300WSM Starting Point

[TexAg08]

Finally assembled all of my reloading equip, and have gotten to the point that I am ready to start dropping powder. The problem I am running into is that different manuals all have different max loads. Below are the specifics with what I am working with:

Powder: H4350
Primer: WLGRM
Bullet: 175gr LRX
Brass: Hornady
Rifle: TIkka T3X 20" barrel (suppressed)

Looking at Barnes website, they list max load with that powder and bullet of same weight at 68.2gr (compressed). Other manuals list 65-66gr as max load. My hardcopy manual (Lyman 50th) doesn't list any loads with H4350. I had initially planned on starting at 60.2gr and working up at 0.4 gr increments to Barnes listed max. That gives me 20rds for my ladder.

Any recommendations on determining a starting load and what increments I should work with for my initial ladder test?

Thanks

 

[Guy]

H4350 proved to be an excellent choice for the 300 WSM when I was using one.

However, since you're using the Barnes bullet, I'd recommend using their load manual for guidance. Looks like there are several powder choices which will get you into the 3000 - 3100+ fps range, which is plenty.

Noted that for the LRX, the Barnes website doesn't even show H4350. Perhaps there's a reason for that? Worth a phone call to Barnes if you're set on using that powder.

Nothing wrong with starting with Barnes' minimum recommended load and working up, towards the max listed charge.

When working with a cartridge with the powder capacity of a 300 WSM, I often have just gone up in one grain incriments until getting closer to the listed max load. Have never had a problem doing so.

Enjoy - that's a sweet cartridge to work with. I recently sold my 300 WSM Model 70 and gave my loading components, dies, brass, etc, to an old friend who is building one.

 

[tdot]

Do you know how to read signs of over pressure? If not, then invest some time into researching that skill, it is a necessity to keep you safe and maximize your efforts.

On a new gun, I always work up slowly, like what you are thinking. Once I have a few loads thru it, I have a better idea how it handles, how it develops pressure in relation to book max, etc. And the barrel is also broken in. Once I know my rifle, then I generally test at 1 grain increments for my first ladder test to find pressure. Then work off of that info to develop my first ladder for accuracy. But the way you are doing it, will give you all the information, if shot in the proper manner.

I usually start at or close to book minimum. If I cant use the exact bullet, I atleast try to find one of similar weight and preferably construction. I dont use powder info from other powders.

What ladder test method are you thinking of using?

 

[TexAg08]

Yes, I am able to spot pressure signs. I have researched enough about bolt guns, discussed with family who reloads, and have personally dealt with pressure signs on my AR rifles when dealing with my first suppressor and adjustable gas block.

Barnes does list another 175gr bullet in their load data with the H4350 powder, but not the LRX. That alternative 175gr is where I got my min/max from. If I go with 20 rds for the ladder, at 0.4gr increments to 68.2gr, that starts me at 60.2gr which is 1.2gr under minimum. Since I am running suppressed, I figure I may see pressure signs earlier, and with 68.2 being a compressed load I didn't see myself being able to go much above that.

I plan to shoot a ladder with chrono to look for velocity nodes. Once node(s) are discovered I planned to fine tune bullet seating depth. Range time is a luxury at the moment with a newborn, so trying to maximize my trips. Planning to do all my work at 200yds, as that is the max range at my local range.

 

[TexAg08]

Update:

Talked to Barnes, and they recommended splitting the difference in load data between the 168gr TTSX and 180gr TTSX. Looks like I have my starting point now. Will update as I get some load data collected.

 

[TexAg08]

Finally got a chance to get out and perform my velocity ladder. Was able to borrow a Magnetospeed to get the chrono data. These are all loaded to mag length for a Tikka T3X (2.91 COAL).

Data below....



Looks like I have a nice node at 64.0 grains. Now to look at seating depth.

Will also be trying a ladder with some RL16 that I happened to stumble upon at a local shop.

 

[Tuby27]

Old post but care to share your seating depth? I’m working on my t3x superlite, Norma brass, cci250, 175LRX, h4350 @ 65.5gr. My initial test seated ogive at 2.234, had avg 3067fps, but not too happy with the group.

 

[HiMtnHntr]

I would load those to mag length, as long as you can get them and still fit in the mag and cycle smoothly.