View Full Version : FAL Wildcat

June 25, 2002, 03:51
What wildcats have been used in a FAL that only need a new BBL and magazine?
I want to neck up a .308. I know that people neck down .308 cartridges (ex. 243 Win) but I want to neck it up. Has anyone got any information on anyone who has done this?
I would love to get just the name of such a cartridge.

June 25, 2002, 06:35
I've been thinking about a 270win FAL myself.

I would think that as long as the rear of the shell casing is about the same size of the 308's rear so if fits the bolt, it fits or can be made to work in the magazine there souldn't be a problem. You would probably have to work on the gas system so you don't blow the bolt/carrier out the back of the rifle or not have enough power to cylcle properly.
Since you'd be using a 308 casing already, the mag shouldn't be an issue. hmmm...what about the feed ramp with a fatter bullet???

Of course a custom barrel is in order but at least you can use the bolt. Do it now while FAL's are still available and cheap. This makes them great as a base for experiments. Just don't be holding the rifle when you shot it incase she blows.

:eek: buon apitit

June 25, 2002, 06:38
OH! one other thing...know your chamber pressure of your wildcat so you don't blow receiver all over yourself!

June 25, 2002, 07:01
OAL( overall length ) of the cartridge must be kept to within .308/7.62 x 51 dimensions or your magazine system will have trouble. This pretty effectively rules out .30-06 length ammo like .270 Win. 7mm-08 should work well and .243 will work. Going up to a .33 or .35 may work but will probably cause a lot of feeding issues, although .33 may not be bad. Chamber pressures must also be kept in the same range or less (.223 like MEEPER does ).

June 25, 2002, 11:12
After a search, I've found that the .358 Winchester in the .308 Winchester necked up from .308 to .358.

Col. Whelen necked up the 30-06 to .35, .375, and .400. The .400 was a flop because there was not enough shoulder to headspace from. "Cartridges of teh world, 8th Ed." says that you can only neck up a 30-06 to .375 before you have problems.

Ackley "Improved" cartridges by making the case slope shallower, and increasing the angle of the neck, thereby giving more capacity, and a sharper neck. This is supposed to be much more of an advantage on a .35 Whelen than on a .30-06.

If I use a .308 Ackley-Improved type design, and then neck it up as large as it will go, I wonder how big I can make the bullet. At least .375, but I want .400. I wonder if the Ackley Improved style would give me enough room.

The reason I want the largest possible diameter, is that a given barrel maker will make a barrel out of a material which determines the maximum pressure (in PSI, or CUPs.) So pressure is fixed.

Pressure * Area = Force

I increase the area by the square of the radius times PI, which means that the force varies directly with the diameter squared.

Force = Mass * Acceleration

With a constant mass projectile (not always possible) I get that the acceleration (which varies directly with the force) varies directly with the square of the diameter.

Knowing that the velocity is the integral of the acceleration, I see that a larger caliber at the same pressure will speed things up quite a bit.

This does ignore that a necked down case will dissipate pressure more slowly as the bullet travels down the barrel, due to the internal volume of the case being larger in relation to the volume of the barrel than in a larger caliber firearm.

Having said that, check a reloading manual for .25-06, .30-06, and .36 Whelen.

Going from a .308 to a .358 in one rifle, that only fires hadloads, is probably not worth it compared to (at the same cost) two rifles that fire military surplus ammo. If I could go up to .375 or .400, or even (dare I dream) .410 would be worth it (maybe.)

.41 Caliber allows you to shoot both .410" pistol bullets (170-230 grains) and .411" big game bullets (300-400 grains).

I need to spend some time in Auto-Cad, before I come back with the dimensions. Then, I will have to study what equations dictate the head

If I wanted all of this in a .30-06, I could go with HAWK cartridges. Having said that, I want to put this in a FAL or CETME for cost reasons.

As for feeding rpoblems, I have only thought of the magazine. I think that cutting the bottom of a 20-round mag parallel with the axis of the bore will take the "curve" out of the magazine, and allow more reliable feeding. This may reduce the capacity to 15, but I think it's worth it. I may have to cut down the mag to 10, to avoid any '94 Mag-Ban hysterics.

I hope that sitting flat nosed bullets farther back will solve some feeding problems. If not, this could get complicated.

Anywho, that's what I'm thinking. I call it the ".41-308 Andy." I hope it will be a good brush gun. What do ya'll think?

Andy Out.

