300WSM build opinions.

[ceard]

Alright, so after much internal debate and flip flopping though cartridges and wild cats. I appreciate the time some of y'all have spent answering my questions. I am going with something semi simple. As much as I really, really want to do something that I don't have, my buddies can't get off the shelf, have to make brass for and try to squeeze as much performance out of a specific case as I can. In the end it will only take up time I could spend with my kids (they are tiny and not close to old enough to help) or at the range. So, I'm going to have a "properly" throated 300WSM barrel cut for my range purposes mostly under 1000y sometime out to 1800y. I also will have a lightweight 7prc barrel cut at the same time for hunting.

My question is when I was speaking with the smith and I told him what I wanted to do with the 300wsm in a long action and final COAL will be much longer than spec. He suggested I load 3 rounds to length and send them in with the rifle. And here in lies my problem. I don't know what bullet I will be going with. I was planning on shooting and testing bullets from 215-230gr and going with whatever gave me the most consistent groups. So is there a free bore length that will let me do a 15gr range in bullet weights? Should I pick one I think sounds good and hope for the best? Am I severely over-complicating this to myself.
Also apologize if I am asking dumb questions this is the first time, I will be loading anything outside of SAAMI spec COAL and I want to make sure I am doing things right.

 

[01Foreman400]

I love my full custom 300 WSM but not sure I'd want one on a long action. Why not go with the 300 Win Mag at that point?

 

[ewnanney]

Or a 300 PRC?

 

[ntsqd]

Curious thing happened when I had to provide 3 dummies for my .308 Norma barrel. I intend to shoot 168 HPBT's & TMK's, 190 HPBT's and 195 TMK's. I set up the dies and slowly walked the 195's into position. Then on a lark I seated a 168 TMK with the same die setting. By eyeball the COAL is the same. That means that the CBTO is the same or extremely close for both bullets, too. I highly doubt that is an accident. I sent 3 seated with the 195's.

 

[Longshotjames]

I sit in the corner with 01Foreman400 on action length, I love my 300wsm but if I put it in a long action I am going 300PRC.

If I were in your shoes I would pick either 208eldm(my choice) or Berger 215hybrid and make your dummy rounds that just fit in the magazine and let them throat it according to the jump you think you want. Then when the rifle is ready, you work up your loads and find out what actually works. I did this with a 300wm and 225eldm before the PRC was invited and it is a lights out 1\2moa rifle!

a story for you about my 300wsm: I had Shilen cut me a match grade barrel with the twist for 208-215gr bullets on a Savage prefit. When I get it back they used a new Fclass Match reamer that ended up shorter than SAAMI. Shilen was great and offered me a new barrel but I wanted to try it. I have to seat the bullet .030 deaper than I intended but everything runs through the magazine and it shoots 1\2moa easily with 208eldM, 208LRHT and Berger 200.20X Hybrid. So I am not worried about seating the bullet slightly deeper for case capacity one bit. Im getting 2750fps out of a short 20" barrel using 6.5Staball.

The point is, I wouldn't be too worried about those dummy rounds. Make them how you want, send them and let the Smith do his job. You can custom tailor your ammo to fit your custom chamber and have a rifle you are proud of! Hope you have fun with your rifle and spend time with the little ones!
Happy Shooting
James

 

[ceard]

As for why not the WM I don't want a belt, the 25degree shoulder and from everything I have seen posted on here the WSM will meet WM or be within 50fps of performance with a few less grain of powder.

And the 300prc is more I already have alot of brass and dies for a 300wsm. I assumed it would be a bit easier to download for my wife or if I was just plinking 500yard steel, with the case capacity it has. And it seems like I wont loose much as far as velocity. There are a few threads on here that claim 2750-2825 with 225s in a long action WSM. and Hornady's website has the 225s @ 2810 in the 300prc.

Also I was told that the 35degree shoulder will let my brass last a little longer vs the 25 and 30 or the wm and prc. Is this correct?

But glad to know I don't need to be worried just load up the dummies and send them in. Now I just need to wait on my buddy to by his s20, he wants my factory barrel and it will be being sent in at the same time to get torque specs for his receiver.

As soon and my kids are big enough to help me with loading and or spotting lol I will be doing a wildcat, something like a 300 norma improved or maybe a large 338 depending on how much I want to spend on the project when it gets here.

 

[Hand Skills]

300WSM on a long action is AWESOME!

This photo courtesy Swamplord - I'll see if I can find the thread;

300 WSM Long Action Build - Input Welcomed

Fantastic thread ! The timing could not be more perfect, I am also on the long anction 300 WSM kick and have two Tikka T3's I'm going to turn to the dark side ! I made a cutaway case not too long ago and modeled some bullets to determine the optimum seating depth I would use, turns out my...

www.longrangehunting.com

 

[lancetkenyon]

This is why you build a .300WSM on a LA, not a SA.

200.20x Berger Hyb. Not even the heavies.

 

[UCzO___]

I built my 7SS on a LA and regretted it from the beginning. It is a slightly different beast, but, you will have issues with magazines. Maybe split the difference and go with a Med/XM action? That is what I am thinking when I finally get around to building a 300WSM. Good luck.

 

[wvbearhunter]

I built mine on a medium action and have been very happy with it. I think youll regret doing a LA when 300 prc is already available

 

[Ross1147]

Go long or XM at a minimum. I think, pulling this out of the cobwebs in my head while I wait for it to get light turkey hunting, a properly throated WSM for the 215 Berger is .188 freebore. I didn't know much when I had my first custom built, so I went a .088 freebore. It's perfect for the 200.20x but just a little short for the 215. Both COALs are around 3.12". Only think I'd change on my is going with a faster twist. If I could do it over I'd put a 1 in 8 or 1 in 9 minimum.

 

[Hans13]

I'm doing load work up on my 300 WSM right now. I have a .220" freebore on a medium LPA Fuzion. If you are wanting to go with 215-230 bullets I think it would work quite well, but you'd definitely want a long action. I have to jump the 215s a fair bit to run from the mag. 208 ELDMs and 212 ELDXs run fine though. I can't imagine you'd have feeding problems as I have a 7 SAUM that feeds like butter out of a LA. If you are worried about it you could always run the Hawkins Hunter magazines with a spacer kit.

 

[Mike D Texas]

You really have several options here.

1. Build it on a short action. Make sure the action has a Wyatt's cut load port and use unknown munitions DBM. This will allow you to seat out to 3.150" in the magazine.
2. Build on a medium length action. A BAT Vesper action and the UM DBM will allow seating out to 3.400"
3. Build it on a Tikka action. I'm slowly warming up to the Tikka actions for builds. They use one action and vary length by a user changeable bolt stop. Also prefit barrels are readily available for them. The only downside is the aftermarket support isn't as good as the 700 pattern actions……..yet. You can get a fully custom Tikka build from a coupe of well know rifle builders for significantly less $$ than most traditional builds.
4. Build on a long action. Personally this would be my least favorite option. If you are going to run a long action, I personally see it as a waste and leaving performance on the table.

 

[LongBomber]

I would just seat a 200.20x or 215 berger where you want it, and know that other choices will be off a tad. If you can get the 200.20 to shoot well you really need to run some numbers to see if you gain much running anything heavier.