Custom 300WM Build From A to Z: The Process / Pics

[Jig Stick]

For the past year I have been planning on building a custom 300WM rifle. This site has been crucial in learning about the process needed to go from an "idea" to a finished rifle. I thought it may be nice to have a post that went through step by step what needs to happen in order to come out with a rifle that will make the owner happy. I know that I have personally spent HOURS doing research and Im hoping my experience may be able to help others.

The first thing I did was talk to friends and guys at the ranges I go to and picked their brains about shooting in general, actions, calibers, ballistics, optics, stocks, performance etc...

Then I came up with a goal of what I wanted to accomplish with the rifle I intended to build. For me it was to have MOA to sub MOA accuracy from 600-1000yrds in a caliber that I found appropriate for hunting, target shooting, and reloading that fit within my budget. Personally, for me, 300WM fit the bill because most of my shooting buddies shoot this caliber and have been making their own handloads for years. So the knowledge base that I could tap into was enormous.

Next, which I found to be the most enjoyable (and expensive) part, was to start picking components. For this I relied on the experiences of my buddies who have built customs in the past, and from my own personal experiences shooting different rifles. My gunsmith was also an awesome source of information.

So this has been as far as I have gotten. I met with the gunsmith over the weekend and got some measurements taken, and started picking components. I am still a little uneasy because I feel that I am forgeting some things. I am hoping that you guys can chime in and add to this post things that I have forgotten to include or havent thought about. I would help me personally with this build, and other first time builders looking for an indepth step by step resource (ie like a check list)that covers all the bases.

Stock: McMillan Adj A3-5 (mine will be Black for now)



Action: Bat Action HR Repeater with Picattany in 300 Win Mag



Bottom Metal: Badger Long Action Magnum



Rings: Badger M40A3



Trigger: Jewell with Safety



Scope: Nightforce NXS 3.5-15 x 50 F1 MLR Tactical reticle



Bipod: Harris HBRM-S



Barrels: Krieger or Broughton 26in with 1:10 Twist (no pic)

These are what I have picked so far. I have a few questions and need advice.

1: I will most likely be shooting heavy loads, so is the
1:10 twist right, or should I go with 1:11.25 or 1:12?

2: What do you guys think about the reticle choice?

3: What magazines fit in the Badger bottom metal, and will
they hold 300 Winmag?

4: What do you coat your actions,barrels with? Teflon?

 

[Kells81]

Re: Custom 300WM Build From A to Z: The Process / Pics

Maybe I just dont get the point of the post...

So have your purchased any of this yet or just jacked pics off the net to ask for opinions?

Cannot say I have done hours of research unless you count sitting at the range trying this or that out. This is where you will figure out what works for you and what does not. IE I used to have a bunch of AICS stocked rifles, now I am moving more towards McM's since I prefer the A5 over the AICS. Or chosing a DBM on a certain rifle cause its a PITA to feed from the internal box mag setup IE my rem 223 and Rem 280AI which is why I went with a M5 on my current AI build. I have found it to be pretty much trial and error on most things. I will buy what I think I might like or may work and sell it to try something else if it doesnt fit.


I have also found the best way to go from an Idea to a finished rifle around here is look at the EE, right now if you dig enough you can find a well built justabout anything there unless you want a freak round IE 280Ackley. I picked up a nice GAP 300WM off there last month in an AICS cheap enough it was almost robbery. With what you have listed it looks like a good build though.

The M5 comes with 338L or 300WM AICS mags so your good there

For the heavy stuff in 300WM you will want to go with the 10 twist tube

Norrels or Cerakote will suit you well for finishes. Black T, Green T, Tan T are also great finishes you should look into

 

[Jig Stick]

Re: Custom 300WM Build From A to Z: The Process / Pics

I didnt "jack" pictures off the web. I included them in the post to give people a visual of what Im talking about. I always thought people liked pictures?

Thanks for the clarification on some of those issues. Do most of you guys do the cerakote yourselves?

And im back and forth on weather or not to put a brake on it. I shot my friends 300winmag with a brake, and another 300winmag without a brake. the one without the brake definitely had more recoil and jump. the one with the brake was much much louder, but had significantly less recoil. I would prefer the brake, but does adding a brake decrease the potential accuracy of the rifle?

