Taurus Thunderbolt, .45 ACP!

[Ian]

Well, maybe. I think so, anyway.

Story is my FIL bought a used one for my birthday a couple of years before he died, and if it weren't for that the rifle would have vacated my premises a long time ago. I wanted one badly for years, which is why he got it, but it's a .45 Colt (also what I thought I wanted) and the basic design is just terrible, little did I know. The chamber is elliptical, a requirement for getting them to feed, and the bolt ways have been filed on so much that the bolt dives forward at an angle to the chamber. The combination of grossly oversized chamber, unsupported feed ramp area, and angled bolt face ruins brass in one firing and spits buckets of fire in my face because there's virtually no chamber obturation taking place even with full loads. A little reading on the 'net revealed a common fix was to rebarrel in .38-40, not much else required to make them work well after that.

But I don't want a .38-40.

Tonight I stuffed the magazine with half a dozen .45 ACP cartridges (it will probably hold about 1400 of them in that 26" tube) and guess what? They shuffle and shuck just fine, only issue is I'll have to make a new extractor with a longer hook and maybe build up a tiny bit of metal on the bottom of the bolt head. The bolt tilt issue can be fixed by moving some metal around at the back of the receiver and making a couple of new bolt guide plates to the correct thickness, but that needed done anyway.

Further study revealed I can turn the barrel tenon, thread it, and cut the shoulder in my mini-lathe. I'll have to do it between chuck and tailstock center because only about 8" of the barrel will fit into the spindle (due to OD and the rate of taper) which means cutting and facing the breech end square by hand, but I've done more difficult things. Got a .45 ACP barrel chamber reamer on the way. Pretty sure my lathe can cut the thread pitch (metric, 1.0mm). All I load for the ACP is powder-coated TC bullets, so no worries about chain firing in the tube. Gee, what could possibly go wrong?

I intend to find out. Anyone see anything magnificently stupid about this plan before I start chopping on this fine Brazilian wall ornament?

 

[fiver]

the bolt face will definitely need some work.

the 38-40 and 44-40 are both excellent rounds, the 44-40 would be just as easy to do.
i really like my 92 in 44-40.
but I have a soft spot for the 38-40 round it's one of those 'what the hell were they thinking?' deals until you get it sorted out and actually use it.
then your like okay i'll deal with the pain.

 

[Ian]

The bolt face is 85% flat, with a little rim support just on the bottom edge which will probably need to be built up so the extractor has something against which to pinch the smaller ACP rim. I'm stuck on .45 ACP because I can just set back and re-chamber the existing barrel, I have a companion SAA-clone revolver for it, the shorter ACP cartridge can turn and go in the chamber without hogging out a bunch of supporting metal, and I have buckets of brass/dies/bullet moulds already.

 

[Cherokee]

Sounds interesting, keep us informed. I wanted one in 32-20 but all the bad reviews killed that. Now, 45 ACP sounds like fun.

 

[oscarflytyer]

if you set the bbl back will you need to rechamber for 45 ACP?

 

[fiver]

ideally you want to go back a thread or so further and then clean everything up.

it's like cutting down the 7.7 jap round for a 300 savage case.
in theory you should be able to cut it off right at a certain point, thread the barrel, and run with it but in reality [shrug]

if the 45 cowboy brass was/is still available this is a pretty easy change, it is essentially a 45 acp case with a 45 colt rim on it.
initially they were making cases from cut down 45 schofield cases, then got someone to make a run of the brass.

 

[freebullet]

Sounds like an interesting project. That would be quite a hoot in 45acp. Lots of work, but if you can pull it off, it would be worth it.

I passed on an original colt lightning rifle in 44-40 at a very attractive price. I regret not getting it.

 

[fiver]

the Lightning and the USFA version are excellent rifles.
just looking at the workmanship and fitment involved in building one is a marvel.
if they built cars like that back then, most of them would probably still be running today.

I think Ian is finding out why the Taurus I had lasted about a week.

 

[Ian]

if you set the bbl back will you need to rechamber for 45 ACP?

Yes, if I don't want to have the same chamber obturation problem I'm trying to fix with the re-chamber. The Colt chamber even if cut to SAAMI modern specs has a larger diameter at the front than the ACP chamber, so in reality I'll have to bob the barrel off at the front end of the existing chamber and re-thread the whole tenon.

