Home Forums Reloading Big Game Rifles 300 win mag loads

New to reloading this year and have reload 308 win, and 257 wby with great results, but I can not get it right for my 300 win mag. I would like to stay with 180 barns TSX because i like their preformance and they have always shot well in factory loads. I started with H4831sc/ 66 and H1000/ 74 with WLR primers,and have worked up and down a little with the charges. Any one have any load or other powders suggestions?

If you have some RL22, give it a try. Somewhere between 74-76gr is probably where you'll end up, depending on your lot of powder.

H4831, H414, RL 22, and IMR7828 all give good groups in my .300WM.

Ive always had good luck with H1000 and Retumbo in my 300 win mag.

plus one on the RL 22


Ed

I don't have a manual in front of me but your H4831 loads sound light; not sure about the H1000 but it also sounds light,since that is about where you should be with R22,which is a quicker powder.The rifle might not shoot till pressures are up a bit more.This is common with many cartridges,300 Win Mag included.

BobinNH, you are right they are below the max recommended load and I we have to try increasing the charge to see if that helps. I was trying to be safe just started loading and was not sure how safe the max recommended loads are.

IMHO RL22 is my "go to" powder for .300 win mag with H4350 my second choice. It may be some other powder will work better but if one of those is not showing some promise, I figure something else is wrong.

You mention X bullets. You said "always shot well in factory loads." Clarify: in this specific gun, or others? If you've already had success with X bullets in factory ammo with this gun, then by all means keep fussing with powders, maybe change primers, adjust overall length, and so on. But if they have not worked in this gun, and you can't get them to work with a reasonable amount of effort / expenditure of components, I'd change bullets. There are just a lot of rifles out there which won't shoot X bullets well no matter what you use to put 'em in motion.

If you want to stick with a homogeneous metal bullet, give the Nosler E-Tip a try. They seem to shoot well more often than the X-es do .. at least, in my limited experience.

Another possibility would be to change X styles from a flat base to boat tail or vice versa or change weights. Some guns are quite finicky about bullet base shape and most are particular to some degree about muzzle velocity so changing weights can move you into or out of an accuracy node for your specific barrel.

G' luck!

Tom

Get a measurement on the factory ammo for OAl and reload your ammo at that length. I have done this with a few guns that shot factory ammo and wouldn't shoot the reloads with the same bullets and it usually works out.

knthartter: Nothing wrong with being safe! But also be careful of substantially reduced loads of slow powders....in the past funky things have been known to happen...

JB has written many times that modern slow powders tend to behave their "best" when loaded up to higher(but safe)pressures. I did not have my Barnes manual handy, but the Speer manual calls for a max of 75 gr H4831SC with the 180 gr bullet; you're at 66 gr..Also with H1000 they call for a max of 81 gr with the 180,and you are at 76 IIRC.

General rule of thumb is to not reduce max loads any more than about 10% with slow powders.....

Sounds like you have a ways to go and I think you have room with both powders to work up while watching for pressure along the way. If you have a chronograph I would watch vels as you work up....you should be OK

My NULA Model 28 likes the barnes 180 TSX with 80.5gr H-1000 That is .5gr under max according to hogdons data..but start low and work up !

Tom, Sorry and yes I have shot the factory X bullets out of this gun and they have prefomed very well. I will try the RL22 and E-tip.

Heavywalker, thanks I will do that.

BobinNH, I here ya on the that, I did read a post on another site were a guy reduced the powder too low and had some gun problems.

Thanks to everyone for your help.

How does IMR 4350 work in a 300WM? I am new to the 300WM and am working on loads for 180 and 165 TSX bullets. I have plenty of RL22 and IMR 4350. I have gotten slightly higher velocities with RL22 but got to the Barnes Manual maximum load without getting very close to the published velocities in either. I think I am going to edge up a bit towards the maximum loads listed in some other manuals to see if I can get a little more zip.

I shot some test loads for the 165TSX today out of a M70 with a BOSS. The manual max for RL22 is 75 grains and is listed at
3143f/s. I got 3045. The manual max for IMR 4350 is 70.5 grains and is listed at 3125 f/s. I got 2984. I was seating the bullets at a COAL of 3.375" whereas the max SAAMI length is listed as 3.34". The rounds chamber at 3.54" but do not fit in the magazine. Would the 0.035" extra COAL be enough to reduce the velocity that much? I suppose I need to try some at 3.34" to see how they do.

I did notice the RL22 loads seemed to have greater recoil than the similar velocity IMR4350 loads. I suppose 4.5 extra grains of powder would make some difference but was surprised it was as noticeable as it was.


With the 180TSX seated to COAL of 3.33 I get 2897 with the manual max load of 69 grains of IMR 4350 and 2916 with the manual max load of 73 grains of RL22.

My Belgium Browning .300 Win mag liked those 180 and 200 grain bullets for hunting big game animals. I used those 190 grain Sierra BT for shooting long range targets.

I used to shoot IMR-4831 powder with the 180 grain partitions and they always group well for me. Later on I tried RL-22 and it also did well shooting 180 & 200 grain bullets. My velocity was around the 3,100fps mark.

Aviator,

The maximum loads listed in manuals are normally quite safe these days. Forty years ago they were sometimes not so safe, but today all the manuals only list pressure-tested data, and unless a rifle is custom-made with an off-standard chamber the max loads are quite safe, as long as you stick to the same make of bullet listed.

Your H4831 experiments sound like they ended on the light side. One of my standard loads for the .300 Winchester is 75 grains of H4831 with about any 180-grain bullet. This often isn't quite as fast as with some other powders, but it does usually get around 3000 fps and is very consistent in a wide range of hunting temperatures, while some other powders are not. This is a characteristic of the Hodgdon Extreme powders.

I use nothing except 180 gr. Hornady #3070s in mine, with a bit more IMR4350 than the books show. It drives tacs, and kills stuff extremely well. Never found a reason to change a thing.

The only thing I would like to add is to differentiate between the "X" and the TSX.

The TSX is a lot more forgiving and a lot better shooter in a wide variety of tubes.

FWIW in thirty caliber and a couple bullet weights, the TSX has shot better than the E-Tip; In three 300 Winnys, the TSX's have shot great.

RL-22 or RL-25 for me with 180's and 200's.

80 to 83 grains of H 1000 is my 300 Win Mag loads with bullet weights from 180 to 220 grain...

notropis, M70 Classics in 300 Win Mag have longish throats; long enough that you can seat bullets relative to the lands and they will not fit in the magazine. This creates a bit of "free bore" effect,and I have swapped out parts to open the magazine to H&H length to alleviate this issue.

This may be obsessive tinkering but it did help bullet to land relationship with 165 gr bullets,and actually helped accuracy with 165's; not so much difference with 180's.

When I had these rifles in 300 WM so altered I worked up with the 165 until velocities were in the 3150-3175 range,and 180's were comfortably 3050-3100, and stopped there. I never suffered any ill effects with this arrangement.

These were of course all M70 Classics.

Some rifles just don't like some bullets.