Scott S
June 25, 2002, 12:32
How about a stretched version of the .44 automag? IIRC, it's based on a .473" head, like the 308, 30-06, and uses a .429" diameter slug. That'd give you some acreage to work with. I guess it headspaces on the case mouth. Trouble with this would be whether the mag would handle such a large diameter bullet and feed it reliably.

June 25, 2002, 13:31
Yeah the .243, .260 Rem., 7mm-08, and .358 are just the .308 necked up and down. :) There are several wildcats out there, like the .33-08 written up in Gun Digest (or .338-08 or whatever they called it) that looked interesting. :p However....the .358 and .410/.416 sizes just seem more interesting (OK, the .260 Rem, being a 6.5x55 Swede clone is also pretty nifty):D Been working on a .40 that will work through a .308 mag, either the .308 blown straight or a .30-06 basicly cut off about the shoulder.:cool: Sort of a big .30 M1 Carbine.;) Not sure if there is enough shoulder there to headspace on in an auto though.:( The .400 Whelen either runs hot of cold. Some people claim if you headspace it tight that it will work fine, and have guns to prove it. Others claim the shoulder is too small and it won't headspace right. I am inclined to agree with both sides, if done right it will work fine, but if you move the shoulder back when reloading (or case forming) then you have problems. :( The Ackley Improved cases only get you about 2-5 grains more powder in the .308 depending on what cases you use, powder type, etc., which is only about 50 fps faster, not enough to charge my batteries and the cost of dies will buy you another gun (or at least parts kit).:( To be a true Improved case/chamber you need to be able to shoot the standard cartridge in the chamber, so this may not be a "true" wildcat if you want something that us unwashed masses don't have.:D Actually when limited to .308 mag length, the .400 is not a great caliber for the .308 case due to lack of velocity.:( That being said, so what?! Why NOT a .400 FAL?! Heck, I may never hunt elephants anyway, and I bet this would make a great short range thumper!

June 25, 2002, 17:50
I have a 35 whelen improved that was built in 1950 on a 1920 Erfurt mauser action. It shoots great but I figure its a little too much for whitetail deer so I dont use it much anymore. I shot up the last of my ammo up on gophers. Them 250 gr bullets vaporize them varmits big time.:D :D

June 25, 2002, 23:05
Originally posted by legion489
1. Been working on a .40 that will work through a .308 mag, either the .308 blown straight or a .30-06 basicly cut off about the shoulder.

That's exactly what I've been doing to form my brass. I am using 30-06 dies to (full-length) resize the case, and then a .41 Mag die to resize the neck, expand the neck, seat the bullet and crimp the bullet. I'll have my first pass at dummy rounds when I get the trimming kit and some bullets.

Originally posted by legion489
2. Not sure if there is enough shoulder there to headspace on in an auto though ... The Ackley Improved cases only get you about 2-5 grains more powder in the .308 depending on what cases you use, powder type, etc., which is only about 50 fps faster

I'm not using the Ackley to give more powder. I will be using the Ackley to insure better headspacing. The sharper angle (40 deg) before the neck combined with a larger shoulder, and the same neck size, will allow me to get more headspace.

If I turn the neck, I will get a few thousandths of an inch more room to headspace on. I will have to see what the common minimum thicknesses are in necks of similar cartridges. I know this is a lot of customization, and it may not be worth the trouble.

Originally posted by legion489
not enough to charge my batteries and the cost of dies will buy you another gun (or at least parts kit

If I can find an COTS (commerical, off the shelf) set of dies that are close, I will use them. Anyone who can ream / turn a .375 or larger barrel with a pre-existing reamer that they have in stock for an FAL or a CETME will get my business.

Andy Out.

June 25, 2002, 23:12
I'm looking over Clymer's (http://www.ClymerTool.com) PDF flyer. I want to divise a system of COTS dies to cut my ideal chamber.

Clymer can custom-modify dies to have removable pilots. So we take a .308 Ackley Improved 40 deg, and modify it for a removable pilot. We install a .41 pilot.

We ream a .41 barrel with the reamer.

Now we take a .41 Special / Magnum reamer, and re-do the neck.

Any thoughts?

Anyone know of a shop that can do this, for less than $300.00.

Andy Out.

June 26, 2002, 09:49
I have one thought. I dont think the .41 mag throat ( neck) is the way to go . you will be looking at about an 11 degree taper ( as the .41 was set up for revolvers) and I think you probably want a true throat with a rifle. You will most likely want to go with a true throating reamer from the same company that provides the chamber ream.

