Everybody has their own dimension for lowering the port wall, but somewhere around .475" from the bottom of the slide is a good one. The flair is usually done with a rotary grinder and a 1/2" to 3/4" sanding drum done freehand.
First off, I can't cut one by hand as uniformly as it can be machined. The way I've done it prior to aquiring a mill was to draw or scribe a lay out line on the side of the slide at the height that I wanted the port to be. If you scribe, don't make it very long, or you'll still see it after the job's done. Clamp the slide in a padded vise and using a rotary grinding tool and a 1/2" sanding drum; make light cuts from the front to the back. Don't stop or you'll cut a dip. Don't let the drum wander out too far, or you'll cut a nasty divot across your slide. Work until you get to your line and check for even lines. Re-cut the bevel on the inside of the port's bottom edge, then cut in your flair. Try to position the slide so that your hands are braced against the vise as you cut. All that being said, I'd suggest practicing on some scrap steel before you do a big gnarly on the side of your pristine 1930's Colt National Match.
Balls, a Dremel tool & a strong right arm can modify (Or destroy) anything..
Thanks for the detailed replies. After I posted, I realized that I could use my Kimber Custom Classic as a pattern to measure from. I'm near the beginnings of a long journey in creating "My" Custom Commander. It'll either be beautiful and functional or end up in the scrap barrel..
More to follow as I succeed or get stuck.
Unsafe, the .475 figure is standard for Gold Cups, and lots of current production makers' slides. I prefer to cut them to .450 because it gives the round an even better chance to clear the port without dinging the edge and bouncing upward. You can make a bit lower (.430) if a scope is to be slide-mounted. I think Les Baer cuts his to .430 these days.
I have been cutting the port opening to a height of .400" to .410" for quite some time now with no issues to date and thousands of rounds fired on these pistols. The inside of the port also gets milled down to a 45 degree angle when I finish milling the port wall height. I just happen to have some Les Baer Bullseye Wadcutters (some iron sights/some dots) on hand and I checked the port wall height on these pistols and here are the results. Pistol #1 - .3915" Pistol #2 - .397" Pistol #3 - .3905" Pistol #4 - .3965" Pistol #5 - .3925" Pistol #6 - .3955" Pistol #7 - .3955" This batch of Baers range in age from six years on the oldest one to just about one year on the newest one and Baer has seemed to remain fairly constant on this height for these models over that time frame - at least in the ones I have here.
I just finished cutting down a Springfield port as well as a Colt while milling them for the BoMar hidden leaf rear sight cuts and they were both at just about .470" in height when I started. I brought both of these down to .400", 45 degree beveled inside the port and flaired them back as well. There are a couple of pistols around here that I did not do that have had the ports cut down to .385" in height, have experienced no issues since being built three years ago and according to the owner of one of them has just in excess of 50,000 rounds through it. The slide on one of these pistols is a Caspain product atop a matching Caspian frame and the other one is a Colt Gold Cup 80 Series slide mounted atop a Caspain frame. I shoot a lot with these guys and I would estimate the one with the Colt slide has somewhere around 12-15,000 rounds through it since it was built.
Hey Bullseye...thanks for the report. I've often wonderd how well a slide would fare with ports lowered that much. I've never done it and am really surprised to hear that Les is doing it that much. I was surprised to see the first one of his at .430 because I hadn't gone quite that far either.
I think I'll try some of those short ones on the next few wad cutter pistols I build, but I'm still a little goosey about going lower than .430 for DCM hardball guns.
Bob: During the next seven to ten days I should be able to get my hands on several more Baer pistols and I will make note of all the port heights on them. I should also be able to get my hands on at least one or two of the Baer hardball models that are floating around here and I will measure them also and when I have the numbers I will post them here. I really can not remember if the ports on the Hardball Baers appeared to be of a higher height or not (if they are they certainly did not catch my eye when looking at them) but I will check at my first opportunity.
AFMan: When I cut down the height of the port wall I will most always use a .375" carbide cutter and once and a while I will grab a .500" carbide cutter but generally the .375" cutter is the one I use. For cutting the 45 degree angle inside the port wall I generally use a .187" or a .250" carbide cutter with the .250" being used the most. All the cutters I use are solid carbide and have four flutes.
Thanks, I'll look forward to it.
