Most people who have owned and/or fired a sizeable selection of 1911 pistols have probably experienced a return to battery stoppage in which the slide is a quarter-inch out of battery with a light to moderate push on the slide. This one is known as a Three-Point Jam, and sometimes it's a true jam. Most of the time, the slide will snap to battery when it's pulled rearward about an eighth of an inch and released. On the occasions that ejecting the round is required, there will be a telltale gouge on the side of the case 1/10th to 1/8th inch below the case mouth.
Rule of Thumb:
If you can push it to battery, it's the extractor. If you can't...or if you have to use excessive force...it's a 3-Point. We're assuming that the stoppage isn't due to the ammunition.
An impending or almost-but-not-quite full on 3-Point Jam can usually be heard when releasing the slide via the slidestop on the top round of a full magazine in the form of a distinctive "Ka-Chunk" that can actually be felt. That's the sound of the lug corners crashing...front of the barrel lugs against the rear of the slide's lugs. Don't ignore it. It damages those corners.
The mechanics of this malfunction is the barrel being pushed forward by the bullet nose, and timing into the slide too early.
The cause is most often an out of spec feed ramp angle. The feed ramp should be 31 degrees +30 minutes/-zip...or half a degree. The barrel ramp angle has a little more latitude, but not a lot more. 29-33 degrees is workable, provided there's a small gap between the top corner of the frame ramp and the leading edge of the barrel ramp...at the bottom. At this point, it might be good to note that an extractor with excessive deflection can cause a 3-Point Jam in an otherwise healthy pistol...so that should be eliminated first.
If the frame ramp is a little too shallow...say 32 degrees...the problem can usually be solved by altering the barrel ramp's angle without losing case head support, but only if the dynamic headspace will allow it. Verifying that with a chamber plug gauge and measuring the exact headspace is a must before proceeding. 32 degrees on the feed ramp is pretty much the limit for this repair, though....regardless of headspace. With a fitted barrel, a skilled, patient smith or armorer can sometimes make it workable with 32.5 degrees...sometimes. Any further out of spec, and the frame will require a ramp insert or a ramped barrel. Personally, I'd opt for the insert.
It's time to let this dog pack do their morning constitutional here at Rotha Manor, so I'll cut this off and return in a bit...but on a final note, consider that the barrel ramp isn't a bullet guide or a feedway. It's a clearance. The bullet nose shouldn't contact it at any point below the top corner...or at most...it should lightly brush it as it climbs over the top on its way to the chamber. If the specs provide for that, the gun will feed so smoothly that you can barely tell that it fed at all.
Rule of Thumb:
If you can push it to battery, it's the extractor. If you can't...or if you have to use excessive force...it's a 3-Point. We're assuming that the stoppage isn't due to the ammunition.
An impending or almost-but-not-quite full on 3-Point Jam can usually be heard when releasing the slide via the slidestop on the top round of a full magazine in the form of a distinctive "Ka-Chunk" that can actually be felt. That's the sound of the lug corners crashing...front of the barrel lugs against the rear of the slide's lugs. Don't ignore it. It damages those corners.
The mechanics of this malfunction is the barrel being pushed forward by the bullet nose, and timing into the slide too early.
The cause is most often an out of spec feed ramp angle. The feed ramp should be 31 degrees +30 minutes/-zip...or half a degree. The barrel ramp angle has a little more latitude, but not a lot more. 29-33 degrees is workable, provided there's a small gap between the top corner of the frame ramp and the leading edge of the barrel ramp...at the bottom. At this point, it might be good to note that an extractor with excessive deflection can cause a 3-Point Jam in an otherwise healthy pistol...so that should be eliminated first.
If the frame ramp is a little too shallow...say 32 degrees...the problem can usually be solved by altering the barrel ramp's angle without losing case head support, but only if the dynamic headspace will allow it. Verifying that with a chamber plug gauge and measuring the exact headspace is a must before proceeding. 32 degrees on the feed ramp is pretty much the limit for this repair, though....regardless of headspace. With a fitted barrel, a skilled, patient smith or armorer can sometimes make it workable with 32.5 degrees...sometimes. Any further out of spec, and the frame will require a ramp insert or a ramped barrel. Personally, I'd opt for the insert.
It's time to let this dog pack do their morning constitutional here at Rotha Manor, so I'll cut this off and return in a bit...but on a final note, consider that the barrel ramp isn't a bullet guide or a feedway. It's a clearance. The bullet nose shouldn't contact it at any point below the top corner...or at most...it should lightly brush it as it climbs over the top on its way to the chamber. If the specs provide for that, the gun will feed so smoothly that you can barely tell that it fed at all.
