300 Win Mag w/ Hornady 165 SST

[ericmac214]

I am trying to build a load for my 300 WM using Hornady 165 SST. I am running 2900 FPS with 70.4 gr of ACC 4350 with no signs of overpressure (not even close). Book max is 69.7 gr.. I am fairly new to reloading and I am not sure how much further I can go past book max with this powder. The gun is grouping around an inch @ 100 yards which is well within what I expect for hunting rounds (all I reload for).
I was wondering if someone out there has a load for their 300 Win Mag using Hornady 165 SST they would not mind sharing or have a little more experience than I do with ACC 4350 and its limits. I plan on building a few loads and working my way up the ladder to get my velocity to 3100 fps but thought I would reach out to the experts before I did just that.

Thank you in advance!

 

[markm87]

Brass is going to be a factor for sure. We run RWS brass, Nosler, and FC. They all have different internal case volumes.

I've never tried PPU brass in 300wm. But we push the heavies (220-225 ELDs/ELDXs) into the 2900 fps range. Our powder of choice is H1000. I'd guess you have some room to come up in velocity (assuming 22-24" barrel) without worrying too much.

 

[ASD9055]

I used PPU brass in 338LM, they hold
A little less than lapua brass, but they are fine

 

[Drop Port]

I am trying to build a load for my 300 WM using Hornady 165 SST. I am running 2900 FPS with 70.4 gr of ACC 4350 with no signs of overpressure (not even close). Book max is 69.7 gr.. I am fairly new to reloading and I am not sure how much further I can go past book max with this powder. The gun is grouping around an inch @ 100 yards which is well within what I expect for hunting rounds (all I reload for).
I was wondering if someone out there has a load for their 300 Win Mag using Hornady 165 SST they would not mind sharing or have a little more experience than I do with ACC 4350 and its limits. I plan on building a few loads and working my way up the ladder to get my velocity to 3100 fps but thought I would reach out to the experts before I did just that.

Thank you in advance!

View attachment 1397777

When I shot a 165 NBT out of a win I used H4350 for target @ 2950 fps it shot an inch at 300 yards. My culling load was with R-22 and it ran 3380 fps and 1/2 moa at 300 yards. You can drive 165's extremely fast and accurate with the correct powder.

 

[markm87]

Yep. We ran some side load with lighter stuff an R-22. I was getting much more speed with less pressure signs with Reloader and lighter bullets.

We were playing with lighter bullets due to high recoil on the particular rifle compared to the other 300s in the bull pen.

 

[Kurz]

.300 Win. Mag., probably one of the most popular cartridges designed in America. There is a huge number of bullets and bullet designs which can be useful in the .300 WM. Powder selection can be surprisingly varied also.

Noted mostly for the heavier bullets, it's not unusual to find hunters and shooters looking at the lighter selections in order to curtail recoil.

The original load for the military featured the Lapua 185 gr. FMJ producing 3,000 fps approximately. Later this was revised for the 190 gr. Sierra.

In your situation, the Accurate 4350 is a pinch too fast. You can't get the case nearly full and still reach the the velocity level you ask about. But, putting a velocity level before achieved accuracy in not where I would start.

I used the Nosler 165 gr. Ballistic Tip for some initial loads since I had them on hand, similar ballpark to your SSTs. Re-19/22 worked better for me although later tests found that Re-26 was excellent! The problem is that Re-26 is difficult if not impossible to find.

If you're stuck with Accurate 4350 then continue your load development increasing 0.3 grains at a time. In the mean time, keep your eyes open for other powders.

I have a load featuring the Badlands 150 gr. BDZ2 (long, solid hunting) and works extremely well with Re-17 but like your load, it's a tad faster than I normally like.

Work on your load some more or maybe consider switching powders.

Enjoy the process!