Has anyone here seen a 308 necked out to 40cal? Adam

Not seen one but are you building one?
Details please.

quote:

Originally posted by boom stick:
Not seen one but are you building one?
Details please.

After my adventure into the 357BR land I figure I would want a bigger rifle. I know the 375 Jaguar but I haveb't heard of the 10mm-08. I figure if I can find a cheap blank I would spin one up, but testing the waters to see if anyone has blazed this path prior. 400 Welen Jr. Adam

What is your max oal?
The 9,5x56 MS is pretty cool
The 10mm pistol bullets would be too soft.
I would go with 405 win bullets at 405 win velocities in the 57mm case
Other cases to consider are the 284 case, 376 steyr case and the WSM.
The 405 win bullet with a long neck on a 2.25" case is potent and flexible using 400 rifle bullets and 405 win bullets in a short action.

Looking to keep the rifle on a SA 722 Remington. That leaves me with the 308 boltface. I know that the pistol bullets are kaput in this cartridge already as the slowest speeds would be well over max form them. The 9.5 MS is another option but I want to use LC brass to keep it to a minimum dollar amount. Right now I am into it for 300$ (for the rifle) and the barrel I found is hovering at 75$, the gun came with a Weaver and rings. So I figure right at 500$ for new trigger, stock, and smith work, reamer too maybe.

I may go to the 375 Jaguar or a variant of it just to make the brass forming easier. Time will tell, but one things is for damn sure, these little SoCal / NorCal Piggies are in trouble.

Adam

Nice pig, AB.
I think the 40-284 would be a good one. 308 bolt face, same length, should feed ok as well.

Why not go for a straight case and make it a 416".
Boatload of bullets in that caliber.
Headspace on the mouth.

Headspacing on the mouth is a not as good as it looks on paper. If you want to try it get a 7.65 Mauser and cut down 30-06 brass to headspace on the mouth. When fired the brass will wind up about .007 to .008 too short.

quote:

Originally posted by The Dane:
Why not go for a straight case and make it a 416".
Boatload of bullets in that caliber.
Headspace on the mouth.

Maybe open up the bolt face a bit and use .307 Win brass so you can control headspace. Or maybe a .416-308 Bellm?

http://www.gunandgame.com/foru...-ishapore-308-a.html

Adam

Adam

ab,
yup, thats just what they looked like!
interesting that the .308 has just enough less taper to hold in place while not being driven in to the 06 chamber to far not to fire.

I was at the range one time and watched a couple of Bubbas firing 308s in an M-1. They couldn't figure out why the fired cases came out looking different.

quote:

Originally posted by ab_bentley:
Has anyone here seen a 308 necked out to 40cal? Adam

Like this?
40-308, 40-300WSM, 40-300WinMag.


Found here: http://castboolits.gunloads.co...wthread.php?t=148885

Used to test pistol projectiles and 40cal swaged pills made from 9mm cases.
Cheers...
Con

You might want to go through the 416/240 Weatherby thread from a couple of months back. AC was thinking of building a 416 on the small Weatherby case. I ended up doing a 416/284. We both had pare barrels that drove this decision. Several here have done the 411/240, I think. Any of these would be a problem in a short action. I chose the 284 since I had a lot of cases, the short length would allow long bullets, and it works in a short action with no mods. The 284 case will work in any 308 action with no bolt work, is easy to get to feed, and has quite a bit more volume than the 308. If I hadn't had a barrel and owned several 416's (components), I would have gone the 40 route, since the bullet selection is much better for an all around round. I don't worry about case prices with a wildcat. Once you pay for actions, barrels, stocks, custom reamers, custom dies and gunsmithing, buying a hundred new cases of virgin brass that will do all your shooting for years is a non-event. You're not goin to put 5000 rounds down the tube, especially if this is a second(or 25th)rifle.

Art I am leaning more towards the 284 Case. I have picked up a few 722's and spare barrel (montana rifle co) so just need the cases. The 284 seems to fit the bill, although I will have to fireform instead of using 06' cases formed down. I will keep you all posted when I start building. Adam

Fireforming is the way to go. I tried forming, but just didn't have a lot of luck. I have run into this before with 284. The 35 deg shoulder causes cae ollapse or crushing if going up or down too much. I ended up loading 284 cases with 8 gr Bullseye, fill with Cream of Wheat and plug the neck with a dob of case sizing lube (the kind in a tub). It seemed like using the lube kept the barrel clean. Fire them off, inside ream the case neck, anneal the neck and you have perfect case. I lost probably 5% to fireforming. This could have been prevented by annealing before and after, but I was using cheap WW cases, so didn't go to the trouble.

The inside neck reaming I have found is often necessary when necking up, since the old shoulder joint ends up in the neck and causes a tight spot. With chambers with lose necks, you don't notice it, but it is there and affects accuracy. With a tight chamber, it will often cause chambering issues with loaded rounds, even though the sized cases fit OK. I have experienced this with several different chamberings.

