Jump to content

Need some insight on rapid fire issue


Shawtgun

Recommended Posts

I recently brought my m4 entry to the range notice that upon recent 6 shot rapid fire attempts, the gun would get hung up on the third shell. What I mean by hung up is that the third shell chambered but gun didn't fire. Upon inspection of the primer, there was no indentation on from the firing pin. I've always has no issues in the past especially when breaking this in a while ago but I can honestly say my finger has gotten faster. Is it possible to out shoot the cyclic rate of the gun? The overall action is well lubed and cycles freely. I've shot mainly 2.75 00 buck shot. Any insight on my situation is greatly appreciated.

Link to comment
Share on other sites

Sounds like you're beating the trigger disconnect. To visualize what is happening, empty the weapon of ammunition. Rack the bolt to the rear and slowly allow the bolt carrier to move forward. As soon as the shell elevator drops, pull the trigger. Even though there is still an inch or more of movement in the action, the hammer will fall. You end up with a live round in the chamber with the hammer down. I've encountered this problem many times myself. There is no surefire solution to the problem. What you can do is to reduce the weight of the bolt carrier by using a lighter than stock bolt handle. Shoot higher dram loads to cycle the weapon faster and inherently slow you down some.

 

I'm currently testing another option to speed up the action. I had the receiver rails, receiver extension, receiver extension plunger and the bolt carrier all treated with Nickel Boron to reduce friction and perhaps increase the action's speed. Hopefully I'll get to test it out on Monday.

 

032_zpse9ce2cf1.jpg

 

046-2_zps9ac2215a.jpg

Edited by StrangerDanger
Link to comment
Share on other sites

Sounds like you're beating the trigger disconnect. To visualize what is happening, empty the weapon of ammunition. Rack the bolt to the rear and slowly allow the bolt carrier to move forward. As soon as the shell elevator drops, pull the trigger. Even though there is still an inch or more of movement in the action, the hammer will fall. You end up with a live round in the chamber with the hammer down. I've encountered this problem many times myself. There is no surefire solution to the problem. What you can do is to reduce the weight of the bolt carrier by using a lighter than stock bolt handle. Shoot higher dram loads to cycle the weapon faster and inherently slow you down some.

 

I'm currently testing another option to speed up the action. I had the receiver rails, receiver extension, receiver extension plunger and the bolt carrier all treated with Nickel Boron to reduce friction and perhaps increase the action's speed. Hopefully I'll get to test it out on Monday.

 

032_zpse9ce2cf1.jpg

 

046-2_zps9ac2215a.jpg

 

Thanks for the insight in this SD. Your explanation seems right on. I can't believe I'm having issues with 00 buck though. This used to cycle pretty reliably in the past but like I mentioned, I know I'm shooting faster. I just bough 00 would have had plenty of cycling power. I'm going to try some 2.75 rifled slugs to see if I encounter this issue. I'll be very curious on your nickel boron treatment. Please update this thread on your findings.

Link to comment
Share on other sites

When you say you're shooting fast, how fast would you say? Like firing 5 rounds in like half a second?

You're holding the shotgun firmly I assume? A weak shoulder will slow the actions cyclic rate.

 

Ya I'm probably averaging a shot around 10-15/100th of a sec so I can empty out a 6 shot capacity on an entry around 6/10's of a sec. And yes I'm holding the shotgun very firm and have a strong lean into the gun.

Link to comment
Share on other sites

That's about my firing rate as well when I start hitting this problem. It really sucks since I have the follow up shot on target through the Aimpoint. I consciously hear myself thinking to slow down before breaking the shot.

 

You can try different ammunition to see if it slows you down some.

 

Some of my other plans were to nickel boron coat a significant amount of the rest of the weapon to try to increase the cyclic rate. I even coated the magazine follower, pistons, shell elevator, shell stop and a few of the trigger group components in hopes of shaving off a few milliseconds.

 

051-1_zps12f20683.jpg

 

017-4_zpsd30fc631.jpg

Link to comment
Share on other sites

Dude that is awesome nickel boron goodness you got there. I'm very anxious to see the outcome. I really don't want to compromise by trying to slow my shooting down rather come up with solutions to accommodate my trigger finger. I'll try by using hotter loads and possible a lighter charging handle. I was also thinking about experimenting with gun grease to see if I gain some lubricity in the process.

Link to comment
Share on other sites

Lubricant choices are important. Avoid the thicker greases that might restrict movement. Brian Enos' Light Slide Glide might be a good option for the bolt carrier rails.

 

I actually have that trigger set too. Lately I've been using the Geisselle hammer instead of the FFT one though. I like how the Geisselle fits tighter around the barrel of the hammer bushing. Probably a personal bias since I really like Geisselle products. I've been thinking about running the FFT one again to take advantage of the finish on it. I forget what finish the hammer has on it, but I believe it is a nickel based finish. It isn't NP3, because that is what the trigger has on it.

 

You won't see any advantage from the disconnector, but the hammer should increase the cyclic rate some from the coated finish on the hammer making contact with the bottom of the bolt carrier.

 

The trigger may be counter-productive for our issue. The lighter pull will make it easier to fire the weapon even faster. I'm not certain if they reset is different than the OEM trigger. The 'break' is certainly more crisp.

 

 

019.jpg

 

030.jpg

Link to comment
Share on other sites

Since you have two Benelli M4's, have you had this issue with both units?

 

I actually have 3 m4's. I have a standard 18.5" m4 hat suffers the same cycling issue and noticed that its happened lately with the rapid fire runs. One of my entry models also gets tripped up on the 3rd shot. The other entry model hasn't been shot yet. I've looked at videos going back almost two years and its pretty noticeable how much faster I run these guns.

Link to comment
Share on other sites

Good video. Looks and sounds very familiar! I'd say with certainty that you're beating the cyclic rate of the action and pulling the trigger while the bolt carrier is still moving. I wish there was a way to keep the disconnector engaged longer. The only thing that can be done with this platform is trying to speed up the action.

 

What you could try is removing the bolt handle all together and do one of these runs. See if you can still beat the action.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...