 

[Kells81]

Re: Custom 300WM Build From A to Z: The Process / Pics

I do my own finish work using norrels but plan on trying some cerakote the next time around. Put a break on it when building and have them make a thread protector. That way you can chose to use or not without problems.

 

[desertHK]

Re: Custom 300WM Build From A to Z: The Process / Pics

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jig Stick</div><div class="ubbcode-body">
1: I will most likely be shooting heavy loads, so is the
1:10 twist right, or should I go with 1:11.25 or 1:12?

<span style="font-style: italic"> </span> <span style="color: #6633FF">I have a 1:10 twist Bartlein barrel at 26". It was chambered and flutted by GAP. It also has a FTE brake. It works great for my 208 AMAX bullet. When you say heavy bullets, how heavy are you talking about? If you are talking about 240 grains then you may have to go to 1:9 twist. At least that was George's recommendation to me</span>.

2: What do you guys think about the reticle choice?

<span style="font-style: italic"> </span> <span style="color: #3366FF">MLR with a F1 scope is awesome. Depending on how far you want to push your heavy projos, may want to consider the 5.5-22 power, but nothing is wrong with your selection</span>

3: What magazines fit in the Badger bottom metal, and will
they hold 300 Winmag?

<span style="font-style: italic"> </span> <span style="color: #3333FF">Don't know about that, I have mine in an AICS 1.5 L/A, so I just use the 300 WM mag, or the 338LM mag with a slight modification at the lip.</span>

4: What do you coat your actions,barrels with? Teflon?

<span style="font-style: italic"> </span> <span style="color: #3333FF">None</span>
Good luck with your build.





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[Elxx]

Re: Custom 300WM Build From A to Z: The Process / Pics

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jig Stick</div><div class="ubbcode-body">
And im back and forth on weather or not to put a brake on it. I shot my friends 300winmag with a brake, and another 300winmag without a brake. the one without the brake definitely had more recoil and jump. the one with the brake was much much louder, but had significantly less recoil. I would prefer the brake, but does adding a brake decrease the potential accuracy of the rifle? </div></div>

Definitely get a brake. It doesn't affect your accuracy and the reduced recoil is almost a must with that caliber. It will be louder, but you can just get better hearing protection. =)

 

[Jig Stick]

Re: Custom 300WM Build From A to Z: The Process / Pics

My gun smith mills his own brakes and can make it however i wish. My friends 300 has a brake on it, and a cap/thread protector for when he wants to shoot it with the brake off. Its machined so well that i couldnt even tell where the brake met the barrel.

Should I have ports placed only on top of the brake, or all the way around? I like the idea of having them only on the top. It definitely helps keep dust down when shooting prone.

Bullet wise im thinking at least 190grain. Is the 5r rifling worth it? i see that it is just starting to be offered by Krieger.

I really like that MLR reticle. We were shooting at 300yrds over the weekend and the scope i was using was only 10x. Im definitely considering higher magnification than the F1.

Have any of you guys seen the new rings being offered by Bat? They look promising, and are only $100.

 

[desertHK]

Re: Custom 300WM Build From A to Z: The Process / Pics

I would NOT want to have ports on the bottom. It can get mightly dusty shooting in prone position. A good brake will make the shooting more pleasurable (for yourself that is, your neighbor in the next lane is another story, LOL).

 

[Jig Stick]

Re: Custom 300WM Build From A to Z: The Process / Pics

any reason why I would want to go with a barrel heavier than a varmint? My 700 Police has a varmint barrel on it and its heavy. anything heavier might be a burden to carry around.

 

[jrob300]

Re: Custom 300WM Build From A to Z: The Process / Pics

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jig Stick</div><div class="ubbcode-body">any reason why I would want to go with a barrel heavier than a varmint? My 700 Police has a varmint barrel on it and its heavy. anything heavier might be a burden to carry around. </div></div>

If that's the same as the Sendero profile, you shouldn't need anything larger. Have it fluted to reduce the weight a little. I have a #5 and have no problem holding .5 MOA 5 rd. groups or better from my 300. I will probably go to a deep fluted #7 or maybe Sendero next time for a little better heat dissipation.

John

ETA: If you're going to shoot 1000 yds. or less, the 190's will be adequate. If you want to explore the limits of this cartridge, you'll want the 208 or 210's. Even under 1000 yds. they cut wind a LOT better than the SMK's.