Interesting Slug from a TC Contender 45LC barrel

[Anonym]

I have a nice 45 LC (not .410 bore) 16-inch barrel for my contender from the custom shop. I've always heard T/C's bores were fairly large, so I had been shooting my cast boolits "as-cast". I have a 454190 mold and a 452424 mold for it, and the larger 454 boolit is pretty accurate for dropping them straight from the mold into a piece of brass. The 452 shoots fine as well, but I thought the results were from the preference of a larger bore.

Well, curiosity killed the cat, so I took one of my 454190 boolits that I had cast 50%coww/50%pure and drove it with a dowel into the breech of the barrel and then back out. I was extremely surprised to throw the slug into my micrometer and find a 0.450" bore! Going to start sizing all my 45 boolits to .452, but thought that was an odd bore size. Anyone else shooting a "tight bore" 45LC?

[MT Gianni]

For curiosity sake, is this a 45 or a 45/410?

[Anonym]

Straight 45LC. Had a 45/410 but sold it for a straight 45LC as it was better suited for my needs. Am I off in thinking this is overly small?

[ktw]

SAAMI spec on 45 Colt is .442 bore/.450 groove. I suspect most modern guns would run in that vicinity.

http://www.saami.org/PubResources/CC_Drawings/Pistol/45%20Colt.pdf

You really shouldn't worry about bore size, other than making sure your throats are the same size or a bit larger. What you really want to size to is chamber/throat, and those can run big in many 45 Colts, even modern ones.

I have a Winchester (USRAC) 94 Trapper in 45 Colt with a very generous chamber. I'm fairly certain the bore/groove runs close to SAAMI spec. I can finger seat .457 bullets in fired brass.

It will shoot .451/.452 jacketed just fine. It does all right with .452/.453 gas checked bullets, provided I use a harder alloy. I could never get it to shoot plain based bullets worth a damn until I started loading .456/.457 cast in it. At that size it handles plain-based cast bullets just fine.

-ktw

[Wayne S]

"You really shouldn't worry about bore size, other than making sure your throats are the same size or a bit larger. What you really want to size to is chamber/throat."

WHAT HE SAID

[Anonym]

Ok! Too new to this stuff to really understand what I'm doing yet. I will check it out and report back.

[Anonym]

I drove another boolit into the chamber tonight. I "squished" the boolit a bit in a vise to enlarge it a bit and make sure I would see exactly what the chamber is doing. Hopefully you fellas can interpret what I have and guide me in the right direction.

I have a measurement of the chamber right at the point the rifling "ramps". Forgive my terminology, but it is at the point the "forcing cone" meets the rifling. At this last point before the rifling becomes defined, it is measuring 0.4525. Quickly the cone tapers away and the rifling jumps to the groove size of 0.450. Am I measuring the correct throat area? And if so, will a 0.452 sizer work, or should I step up to a 0.454?

My unsized boolits are measuring 0.455ish for the 454190 and 0.453ish for the 452424.

[bigted]

so here is a fast way and painless to figure out what your throat wants for the boolit diameter ...[in cast]...

take a fired case from this rifle ... take your unsized case and slightly flair the mouth so as to remove any of the former crimp ... now measure the inside diameter of the flaired unsized case mouth. this will give the maximum diameter of your boolit needs. i usually go a thou or so smaller in diameter ... sorta like this for an example ... my 43 spanish ... the groove diameter of the barrel is .439 ... the case measurement however is .454 ... so i load .452 patched and .454 cast boolits to great effect. the boolits do well in my tighter bore and i dont have leading problems with either.

that is my procedure that seems to work very well for me. good luck!

[Anonym]

Thanks bigted! Took a handful of fired cases I had from this rifle and did as you suggested. Inside of the cases all measured 0.456". No wonder my rifle liked the 454190 so well. Wonder how hard it would be to find someone willing to trade a 454424 for my 452424? Dang nice mold with the flat bottom lube groove. Hate to get rid of it, but if it's not ideal for my rifle...

[leadman]

With a Contender or other single shot just load the boolit so it almost engraves in the rifling. I don't worry about a crimp on the boolit even if it is a pistol cartridge, just load it like a rifle. If you go out too far with a Contender/Encore the interlock won't allow the gun to fire.
I have slugged many Contender/Encore bores and have not found one oversized yet.

[Anonym]

I will play around with it some and see what I can come up with. In the mean time, I'm going to see if someone has a 454 version of this mold they would trade with me.

[Larry Gibson]

I picted up a custom shop 12" 45 Colt a few years back. Didn't shoot it until I was running pressure tests a couple years ago. It was beautiful barrel BTW with very good looking rifling. Since I was pressure testing factory ammunition and commercial .452 sized cast bullets I didn't bother to slug it......big mistake! I simply check the iron sights of a 25 yard zero and the 1st shot hit 1" to the right of aim so that was close enough for the velocity and pressure test of various ammo's. Hooked it up to the M43 and 1st shot through the screens took out the front 2 screens. Went back to the zero target and the next 5 shots all key holed and barely stayed on the target board at 25 yards. Went home and slugged the barrel and it was .459 groove diameter! A 45-70 barrel had been used!

On the other hand I've also had numerous other Contender barrels and haven't found another oversized yet just as leadman says also. Picked up an older octagon 45 barrel from a member here and it is an awesome shooter with .451/.452 sized cast.

Larry Gibson

[Anonym]

Well, I tried adjusting the seating depth of the SWC and you can't seat out long enough to touch the rifling. May shoot some with the brass just covering the lube groove and see how they shoot. Anyone else have any tips to try? Guess I shouldn't complain much. Those SWCs seem alright, just not quite the RF...

[cbrick]

I've never found a problem with groove diameters with T/C but as you found out, they aren't called Linda Lovelace throats for nothing.

Every T/C I've loaded for was deep throated, some in the extreme. Can't swear to the reason but I've always suspected it is to help relieve pressure on the Contender frame. Stretched frames is a fairly common occurrence with the Contender.

You could do a chamber cast and determine exactly the dimensions your working with and then use shortened 454 brass to fit your chamber perfectly. You don't need to use the 454 brass for the purpose of loading hotter, just for a proper fit (longer brass) in the chamber/throat.

Rick

[leadman]

I used shortened 460 S&W brass in one of the 45/410 barrels just for the reason cbrick stated. Helped some but still not as accurate as a straight 45 colt barrel so sold it.

[Anonym]

Hmm, interesting. I may have to give the 454 brass a shot sometime. I'm assuming it's a "trim to fit" situation? Now I don't think I have any issues with the 454190 mold I have due to the thicker nose finding the throat quicker.

Dang being broke all the time. Just saw a 45LC barrel for the Encore in 22" that would have made a dandy partner for this 'Tender barrel...