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Posted: 12/27/2016 4:45:40 PM EDT
[#1]
How does it cycle without the suppressor?
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Posted: 12/27/2016 5:00:47 PM EDT
[#2]
Haven't tried that. I'll try that and report back. The reason I haven't tried that is because if there isn't enough pressure with a can, I wouldn't think there would be enough without a can.
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Posted: 12/27/2016 6:51:40 PM EDT
[#3]
Good chance it might be over gassed! Had a upper that would shoot fine with out suppressor mounted. As soon as I mounted the suppressor I started having the same issue you are describing. An adjustable gas block fixed my problem.
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Posted: 12/27/2016 7:05:05 PM EDT
[#4]
I have an slr sentry 7. I have it all the way open because it believe it was under gassed. How would over gassed cause that problem?
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Posted: 12/27/2016 7:12:16 PM EDT
[#5]
Carrier velocity is so high the mags can't feed.
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Posted: 12/27/2016 7:18:16 PM EDT
[#6]
First you need to set up your gas with out the suppressor mounted. Close gas, open it one full turn, insert magazine with one round. Repet single loading magazine and adjust gas one click at a time until the bolt locks back on empty mag.
Once you have the gas adjusted mount your suppressor and try again. The problem you might be having right now is carrier speed. The bolt carrier is moving to fast and is over running the next round in the magazine. This is the problem I was having. |
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Posted: 12/27/2016 7:37:02 PM EDT
[#7]
Most of the time it won't even eject the spent round. It is hit or miss, but most of the time I have to manually eject the spent round. With the suppressor on, I've taken the adjustable gas block from completely turned off to completely on. No real change
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Posted: 12/28/2016 11:08:06 AM EDT
[#8]
Does anyone else agree that shooting without a suppressor will create less gas for blowback? I went to the SAAMI site where they list pressures. 204 has higher pressures than 223. I haven't tried a different lower. I did measure the barrel shoulder to gas port at 0.030" and the slr sentry is the same. I did notice that the distance from chamber to gas port measures the same as a carbine even though the barrel is 20", which should be rifle length.
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Posted: 12/28/2016 11:41:40 AM EDT
[#9]
Jesus fuck we found your problem. You need a new barrel and it should have a smaller port than a 20" 223.
Who made your barrel? |
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Posted: 12/28/2016 12:01:15 PM EDT
[#10]
Not sure who made the barrel. The upper was custom built a few years ago by Scott Milkovich with Specialized Dynamics. I could never get him to tell me who made it. @Combat_Jack, I'm not following your comment "You need a new barrel and it should have a smaller port than a 20" 223". Why would it need a smaller port?
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Posted: 12/28/2016 12:03:22 PM EDT
[#11]
204 has more powder going through a smaller bore. So higher port pressure.
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Posted: 12/28/2016 12:12:25 PM EDT
[#12]
So is the gas port in the wrong location? Do you still think it is being over gassed? I can't understand why it wouldn't be ejecting the rounds if it was over gassed.
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Posted: 12/28/2016 12:17:18 PM EDT
[#13]
Gas port needs to be in the rifle location. I suspect it's badly over gassed. What's the port diameter? In theory if a gun has way too much gas the action can cycle while the case is still obturated and the extractor can slip off the rim. That's rare to see is there rim damage on spent cases?
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Posted: 12/28/2016 12:28:15 PM EDT
[#14]
I didn't measure the gas port diameter. I wasn't sure how to do that, other than sticking drill bits in the hole to determine size. The gas port is definitely 9" away from chamber. According to an interweb search a "mid length" barrel (14-20") should have the gas port at 9". The interweb shows a rifle as20" plus and the gas port should be 12" away from chamber. I've already had to send this back to Scott once because it wouldn't shoot less than a 3" group at 100 yards. He ended up replacing the barrel. I wonder if I got another dud.
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Posted: 12/28/2016 12:53:44 PM EDT
[#15]
I think you should move on and try something new.
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Posted: 12/28/2016 1:09:11 PM EDT
[#16]
I just shot 10 rounds. I shot a round and then based on whether or not the round was ejected I adjusted the sentry gas block. It will never eject the spent round. Sometimes it appears the bump the bolt back but then the bolt doesn't have enough energy to close back all the may. Maybe 1/4" remaining to close. Maybe I need to try another bcg. Can't imagine that would make a difference but worth a try.
@combat_jack go f$&@ yourself |
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Posted: 12/28/2016 1:20:59 PM EDT
[#17]
Do you speak like that to everyone who tries to help you?
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Posted: 12/28/2016 1:23:45 PM EDT
[#18]
How am I supposed to take your comment. Why would I move on? I have $600 in this upper. I'm not going to just give up. If someone is acting like an ass I sure would speak to them just like that. So yessir I would.
