Inadvetant bump firing

[Vorpal 0]

I got my conversion done about a week ago and have been enjoying some range time. I used a Tapco double hook trigger group and a Choate Dragunov stock and hand guard. The trigger was immensely lighter than the stock fcg but still long and creepy, like Halloween night in a cemetery! I saw some good feedback on the RSA/Powers fcg and tried to find install and adjustment info on the net, but was unsuccessful. When I looked at the fcg it was pretty obvious that a shim under the rear legs of the trigger would effectively reduce the creep. I made and installed a .110" shim. I checked for disconnecter function and discovered that it could not travel enough to release the hammer. A shim under the front of the disconnecter allowed release. The trigger worked fine hand cycling the hammer with the cover off. The pull was SWEET! I bought several boxes of various brands and bullet styles to see if there was something that it liked. At the range, I loaded 3 rounds (in case of doubling). The range was deserted. I was shooting off a bench on bags. First shot doubled so fast that it almost sounded like one shot. I loaded single after that and tried to concentrate on following through and not shorting the trigger. I was thinking mechanical problem at the time. The hammer was routinely dropping on the empty chamber after each shot. After work today, I made a .090" shim and installed it. Back to the range. It was obvious that I was pulling the trigger due to the recoil of the rifle on the bags. I pulled out the shim when I got home and I might add .010" at a time and see what is safe. The bottom line question is, has this happened to anyone else? Maybe everybody knew this except me. There's always one guy that doesn't get the word!

Vorpal

Edited May 7, 2008 by Vorpal

[UnidenStew 1]

Read the FAQ portion of the instruction sheet that came with the RAA. It discusses this.

[Vorpal 0]

I found the link to the instructions. The faq references hammer follow rather than bump firing. Very good adjustment info however. Thanks.

Vorpal

Edited May 9, 2008 by Vorpal

[Catahoula 0]

Mine did the same thing when I was carefully trying for a surprise release and shooting off the bags for accuracy. Scared the wits out of me! The closing bolt pulls the rifle forward before I can follow through with the trigger. It only does it under those circumstances. Off the bags it works fine. The solution on the bags may be to pull through rapidly. Not the best technique for accuracy but it should avoid the bump firing.

 

Another technique that might work and retain a good trigger pull is to carefully reset the trigger after each shot. Do that by pulling through the first shot and then slowly releasing the trigger only as far as necessary for it to reset. You will hear the loud click. You then have a very light trigger pull from there and very little creep. Pull through the trigger for subsequent shots with sufficient follow through to avoid the bump fire. I have not tried this technique on the range yet, so I cannot guarantee it will prevent bump firing. Gabe Suarez teaches this trigger technique for attaining a good trigger pull with an AK.

 

When shooting from the bags, pulling back on the rifle with the weak hand will probably also avoid the movement of the rifle that causes the trigger to bump fire.

 

Catahoula

[Vorpal 0]

That is exactly the condition that I'm experiencing. It isn't the recoil, it's the bolt slamming into battery causing the second uncontrolled trigger pull. DUH. I hadn't tried pulling back hard with my weak hand. I've really concentrated on my follow through and still cannot seem to avoid that second pull. The altered technique with the weak hand may be what makes the difference. Maybe I need to come up with another type of accuracy test rather than my normal sandbag approach. I'm working on a full floating aluminum hand guard. Maybe a sling swivel stud threaded into that with a short Harris bipod would be workable. I really appreciate you taking the time to read the post and respond.

Vorpal

[UnidenStew 1]

This should help. You need to download the pdf file to from Red Star to get the pics of the areas discussed, but it sounds like this should take care of the problem with uncontrolled trigger pull.

 

From the pdf instructions:

 

3. Adjust the amount of disconnector engagement and the length of the second stage of the second stage of the trigger engagement trave. Rotating the set screw (D) clock wise decrease second stage engagement. When pulling the trigger threw the first stage travel length, the top of the hammer (Area I) should contact the disconnector face (area H) when there is a minimum of 0.020 inch engagement at sear (Area F) and hammer hook (Area K). If the minimum disconnector engagement is not met, the gun may malfunction, with the hammer following the bolt which may result in accidental discharges.

