300 win mag questions.


September 29, 2011, 08:09 PM
So I took the plunge and picked up some 180 grain Hornady BTSP's.

My question is this, where should I expect to find the best accuracy, low mid or upper end of the recommended charges?

I am using 7828 SSC.

I had great results with Hornady's starting load and their 165 grain SST over 7828SSC. But I would like to try 180 grain bullet to see what I can get out of it. I think the heavier bullet would be a better choice for hunting large and sometimes dangerous game such as Moose and Bear.

Thanks for your input

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September 29, 2011, 10:24 PM
Many manuals point out the most accurate load tested, my Nosler book shows their 180 gr bullets 75.5 gr of RL22 it is a max load so use with cautionI use that load with SGK 180's and it is good.

September 30, 2011, 12:45 AM
Where you find your accuracy is mostly dependant on your particular barrel. With IMR7828 you'll likely find it on the "lower end" of recommended charge levels like you did with the 165gr bullets. With the slower powders such as RL25, or Retumbo, you'll likely see best accuracy at the higher end loads.

My .300 is the .300RUM. However, with the starting loads, with IMR7828 I get excellent accuracy and better velocity than the manuals suggest. This is because my Savage M110 has a 26"bbl and a long "Weatherby" free bore throat which boosts velocity somewhat.

Only by loading and shooting will you find out what YOUR barrel prefers..... re: the Hornady 180gr BTSpt., by .30cal bullet standards, they're rather "soft". I've shot them both from a .30/06 and .300RUM. They are the "factory load" bullets in the Weatherby ammo, and have been for years. For large deer and elk, and smaller moose or bears they are great... But, they do expand readily and may not penetrate as much as some stronger constructed bullets such as the Interbonds or GMX.... I've only had poor experience with the SST's so can't recommend them for ANY use. (accuracy, and failure to expand in some intances.).

For something such as Moose or great bears (Grizzly, Brown/Kodiac) I'd use at least a Nosler 180gr Partition or Swift A-frame. If purposely hunting Moose/great bears, I would definitely use the Swift or Nosler in either 200gr or 220gr with the Nosler.......from the various .300magnums.

But then again, I'd use either a .338 or .375 rather than a .30..... if on purpose hunting said game, that is...(I have both....also).

September 30, 2011, 01:03 AM
Thanks GooseGestapo That's the info I needed. If I Moose hunt on purpose it will be with a 45/70 or a BP gun. I mostly got the BTSP to try to develop some load data. If I decide that this bullet weight it what I want then when loading hunting ammo I will likely purchase a premium bullet.

Thanks again for your response.

September 30, 2011, 01:14 AM
You can safely load for maximum performance for that cartridge using RL22 or RL25 and depending on how heavy the bullet. The 180gr. goes well with RL22 for producing some very high velocities and certain to group decent as well.

Start your load just below in most actions, so just start your work up at mid range, or you'll just be wasting powder trying to get to where you want to be, and the 300 WM can eat a lot of powder real quick.

Don't be too worried about trying to seat up close to the lands. The 300 WM doesn't usually have enough neck to reach the lands on many actions, while still providing enough neck tension to prevent set back.

September 30, 2011, 05:50 AM
i started reloading for my 300 win mag last year and have had very good success with it. i am using a 180 grain Nosler Partition over 73g. of IMR 7828. My groups have been really good, and it is a brute when placed through the shoulders of a whitetail. I don't have a chrono so i can't tell you velocities. The Nosler book does state that the most accurate load tested was the 73 grain load. Cheers, hvychev77

September 30, 2011, 07:51 AM
I use RL 19 and about 2 grains below max in my Savage gives me the best accuracy using a 180 grain bullet. All the brands I tried seem to give about the same accuracy with the same amount of propellant. I have seen no need to try improving my groups with different bullets as I think that they all shoot better than I can hold now.

September 30, 2011, 08:02 AM
My question is this, where should I expect to find the best accuracy, low mid or upper end of the recommended charges?
Or maybe both. With some loads I've found good grouping in the lower pressure and higher pressure. Groups started out tight, opened up, then tightened back as I went through load development. I tend to prefer hot rifle ammo.

My best loads in 300wm have been with H1000 and R25. Both liked high pressure (+/- book max).
R22 with mid-weight bullets in the 165 to 180 gr range shot very well and grouped best toward (but under) book max.
H4831sc with mid-weight bullets grouped best mild-med pressure. Was cleanest at upper pressure. Never really got 4831 to work right for me.
Varget w/ 125gr bullet (yes Varget!) shoots a pretty good group loaded at listed max. I didn't do a lot of load development on this one, I just worked it up to max, then tested for accuracy. It's a fun combo!

October 1, 2011, 11:59 PM
Well GooseGestapo was right on. I found the most accuracy at the lower range. 66 grains of the 7828SSC seems to give great accuracy. I will be interesting to see if or how much I have to change my load when I switch to a premium hunting bullet.

I will also try some Reloader 22 and see how it does. But for now I have some great shooting 165 grain bullets that will be more than adequate for this hunting season.

October 2, 2011, 09:17 AM
in my gun (Remington 700 BDL 300 Win Mag), with that bullet / powder combination, my best results are with 76.0 to 77.0g of 7828. they are not stupendous by any means, but good enough for hunting. the best i have been able to get out of it with 7828 is 1.6" groups. from a barrel that is capable of real 1/2 sub moa groups. i am i excited about them, no. but i will obviously shoot the rest of them up, searching for the evasive sub moa mark. imr 4831 is a little better, but not enough to warrant buying a new bottle. i am going to buy a bottle or reloader 22 or 25, and see how that works

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