Waiting on the BCG?

[millsusaf]

I built a new rifle this year to shoot for 3gun and changed some things up over what I've shot in the past.

DD 14.5 barrel mid length gas

FA BCG

BCM Mod1 comp pinned

Spikes Tactical T-2 buffer

Damage Industries enhanced recoil spring

Its a smooth gun with a very low recoil impulse and stays on target well but it seems like I am almost waiting on the BCG to get back into battery before I can pull the trigger again.

Is that normal? I've never shot a comp gun before. Thanks

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Edited March 12, 2014 by millsusaf

[ac4wordplay]

How quick are your splits?

[millsusaf]

Not sure, I need to grab a timer the next time I'm at the range. I am going to try to get back there again tomorrow since it will be nice again.

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Edited March 11, 2014 by millsusaf

[ClintDismore]

I've never had this problem with my rifle but I have a different set up. You may benefit from a low mass operating system to speed up your cyclic rate. At least I think they do. Someone kick me If I'm wrong

[jonny4523]

Is your barrel a carbine length or mid length?

Brand of your BCG? (is the gas key both properly torqed AND staked)?

Do you have any other buffers that you can play with?

Even with my rifle length gas system, BCM FA carrier, rifle buffer, and a Geissele SD-3G trigger, I can't outrun the system. Something sounds wrong.

Brand and type of the glass block you're using? Any excess carbon build up around the gas block?

is this your first build? Are you positive you got the gas block properly lined up and didn't just throw it back against the gas block diameter shoulder?

Lots of questions, but it sounds to me like you're under gassed for your system.

[ac4wordplay]

Yeah, I asked about your splits. An AR (depending on bolt carrier weight, buffer weight, etc.) usually cycles in 0.10 seconds or quicker. If your splits are that quick (or quicker) then that's great performance from your finger. I think I'm doing quite well when I achieve 0.12 splits and I don't know that I've ever achieved quicker. For most of us, the ability to "beat" cycle time indicates that something is wrong with the firearm.

"...but it seems like I am almost waiting on the BCG to get back into battery before I can pull the trigger again."

Figuring out if you are (in fact) having to wait for the gun to return to battery before you can fire another shot is important (diagnostically). Sometimes things seem one way, yet they are not as they seem.

Edited March 12, 2014 by ac4wordplay

[Therealkoop]

Is it a 14.5 middy?

If the bolt seems to be slow, try using a lighter buffer weight.

Could also be an alignment issue with the gas block.

[waktasz]

Heavy carrier and heavy buffer...shot my buddy's gun with a similar setup. He loved it because it was "soft"...but it felt slow to me, and the dot moved all over with all that weight shifting around.

[BBJones]

You are probably not actually waiting, but guns like the one you built have a more rolling impulse (more wieght but moving slower).

Ditch the spikes buffer. They just aren't good even if you want to run a heavier buffer a conventional buffer is better than the tungstun powder spikes uses. Guns with full auto carriers, lightly gassed (as most 14.5 middies are), and heavy buffers are going to feel sluggish compared to competition style guns that are somewhat similarly lightly gassed but lightened carriers, buffers, and springs.

Sounds like you are cylcling everything (since you didn't mention it wasn't). So you have built a gun based on solid operation with a somewhat slower action and rolling (but soft) recoil impulse. Good for a hard use "military" type gun but not ideal for gun games. I am sure you can make it work.

[millsusaf]

All great questions guys, thanks.

I've built a dozen or more ARs, the gas block is properly located. I learned that lesson a while ago. Lol

The barrel is a mid length using a BCM block.

BCG is GTG, everything is tight and staked properly. The gun functions flawlessly.

At this point it is most definitely a "feel" thing not a fact thing but what you guys are saying about it being a rolling cycle makes sense. This is my first mid length gun and comped gun so it feels completely different.

I ran a quick test using a crappy phone app yesterday and got similar splits between the two uppers, well on the shots that it would record. It missed several shots so I am not sure how accurate it was. Note to self, get a shot timer.

I may try dropping back in a USGI buffer and spring and see if that makes a difference. I can get to the range at least one more time before the match this weekend. I had really hoped to get these issues straightened out before now but time got away from me.

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Edited March 12, 2014 by millsusaf

[mpom]

So if I am understanding this discussion, using a non adjustable gas block with a midlength gas system and a good comp, varying only the buffer weight, a lighter buffer will not only cycle faster but will also reduce felt recoil and sight disturbance while a heavier buffer will slow down the cycling and the added mass will increase recoil and sight/dot disturbance?

Thanks,

Mark

Edited March 12, 2014 by mpom

[joshs]

So if I am understanding this discussion, using a non adjustable gas block with a midlength gas system and a good comp, varying only the buffer weight, a lighter buffer will not only cycle faster but will also reduce felt recoil and sight disturbance while a heavier buffer will slow down the cycling and the added mass will increase recoil and sight/dot disturbance?

Thanks,

Mark

There are other factors that need to be considered like barrel length and gas port size, but I've generally preferred either a standard carbine buffer or the JP light rifle buffer in the 16 inch midlengths I've owned.

[mpom]

No doubt other factors will affect how the firearm feels and recoils; 16", .078" port size, VLTOR A5 system (receiver extension), green Sprinco rifle length action spring.

Asking about changing a specific variable, buffer weight, say going from the standard A5 buffer, their H2 which I believe weighs around 5.3 oz to a lighter buffer.

Mark

[BBJones]

No doubt other factors will affect how the firearm feels and recoils; 16", .078" port size, VLTOR A5 system (receiver extension), green Sprinco rifle length action spring.

Asking about changing a specific variable, buffer weight, say going from the standard A5 buffer, their H2 which I believe weighs around 5.3 oz to a lighter buffer.

Mark

Perhaps but, when going to a lighter buffer you want to tone down the gas also to get the desired effect. If you just lighten the buffer without reducing gas, cycling will speed up and can introduce all sorts of malfunctions and probably will not affect recoil very much (lighter carrier hitting end of buffer tube at higher velocity).

A5 system is based on reliability. I would not go messing with a lighter carrier. If you really feel the need to tinker you can remove the tungsten weight/s in the A5 buffer and replace them with lead weights (uses same size weights that are found in a typical carbine buffer).

[mpom]

No doubt other factors will affect how the firearm feels and recoils; 16", .078" port size, VLTOR A5 system (receiver extension), green Sprinco rifle length action spring.

Asking about changing a specific variable, buffer weight, say going from the standard A5 buffer, their H2 which I believe weighs around 5.3 oz to a lighter buffer.

Mark

Perhaps but, when going to a lighter buffer you want to tone down the gas also to get the desired effect. If you just lighten the buffer without reducing gas, cycling will speed up and can introduce all sorts of malfunctions and probably will not affect recoil very much (lighter carrier hitting end of buffer tube at higher velocity).

A5 system is based on reliability. I would not go messing with a lighter carrier. If you really feel the need to tinker you can remove the tungsten weight/s in the A5 buffer and replace them with lead weights (uses same size weights that are found in a typical carbine buffer).

I apologize to the OP, millsusaf, for the thread drift I am causing.

BBJ, I just may tinker with a lighter weight buffer, as I said in my posts, not a lighter carrier. Will keep everything same except compare how carbine feels with different buffers.

Adjustable gas blocks are certainly a possibility in the future, though not an inexpensive one.

[Therealkoop]

I went and dug my 14.5 BCM middy out of the safe this morning.

In comparison to my 3 gun rifle, it does feel really slow on the bolt speed. very deliberate "per-clunk" each time you pull the trigger.

Using an H2 buffer.