I see a tendency lately of folks wanting big bores on little cases, and that is definately counter porductive and just simply does not work unless perhaps one is dealing with cast bullets and even that doesn't have much to offer..

A .40 caliber should be on a magnum case and begin with the 40/338 (Chatfield Taylor) to be an effective DG rifle, or even a elk rifle. Maybe a 40-308 would be a whitetail rifle but even then it wouldn't be much better than the 44 mag. rifle IMO.

I played with the 40 Whelen some many years ago and wasn't very impressed and that would be a tad more gun balistically than the 40-308.

ab_bentley,

Is this what you had in mind. Your idea inspired me to play around with my 400 Whelen dies and my expander dies. This is the 308 case with no other changes than to be opened to .411. The bullet is a 300 grain Hawk. It is a good looking round. I love my 400 Whelen. Now you have me thinking I might need to built a 400 Short Whelen. The madness never ends.

Mart

2.25" case and you can shoot 405 win bullet in a short action still.

Lol, I just got my reamer today. Adam

quote:

Originally posted by Atkinson:
I see a tendency lately of folks wanting big bores on little cases, and that is definately counter porductive and just simply does not work unless perhaps one is dealing with cast bullets and even that doesn't have much to offer..

A .40 caliber should be on a magnum case and begin with the 40/338 (Chatfield Taylor) to be an effective DG rifle, or even a elk rifle. Maybe a 40-308 would be a whitetail rifle but even then it wouldn't be much better than the 44 mag. rifle IMO.

I played with the 40 Whelen some many years ago and wasn't very impressed and that would be a tad more gun balistically than the 40-308.

Ray, I gave this some thought. I understand where you're coming from, but with the powder technology we have today there are have far more options for small cases than ever before. I mean I have a little round on the 221FB, the 20 Vartarg, and with the 21gr of the right powder I am hitting 4200fps. I am betting it's a tad better than the 44Mag. Adam

quote:

This is the 308 case with no other changes than to be opened to .411.

There may be a problem with head spacing on that rather not so well defined 'shoulder'. Two solutions come to mind, head space on the case mouth or straighten the case out completely then reform the neck and shoulder. I like the idea - it would make a great carbine cartridge. Or just make it and shoot it like in the mock up! It will recoil a bit on the stout side in a lightweight carbine but that would be reassuring in the bush!

There will be a bit of neck thickness variation from where the shoulder once was but a fairly simple ironing die would sort that out.

quote:

Originally posted by 303Guy:

quote:

This is the 308 case with no other changes than to be opened to .411.

There may be a problem with head spacing on that rather not so well defined 'shoulder'. Two solutions come to mind, head space on the case mouth or straighten the case out completely then reform the neck and shoulder. I like the idea - it would make a great carbine cartridge. Or just make it and shoot it like in the mock up! It will recoil a bit on the stout side in a lightweight carbine but that would be reassuring in the bush!

There will be a bit of neck thickness variation from where the shoulder once was but a fairly simple ironing die would sort that out.

There is substantially less surface area on the case mouth than on the shoulder of that case. How is headspacing on the case mouth going to offer a better headspace dimension than the shoulder? My 400 Whelen has a very similar shoulder and has nearly a thousand rounds down range so far with no failures to headspace correctly. The neck of a cartridge firing a .411 bullet is .430 and the shoulder of the 308 case is .454. I doubt that anyone would be able to move that 454 shoulder into the 430 neck with the limited amount of force one can apply with a bolt handle.

The idea that a large shoulder area is necessary to establish the headspace is mistaken. A Google search for Michael Petrov will turn up some excellent material on the headspace myth associated with the 400 Whelen.

Firing the round would further "define" shoulder. That case was formed with expander dies and finished with a 41 mag sizer to get the neck size correct. It won't be as well defined as a fired round. After firing, the shoulder and neck juncture would be better defined.

Mart

The shoulder diameter of the 400 Whelen is .458"
You could on a short action run in a 400 Whelen reamer and trim to 2.3" for a short neck 400 Whelen to use the 405 Win bullets. This allows you to single load full size 400 Whelen rounds.

Thanks for the clarification, mart. I was only speculating but obviously the problem does not exit. That's good news! The 35 Remington has a very shallow shoulder too. Anyway, the shoulder only has to resist the firing pin impact. You know what this means for a 35-303? It'll head space on the shoulder just fine! (It has the added advantage of head spacing on the rim if the cases are not well formed initially). In fact, a 375-303 IMP sounds very interesting.

quote:

Originally posted by mart:
[QUOTE]Originally posted by 303Guy:

The idea that a large shoulder area is necessary to establish the headspace is mistaken. A Google search for Michael Petrov will turn up some excellent material on the headspace myth associated with the 400 Whelen.

