338 Edge Throat Length and Cartridge OAL

[nchunter182]

Would like to get some input from users that have built a 338 Edge. I'm building one now and will be ready for chambering soon. It will be built on a Stiller Predator action, 30" 9.5 Obermeyer with a CSR 4-port brake. I would like to shoot the 300gr Nosler AB in it. I'd like to know what OAL most people who have used this cartridge load it to. I know the Stiller Predator comes cut for the Wyatt's extended mag that will allow 3.820" but I'm looking and installing the Wyatt's extended center feed mag that will allow up to 4.000". It seems that with these long bullets, you would lose a lot of power space with the bullet base so far into the case. I'm considering throating the chamber to allow a OAL of 3.950" (touching the lands) with the 300gr NAB and can back it up from there as needed. This length would put the boat tail transition right at the body/shoulder junction. The picture below is a dummy round made up to a 3.950" OAL.

Let me know what you think. I want to make sure I'm headed in the right direction. I can always throat it out longer if needed but hard to put it back when you've gone too far!!!

 

[nchunter182]

OK... Did some more searching on this site and found a post where a member had a reamer built for the 300SMK loaded to 3.950" OAL. The measurement from the bolt face to the end of the lead was 3.129". Loaded up a dummy round with a 300SMK seated out to 3.950" and marked the bullet at the ogive/bearing surface junction (used dial calipers set to .337" - not perfect but pretty close). Did the same with a 300NAB and marked it in the same fashion. Measured both rounds from the cartridge head to the mark on the bearing surface - both were so close to 3.129" it was hard to measure the difference.

Looks like this length is a viable option with the 4" Wyatt's box. Picked it up today and the dummy rounds will fit through it with no problem. If I'm not happy with the way the NAB's shoot, looks like I can fall back on the SMK's which is a proven performer in the round. I've considered the Berger Elite Hunter 300gr but don't have any in hand to play with. From the information I have been able to gather on the web, in this configuration the bullet will be to long the feed through the mag when loaded to the lands. Looks like it will have to be a single shot if I want to run them.

Below is a picture of both dummy rounds.

 

[M1AShooter]

What kind of stock will you be using? Will the 4" Wyatt box allow use of a hinged floor plate or will you have to use a "blind" stock?

 

[nchunter182]

I have purchased a B&C Medalist M40 Tactical. The magazine box will fit (with some minor fitting - it's tight) and will allow the use of the hinged floor plate. I purchased the PTG bottom metal and am fitting it to the stock inletting right now. Since I don't have the barreled action back from being chambered, hard to say how it will all go back together but I'm confident it will work. I know others have used this mag box with success.

 

[ultraedge]

The 300 gr Berger bullets do not have to touch the lands to shoot well. I use both the 300gr OTM and the 300gr Elite Hunter . When loaded with the same powder charge and seating depth they will shoot in the same group. They are a hybrid design and shoot well off the lands. I also have an Obermeyer .338 barrel with a 9.5 twist that is very accurate with the 300gr Bergers and 93gr of Retumbo. Gary

 

[nchunter182]

Gary,
Good to know. How far off the lands do you typically load them? I have been using Retumbo for other loadings so I have some on hand that I will try as well. From what I have read, H1000 seems to be the go to powder for the 338 but always nice to know that will work as well. Seems since Retumbo is a little slower burning it would work well with the extra case capacity you would gain by seating the bullets out long.

 

[Treash]

Sorry to dig up an old thread but this is the only thing I've been able to find on the whole internet about fitting a 4" Wyatts mag to a stiller predator - how did you go? Did the action need modification to fit the magazine? I'm in the process of piecing together parts for a 338 edge sambar slayer.

Cheers!

 

[nchunter182]

Wow... this does go back a ways! The rifle has been built and shoots very well. I used it last year to take a mule deer at 750 yards using the 300 Berger Elite Hunter.
The action does have to be modified to take the longer box. I took it to a local smith and he did the work for me. Anyone skilled on a mill can do the work. Since the Stiller action is a Remington clone the work is very similar to what is shown on the Wyatts website. Will limit your capacity to two in the box and one in the chamber - but that has been plenty!
I ended up having PTG make me a reamer to do just what I mentioned with the 300 NAB in the earlier post. Using the 300 Berger, it put me .080" from the lands with a COL of 3.975". Using the 300 SMK put me .060" from the lands with a COL of 3.865". All bullets shot very well but liked the BC that the Berger offered so I mostly stuck with those.
If you wish, send me a PM and we can discuss further.

Jay

 

[anthonyinva]

any chance you could post a pic of the action that has mod done to take 4.0" mag box. I have the predator action on the way to build an Edge with and looks for any advise I can get.

Thanks

 

[nchunter182]

Anthony,
You are in luck. I took and sent some pics to Treash a while back and still have them. Since this thread was first started and last posted I did make one change to the rifle. Since I have only been shooting the 300 Berger, I had my reamer modified by Manson to shorten the freebore so I could seat the Berger to the lands if I chose and still fit the 4" box. I had the barrel set back and rechambered here in Ohio by Custom Blue. I ended up seating them .005" from the lands and they shoot great!
I hope this helps out with your build.
Jay

 

[anthonyinva]

nchunter and treash sent you a pm

 

[nchunter182]

Anthony,
You mentioned the concern was being able to shorten the bolt stop enough to allow a round to be picked up from the box, but still have enough bolt stop left to stop the bolt. Attached is a pic I took tonight with a ruler next to the bolt stop. As best I can measure without taking the rifle apart, is I took about .150" off the stop. This makes sense since you said the box you have is 3.850" and the longer one is 4.000". Unless they have changed something since I bought mine, there is still plenty of bolt stop left to stop the bolt. Never had any issue with it. I'd carefully measure yours before cutting.
Good luck with your project!
Jay

Also attached a pic with the 4.00 box installed.

 

[ATH]

Thanks for posting the pics. I picked up my Predator tonight and am in the process of fitting the mag box to the action; the bolt stop is next. It is a slow and tedious task with a Dremel. It would be an expensive project to F up!