Short Stroking AR

Infantry-Soldier

Infantry-Soldier

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Hey Guys...

Had my Sabre Defense XR15 20"HBAR out today for the first time... Man am I pissed! This gun has been in my safe for a YEAR! I finally got my ATT, and went to the club to have some fun!

So after every round fired, it fails to pick up the next round. Sometimes it will double feed, or just jam one round into the chamber. I used the SEARCH function, and found that this sounds like it was short stroking.

I tried loading one round into a mag, and firing it, and it would not engage the bolt catch.

My best guess is is that when my smith installed my ARMS folding front sight, he didn't get the holes 100% lined up. I also have a MagPul MOE stock on, and the buffer and spring is correct.

How hard is it to fix the front site issue, if indeed that is what's causing the issue. Would it be something I could do myself?

Is there anything else that could cause this? For a $2,000 rifle plus accessories, I expected better :( I was pretty damned pissed off actually. Ended up going home in a pissy mood...

Ah well..

Thanks

IS


EDIT. I was using 2 Sabre 5/30rnders, 2 LAR 10 rnders, and 3 other 5/30 rnders. So I ruled out mags.

I also tried three different ammo types.
 
As I recall Arms folder (correct me if I'm wrong but its the one that kind of replicates the original) is just two bolts and it should come right off. Check the alignment of the gas ports and for blockages. You may need a torx wrench if I recall...

That said, I wouldn't know if that is the issue or not.
 
What kind of ammo are you using? I had an AR which would short stroke because of the FA bolt group and heavy buffer and spring. It was running wolf but ran fine with most others.
 
check the gas port size, gas block and gas tube. I've seen some gas block that where only partly drilled. Check alingment of the gas tube with the gas key and fit betwin the two.

If you cycle it by hand does it cycle properly? Do you have access to a carbine buffer if so give it a try?
 
had the same problem check for sighns of leakage around frount sight. mine was leaking and casing the same result gas was leaking at back of sight under hand gard
 
Your gun smith should of test fired it before shipping it you you. If the bolt catch isn't engaging( i assume you tried an empty mag and cocked it by hand) its an insufficient gas issue. Also it can be ammo or a port misalignment. Before you start taking every thing apart make sure the carrier itself isn't getting stuck on its rearward action. Sometimes new parts with a coarse phosphated finnish can cause sticking issues. Lube it and eventually it will wear in.
 
I had it sufficiently lubed I believe. The action feels silky smooth on this gun... Which for the price I would hope it would. By using the cocking handle, it would work fine, just not going back far enough to pick the next round out of the mag when fired.

Im going to call my smith when he opens on Tuesday to see if he can recall test firing it.

I took my quad rail off and looked around the FSB, and don't see any signs of leakage... But who knows.
 
new gun i understand?

lube it up and repeat it a couple hundred times. might be bunged up with paint and tight fitting.
 
I'm sorry to hear you got a lemon. I have an SDI subcarbine, and it works great. Only it's a little picky with magazines, where the bolt catch doesn't engage after expending all ammo with some. Not a big deal, and perhaps there's a simple way to micro-adjust the bolt catch mechanism to make it more sensitive to the magazine follower.

Anyway, have you inspected the gas tube's alignment with your bolt? How does it look? Also, is your rifle pre-assembled from various parts by the vendor you purchased it, or is it all stock (as is from the SDI factory)?
 
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You may have a carbine buffer but check to see that you also have a carbine recoil/action spring. Does the bolt lock back on an empty mag when you cycle it by hand?? I couldn't tell from what you wrote already. If not you may have an insufficient gas problem as already noted...


blake
 
It's an all stock Sabre Defence rifle purchased from Wolverine Supplies, minus the front sight and other cosmetic features.

Yes, it locks back fine when cycled by hand. How to I check the alignment of the gas tube w/ bolt?
 
send it back to the smith that did the work for you, Just explained to him that you never had a chance to fire it since he did work, any professional smith wouldn't have a problem with looking at it.
 
When I was shooting cheap Wolf ammo, all the Stag would short-cycle if the carrier was not swimming in oil.

Plenty of oil and/or a hotter load should fix your problem.
To stick with your actual load, you want the lightest action: a semi-auto carrier and a standard carbine buffer (not H or H2).
 
Hey man sorry to hear I’m not an AR expert or anywhere near there but my first Ar was a Norinco m4 and I’ve never had an issue with it (1500 RNDS) loll it might sound funny but I haven’t found anything different between a Norinco and a Colt (my friend has colt Ar) maybe the finish but at least you don’t have to worry about anything when you drop the babe and what else do you want to do with it Show of to your friends that you’ve got an expensive m4 or shoot paper and practice on your shooting skills?
 
Thanks for your input.


deagle2008 said:
Hey man sorry to hear I’m not an AR expert or anywhere near there but my first Ar was a Norinco m4 and I’ve never had an issue with it (1500 RNDS) loll it might sound funny but I haven’t found anything different between a Norinco and a Colt (my friend has colt Ar) maybe the finish but at least you don’t have to worry about anything when you drop the babe and what else do you want to do with it Show of to your friends that you’ve got an expensive m4 or shoot paper and practice on your shooting skills?
Click to expand...
 
I had a similar issue when I built my own AR last year.

If the fired cases are coming out of the chamber easily then I would suspect it is your gas tube or port that is not functioning (not enough gas to cycle it).

If the cases are stuck in the chamber AND the extractor claw is tearing bits off the case lip then the chamber may need to be polished a bit.

You may also just need to clean or even upgrade your extractor. There are good videos on YouTube on how to clean the bolt assembly and upgraded extractor kits are available (at least in the US).

I'm in no way an expert but these are some of the tips I learned when I had issues.

In my case I needed to polish the chamber a little.
 
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