330 Dakota vs 338 Sin

[sinman]

When I started developing the 338 Sin I was told I should just make a 330 Dakota. That would of been easier but my goal was to develop a cartridge that fit std actions with out mods and be able to have the most case capacity safely. That is why I developed the 338 Sin. It is as long as it can be to seat the bullets where they need to be and hold the most powder. I use 330 Dakota brass (made by norma) and I bump the shoulder forward, change shoulder angle, and take out some body taper. Below is a pic of a fire formed 338 Sin and next to it is a 330 Dakota before forming. The 338 Sin will drive a 250gr bullet at 3,000 fps out of a 26" barrel and a 300gr bullet out at 2800 from the same barrel and feed perfect with a coal of 3.500"

http://i290.photobucket.com/albums/ll272/sinarms/IMAG0165.jpg

[mopar440]

whats it look like compared to the 338edge speeds look real close at over a 1/4 shorter in oal

[geargrinder]

whats it look like compared to the 338edge speeds look real close at over a 1/4 shorter in oal


I've got a picture of some un-fireformed 338 Sins next to 338 Edge and 338 RUM. Give me a few and I'll post the picture.

[geargrinder]

Here it is.

They are all aligned by the tip of the bullet.

Left to right

338 Edge- 3.800" - This is my normal Edge length,
338 Sin- 3.500" -This is what fits in my Savage Centerfeed DBM
300g SMK
338RUM- 3.680" - This is what fits in my factory Rem 700 LSS
338 Sin- 3.500" -This is what fits in my Savage Centerfeed DBM
225g NAB

http://i234.photobucket.com/albums/ee269/geargrinder123/S8001758.jpg

[sinman]

The Rum has about 6gr more powder capacity compared to the 338 Sin. The 338 Sin has 13grs more powder capacity then the 330 Dakota, The 338 Sin has about 5grs more powder capacity then the 340 weatherby. So you can see where the 338 Sin falls in comparison. It will shoot right with the edge/rum and be a repeater on any std long action with a magnum bolt face and the availability of the Norma brass is a plus over the edge.

[CJ in WY]

Looks good!
Now get going on the 7Sin, my 7 Mag needs a new barrel ;D

[helotaxi]

Now get going on the 7Sin

Now that would be interesting.

How has accuracy worked out with the .338? What actions have you built them on?

[pdog06]

Nice job Devin.

I commend you on your willingness to try new designs. Looks like this one has worked out just as you had hoped, and I cannot wait to see the 6.5SIN and 7Sin reports.

I really enjoyed your thread over on LRH. You had alot of nay-sayers on there and have pretty much proved them all wrong. For some reason they cant understand the reasoning behind your thoughts and designs, but what do you expect from those Remmy guys...LOL They would rather spend much more money and end up with the same or less resluts.

[bajabill]

if you have the data, could you expand on the case capacity comparisons you showed

338 win mag - xx grn water
340 - xx grn water
330 dakota
338 sin
338 rum
338 edge
338 lapua

I also think this is an interesting prospect as a rechambering of standard 24" 338 win barrels. Sure longer is typically faster, but this should be a similar expansion ratio as 300wsm perhaps, which performs well in 24" tubes.

[efm77]

Looks great Devin! Now when will you be offering loaded ammo?!

[sinman]

Thanks everyone and yes it is true some people don't care if they buy an action for $1500, bottom metal and mags for $350, custom stock for $450 just to have an edge repeater or likes when you can pick up a $200 action an a stock $125-400 for the savage and put the same barrel on it. I'm cheap so I like to build stuff as reasonable as I can. Sure a $6,000 Edge would be nice but a $2,000 Savage custom is no slouch either.

This is a case capacity comparison with H-870

338 Win Mag 86gr
330 Dakota 89.5gr
340 Weatherby 98gr
338 Sin 102.5gr
338 Rum 107gr
338 Norma mag 107gr
338 Edge 110gr
338 Lapua 114gr

From the case capacity stand point it is within 10% of the Lapua and by case design it will work great with shorter barrels, 24-28" for optimum results and could be used in a 20" barrel and still have high velocity. I will mess around later on with larger bullets than the 338cal for big game guys, the 375 Sin will do what the H&H will and maybe more. The 6.5mm and 300 Sin will be next in line as I already have a tester and request for them.

[mopar440]

what do use for dies sinman

[sinman]

I had a die reamer cut so I make my own dies. I started with RCBS parts but I am switching to redding s type so I can swap bushings because the Norma brass is a little thinner than the remington brass that I started with.

[mopar440]

So do you make the die and just use the guts from redding ?

[sinman]

Yes sir, I can use just about any of the guts in there from any brand.

[KRP]

a 250gr bullet at 3,000 fps out of a 26" barrel and a 300gr bullet out at 2800 from the same barrel


What is case life like pushing 300s that fast?

[sinman]

To early to tell nut that won't be the accuracy load. That's pretty much full throttle

[Senderofan]

Devin:

Are there any plans in the "Works" to have brass ready to go?? Or will it be strictly fireforming of the Dakota round?

Also....talked to you about my rig ( a while back ) that currently has a long action from the company that starts with an "R".....30-06 bolt face. Would this round function in this action?? Obviously the bolt face would have to be opened up. Plans got put on the back burner when we had to do a bathroom remodel....but I'm trying to make a plan for a .338 conversion for my custom that I don't use.

Thanks for this exciting new round!

Wayne

[mattri]

Any range reports?

[sinman]

I tried doing accuracy loads on Saturday but sheared my rear dove tail so I ordered a new base and heavy duty rings. I'll shoot again this weekend.

Wayne, I will probably offer hydro formed cases but not proper head stamp unless it really takes off. And yes this round would work perfect on your rifle too.