124gn Hammer Hunter in a .300WSM - powder recommendations?

Hi All,

I've got a Kimber Montana in .300 WSM. I had some accuracy work done on the rifle, and it is a real shooter. I really like Hammer Bullets, and that is pretty much all I load in my rifles. And, I like speed.

The last couple of years I have been shooting 124gn Hammer Hunters in this .300 WSM for deer and antelope. I know this is lighter than what most people would run in a 30 cal magnum, but holy cow it is pretty much a "point and shoot" proposition, and is like flipping the "off" switch when the bullet hits. Consequently, the typical powder recommendations don't apply, here. In my rifle, there is an excellent accuracy node at 3550 fps with IMR 4064. I have finally shot up that batch of ammo, and now is the chance to revisit the load for the rifle.

With IMR 4064, the rifle pressured out at 3760 fps, but I wasn't finding accuracy in that speed region, which is why I dropped down to the 3550fps loading. Velocity data is from a Labradar, which is spot checked with a Magnetospeed at the beginning of each shooting session.

I also tried Vihtavouri N550, which is considerably slower burning than IMR 4064. I never found max pressure, and had to stop at 3825 fps because hunting season was upon me and I ran out of time to further experiment. I did not find an accuracy node in the 3825 fps region with the Viht N550, but I will continue further development.

Since I am always trying to pick up more speed, can anyone recommend a powder to try out in addition to N550?

The rifle and some factory loads I had laying around:


Results with IMR 4064 and 124gn HH:

If you have RL17, H414, or Win760 I'd give those a look.

I had great results with H4350 but I was shooting 166 g

Thanks

Buck

I'm thinking trying the n550 at 3825 fps and adjust seating depth to see if it will come in.

RockyMtnMT said:

I'm thinking trying the n550 at 3825 fps and adjust seating depth to see if it will come in.

Click to expand...

Good suggestion. Thanks.


This is the graph of powder vs velocity & group for the 124gn HH and N550. I got a good 5-shot group at 67.7gn (about 0.7") , but couldn't get it to repeat. Bullet jump was .027", neck tension was .0017". I'll next probably find max pressure, then go back and play with bullet jump (i.e. seating depth) at whatever showed the most potential.



In addition to Zen's suggestions, I am thinking H4350 is worth a try, since its burn rate falls between IMR4064 and N550, and it has a reputation as being temperature stable.

A little more neck tension could be helpful too. One thing at a time though.

Copy on the neck tension.

Now that I am revisiting the data, 0.0017" is on the light side. Not sure how I ended up at that value.

Bucklowery said:

I had great results with H4350 but I was shooting 166 g

Thanks

Buck

Click to expand...

Me too.

Varget or IMR4166.

I used n550 with 152 hh and it worked great in my browning abolt 2.

Looking at Nosler load data for the 125gn Ballistic Tip in a .300 WSM, N550 seems to be the peak for speed and accuracy of the 10 powders tested.

As usual with the slower burning powders, the challenge is stuffing enough powder into the case to get good velocities. N550 is close to, if not at, that limit. The Nosler data shows their max N550 load at 102% load density, meaning it is slightly compressed. Considering all-copper bullets tend to take up a little more case volume, powder compression could be the reason that my previous load work with N550 stopped a 69.5gn despite no pressure signs.

Looks like I definitely need to redo my N550 load workup at the higher end. And go in smaller powder steps, and take better notes.

I use RL 16 in my 300 WSM with the 152 HH. It's right at 3400fps no pressure. Super accurate also.

I just started playing around with the super formance powder I'm also loading 180s and 165gr out of the wsm. Not sure if there's a recipe for later bullets

H414 and 4166 both give high velocities with the 124s as stated above. Look at Hammer Hunter Load Data on this Forum.