At the match last Saturday a local shooter handed me his Para P16-40 and told me to “Fix it”. Apparently it would not cycle with Federal factory ammunition, and it had about an 11 pound trigger pull weight.
My first priority was to make it run with the short Federal ammo. Most factory .40 S&W rounds are loaded to a short Overall Length (OAL) so they’ll work in modern handguns like Glocks. Unfortunately this shorter OAL causes feeding issues in 1911s because the feed ramps are steeper. So, as the bullet comes out of the magazine and up the feed ramp, it makes a turn into the chamber. With a longer OAL the bullet doesn’t have to make so drastic a turn, but with short ammo the bullet will hit the top of the chamber and bind up in a “3-Point Bind”.
Here’s what a “3-Point Bind” looks like.
To eliminate the 3-Point Bind, the barrel must be “ramped”. Ramping the barrel means removing material from the mouth of the chamber where the feed ramp meets the chamber. Rounding off any sharp edges there makes it easier for the bullet to make the turn in from the feed ramp to the barrel, so shorter ammunition will function reliably. To “ramp” the barrel, a Dremel tool and various bits and polishing compounds must be used. First I use a Carbide Cutter to remove the bulk of the material, following the radius in the chamber.
Then if I need to remove any more material I use a Grinding Stone:
Then polish it out with some Red Rouge on a Felt Bob:
Once the barrel’s been ramped I true up the feed ramps with a fine sandpaper drum: