Taming the JA-380: Chamber and Feed-Ramp

I found that the chamber needed to be altered on the JA-380 for good flawless function. There were sharp edges that caused chambering and extraction issues. The feed-ramp also needed to be altered to prevent loading/chambering issues.

These sharp edges needed to be chamfered (rounded). I used fine emery cloth and a sharp, hard-bladed pocket knife. The knife is a small stainless-steel lock-blade folding pocket knife that has a very hard 440 stainless blade. The metal used for the chamber on these guns is rather soft, so it was easily worked. I didn't want to get carried away, just rounded the edge enough to remove any chance that the edges might bite into the cartridge's brass case. [NOTE! I say brass, because that is what these guns were intended for. Steel and aluminum cased ammo will usually have extraction issues in this handgun.]

Now the feed-ramp and chamber-ramp. Both the chamber-ramp and the seam where the chamber-ramp meets the feed-ramp in the gun frame, needed work. Below, I have marked the area on the chamber-ramp with a yellow arrow, and the seam in the feed-ramp with red.

It was necessary to smooth these surfaces. In the chamber I smoothed out the rough work done on the chamber-ramp at the factory. I made the chamber-ramp nicely even and rounded, and as smooth as I could. This transition area is very important. The idea was not to remove more metal then was necessary, because this is the area of the chamber where there is not much support for the cartridge case to begin with. I did not want to remove an excessive amount of material and make things dangerous by causing the cartridge to be even more unsupported here. The seam in the feed ramp needed to be smoothed so that there was no longer a lip, or edge, created where the chamber was pressed into the frame and meets the feed-ramp. I smoothed it down until there was nothing that could snag the bullet nose as it slides up the ramp and into the chamber. If a person wanted to, they could smooth and polish the entire feed-ramp, as this will only improve function.

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