as which primer will lower ES, you just have to try some of the ones mentioned. Some guns shoot lower ES with brand "x" and some shoot lower with brand "y" and then again it could be the brass or the powder! Good luck.

 

[Reloader222]

Then preperation is 100% and that is not the cause for the extreme spread. I realy think a change to Fed215Match primers will do the thing for you. Federal is known for lower extreme spreads. But remember you need to fine-turn the load to the primer - It is like turning a carburator on an old car. With large magnum size cases it is also preferable to get a powder that would fill the case nearer to the case neck. This will also contribute towards more consistent burning of the powder. Regarding neck turning - I also did it long ago, but that did not improve my groupings/ES. My guns are all factory rifles. If you shoot heavy competition then it might be beneficial. It was finding the right combination that helped me the most.

 

[Heym500]

all 300wm I've loaded for did best with fed 210m

 

[rsmithsr]

I would think a SEVENTY gr load would clear that up.

Is your rifle a 300 Win Mag, or 308 Win? Referring to it as "300 Win" is unusual, and most of the replies are assuming you mean 300 Win Mag.