.300 win mag brass?


Well-Known Member
Sep 3, 2002
I have a .300 win mag and am working up loads and to start shooting 600+ yards hopefully out to a 1000 yards if i can find the place to shoot that far. One of my quetions is i had bought 300 pieces of remington brass and did prep work ie: primer pockets flash holes neck turned etc. and can only come out with 50 pieces of brass that are all within 1 grain of each other. This might by okay but i would like to get the consitency a little better. I have chronographed my loads and velocities show inconsistence due to brass.I hand weigh all my loads so i know that is consistant.Does any body recommend any other brand of brass? My other question is does anybody know who makes a die that will size just above the belt. I have found Innovative Technology makes one and am wondering if anybody has used one or any recommendations? I am kinda of in need of a die that will take care of this problem beins i have shot this new brass 3 times and am noticing some will not chamber anymore unloaded. Am i missing something or any simple solutions. Any info is greatly appreciated.
Howdy Matt,
I shoot a 300 Win. Mag alot, and I have been using Winchester brass and a old Pacific full length sizing die. I do not weight cases, I just deburr the flash hole, trim every time, and polish the inside neck with steel wool. I size only down to the shoulder, but do not touch the shoulder as to headspace on the shoulder. I am able to maintain 1.5" and some times better at 300 yards. Am able to keep 5 shots at 1000 around 10", but only did 14.5, 10 shots at a 1000 benchrest match.I can get 15 reloads per batch of brass, no chambering problems. The necks start spliting about then, so I toss that batch and start on another. I suppose if I weighted, sorted, etc., like you are doing, I would see better results. But I guess I am lazy, and not very competitive. My friend is heavy into 1000 yd benchrest and uses a 300 Win. Mag..His choice is Federal brass and he is getting pretty good results with no problem. Hold on to your hat, as I am sure more information is on the way from people who are more experienced with this subject, and good luck with your shooting project!
Hey thanks meathead. I am sure i will get responses at least i hope so. I am finding alot of info on this forum.I stumbled upon it searching the net one late night.Whoever started this is a very smart person. With the load i have settled on i am shooting 220 MK with RL-22 72 grains.I know the books say it is over max but i don't see any pressure signs ie: primer is still round and the bolt isn't sticky and the weather is getting cooler
Through the chrony i am pushing these 220's 2930fps and shot .620 5 shot group at 100 yards. I have just a factory .300 win mag sedero with 26" barrel and factory trigger. A jewell trigger is on order and hopefully here soon.I have been able to push the 220's 3050fps but haven't had the the good groupings like the 72grains have. Thanks to all for info and look forward to learning more about long range.
Matt27, go to Long Range Hunting. There is a recent post about 300 Win. Mag. brass. I checked it out and Lapua is making 300 Win. brass. Spendy, but who knows? Just might be the ticket!
Thanks meathead. I saw that post and am waiting for my buddy that has an ffl liscense to get back from vacation and am going to order some lapua brass.Will get a better discount with him.
if some shooters are interesting I can get a nice quantity of RWS brass in 300 Win Mag once fired at good price

let me know

good shooting

matt27--I've found that Federal Gold medal brass is pretty consistent for weight and accuracy. I bought 100 cases, sorted by weight, and use the ones that were more than +/- 1.5 grains for sighters during competitions. I try to shoot a 10 shot string for score with cases that weigh the same(no more than +/- 0.2 grains) If you sort the brass and mark the weight on the case in permanent ink (its not permanent-sizer lube takes it off) near the belt, you can at least minimize another variable. Try small batches of other brands of brass and find one you are comfortable with. Good luck and have fun!
Matt, I found the Winchester to be all within a two grain spread, and Federal to be about a five grain spread on the 308 win brass in the past. I'm starting to load for the 300 WM now and will start with Winchester for that reason. Remington is out of the question. The Federal brass was not the gold medal so I can't speak to what the spread might be with it. Onother thing, the batches of Federal and Winchester both were about 5 grains off from the previous batches of each too, so buy a bunch. With the Win, about 70% was within 1gr and that fell about in the middle of the overall weight spread. I'd buy Lapua if I wasn't so impatient.
Thanks Brent and all. I have a shipment of Lapua brass on the way.Got 100 pieces of Norma brass and just wasn't happy enough.I guess the saying is true you got to spend money to get qaulity!!
Hi Matt, I also have a Remington Sendro in 300 Win Mag. The Action has been trued, Kreiger barrel, muzzle brake, and the trigger lighten. I've shot a .189" five shot group at 100yds and a .685" three shot group at 400yds with it. The load I use is 68gr AA-4350, Federal GM brass weighed to within 1 grain, Hornady 178gr A-Max, and a Federal 215GM primers. I just got some Norma cases but haven't worked up any loads yet. I used to think that factory barrels were great but after having a few custom barrels, I was wrong. I've had some custom barrels that I'm not impressed with while others I'd buy in a heartbeat. Something else I've learned. I don't care what kind of barrel you have. It still comes down to the loads. Good luck and good shooting
Big Dog

I know it is all bout the load. I shoot in the .2's to .1's at a hundred yards also.I am just trying to get all the variables down to a nill.I know my rifle is not a custom but after hunting season it will be getting a 30" lilja or pacnor on it with muzzle break.I do shoot 2-1 inch groups at 600 also with my load.
Thanks matt
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