300 jazz


Well-Known Member
Feb 18, 2008
Thought I would post a thread to introduce a new caliber. The 300 JAZZ.

This rifle was built for me by SSG gunsmithing( Nathan Dagley ). All work was done by Nathan, except the digital camo on the stock was done by Travis Redell.
This caliber is based on the 338 Norma Mag necked down to 30 cal, with an improved shoulder. This project was started last July, when I looked at the 338 Norma, and liked what I saw in the cartridge. I thought at the time that the 338 reamer was proprietary, so I decided to neck it down to 30cal. Nathan and I agreed on a 30 degree shoulder for it, and Nate ordered the reamer. After pressure testing and load developement, I have 2 loads. One for the 210 gr Berger VLD and one for the 240gr SMK. One plus of this caliber is that you can seat the long 210gr Berger or the 240gr SMK with the BT at the neck/ shoulder junction and it fits in a standard size magbox of 3.60"
With a 28" Brux barrel I am getting 3150 fps with the 210gr Bergers, and 2850 fps with the 240gr SMK. I am still using the same 20pcs of brass I started with and have 10-12 reloads on them and the primer pockets are still good. The 338 Norma brass seems to be top quality.
Nathan does excellent work, and this is an extremely accurate rifle, more accurate than I can do it justice.
Here are the listing of components:

-Phoenix action, SSG fluting and knob
-Manners GAT stock
-Seekins recoil lug/ keyed into Seekins 20 MOA rail
-TPS rings
-Jewell trigger
-HS Precision DMB
-SSG muzzlebreak. I love this break.
- Nightforce 5.5x22-50 mm scope
Yeah, +1 on the more pics idea!

Looks like a *** to me.


"Pretty Outstanding Setup!" :D
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That is one awesome looking rig and a good shooting one as well I'm sure.
Is 3150 the max velocity with the 210's or is it the most accurate velocity?\
Just wondering what the cartridge is capable of.
I am not sure what the top end of this cartridge is. Being as this is the first wildcat I have done load developement on, I am being on the careful side.
Got advise from Joel Russo on how to measure my brass expansion at the base of the brass to help determine pressure. Also, watched primer cratering and bolt lift . Also, payed attention to bolt pressure it took to rechamber a once fired brass in relation to headspace.
Based on the 10-12 reloads I have on the brass, with the primer pockets still holding tight,I suspect that the 300 JAZZ could be pushed harder. However, I am satified with the accuracy and velocity of both of my loads.
Again, my 210gr Berger load is at 3150fps and shooting 1/2 MOA at 725 yards,
and the 240gr SMK is at 2850fps and 1/2 MOA as well. Have not streched it out farther than that yet.
Nathan Dagley of SSG built me a very accurate rifle.
Did a search on that name but no results,was going to pm. A phone # or email for the buisness would be nice Thanks Dan

Nate Dagley of Straight Shot Gunsmithing is the creator of the Jazz line.

He can be pm'd here under the name of 308nate.

Here is his website:


and contact info:

Nathan Dagley
2175 41st Ave. S.W.
Center, ND 58530
E-mail : [email protected]
Thought I would post an update . I shot this group on Friday, the 18th.
It measures 2 1/2" wide and 1" of verticle @ 723 yards. My load was 83gr of Retumbo pushing the 240gr SMK. Trajectory validation at this distance puts me at 2840fps. I have since repeated this performance this morning. Shot some 3 shot groups with 83gr/83.5gr/and 84gr of Retumbo. All 3 loads shot 1/2 MOA or less, but I had alittle less verticle with the 83 and 83.5 gr load. I was shooting with a bipod and no rearbag. I used my hand as a rear support, as I left the bag at home.

I was talking about the man that did the stock. I know Nate. He has done work for me on several different guns including 2 complete units. I would like to get a stock done for the one he is working on now. Dan
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