Mart

X2 roger

Look what I did, used a standard 40SW die ran a 30/06 through it until the shoulder matched the 308 trimmed to about 2.015" seated a 40cal (pistol) bullet for show. Just using 40SW dies it was only three steps to create the brass form 30/06. It also fits and feeds from a short action magazine. I think I am going to build it. Adam

Maybe a 40-308 would be a whitetail rifle but even then it wouldn't be much better than the 44 mag. rifle IMO.

See this http://castboolits.gunloads.co...wthread.php?t=154680
Frank

And this
http://castboolits.gunloads.co...wthread.php?t=165086

AB

I saw this thread by accident and was interested, as I'm working on a .416 / .308 project myself.

My project is a little different from yours, but seems to have the same motivation. A big bore for close range pig busting.

I started using a .44 Mag lever action in the thicker scrub many years ago as a compact, fast follow up rifle. It's pretty effective at close range, but somewhat limited if the range opens up, due to its low velocity and rainbow trajectory. I would usually only carry it in the sort of terrain where a 100yd shot was likely to be the maximum, and less than 50yds was more the norm.

In recent years I've gotten myself mixed up with big bore rifles and now really love them. However, I have a mix of rifles in calibres from .17 to .500. The calibre that has seen most action against pigs is my .308 Win. I'm a very big fan of this cartridge case size and have most of the variants: .243 Win; .260 Rem; 7mm-08 Rem; .308 Win; .338 Federal; .358 Win; and .375-08.

Now I'm working on a .416 variant, but with a difference. The case is made from cut down .30-06 brass (you can use the .308 Win case, but it's neater with the .30-06, as there's no remnant shoulder). The case is a straight wall that is designed to headspace on the mouth. It means keeping your brass trimmed to the right length, but I can live with that.

The difference is that my wildcat has a case length of only 1.7716" (pretty much the same length as a .223 Rem case). The cartridge overall length is only 2.244" (again, pretty much the same as a .223 Rem).

I've done this for two reasons:
1. To keep recoil to a minimum for fast follow up shots (I don't fear recoil, I shoot plenty of big bores, but in this application, I waqnt to keep it light).
2. So that I can use a modified AR15 magazine for extra capacity, for when you come across a mob of pigs.

I'm going to try this cartridge out in a rebarrelled Mossberg MVP with detachable AR15 magazines. I've already modofied a Magpul PMAG20, which will hold 8 rounds of .308 head size. The rifle will have a 16" barrel to keep it short and handy.

Now, the real key to this project is the projectile. I originally considered .400 calibre for this project, but the range of projectiles was limited to pistol offerings, so I started to look at .416 instead. Problem was that it was hard to find a projectile light enough for this small case. What to do?

Fortunately for me, I have an ace up my sleeve. I am the Australian distributor for Cutting Edge Bullets (CEB), who are based in PA and who make the finest hunting projectiles around. You may think that's a big claim, but if you try them, you'll soon understand that it's true (Boom Stick will back me up here, I'm sure). Anyway, I realised that being CNC lathe turned, I can order a custom design, provided I order enough projectiles to cover the cost. Easy.

I've designed a 175grn .416 brass projectile along the lines of their DGBR-HP line. Big hexagonal cavity that shears into 6 blades when it hits pork. Solid base that punches through the other side as well. Trauma & penetration, best of both worlds. It will drop pigs fast.

Quickload internal ballistics software estimates that the cartridge will be able to generate 2,600fps from a 16" barrel. Not too shabby at all. Ample power to deal with wild pork. Many people get too carried away with trying to wring out every last fps from a cartridge. I've learned that with the right projectile, even a modest cartridge will perform wonders. And they are so much quicker to shoot.

I've attached an image of my cartridge (centre), along with it's bigger brother (the one you'll like that fits into a standard Short Action magazine of .308 Win length) and a prototype CEB projectile. The final projectile will look a little different. The one in the photo is just one I adapted from a 300grn ESP Raptor.



Hope you like the food for thought.

MeplatFS

Thats quite the wild kitten there MeplatFS.
With these bullets redefining the performance of carts that makes that quite the killer.
I had an idea of a similar cat that is simply an 06 necked up no shoulder using extractor to headspace to .410" to push the conventional 300 grain pills @ 2,400+ but a 200 grain version of a tipped Non Con @ 2,700+ would be awesome. Yes these bullets are the most ferocious things out there!

This could be sweet using the 6.5 Grendel case on an ar15 necked to 410 or 416

Boomy

We can't use semi-autos here in Australia, as you're probably aware, so trying to fit it in an AR platform is not so much a consideration for me. .308 head size is the smallest case that will support a .416 cal projectile. If you go too small with the case, then your case capacity and velocities will drop considerably also.

You're right though. With the CEB brass projectile technology, this cartridge will kill out of all proportion to its size, of that I'm very confident. And in a very compact rifle too. The Mossberg MVP's action length is made specifically for .223 Rem length cartridges, not just a standard length action with a shortened magazine, like many other makes use.
With a 16" barrel, this rifle with have an OAL of 35.25".

MeplatFS