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Posted: 12/28/2016 1:49:38 PM EDT
[#19]
Based on your description I believe your gas block isn't properly aligned with the gas port. It's misaligned enough to restrict some of the gas flow. I have several rifles that needed the gas block shimmed forward of the barrel shoulder by around .025" to .030" to get 100% gas flow. Use a feeler gage then tighten the set screws.
You have nothing to lose by trying this. I have never heard of Cactus Jack, but I wouldn't automatically jump to the conclusion that he did something wrong. Gas blocks, as well as barrel makers can use slightly different dimensions based on whether the rifle will use a sight tower or a low profile gas block. Tolerance stacking does occur. |
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Posted: 12/28/2016 2:15:45 PM EDT
[#20]
Ill re-measure everything just to make sure. When I measured the first time both holes were at 300 thousandths (0.300"). The best I can tell and adjust, the gas block is vertical and not canted.
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Posted: 12/28/2016 2:39:11 PM EDT
[#21]
Quote HistoryQuoted:
Jesus fuck we found your problem. You need a new barrel and it should have a smaller port than a 20" 223. Who made your barrel? Except for the fact the bullet is running 4000fps and has a very short dwell time past the port. With a 24" barrel and rifle gas system, the 204 needs a port around .101"......way larger than a .223. Tony Rumore Tromix Edited: I found my notes, and the .101 port was for a 24" barrel not a 20" as I previously stated. |
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Posted: 12/28/2016 3:30:07 PM EDT
[#22]
@Tony Rumore: The port is 9" away from chamber. For some reason this barrel is drilled at a carbine length. Not sure on the hole diameter.
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Posted: 12/28/2016 7:02:28 PM EDT
[#23]
Quote HistoryQuoted:
@Tony Rumore: The port is 9" away from chamber. For some reason this barrel is drilled at a carbine length. Not sure on the hole diameter. A gas port 9" from the chamber would be mid length. Personally if it was me, I would send it back or sell the barrel and get one from WOA or BHW. |
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Posted: 12/28/2016 11:43:04 PM EDT
[#24]
If you have to send it back a second time, I would send 100 rounds with it, just to make sure they don't skimp on the test firing/ QC after they "fix" it.
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Posted: 12/29/2016 9:53:37 AM EDT
[#25]
Finally enough info to fix. You have a mid length with not enough gas. Probably has carbine size hole in barrel (.062+-) and need to open to mid (.072+-). Have your guy open the gas port to bigger than mid if you have an ajustable gas block and you will be good to go.
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Posted: 12/29/2016 10:55:53 AM EDT
[#26]
I just found my notes when I was making small bore barrels 10 - 15 years ago.
204 Ruger 24" barrel, rifle gas, .101" port. 20 Vartarg 18" barrel, mid-length gas, .081" port 17 Remington 24" barrel, rifle gas, .078" port 17 Remington 20" barrel, rifle gas, .089" port 17 Mach 4 24" barrel, rifle gas, .110" port Based on the above data, if I were to take a guess on port size for the OP's barrel, it should be about .076", unsuppressed. On a 20" 204 Ruger, you would have to run a mid-length gas system. It would be nearly impossible to flow enough gas through any size gas port, to get it to run with a rifle length gas system. Tony |
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Posted: 12/29/2016 12:51:05 PM EDT
[#27]
I appreciate all the input. It has been mentioned to run a mid length gas system. Are there different diameter gas tubes or does "mid length gas system" simply mean a larger hole?
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Posted: 12/29/2016 1:05:32 PM EDT
[#28]
Mid-Length refers to the position of the gas port on the barrel. It's usually measured from the front edge of the receiver, to the hole in the barrel or the measurement is taken from the OAL of the gas tube. The term "mid-length" was derived because it is about mid-way between the original carbine length and rifle length. Mid-Length and Pistol length were never original gas port positions and there are actually two different Pistol length positions. One uses a 6-3/16" gas tube and the other a 6-5/8" tube.
The diameter of the hole can be of any size regardless of port position. As far as I know, there is only one internal diameter size of gas tubes. Tony |
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Posted: 12/29/2016 2:04:49 PM EDT
[#29]
We just measured the gas port on the barrel. It measures 0.083" diameter. Gas port is 9" from chamber and barrel is 20". Should we open it up?
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Posted: 12/29/2016 2:41:07 PM EDT
[#30]
It should be running with an .083" port.
Are you shooting factory 204 Ruger ammo? Tony |
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Posted: 12/29/2016 3:32:32 PM EDT
[#31]
We drilled the hole out to 0.110". Reinstalled the gas block and adjusted 8 click open. Shot factory Hornady ammo. It cycles perfectly. At 7 clicks open it won't eject. At 9 it appears over gassed. Problem solved.
Thanks for all the help. |
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