I'm fairly new to loading a FN action 300, 23" barrel and 10.5 twist. Getting 180 gr Nosler partitions set up for the first time. Various loading manuals are all over the map on max loads, ranging from 63.5 Hornady for 2800 to 73 gr (IMR manual) for 3035 fps. Nosler manual goes to 66 grains for 2990.

Yesterday I chrono'd 67 grains at 2790, using Federal 215's.

I'd be interested in your experience with the 300 and 4831.

My plan is to go up 1 grain at a time until I reach 2900 or so. I don't see a need to push the H&H to it's limit at this time. Thoughts on this plan?

73grs sounds VERY HOT. More like a H4831 load not an IMR. Never loaded the part but did load the 180 CT silver tip few records I still have show 69 as where I stopped. Sorry no velocity record. I show I ended up with MRP for accuracy and velocity.

Bob

I've tried various 300 H&H loads (RL 22, H4831, H4831sc, IMR4831,H414) with 180 & 200 gr bullets, no Chrony data, but I found RL 22 (very close to Norma MRP) gave me the best accuracy in both weights - 67 gr for 200; 70 gr for 180

If you are set on IMR 4831, I loaded 66 gr for 165, 62 gr for 180, 61 gr for 200

Other thoughts:

As far as manuals, when they vary a lot, I go with the bullet manufacturer's manual; so I would stick with Nosler's manual in your case

I would go up 1 gr till you get close to max and then go with .5 gr increases, watch for tell tale signs of pressure since every gun is different.

I don't chase velocity unless it dramatically impacts accuracy. Why add the punishment. Most of my guns are capable of greater accuracy than my shooting skills can provide. I'm pretty good off the bench but others (including my 16 yr old son) kick my butt when shooting off sticks or supported positions like sitting or kneeling. In the field, I usually bring home the bacon but only take shots over 200 yards when it is the only choice.

If you find a load you are happy with before you hit your desired velocity, I would would stop and call it good. I don't think your quarry will notice the difference if you hit them in the sweet spot.

Also, I have been experimenting with Large Rifle primers vs Magnum primers and so far I have not noticed any impact to accuracy.

Hope that helps

It's interesting that my Nosler info shows that they use the same data for the regular partition, protected point partition, and ballistic tip 180's. My test load was one grain over their max but 150 fps slower. Since almost every load for the 300 goes 3000+, I think I'll be safe creeping up from 67 and not going past 2900. 73 in the IMR manual does seem way over everybody else's data.

I use almost nothing but Nosler bullets. That said I find their manual very optimistic on velocity and conservative on powder.

For your info from a 23" QL calls 67grs of Imr 4831 behind a 180 Part as 2846 at 57600psi. I'd call your measure of only 56fps less darn close.

The Nosler book has a 24" I would do as you plan slowly work up.

If I slow the burn rate down to give 2790 with 67 grs the pressure drops to 52000 at the slower burn 69 grs gives you 2873 and 57,000. 69.7 gives you 2900 and 58,970psi.

bobc

With 180-grainers my 721 likes 70 grains H 4831SC, and at 2800 fps that's good. IMR 4831 is hotter, and noticeably so. Take it slow!

Well, first and foremost, we must remember that every rifle is different. What is good in one might not be in another.. But, you already know that.
So, the prudent thing to do is work up from 67.0grs and see how it goes.

IMR indicates that the .300 H&H has a max working pressure of 54000 CUP. In it's hay day this was probably the case. I don't believe a lot of current data, or ammo makers, load it that high.

My .300 H&H, an 80's vintage Model 70 with a 24" barrel, likes 72.0grs IMR4831 with Sierra 180gr Spitzers.. Winchester cases and primers.
Velocity averages around 2980fps. No signs of excess pressure.
It's the most accurate load I could find in this rifle with this bullet weight and I've tried about everything available. I can equal the accuracy with N-560 but I don't get near the velocity before I reach max.
When I worked up this load, I started at 68.0grs and went up 0.5grs at a time, just like you are about to do.
At 72.0grs, groups were small clusters so I stopped there.

Winchester doesn't make .300 H&H brass any more, so when this brass wears out I'll have to do something else.
I did pick up some Norma brass a while ago and found the internal capacity to be a little less than Winchester and pretty equal to Remington. I have not tested any other make.

So the brass you are using will play into where your rife will max out. I can't load Norma or Remington the same way as Winchester.

It is weird that data for the .300 H&H is so scattered. I've always wondered about that..