If. Your Series 70 GC has been modified with light recoil springs in order to cycle a lighter low velocity wadcutter target load then don't shoot full tilt 230 gn through it. If it is stone stock then no problem with the heavier bullets. Yank the slide and measure the recoil springs tension. See link above and scroll down to where you need to be. OEM is 16 lb. If yours are lighter it will slam the slide back so hard it will hammer-peen and deform internals. Heavier it may not cycle completely and will smokestack a lot of empties.
The bullet weight itself is no problem. That is the bullet the gun was designed for, and how would people shoot the hardball leg match without it?
The key is, don't use the light 13~15 pound spring with full-power 230 grain hardball loads at 830~850 fps. If there's any doubt, replace the spring with a new one of known poundage. They're only, what, 8 bucks? (And I have found, they do need to be replaced periodically, even if they were the correct poundage to begin with. In a year and a half, my recoil spring needs freshed-up. The factory assumes the user will never do this, which I think is part of the reason they put such a god-awful heavy one in in the first place).
I have a "pre Gold Cup" National Match that Colt sold for target shooting using semi wadcutter match loads. The top inside of the slide is factory lightened to reduce mass. If your slide is like this, I suggest you stick to light target loads, even with a heavier spring. These pistols are becoming hard to find. If you have the regular weight slide, take the advice above and just go ahead with replacing the old spring with a new one of correct rate. -Ed
Two problems I have seen are the front sight departing the slide (it's peened in place vice silver brazed), and the rear sight pivot pin will break (it's a roll pin vice a solid pin). If you want to shoot hardball ammo instead of wadcutters, replace the recoil spring with a heavier one, and replace the rear sight pivot pin with a solid one. Then just be prepared to replace the front sight when it flies off.
Some good advice here. The older 'Cups with lightened slides, staked target front sight, and rear sight held in with the roll pin don't do well with Hardball. The Trophy models with dovetail front and rear sights will survive the big load with the big (18lb) spring.
I use a 16 lb spring and Buffer in my accurized Gold Cup Trophy, but do not shoot Hardball through it. The pictured Trophy will SHOOT, and gets lovingly crafted Match ammo. Small primer brass has given me better scores, and has better consistency with lower velocity variations (ES).
I am fortunate to have an Optometrist who knows how to set up glasses for Bullseye. Cliff Sites (Sites Vision Clinic) in Clarksville, Tn is one of the best in the country for setting up shooting glasses. He has also done my rifle and shotgun eyeglasses for many years. With diabetes and resultant poor eyesight, it has been a challenge for both of us.
Actually, John Browning designed the 1911 to shoot a 200 gr Flat Point bullet at 900 fps, imagine a really big 40 cal.
In another life, I shot over 1/2 million rounds of Major Power factor 230 gr ammo through a Springfield Armory custom 1911. I only replaced small parts such as sear, hammer, disconnector, ect.
I did keep a fresh 18 lb recoil spring and buffer in the gun.
As bigM said, use a 18# recoil spring with factory 230
ball. Replace the spring every 2,500 to 3,000 rounds.'
It's the rear sight pin that breaks, not the front. Lot's
of shooters replace the sight pin with a nail. It holds
up better than the factory sight pin.
If you shoot the gun much then you will need to replace the recoil spring fairly regularly anyway. I use 17 pound Wolf springs in my .45 acp 1911s and shoot 200-230 grain ammo @ 850 fps with no functioning problems in either loads.
The series 80 Gold Cup that I have broke the pivot mount pin holding the Ellison rear sight after only 5K rounds. I went though several replacement pins and even tried small drill bits and nail sections - eventually the holes in the slide got egged out and I finally made the proper repair which was to mill the slide out for a BoMar low profile rear target sight and also milled a dovetail slot in the front for a good square front sight.
The other thing that will probably happen to your gold cup is that the collet bushing will probably break and you will need to have a good solid bushing fitted to the barrel. And if you are going to that expense you will probably want to replace the barrel at the same time with a higher quality barrel.
I have 2 Colt Series 70 National Match's.
For 200 grain swc's, one of them prefers a 14lb
and the other a 16lb.
When I switch to 230 grain lead at 810fps, one likes
a 16lb stocker and the other an 18 lb.
Ed Brown recommends changing springs every 3000 rounds.
Brownells has Wolff springs. I would get one in 14lb,
a 16lb, and an 18.5lb. This will only set you back $15.53.
I would stay away from the Poly buffers. I have had at least
three brake apart during USPSA match's When they come apart,
they will tie the gun up. Even though they look good, you can't tell
when they will let go. To light a spring and the slide velocity
increases. With that increase comes the possibility of frame cracks.