.458 heavies in .45LC?

[rodgervich]

I wasn't sure where to post this question but figured it's lead bullets so this may be the place.
I am building a falling block rifle and intended to chamber 45-70, I picked up a used barrel chambered in .458 Win Mag. As it turns out the action won't accomodate the long .45-70 case and I have to go down to .45LC cartridge length. The barrel is .458, the .45LC is used with .452 bullets, I am quite sure I can stuff .458 bullets in the LC case (done a couple).

My questions are:
1) can I safely shoot the heavy (300+ gr) .458 bullets in the .45LC case through the .458 barrel? If so, I want to use black powder or Pyrodex/777 or the new IMR Trail Boss to keep the pressures down, can you give me a starting load?

2) Or can you direct me to lighter weight , 200-250gr, .458 diam bullets?

3) What other options or suggestions can you give me?

I am an experienced rifle and auto pistol reloader but not much with big bore/handgun cartridges. Any help would be appreciated.

[John Traveler1]

Rodgervich,

That action that won't fit a full-length .45-70 round is a bummer!  What action is it?

Yes, heavy 300 grain bullets can be loaded into a .45 Colt case, but it would be a BAD idea all around.

First, the .458" non-standard .45 Colt ammunition would likely be unsafe to fire in most .45 Colt guns.  It might not even chamber in a standard .45 Colt gun. Getting a good chambering job is another challenge.  The .45 Colt reamer pilot is designed for standard .45 bores.  The resale value of your gun is hurt by the non-standard chamber.

Even with a full case of black powder (or substitute), your velocities would be dismal... say, 600-800 fps.  Accuracy probably won't be much to brag about either, since the standard 1-22" twist is intended for 300 to 405g bullets at .45-70 velocities.

Loading smokeless in such a small case with the heavy bullet is risky too... you know that the revolver shooter boys routinely overstress their .45 Colt revolvers using heavy bullets.

You might want to consider chambering for the .45-60 cartridge.  Cases are easily made from .45-70.  Another possiblity is the .458x2" American.  It's made by cutting .458 Winchester cases down to 2.00".  Both cartridges offer more flexibilty and performance than a wildcat .45 Colt chamber.

HTH
John

[Castaway]

I wouldn't shoot a 45 Colt out of your contraption.  Chamber dimensions would insure a case rupture each and every time you pulled the trigger.  I guess I don't understand your question.  If you are putting together a falling block rifle, what limitation does the action have on your ability to chamber rounds of 45-70 length.  In a falling block, you are the "action" by virtue of the fact you are the one chambering each single shot round.  Take it to a smith to chamber the barrel to accept a 45-70.  He'd have to turn it far enough to get past the recessed portion that accepts the belt of a 458 but it shouldn't be a big deal.  If he can't or the cost is too great, cut down 458 cases to 45 Colt length and use 45 Colt data.  Falling blocks are strong actions, rolling blocks are not.  If it is a falling block, I'd be tempted to use Ruger data.

[Leftoverdj]

What kind of action? I assume you are going to shorten your barrel from the breech and rechamber? You sure you have a falling block? Martinis have issues with case length, but falling blocks don't that I have ever seen.

[rodgervich]

I purposely left out the details on the rifle since it would most likely take this off track of my issue of the bullets. I am building it from scratch, my own design. It is made of mild steel and TIG welded together, I have calculated the strength of the design to be safe at 45-70 low pressure loads with a helathy safety factor. That is the reason for the BP/lead loading, to keep pressures low but still be fun.
In doing the design I omitted an actual cartridge in the model so I didn't get to actally "see" if the long cartridge would fit, my bad. The issue of fit is that the hammer is too high in relation to the chamber and does not allow the long 45-70 to fit without hanging up on the top of the hammer. I cannot cut the hammer lower or it will no longer contact the firing pin.
The barrel is chambered in .458WinMag, I can turn down the tenon to fit my reciever and shorten a little and it will basically be a 45-70, I thought I was going to get lucky. I can still cut it down even more and it will accept the 45LC cartidge with the big .458 bullet. I'm trying to do it without a custom reamer which I can do but would rather not. The .458 American is a good idea that I had not thought of but would indeed require a full rechamber and I would prefer a rimmed cartridge that is easier to extract.
As long as the 45LC case didn't rupture the first firing I can size just enough to hold the bullets and leave it at that, basically fire formed. I can modify any dies I need to, or even make some if I have to, that is not a problem but really want to use off the shelf parts.
I don't have any other .45LC guns and don't really plan on any but if that happens I can keep this batch of brass dedicated to this rifle. Since it is a homebuilt (yes it is legal) I cannot ever sell it so it won't be a safety issue for anyone else regarding ammo.
As far as accuracy and velocity goes, since this is a first time design I'll be satisfied if I can hit milk jugs at 50 yds.
So there is the whole story.