I don't sell Baer's and therefore the only ones I see are when someone has a problem with one...which isn't all that often as there aren't that many of them around here. And the ones I do see are usually just a little trigger tweaking or lightly lapping those doggone too-tight slides.
I do remember that the last two I've worked on were both his hardball guns though and it sure seems like those ports were at .430. Oh well, we'll soon find out.
Bob: I ended up making a trip to the range today to pick up a Colt 80 Series slide that needed to have a BoMar sight milled into it as well as a front sight change and while I was there I checked out a couple of pistols that happened to be on the line. One was a Baer and the other was a Springfield Trophy Match of the latest series that has had nothing done to it at all - box stock.
The Trophy Match measured out at exactly .400" on the port wall height but could have used just a little bit more work on the inside beveled area. The Baer that I checked is about three years old and had had nothing but factory loaded hardball fired through it since the owner purchased it. It's port wall measured out at .3985" and the inside angle was pretty much acceptable. I know for a fact that this particular pistol is exactly the way it came from Les's place as the owner will not allow anyone to do anything to his firearm. Once I get a few more Baers looked at over the next several days I will let you know what the results are.
Bob: Had a chance to run out to the range again today to deliver the slide I cut the sight in on and shoot the bull with some of the guys. While I was there I gathered up this batch of numbers on the Baer port heights. I think this batch along with the other numbers I have already posted will give you a pretty good idea of what I have found.
#1 - .392" Bullseye Wadcutter
#2 - .395" Hardball Model
#3 - .390" Bullseye Wadcutter
#4 - .390" Bullseye Wadcutter
#5 - .385" Bullseye Wadcutter/3 digit serial number
#6 - .387" Hardball Model
#7 - .390" Hardball Model
So far I have not come across a Baer around here that has gone up to or exceeded .400" in port wall height and all of the ones I have examined have had pretty good angles cut on the inside of the walls as well. Based upon my own personal experience and the fact that all of the pistols I have looked at lately I do not feel uncomfortable at all with going down the the .400" to .410" height that I generally work with. Like you indicated in an earlier post, perhaps on your next project you may want to try coming down a little farther in your cut and see how it works out for you. I know one thing for sure, at the .400" height there are no issues with getting the empty cases out of the slide no matter if they have iron sights, slide mounted red dots, or frame mounted red dots.
Thank a lot for your efforts. I would never have been able to find that many Baer's on our firing line at one time, and I certainly agree with you about ejection at that dimension. I'm going to start cutting to .400 now. Most of the 1911's I build are for match competitors and they nearly all use slide-mounted dots. I suspect the days of "bouncing brass" are over. Thanks again.
Bob, no problem at all. As far as finding Baers on the firing line - in this area is it very easy, in fact the ones I have listed here in this thread are just a small sampling of the ones that are in almost daily usage here. I would be curious to hear how your next project works out and what your impressions are after you start cutting to this port height. I would imagine that the first one you cut to this height is going to really look short to you to say the least.
You're right about that. The first one I saw at .430 looked pretty doggone skinny! I think the only ones I've seen shorter than that, over the years, are some that guys have brought in because they cracked...right at that sharp corner, naturally.
Bullseye45acp and Bob Brown, nice posts. I always learn from you guys.
Back to the hand cut methods. I scribe my slides just a little higher (about .010") than where I want the bottom of the port to be. I then use a carbide cutter to lower the port, working slowly to keep it as level as possible, and cut rough radii.
Then use a .375" white stone on slow speed to shape the corners of the port. I pay close attention to the horizontal part of the radii, front and rear to keep them equal distance above the slide rails.
After this I rough cut my inner bevel with a flat file by placing at about a 45 degree angle to the flat of the port lower surface. I place leather on the inside of the slide to protect the inner surfaces of the slide and the other rail. This will reduce the metal I have to remove in the next step.
I then use a flat smooth file to finish lowering the bottom port edge and blend it into the front and rear radii. Since I am filing flat across this surface to the other side of the slide I place a piece of leather on the inner far side of the slide.
To smooth finish it all I put smooth abrasive cloth around the stone I used for the radii and around the file to obtain the texture I desire. I finish the inner bevel.
Then I tackle the rear port relief as described by the others.
I am a total novice here and most likely have no bussiness sticking my foot in but the 2 1911s i have worked on, i lowered and flaired the port by hand in a vary similar method to the one described except i used masking tape to lay out as well as protect the slide.