Short stroking problem... - XDTalk Forums - Your HS2000/SA-XD Information Source!

petey1 · 01-26-2008, 10:00 AM

Having some problems with my new upper and I'm in need of some advice. I am in the process of assembling a new 16" carbine. So far I've only purchased the upper (a Stag 3H with a low-profile gas block). So today I was able to put several mags of Wolf through the upper using a RRA lower half with an Ace A2 length skeleton stock. Not too sure what the buffer weight is, but the RRA lower half is from a factory midlength. Well.....I had several problems with shortstroking and failure to lock back on last round. I will try to use some quality ammo later in the week (it was freezing cold today), but for now I'm wondering what's going wrong. Is the A2 length stock causing the problems.....Wolf ammo maybe???? The carbine length gas system is brand new for me, so any input would be greatly appreciated. Oh, as far as mags are concerned...I was using 3 different USGI mags (two 20 round and one 30). It didn't short stoke every time (had several 5-10 round strings with no issues)...but it was frequent enough to be a problem. What do ya think? Many thanks.

**mvician** · 01-26-2008, 11:10 AM

Check the bolts on the gas key to make sure they are tight. Try some "hotter" ammo than Wolf. Clean and properly lube it and try agian.

Badshot · 01-26-2008, 11:13 AM

Also check the gas port for excessive carbon build up at the FSP.. could indicate a leak.

Stan9106 · 01-26-2008, 12:24 PM

I have a Stag 4HL on a Stag lower with an A2 buttstock. It short strokes on Wolf, Privi Partisan, Sellier&Belloit. It does fine with Ga Arms, Aquila, and PMC Bronze. There's a couple of other brands I want to try, but I think it's just picky about what flavors it likes. You might go over the M4Carbine.net and read this thread:

http://m4carbine.net/showthread.php?t=138

**nikon777** · 01-26-2008, 12:30 PM

Mags, gas leak, weak ammo, or buffer is too heavy. Try those to start.

Polymerhead · 01-26-2008, 01:25 PM

You're using a 16" carbine setup with an A2 buttstock and buffer. I'm guessing you're going to have to use a carbine buffer setup or otherwise lighten your spring somehow. Sounds like classic overbuffering to me.

petey1 · 01-26-2008, 04:14 PM

Thanks everyone! I'm going to check out all those things you guys mentioned. Hopefully tomorrow I'll head to the range and put a variety of brass through it. My intention all along was to build this with a carbine length buffer, so I'll have to wait until I get my lower to see if that helps too. Thanks again

T.J. · 01-26-2008, 06:07 PM

i had the same problem and after i switched to hotter ammo and started making sure i had a good shoulder weld my problem disappeared almost completely every now and a blue moon my bolt will not lock back but today i fired around 300 rounds with zero problems well zero problems from the rifle anyhow.

INDY-XD · 01-26-2008, 11:25 PM

Your Ace Stock, Does It Have One Of The Recoil Pads Installed.

The Top Bolt Might Be To Long ,check The Back Of Your Buffer And See If There Is Bolt Mark On The End?If So Replace With Shorter Bolt Problem Solved!! Same Thing Happend To Me Indy.

01-26-2008, 10:00 AM	#1
petey1 XDTalk 500 Member Join Date: Oct 2006 Location: Upstate NY Posts: 673	Short stroking problem... Having some problems with my new upper and I'm in need of some advice. I am in the process of assembling a new 16" carbine. So far I've only purchased the upper (a Stag 3H with a low-profile gas block). So today I was able to put several mags of Wolf through the upper using a RRA lower half with an Ace A2 length skeleton stock. Not too sure what the buffer weight is, but the RRA lower half is from a factory midlength. Well.....I had several problems with shortstroking and failure to lock back on last round. I will try to use some quality ammo later in the week (it was freezing cold today), but for now I'm wondering what's going wrong. Is the A2 length stock causing the problems.....Wolf ammo maybe???? The carbine length gas system is brand new for me, so any input would be greatly appreciated. Oh, as far as mags are concerned...I was using 3 different USGI mags (two 20 round and one 30). It didn't short stoke every time (had several 5-10 round strings with no issues)...but it was frequent enough to be a problem. What do ya think? Many thanks. __________________ "No free man shall EVER be barred the use of arms." -Thomas Jefferson springerprecision.com bcsportsmen.org gunfacts.info

01-26-2008, 11:10 AM	#2
mvician XDTalk 2K Member Join Date: Mar 2007 Location: Indiana Posts: 2,854	Check the bolts on the gas key to make sure they are tight. Try some "hotter" ammo than Wolf. Clean and properly lube it and try agian. __________________ AR15s...ya I've built more than a few http://www.xdtalk.com/forums/ar-talk...ar-family.html

01-26-2008, 11:13 AM	#3
Badshot XDTalk 1K Member Join Date: Dec 2006 Location: Colorado Posts: 1,433	Also check the gas port for excessive carbon build up at the FSP.. could indicate a leak. __________________ --------------------- Stupidity should should be painful! On AR15's: Learn to use your Iron Sights before you go adding all that extra crap on your gun!

01-26-2008, 12:24 PM	#4
Stan9106 XDTalk Member Join Date: Jul 2006 Posts: 31	I have a Stag 4HL on a Stag lower with an A2 buttstock. It short strokes on Wolf, Privi Partisan, Sellier&Belloit. It does fine with Ga Arms, Aquila, and PMC Bronze. There's a couple of other brands I want to try, but I think it's just picky about what flavors it likes. You might go over the M4Carbine.net and read this thread: http://m4carbine.net/showthread.php?t=138 __________________ Stan

01-26-2008, 12:30 PM	#5
nikon777 XDTalk 5K Member Join Date: May 2003 Location: Cleveland, OH. The Danger Zone. Posts: 7,014	Mags, gas leak, weak ammo, or buffer is too heavy. Try those to start. __________________ Wu-Tang Killa' Bees on Da' Swarm! Liberals Click Here!

01-26-2008, 01:25 PM	#6
Polymerhead XDTalk 1K Member Join Date: May 2005 Location: MO, USA Posts: 1,402	You're using a 16" carbine setup with an A2 buttstock and buffer. I'm guessing you're going to have to use a carbine buffer setup or otherwise lighten your spring somehow. Sounds like classic overbuffering to me. __________________ No alarms and no surprises, please.

01-26-2008, 04:14 PM	#7
petey1 XDTalk 500 Member Join Date: Oct 2006 Location: Upstate NY Posts: 673	Thanks everyone! I'm going to check out all those things you guys mentioned. Hopefully tomorrow I'll head to the range and put a variety of brass through it. My intention all along was to build this with a carbine length buffer, so I'll have to wait until I get my lower to see if that helps too. Thanks again __________________ "No free man shall EVER be barred the use of arms." -Thomas Jefferson springerprecision.com bcsportsmen.org gunfacts.info

01-26-2008, 11:25 PM	#9
INDY-XD XDTalk 1K Member Join Date: Dec 2007 Location: SOUTHERN,INDIANA Posts: 1,544	Your Ace Stock, Does It Have One Of The Recoil Pads Installed. The Top Bolt Might Be To Long ,check The Back Of Your Buffer And See If There Is Bolt Mark On The End?If So Replace With Shorter Bolt Problem Solved!! Same Thing Happend To Me Indy. Last edited by INDY-XD; 01-26-2008 at 11:29 PM.

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