June 26, 2002, 10:49
One other thing to consider..... ever thought about using the .284 winchester brass ? it is of the rebated rim design. many wilcats based on it as it allows you to use a .308 bolt face but with a larger base. it might be a better starting place for a truly large caliber. Also do a search for .458 SOCOM as near as I can figure it is based on the .284 as well and gives you a true .45 cal and is adaptable to feed from the maazine in an AR. One thing you want to watch closely is magazine Overall length. if you start going larger caliber and not reducing brass length you can quickly run out of room for heavy bullets ( heavier being better retainers of energy... otherwise you are just making a huge subgun)
Good Luck.. I m gathering parts an info myself on a ".358 whisper" based on the BR series of cartridges

June 26, 2002, 21:07
The 284 winchester case is going to give you all the case volume you are going to get in a length that will fit in the FAL, it also uses the 308 case head. That means that the bolt is a go with no mods. It will provide 280Rem or 30-06 performance in the short action. The sharp shoulder is already there, so no extra forming processes. The sharp shoulder is the only obstacle I see, it can make feeding difficult. There have been commercial 284 gas autoloaders made, so it is not too hard. 338-06 performance out of an FAL? Sounds interesting.

June 27, 2002, 03:00
I love the .284 Winchester.

I intend to buy a box of them, and see if they will fit in an FAL or G3 Magazine (I'm still not certain if I want an FAL or a G3 as my wildact.)

The larger diameter of the .284 Winchester may reduce magazine capacity further, but I'll live with that. Of I can cut up a $5.98 20-round used mag, and get a usable 10 rounder, I'm happy.

Using these new cartrdiges in high capacity magazines may cause problems until the high-cap mag ban sunsets in 2004. (Note to self, march in the streets if this is renewed.)

The larger shoulder dimension of the .384 Winchester vs. the .308(.475" vs. .454") definately allows a larger bullet.

I do not want to repeat the mistake that Col. Whelen made when he made the .400 Whelen. It seems that going from a .462 Shoulder to a .436 neck does not allow sufficient room for headspacing (in the .400 Whelen). So a decrease of 0.026" at an angle of about 17 degrees is BAD.

The .375 Whelen worked well, and that had a .442" shoulder and a .402" neck. So a decrease of .040" at an angle of about 17 degrees is OK.

Taking the .284's shoulder of .475" and subtracting 0.040" give 0.435" as the largest neck diameter that I am confident in.

The brass around the neck has a thickness. I took 3 examples to find a tpyical thickness of this brass:
1. In the .284 the neck (0.320") minus the bullet diameter (0.284") gives a neck wallthickness (both sides added togeather) of 0.036".
2. The .375 Whelen has a neck diameter of 0.403" and a bullet diameter of 0.375", for a total (both sides added) neck thickness of 0.028".
3. The .35 Whelen has a neck diameter of 0.388" and a bullet diameter of 0.358", for a total (both sides added) 0f 0.030"

So we subtract the thickness of both sides of the brass (0.030")from the maximum allowable neck diameter of 0.435" to get 0.405" as our maximum possible caliber.

Hmm...taking a quick look through Brownells latest catalogue for barrels in a maximum of 0.405" caliber, I see: .375 diameter. I have spent enough time looking at prices of barrel blanks to know that we should go with a 0.375" or a 0.416". There are not many barrels inbetween.

OK...we take a .284 Winchester and neck it up to .375 caliber.

There has to already be a wildcat out there. I'll be looking.

Andy Out.

June 27, 2002, 03:15
There is a ".375-284." It is use in the Thompson Contentder and XP-1000 pistols.

There are dies, etc. in existance.

Now to find out what this little job would cost...

One guy wants $1300 for a complete XP-1000 with dies, etc.

Also, please forgive a tpye-oh in my last post, the .384 Win was actualyl a .284 Win; only a type-oh.

Andy Out

June 27, 2002, 04:20
I hate to harp on this ... but did you miss the point about shortening the brass a bit ? one advantage ... with a tapered case the shoulder area is now even larger ... might want to take a look at the 1.5 inch mark on the .284 and see what is possible

June 27, 2002, 04:35
Shortening the brass is a very good idea. If this were a military rifle, a 1.5" length would be fantastic.

You have a good point about the large bullets.

I'll look into the SOCOM round a bit more.


If I did go with an unmodified .375-284, the dies are available for $123 for a 2-die (custom) set from Redding-Reloading on a custom-order basis.

There are a number of TC / Encore / XP-1000 barrel makers that make .375-284 caliber FAL or G3 barrel.

Andy Out.

June 27, 2002, 04:36
I meant that the BBL makers COULD make a FAL bbl.

June 27, 2002, 09:45
Check out www.sskindustries.com. JD may have a wildcat to interest you.