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View Full Version : bolt cycles to hold open any gas setting-regulator working?


faltj
December 09, 2009, 22:15
Hello,

I have a SA58 purchased in April 2008 and the bolt cycles to hold open whether I put the gas setting on 1 or 7 (or anywhere in between). It never short strokes as the manual says. This would be OK but I am wondering if the gas regulator/valve is not working and therefore the gun is taking more wear and tear because the action is always seeing max pressure? Not sure of this just wondering. It should short stroke when the gas valve is completely open according to the manual, yes?

Has anyone else ever experienced this?

Thanks in advance.

Edited to add: Using GA Arms 150 gr fmj Velocity: 2750 FPS

ggiilliiee
December 10, 2009, 14:45
if everything else looks good ..take a few thou off the OD of the piston ...can do it with a GOOD drill and some sand paper and a piece of flat steel .
paper wrapped around flat to make sanding block...that will blow off some gas ..

an option ...or buy one with smaller OD ..

W.E.G.
December 10, 2009, 15:40
Originally posted by faltj
Hello,

I have a SA58 purchased in April 2008...

What length barrel?

Did you buy this as a new-from-factory gun?

Have you fired any other ammo than the .308 load?

faltj
December 10, 2009, 17:53
Originally posted by W.E.G.


What length barrel?

Did you buy this as a new-from-factory gun?

Have you fired any other ammo than the .308 load?

18" barrel

Yes, new from factory.

No, same ammo...(seems pretty standard velocity and weight for a fal?)

Rich@CGW
December 11, 2009, 00:17
Are going by the (1) round in a mag instructions, or starting off with a full 20 ?

ps. I have seen a bunch of them lock open on 7 with just 1 round in the mag. ( less drag on the bolt with the mag spring fully relieved.)
Most of which needed to be final set at 5-6 to run a full mag reliably from the start.

Bwana John
December 11, 2009, 11:01
What size is your gas port?

Try removing the front sight and slipping numbered drills into the gas port to determine the diameter.

I have heard DSA goes pretty big on carbines, ~.125"


ALSO, try setting the gas with a "weak hand" hold, hold it loosely at your side and let it recoil.

faltj
December 12, 2009, 18:20
Originally posted by Rich@CGW
Are going by the (1) round in a mag instructions, or starting off with a full 20 ?

ps. I have seen a bunch of them lock open on 7 with just 1 round in the mag. ( less drag on the bolt with the mag spring fully relieved.)
Most of which needed to be final set at 5-6 to run a full mag reliably from the start.

I was using both 1 round and also 5 rounds in the mag. I did not try 20, maybe I should.

I appreciate all the repiles so far. I can see myself trying further "tests," but am presently not inclined to work on the gun myself in any way that may alter parts somehow. I am wondering whether this might be a malfunction and warranty issue that I should leave to service reps from DSA (although I would sure like to avoid the whole "ship back to the factory" thing if I can. Again, I realize one way to look at this is that it is cyclying, so why worry? However, if the action might be taking a beating more than it should I want to get it to run properly to enhance longevity and keep long-term wear within normal limits.

Are they (DSA) pretty good about answering questions here? Thanks again for the help so far. :)

DSARep
December 14, 2009, 08:53
Please call DSA directly and ask for customer service.

Thank you!

John

MBR29
December 14, 2009, 09:59
What gas system short or long? I have seen short ones do this because of pressure curve of certain types of ammo. The short gas system FAL taps the gas much closer to the chamber which opens the door to this "issue". The port on a short gas 16" can be anywhere from .090 to .112 which for a 16" carbine is considered small.

Like shooting a M14 with H380 and heavy bullets it will work but will bend an op rod in some guns. Point is, ammo always needs to be thought about before adopting as "your load". This is why HK made 50 different locking peices to sell or install in the G3, depending on what ammo that country was using they would send reps there and change them out to allow for better functioning, longer life or better accuracy.

W.E.G.
December 14, 2009, 11:06
2750 from an 18" barrel is some pretty zippy ammo, especially if fired under the cool temps most of us are experiencing now. If those chrono numbers were obtained shooting in hot weather, try it again to see if you get the same result in the cold.

Compare your 2750 to numbers at http://www.falfiles.com/forums/showthread.php?postid=654048#post654048

faltj
December 14, 2009, 22:19
Originally posted by DSARep
Please call DSA directly and ask for customer service.

Thank you!

John

OK, will do. These days, I am more of an email guy myself...don't do well with busy signals, being on hold, pressing "1"for English, voice mail, etc. but I will ceratinly give a call ! (BTW, I have already, over the past month, sent a couple emails to DSA with this question but have not received a reply yet...maybe I should try a phone call :wink: )

Thank you!

faltj
December 14, 2009, 22:21
Originally posted by MBR29
What gas system short or long? I have seen short ones do this because of pressure curve of certain types of ammo. The short gas system FAL taps the gas much closer to the chamber which opens the door to this "issue". The port on a short gas 16" can be anywhere from .090 to .112 which for a 16" carbine is considered small.

Like shooting a M14 with H380 and heavy bullets it will work but will bend an op rod in some guns. Point is, ammo always needs to be thought about before adopting as "your load". This is why HK made 50 different locking peices to sell or install in the G3, depending on what ammo that country was using they would send reps there and change them out to allow for better functioning, longer life or better accuracy.

Long gas, 18" barrel :shades: :fal:

faltj
December 14, 2009, 22:29
Originally posted by W.E.G.
2750 from an 18" barrel is some pretty zippy ammo, especially if fired under the cool temps most of us are experiencing now. If those chrono numbers were obtained shooting in hot weather, try it again to see if you get the same result in the cold.

Compare your 2750 to numbers at http://www.falfiles.com/forums/showthread.php?postid=654048#post654048

Thanks for that link...those were manufacturer's numbers for the ammo that did not raise red flags for me given other numbers I have seen (I did not chrono myself). I guess I thought 100% bolt open on any setting was not due to the ammo. But I do have some South African surplus and also some 168gr Gold Medal Match I could try, I suppose.

W.E.G.
December 14, 2009, 22:32
I see.

Those chrono numbers would be about right for a 21-inch or 22-inch barrel.

I doubt then you are getting that kind of velocity from the 18-inch. Probably not a great loss, but most likely somewhere in the 2600's.