auto loader - supressed ejction

[bosulli]

Hijacked this quote from another thread -

"When the autoloader is cycling under pressure loads, it will often eject them forward. And when it is cycling loads with excessive it will often throw the cases backwards. Finding an accurate load that drops the cases in a neat pile off your right sholder is the task at hand."

I thought this was interesting observation. With my 6.5L AR, my loads were border line hot. THe brass was throwing behind. Got a can, and increased my load 0.5 grains. With a bigger charge I am showing less pressure signs, the brass is throwing forward.
Velocities increased with the heavier charged loads.

Is the can lower pressure that much?

 

[Darkop]

Re: auto loader - supressed ejction

I don't know where you got that information but I have found just the opposite to be true for me. If my rifle is ejecting/extracting to 4 O'clock and then I install the suppressor, the rounds will eject forward. Suppressors INCREASE pressure not lower them. this is why there are "Switchblock" type devices out there.

To prove this point, as I increase the charge in reloaded ammunition the ejection pattern moves from the 4 O'clock to 2 O'clock position. The brass is more dented as it is smacked harder against the brass deflector.

YMMV

Until that day,
Darkop

 

[Pat M]

Re: auto loader - supressed ejction

I put the adjustable gas block on my DPMS 308, turnned it down (3/4 turn open ) and i can tell it's not as hard on the brass and instead of throwing brass at 2-oclock it now throws 5-oclock

 

[bosulli]

Re: auto loader - supressed ejction

Got the info from a post that was current at the time.

It said brass ejects forward at lower chamber pressures and ejects to the rear if pressures are higher.

For sure, my brass ejects forward with suppressor and to the rear with out.

I did increase my load .5 grains after installing suppressor. So, I am assuming my pressure chamber is is now higher after the charge increase. Velocities went up 25fps or so with the can.

My brass at the higher load is showing less pressure signs then it did while load developing with out suppressor.

On another note, the barrel maker left the port tighter then usual, knowing what I was going to the with it. He said, if after load development if its not cycling the way you want then open it up. But, since I was building a long range precision gun that he did not want it to unnecessarily a hammer. At the current load, I have not had any cycle problems, so I dont THINK I need an adjustable gas block, assuming why you got one was to make the port smaller.

I am trying to understand the effect of a suppressor on chamber pressure.