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Old 07-05-2013, 10:43 PM   #21
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Quote:
Originally Posted by AgentTikki
Mostly because cheap russian steel ammo is underpowered. They don't put a lot of powder in there. Since the gas system relies on gas pressure, less powder means there is less pressure, less pressure means less gas to drive the system.

Buy full power 5.56 nato ammo like m193 or m855 and shoot it back to back with the cheaper russian Tula or Wolf. You will feel a difference in recoil.
Well he said it was the brass ammo that was causing the problems, which confused me. But I understand now.

Does this mean that piston systems will eat more ammo than a gas system? They seem to be less dependent on the gas as long as it is strong enough to push the piston all the way. Idk. Maybe my philosophy is flawed.
I'm a total n00b..
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Old 07-06-2013, 05:20 PM   #22
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Doesn't matter if its piston or DI, both are really pistons to be honest. Both systems rely on gas driving the system. The Di system reroutes the gas down the gas tube and pushes the BCG back via the gas key. The gas is then released into the upper receiver after driving the BCG.

Pistons are all a little different but work pretty much the same, driving a rod (piston) back and cycling the bcg and venting under the handguards or by the gas block.

Either system is dependant on the size of the gas port. The hole in your barrel that reroutes gas into the gas block. If sized to small, it doesn't allow enough pressure for the gas system. If sized to large, it will provide too much pressure increasing felt recoil and increasing wear and tear on your rifle's internals.

Most manufacturers err on the side of larger ports, allowing the use of cheaper underpowered ammo.

A correctly sized gas port, lets you use just about any ammo, while minimizing felt recoil and wear and tear on your parts.

An undersized gas port, won't allow your gun to cycle effectively making your AR a single shot bolt action.

Doesn't matter if its a piston system or di, if the hole's too small it won't cycle.



I've had a couple Spikes uppers and they have been overgassed. This allowed me to shoot underpowered russian steel case ammo with just about 100% reliability (only failures where ammo related (duds)). But even tho the system was a DI midlength recoil impulse was harsh, I was even able to use a 5.8oz buffer which is heavier than a h3 buffer almost twice the mass of a standard carbine buffer. The heavier buffer did help tame it a bit, but it really slowed down the timing. It also made the muzzle hard to control so I sold them looking for something else.

High end ARs by manufacturers like LaRue, Knights Armaments and others are notorious for not running the underpowered stuff. They tuned their rifles around 5.56 nato pressures, opting to make their gas ports for those higher pressures, to smooth out recoil impulses and decreasing felt recoil.


Long story short:

Everyone gun is a little different, kinda like having a personality. Try out some underpowered stuff, try some mil spec stuff. If it runs fine with everything (and most likely it will) just shoot it and enjoy it. Take your new baby out and run a few thousand rounds through her, and take lots of pics and share your experience with us! Chances are you will not run into any issues. Take a few different types of magazines, a few different types of ammo, and a shooting buddy or two.

I bet you'll have lots of fun. Don't forget the porn!

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Last edited by AgentTikki; 07-06-2013 at 05:23 PM.
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Old 07-14-2013, 02:08 PM   #23
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Quote:
Originally Posted by DickTheNickhead View Post
Well he said it was the brass ammo that was causing the problems, which confused me. But I understand now.

Does this mean that piston systems will eat more ammo than a gas system? They seem to be less dependent on the gas as long as it is strong enough to push the piston all the way. Idk. Maybe my philosophy is flawed.
I'm a total n00b..
Depends on which AR, and it depends on which piston system. There are enough different piston systems out there to not blanket them all in one group. I have good luck so far with pistons, but I haven't tried them all. I think it has to do with the port like Tikki said. Sometimes the piston systems can make up for an undersize port, but it is an expensive solution for what might be a barrel or gas block problem. I like the piston as overall the ones I have installed have been easier to clean. I really didn't get into pistons to solve a problem as much as I wanted an excuse to tinker, it just worked out really well for me. Take your gun and run a few hundred rounds through it. You should be fine.
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