 

[Ian]

the Lightning and the USFA version are excellent rifles.
just looking at the workmanship and fitment involved in building one is a marvel.
if they built cars like that back then, most of them would probably still be running today.

I think Ian is finding out why the Taurus I had lasted about a week.

Yep, no tears will be shed if I bubba this Taurus one to death. The innards are actually pretty decent, seen plenty worse fit and finish but also seen better on cheaper guns. If I can make a fun range toy out of this it's a win.

I'd like an Uberti, but they're just too spendy for me, I'd spend the same money on a NM M1A.

 

[RBHarter]

Outside of having a companion gun for it already why not just fix the chamber ?

You'll cut it back ,what like .7-8 to get the chamber short enough to fix anyway .

I figured about a dozen ways to "fix" the 92's in 45 Colts with the .490 gross chamber and the 1.35 length . I went so far as to cut some split neck 308/Mauser/06' brass but it would get to about 1.1" out of the chamber slip the ejector and pop back in the chamber . I never did fire form it .
The Rosschester 92' will only take 2 Schofields in the mag but feeds them fine , the rim od is just a little big for the extractor to slip over consistently .

 

[Ian]

I would just fix the chamber, except from what I read it wouldn't feed if I did. This isn't just a case of the typical grossly oversized .45 Colt chamber here, it's that on top of the fact that to make the .45 Colt feed in this original Lightening design without modifying the action, Taurus literally had to curve the bottom of it like a shoe spoon to make the cartridge feed from the angled lifter and turn into the chamber. The only way I've come up with to really fix it is to change to a different cartridge; either a smaller one, a shorter one, or one with a taper.

 

[freebullet]

Are ya guna thread it to share a can?

I would shorten it a bit. Maybe down to 16-20" would be very fast handling.

 

[RBHarter]

I guess it can be chambered for ACP and try Schofield for feed . Maybe a 45 mag length ?

 

[Ian]

I plan to thread the muzzle but will have to bore the spindle out a little bit on the outboard end to do it on my benchtop lathe. Not planning to shorten the barrel very much at this point, maybe later. It would be really neat to make it a carbine, but I like being able to see the front sight clearly and carbines put them too close for me now. Quickload predicts 320 psi muzzle pressure with the barrel shortened to 25", so it may not even need a suppressor to be hearing-safe.

If I were just trying to come up with the best option for the rifle I'd probably lean toward the 38-40 chambering since it would be the most "correct" possible option for the feeding and functioning and would require no modifications other than replacing the barrel. The bolt ways and rear of the receiver will still require attention no matter what I do.

 

[L1A1Rocker]

I'm embarrassed to say, I had to look up what a Taurus Thunderbolt was.

Looks like a pretty involved project. You will have a very unique one once it's done.

 

[Ian]

"Involved" is relative. You didn't see the ancient take-down rolling block I bored, relined, and converted to .22lr from .32RF for Dad. Had to cut off the mangled barrel tenon/chamber and file a new tenon by hand.

 

[oscarflytyer]

"You didn't see the ancient take-down rolling block I bored, relined, and converted to .22lr from .32RF for Dad. Had to cut off the mangled barrel tenon/chamber and file a new tenon by hand.

Local guy does the rolling blocks. rebuilds/rebarrels/re-case hardens... One is on my bucket list if I can ever afford it.

 

[freebullet]

Quickload predicts 320 psi

Exactly Why I figured lobin off a big chunk might be worthwhile but, with all the work to cut back & refit the chamber end makes waiting smart on the muzzle end. If you did shorten it substantially a red dot might be fun.

I really really like those. Went back to look at the original colt the next day, she was gone. Immediately begun kicking myself, it was like 12yrs ago & I haven't stopped yet. I wouldnt have modified that though, this tortoise is a nice candidate for such.

I wonder how many guns fiver has broken by his standard usage methods.

 

[Ian]

If I shortened it back to 14.6" and pinned a suppressor-mount brake on there to keep it legal rifle length it could sure be fun, maybe with a Delta Point or something really slim installed in the rear sight dovetail. It would hold a lot fewer rounds, but still a bunch. Thing is, I have a single-shot .45 Colt NEF shortened and braked already, with a red dot on it. Also an AR-45, .458 Socom, etc. If I can keep this one traditional and still fairly quiet without a can, it's a win. If it don't work out, I can still chop it off, duracoat it, install a full-length picatinny rail, slap a VG on the fore-end, a flashlight, and some optics. I'm only half kidding.