SubSonics from an unsupressed pistol, possible??

[wadebrown]

Wanting to dip my toes into the 300 Blk water I recently bought a 10.5" 1-7" twist barrel from Bear Creek, having a carbine length gas tube/port and the gas port measures 0.125". I assembled the upper with parts I had in the shop and put it on a new Anderson pistol lower I got at a great price.

I want to shoot subsonic bullets above 200 grains in this pistol, the problem is I can't get the pistol to cycle. The gas block is adjustable and running fully open I checked twice. I have used 208 AMAX, 220 Sierra Match Kings, with H110, A1680, and CFE BLK using both heavy and light subsonic loads listed in loading books.

Like I said I was just dipping my toes in the 300 Blk I decided I would ask the experts to see what I might do to get this running.

One thing I have thought of is putting the barrel in the lathe and reducing the barrel radius to 0.750" back so I can use a pistol length gas tube. Yes, I know I would have to plug the original gas port. If I get the pistol running I would be happy even if the barrel was trashed, at $69 I can easily buy another barrel if I have the recipe in hand.

By the way, I loaded up some supersonic 175 Sierra Match Kings rounds and they functioned fine, although the ejection was somewhat anemic.

Thanks
wade

[smustian]

Carbine length gas can be very finicky as you have fond. Dellet has done extensive testing and would be the one to listen to. Hopefully he will be along soon. Plugging the carbine hole and drilling at the pistol position would be an option, especially on a cheap barrel.

[rebel]

Carbine gas will work with no problem. Before you do anything drastic, how about starting with DETAILED load info. I want to know what you loaded, I know what's in the books. Then we can trouble shoot equipment and load. Before you do that, insure you have no leaks in and around the gas system - block, tube and key. If that is resolved and there are no leaks, there is no reason why what you described shouldn't cycle.
edit - buffer weight would be nice info have.

[wadebrown]

Carbine gas will work with no problem. Before you do anything drastic, how about starting with DETAILED load info. I want to know what you loaded, I know what's in the books.

Then we can trouble shoot equipment and load. Before you do that, insure you have no leaks in and around the gas system - block, tube and key. If that is resolved and there are no leaks, there is no reason why what you described shouldn't cycle.
edit - buffer weight would be nice info have.

For the subs:
A1680 12 g and 12.4 g for both 220 g Sierra Match King Wolf small rifle primer, COAL to fit magazine, brass LC 5.56 (mixed years) brass modified to 300 BLK by Top Brass

For the supersonics 15 g A1680 under 175 g Sierra Match King Wolf small rifle primer, COAL to fit magazine, brass LC 5.56 (mixed years) to 300 BLK brass modified by Top Brass

Buffer Weight 2.9 ounces, I have checked for leaks around gas block by looking for carbon traces on barrel, have about 80 rounds so leakage should be apparent and have also felt by hand for leakage while firing. Seems to be no leakage on gas key either.

Thanks
wade

[ARHuman]

According to Steve's Pages you may be 1-2 grains light

[wadebrown]

Please ignore my ignorance, where are Steve's Pages.

[rebel]

Wade, as far as subs, 12 gr of 1680 would have put you well into super range from my experience. Just going on the facts given, carbine buffer and anemic heavy super ejection, I'd say leak, which you have checked or blockage/misalignment of gas system. We have had some some guys with the cheaper barrels have a burr where the gas port was drilled that resulted in copper flakes in the port. That bears a look. In any case, it doesn't know whether it's a rifle or a pistol. sounds as if you have the correct stuff to make it work from what you have provided here. I would take a hard close look at every part of that gas system. Let us know what you find and we will help you get it running.
edit - I don't know who Steve is but he has problems as well.
edit 2 - real info, steve definitely has issues. viewtopic.php?f=141&t=81563

[dellet]

Subs without a suppressor on a 10" barrel is tough but doable.

What was your CFE load and what was the velocity of all loads?

[ARHuman]

http://stevespages.com/308p_6.html

This.

A lot of suppressors and lightened buffers in the other topic.

If you don't hear the crack, you haven't passed over to supersonic.

It is encouraging that you almost got full function with the super.

[dellet]

http://stevespages.com/308p_6.html

This.

A lot of suppressors and lightened buffers in the other topic.

If you don't hear the crack, you haven't passed over to supersonic. let me put this as simply as possible BULLSHIT

It is encouraging that you almost got full function with the super.

Which one of the loads on Steve's pages would you suggest to try?