Now what do you think about the .458 bullets in the .45LC case? What can I load it with?
And yes, I will pull the trigger with a loooong string the first 10 shots!

[John Traveler1]

Hi, Rodgervich!

I was fascinated at the description of your homemade singleshot action.  Care to share the idea with pictures or more details?  When you stated that it was TIG welded together, I envisioned a Frank DeHaas-type design, made from mild steel plates and silver soldered together to minimize milling machine work.

In answer to your question, I would offer a CAUTIOUS "yes" to your idea of chambering it for .45 Colt and loading .458" diameter bullets.  It would depend on the following:

1.  Make sure your loaded rounds will chamber in a standard .45 Colt chamber.  If they do not, you will have to cut a custom chamber to completely remove the traces of the .458 Win mag chamber.  a cheap way to do this is to regrind a standard size straight shank reamer to your custom .45 Colt throat and pilot dimensions.  Any machinist with a tool post grinder can make you such a reamer cheaply.  As you may expect, using factory .45 Colt ammo will give lousy accuracy in that .458" groove barrel.

2.  Load ONLY full-case charges of blackpowder or BP substitute!  Loading cartridges with BP or substitute with an airspace is asking for trouble!  I would completely forget about using smokeless loads in this project.  Mild steel will simply not hold up to the battering that even modest smokeless pressures give.

3.  Consider the use of .452"-.458" round balls in your loading.  I've played with squib and multi-ball loads in the .45 Colt and .45-70 cartridges, and the soft lead balls for BP muzzleloader shooting seems to slug up to fit the bore and give acceptable accuracy.

Let us know how the project work out!  Pictures would be nice!

HTH
John

[captainkirk]

I would second the above idea of using a "shortened" 45-70 cartridge over the 45 LC idea even if you have to go with custom dies.  The 45-60 is fine as might be the 45 silhouette, which is the 45-70 shortened to around 1.5 inches if memory serves.  Both are made to handle 458 dia bullets without crowding or splitting and would use readliy available brass.  Reloading data should also be fairly easy to find.  Sounds like quite an ambitious project you have taken on there.  Hats off to you.

captainkirk

[Leftoverdj]

Gotcha.  Common 1/2" reamer that you probably have will cut a chamber for a shortened, blown out .45-70 case. Throater is about $40 if you don't feel like making up your own, but a home made half reamer to cut the leade is all you really need.  You're also going to have to inside neck ream the cases because of the internal taper. Polish out the chamber a few thous, use the same 1/2" reamer to make a sizer, and you're home free.

Gonna be a little odd with thicker than normal neck walls, but should work.

[rodgervich]

The link below takes you to the entire project that has been documented since the beginning a year ago. Didn't realize it has been that long, had a baby and some other projects came up that took time away.
I think I will go ahead and fit the barrel like I have proposed just cutting to LC length and see what happens with 100% load density Pyrodex. If it blows up then I'm done, if the bullets come out and the rest stays together then I will shoot at some big paper and see what the cases look like and if I can hit a barn door. If the cases split then I will go to a custom chamber.
Thanks for your input and interest, I'll let you know what happens.

http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?act=ST&f=3&t=1076

[w30wcf]

Rogervich,

Sounds like an interesting project.  The SAMMI maximum chamber dimension for the .45 Colt is .492".  

Regarding shooting .458" bullets in the .45 Colt, based on my experience, no problem whatsoever.  My .45 Colt Marlin Cowboy rifle has a chamber that is .488" diameter and a fired case will accept a bullet that is .459" diameter.  To get an even case expansion all the way around on the first firing, I put a piece of .005" thick tape x .01" wide just forward of the rim.
I then neck size only.

My rifle's groove diameter is .4525" but I regularly shoot .457" diameter bullets in it to help seal the case better.  The cast bullet swages down easily to fit the smaller groove diameter easily, even with maximum loads (330 gr. at 1,640 f.p.s.) with no problem at all. It is one accurate rifle.

Regarding the velocity of a 300 gr. bullet (Lyman 457191)and b.p. in a .45 Colt rifle....... I have used 36 grs. of Swiss 3F and the velocity was 1,180 f.p.s. from my rifle's 24" barrel.

Good luck,
w30wcf

[HHI 812]

I knew a gunsmith many years ago, who converted revolvers in various wildcatts and calibers. Two of his wildcatts utilized .458" diameter bullets in his revolver conversions. One was a Maximum length cartridge, and the other used the standard .45 Colt brass. It was a particular brand brass, but which one I don't recall right now? I still have his drawings somewhere? Too bad he didn't get in the magazines, because he was doing these conversions in the early 80's. I'll see if I can find any of his loads and ballistics.