Introducing the 400 BTS Mag!

[BT Sniper]

I've been droping a few hints about a project I have been working on for a while. As many of you know the 40cal/10mm bullet from 9mm brass is one of my fovorite bullets to make and shoot. I have told many of you it is the easiest and cheepest bullet to make and shoot.

For allmost 4 years now I have been making and designing bullets out of brass cases to fit know cartridges. Now for the first time I have designed (with a bit of help) a new wildcat cartridge to fit a known bullet.

My goal was to be able to test my fovorite 40 cal bullets out of a bolt action rifle. I wanted to prove these bullets are capible of accuracy way and beyond their orginal design purpose as a pistol bullet. So away I went necking up various cases to 40 cal.

With a bit of guidance and suggestions from a good friend I settled on 2 parent cases. The 300wm and the 308 win. I had a large supply of 300wm brass so this had a bit of influence on my decision.

So what I have now is a test platform in an accurate bolt action riffle to test my favorite 40 cal bullets made from 9mm bras up to 3100FPS and beyond with anything inbetween as far as velocity.

Let me introduce you all to the

400 BTS Mag











typical 40 cal bullet, 40-308, 40-300WSM, 40-300WM aka 400 BTS Mag






It is a powerful 40 cal made from necked up 300WM brass. So far I have been able to push my 190 grain 40 cal bullets to 3090FPS and also the 40 cal Hornady XTP Muzzel loader bullet to 2900 FPS with great accuracy.

I would imagine the potential and performance of this cartridge will be similar to the current wildcat, the 416 Taylor which is simply the 458 Win necked down to 416.

This 400 BTS Mag is more power then anything I'm sure I need but with the advantage to shoot my easy to make one step 40 cal bullets from 9mm brass I couldn't resist

I had a good friend thread a Walter Lothar 40 cal barrel to fit a Savage 110 action. It has a 1-16 twist and finshed out at about 18" in length. I installed the barrel myself and so far the testing looks very good. I expect to put some large holes in many different forms of test media with this bullet.

Enjoy the pics and I'll have more info to add I'm sure about this powerful new cartridge to shoot my favorite 40 cal bullets from. Who would have thought a 9mm piece of brass would be shooting 3100! Well I guess I allready did that with the 308x9mm bullet but this one is a lot easier to make and potentialy more accurate

Good Shooting and Swage On!

BT

[frank martinez]

Very creative BT. I applaud your insight and all the work you put into it. If you don't mind I will also post this over on the Accurate Reloading Wildcat thread. Those guys really love using over 40 rifles.
Frank

[BT Sniper]

Feel free to post and pass on.

Thanks

BT

[rockrat]

What dia. is the bullet, and how much for a die. I have a 405 Win that could use some new food.

[BT Sniper]

.400 same bullet that we shoot in the 40 S&W and 10mm.

Is that the same diameter you need?

BT

[khamill2000]

I want a 40-308 barrel for my LR-308

[BT Sniper]

I got one for my Savage. I intend to shoot it next very soon. Allready got a $300 donor savage gshort action to put it on.

If interest is enough we might be able to put somthing together for a group buy of some sorts.

BT

[khamill2000]

Wouldn't necessarily need a group buy. Just a talented machinist to ream the chambers and make some reloading dies. Or am I missing something?

Edit- I guess the bore would still need enlarged/rifled

[375RUGER]

so when will we see targets?

[375RUGER]

never mind. found the other thread.

[rockrat]

Nope, need a .411" for the .405Win

[Grandpas50AE]

Brian,
Really nice looking work there. Great looking cartridge and it will be interesting to see results from a hunting trip. You are an intrepid explorer indeed.

[41 mag fan]

Man.....I just got electrocuted from drooling all over my laptop. I'm glad Ihave GFI circuits in the house!!

Man that's a gorgeous rifle.

Now I've got to go change my shirt...it's wet down the front.

[BT Sniper]

Thanks guys,

Here is the targets i shot with the 190 grain bullets from 9mm brass loaded with H-335 powder. Target was only at 75 yrds but I'll soon be testing them much farther. You should be able to see the charge listed on the target.




and here is some targets from the 200 grain SST bullet. In both cases the 75 grain load shot best. The first two shots with the SST and 75 grains of H-335 went into the same hole then the target sticker fell off so I lost my POA and didn't fire the third.







DATA

RP fire formed match prepped brass
RP 10 year old mag large riffle primers
H-335 powder
Hornady SST 200 grain ML bullets
BTS 189 grain CH profile .250 meplat bullets from 9mm brass Wheel Weight cores.
80 thou off lands at 3.250 OAL
Stevens long action, BVSS stock
Target trigger less then 1lb


Load - SST Bullet FPS

64.5 - 2583

68.0 - 2717, 2689, 2728

71.0 - 2822, 2793, 2741

73.0 - 2829, 2846, 2850

75.0 - 2867, 2914, error

76.0 - 2882, 2887, 2920

77.0 - 2930, 2863, 2969


Average group size

.90"

Best group was 1 hole, only two shot though with the 75 grain load



Load - BTS Bullet FPS

73.0 - 2833, 2860, 2899

75.0 - 2914, 2882, 2965

77.0 - 3075, 3046, 3030

78.0 - 3005, 2918, 2957

79.0 - 3092!


Average group size 1.4"

Best group was 1.2" with 73 grain load but less vertical stringing with 75 grain load.

Heck it was all shot off a boulder while standing and a new barrel. I would hope I can improve upon the group size


Good shooting

BT

[BT Sniper]

Nope, need a .411" for the .405Win

The 41 mag dies make good .410 bullets and I could lap it an extra thou to get you great .411 bullets from 9mm brass. Two die set runs $385.

BT

[BT Sniper]

Another look at the rifle and set up day of testing.










and check out the size of that mouth! Loaded round has a 225 grain SP made from 9mm brass. I used a 158 grain .358 for the core. Think I'll try those bullets out next. Should make a heck of a hole. Matter of fact I intend to try bullets up to atleast 350 grains. Probably size down some 40 S&W for jackets, maybe even soem 3/8" copper tubing bullets?

[475AR]

Them some great looking bullets, is the FP one you can make with your dies?


Also Love the "Nosler" like HP. (Can that also be done with the .500 dies?)

[toolz568]

I have a donor FN mauser 98 that needs a barrel and no gunsmith in the area. I would be interested and I need the Airsoft BB tipped bullet option. PM sent.

[BT Sniper]

YEP! You can make bullets like this with any of my dies, Typicaly I set them up with a standard HP nose punch but any shape HP or FN nose is possible. It is nothing more then a simple swap of the nose punch pin in the die. let me know if you want a Flat nose punch with your 500 die. I'm not fimilar with the "nolser" nose shape or HP but I love this HP look. Imigine those cheap plastic oil funels, that is what the HP punch looks like. http://www.buytikitorches.com/tiki-t...l/funnel-small

I'll make a cross cut of this HP one of these days.

I got your PMs, I'll get back to you as soon as I can.

BT

[BT Sniper]

I don't know about actions other then savages to fit barrels to. The savage is so easy to swap barrels that anyone with a bit of smarts can do it. I'm not an official GS myself but I did set the headspace and install this barrel myself on this Savage/Stevens 110 action.

BT