Home Forums Hunting & Shooting Hunting Rifles 300 WM, 180 Accubond and IMR 4831

Ok, two questions, bear with me; First does anyone use IMR4831 & 180 accubonds in a 300 Win Mag? If so, how much powder and what velocity/accuracy are you getting? When I use Noslers max load I only get 2900 fps instead of the published 3160? Im using CCI LRM primers and a 24" barrel....Second question and this is strange...in Nosler edition 6, 73 grains of IMR4831 is max load and 101% (compressed) fill but in Nosler edition 7, 73 grains of IMR4831 is max load and ONLY 94% fill??? How does the case capacity change? Could this be a typo?

Years past I burned a lot of IMR4831 in a 300 Win Mag;velocitie un that particular barrel were in the 3125-3140 range with a 180 gr Nosler Partition.

But the rifle had been "long throated",meaning bullets could be seated out to a longer OAL. Charges were heavier than the manuals show; how much is not really important. The load was fine with my components in my barrel.

What you are seeing is not that unusual...many manual loads will do in the 2900 fps range with 180 gr bullets from 300 win mags and 24" tubes ,and will vary from what the manuals say you should get, due to test barrels being held to tighter tolerances as opposed to your factory barrel.

Different throats alone can show 100 fps difference. Not to mention the differences in lots of components between what you are using and the manual components.

And yes brass can have different internal dimensions resulting in some of it holding more powder than others.

Add all this stuff up,and you end up with velocity variations between what the manuals say and what you are getting.The manual people are not lying to us;we are simply using different components and different rifles.

In your case, I would say the manuals did what they are supposed to.....give you a trouble free load that works in your 300 Win Mag(and likely thousands of others)without risk of blowing yourself up;yet delivers a decent velocity level at safe pressures.

These differences are intellectually stimulating sometimes and make for great conversation but I suggest anyone not dwell on them too long;concentrate on what your rifle does, and just go shoot it.

Yes but it's not a load I use all the time because I tend to use H1000 with Acubonds and H4831SC with 168 TTSX's, Imr 4831 has worked great in both of my 300's the best load was 72.5 grs as both my 300's have always reached max velocity just below Noslers max load, at 72.5 muzzle velocity was 3140-3150 and the best accuracy, 73.0 was even faster but accuracy suffered as did primer pockets,
couple groups....

Yep, BobinNH, I missed that the two manuals were using two different brass manufacturers. That is the discrepancy in case fill... Also, I loaded all the way up to 74.5 grains of IMR4831 with no signs of pressure, but still just barely getting 3000 fps. Looks like I should try federal primers (when I can find some) and see what happens. Ackleyfan, groups like those at that velocity is what Im after.

RMEF try RL22 with the 180's. You won't be leaving anything on the table in moving from IMR4831.

That said once you are at 3000 fps with a 180 gr bullet from a 300 Win Mag you are only 50-75 fps off what the average 300 Win Mag delivers with safe loads from a 24" barrel.

I wouldn't worry too much about it.It'll kill those Montana elk just fine

I found that with some 300 win mag rifles I get nearly the same max velocity with the 200gr AB or Partition As with the 180gr. Limited # but it is worth a try.

Another vote for RL-22. I use 74.3gr with 180gr AB's in my Sako m75ss 300WM. I use Federal 215 primers. Great load. Only powder I reloaded with for my 300WM and will not change it....been using this load since 2005.

Thanks guys, I will give RL22 a try also. It seems to be a popular choice. Now I just need to find some...