[UnidenStew 1]

I got my RAA FCG installed, and took it out to the range today for a tryout. I adjusted the weight of pull so that it is not so light. Geez, what a hair trigger this thing can be. I tightened it up to around 4.5 lbs before I felt comfortable. Nice real two stage pull. Unlike the G2 and Kvar, you feel a profound difference between the first and second stage tension before she lets off. No bump fires. Breaks real clean. Hardly any creep.

 

I've had both the G2 and the Kvar FCG in it, and got occasional bump fires with both of them. No issues with the RAA though. It's the best FCG out there for the AK IMHO. I know people that have the aforementioned FCG's like em, and I do too, however, you've not experienced anything like the RAA until you've tried it.

[Vorpal 0]

Midway had the Tapco fcg on sale for $30.00 when I did my conversion and I looked long and hard at the RSA. The price difference made my decision for me. Maybe I should of held off and gotton the RSA. Maybe the next conversion. Were you firing benchrested on bags?

Vorpal

[UnidenStew 1]

Midway had the Tapco fcg on sale for $30.00 when I did my conversion and I looked long and hard at the RSA. The price difference made my decision for me. Maybe I should of held off and gotton the RSA. Maybe the next conversion. Were you firing benchrested on bags?

Vorpal

 

Oh yes, I was using bags with all the different ones. The G2 was the worst offender, but it's a clean trigger none the less. I just didn't feel safe with it acting like that. Hell, the last time I went out with the Kvar before I installed the RAA I had so many bump fires off the bag that I expected black helicopter activity.

 

It's not to late to swap FCG's out. You could sell the G2 and recover part of the cost of the RAA. The RAA has a Wolf disconnector spring in it. I suspect it's the quality of the disconnector springs causing the otherwise good after market FCG's to bump on occasion. With the RAA you can adjust for that as posted above.

[CheepJerokee 0]

Ok guys. First time at the range with mine after the conversion.

Smartly, I didnt put a 30 rounder in it to start with. Just 3 rounds in the factory mag. It spent all 3 at the same time........and I spent myself! (Just kidding, but it did draw some attention.) I tried several more times and sometimes got singles, sometimes twos and another three. NOT Comfortable!

When I reassembled it I used the factory hammer withe the Tapco trigger group because the bolt would not slide over the Tapco hammer. ( And, I was going to install the BHO until I realized where it hung over the trigger.)

Could this be the cause if it? If so, how do you make the Tapco hammer clear the bolt on reassembly?

What am I doing wrong?

[Vorpal 0]

I don't know if the OEM hammer could cause it. I used the Tapco parts and ground the hammer to allow use of the BHO. The bolt interfaces fine with the hammer. Were you shooting off bags? Mine doubled fast, but with concentration it was possible to feel the bolt slamming into battery cause a trigger pull. Is that how yours felt?

Vorpal

[CheepJerokee 0]

Felt just like the M16A1 does with a 3 or 4 round burst. I didn't try it alot...............Mainly because Law Enforcement was shooting down range from me and I didn't want a all expenses paid vacation!

The recoil might be developing it, I managed to squeeze off singles most of the..........But unless TSHTF tomorrow, I'm not comfortable with it. I'll change it back to the tapco hammer if you guys can tell me why it wont clear the bolt during reassembly. (And, yes, I am pulling the trigger and letting the hammer down, the bolt just won't slide past it. It was snug on the factory hammer.)HELP?

[CheepJerokee 0]

Just a quick note to anyone reading this................I found my issue. I placed a small screw where the old trigger hole was, below the hammer.....to fill the hole. Dumb idea on my part. It was not letting the hammer go all the way down.

I think this was the source of my problem. I check it out at the range later this week.