I like internal better myself.

Same here, I prefer the look of the internal extractor. I own one 1911 with an external extractor, its a Kimber ProCarry and I have had no problems with it. Aesthetically the external looks great on the Sigs but I guess that I am too old school on this.

Internal 1911 Extractor
Plus:
It's the original design, and it's an elegant engineering solution.
Fewer parts to break or go wrong.
Easy to replace, when it breaks.
You can get it really clean.
No external projections to catch the fingers.
Minus:
Must be removed to properly clean.
One more part to remove and replace when cleaning.
It can break, if its metal gets fatigued.

External 1911 Extractor
Plus:
You don't have to remove it during cleaning.
It's less likely to break unexpectedly.
Acts as very effective loaded-chamber indicator.
Minus:
Adds materially to the parts-count.
Probably not user-repairable or -replaceable.
Can lacerate the hand during slide manipulation.
Harder to clean.

Internal it is.

Thank you Steve.

Listen to what steve1911a1 is telling you----stick with the original browning designed internal extractor whenever possible. Old john moses browning can still be trusted after almost 100 years !!!!!!! Ooooo-rah steve

Thanks for the boost, Guru.
But note that this thread is a couple of years old, and wasn't continued once the OP's question had been answered.

Something else to think about. Internal extractors need to be tuned, external don't. Tuning a 1911 extractor can be tricky and frustrating. In a lot of cases, its not a drop in fit.

Originally Posted by gpo1956

Something else to think about. Internal extractors need to be tuned, external don't. Tuning a 1911 extractor can be tricky and frustrating. In a lot of cases, its not a drop in fit. [emphasis added]

Um, that's not exactly true.
External extractors, too, can misbehave, and can have to be filed and polished here and there.
And then there's the ejector...

Originally Posted by Steve M1911A1

Internal 1911 Extractor
Plus:
It's the original design, and it's an elegant engineering solution.

Great informed answer!
Eli

Originally Posted by Steve M1911A1

Um, that's not exactly true.
External extractors, too, can misbehave, and can have to be filed and polished here and there.
And then there's the ejector...

Steve,
If you will read my post, I never said external extractors don't ever have problems. He's asking about building a 1911 from scratch. Nine times out of ten a new internal extractor won't just drop in without tuning. In most cases, the external extractor is more forgiving. Obviously you've never had to tune an internal extractor. It can, indeed, be very very frustrating.

Originally Posted by gpo1956

Steve,
If you will read my post, I never said external extractors don't ever have problems. He's asking about building a 1911 from scratch. Nine times out of ten a new internal extractor won't just drop in without tuning. In most cases, the external extractor is more forgiving. Obviously you've never had to tune an internal extractor. It can, indeed, be very very frustrating.

Hahahaa... I think he's probably done a few.

Truth:
I am not a gunsmith. I do a little kitchen-table gunsmithing, and the only machine tools I own are a small drill press, a grinder, a polisher, and a Dremel.
However, while I lived in Southern California, I was close friends with a very talented gunsmith. I started out watching him work, and then I graduated to doing some of my own work under his watchful eye.
I've never fitted either kind of extractor myself, but I watched him do many, so I know what's involved.

Once another 'smith brought a 1911 to practice, and he bragged that this gun would drop all of its empties into a bucket that had been placed just so.
He demonstrated his extractor and ejector fitting to us, and by golly he was telling the truth. Every empty that came out of that pistol went into the bucket!
Trouble was, the pistol was woefully inaccurate. It wouldn't shoot groups; it shot patterns. But, by golly, every empty case went into that bucket.

Originally Posted by zhurdan

Hahahaa... I think he's probably done a few.

Hahahaa, I guess he hasn't, has he?

Originally Posted by Steve M1911A1

...I've never fitted either kind of extractor myself, but I watched him do many, so I know what's involved...

Um, gpo1956, I believe that the laugh's on you.