View Full Version : Geissele short stroking????
Jamessdp115
09-16-21, 09:44
I have a brand new Geissele SDP, 11.5", 556mm/DDC in May of this year....NO Mods...put some new ammo(can't remember the brand name), on the magpul mag and when out shots some ~100 rounds at the range. Got home put away without cleaning or lube. Last Monday, taken the AR out to the range and shots few round but this time it wouldn't cycle so I'd manually feed the next ammo by using the charging handle,...I'd change the new mag and still doesn't function correctly. So on the next day, I'd cleaned out upperrecevier; BCG, bolt, rail, barrel, charging handle, buffer, buffer spring....and lubed! I'd taken out to the range and 1st shot fired and it would cycle the 2nd round and fired but the 3rd round would jammed by the bolt and pushed it up against the upper bolt chamber and the 4th ammo would pinned underneath the 3rd ammo!!!! does this makes any sense??!!
any ideas what is world going with my baby?? This is more than $2200.00!! I should've gotten the DD/MK18!!! The tech guy from Geissele suppose to call me today.
HELP
lonestardiver
09-16-21, 12:02
Sounds like a gas issue.
Check your gas tube to ensure it isn’t clogged up.
Also make sure the gas block is still in place and tight.
Then go through your BCG.
Jamessdp115
09-16-21, 12:15
Thanks "lonestardiver"....I just got off the phone with Geiessele tech guy... he said I should run the different type of ammo's & mag and re-run the test and take a few pic's of each ammo's & mag and send the pic's to them if I problems continue. This driving me NUTS!!!!
lonestardiver
09-16-21, 12:41
I have seen a gas block shift to where it is just enough off center of the gas port to impair function.
Different ammo based on powder type also changes the pressure curve which can also affect things. Go back to the same ammo you tried at first when you did not have any issues. That being a known quantity can be an important fact.
Jamessdp115
09-16-21, 13:00
The ammo is same ammo & Magpul mag that I used on 1st & 2nd test runs.
lonestardiver
09-16-21, 13:15
Look under or through the rail to see if the gas block has shifted forward or to the side. An 1/8” of an inch forward shift can cause issues in some uppers.
If I understand you correctly, the third round fires, the action cycles but the third round does NOT eject. The bolt picks up the fourth round and the AR is jammed with the third (fired) round and the fourth (live) round.
AR might be short stroking. The only way to check that is to do a lock back check- that is, place a single round in the magazine, load the rifle and see if it locks back.
But the AR definitely has a failure to eject. We know this because the only way the bolt can travel far enough to push a round from a good mag is if the bolt passes the point where the empty is ejected. In its reward travel, the bolt passes the point of ejection before it reaches the point it can strip a round from the mag.
The most common cause of failure to eject in an AR is a failure of the extractor. Not only must the extractor pull the round from the chamber, it must also hold the case tight against the bolt face to compress the ejector. If the ejector isn’t fully compressed, it cannot apply its full force to the extracted round. Extractor springs fail far more often than ejector springs.
Start with installing a new Colt extractor spring, then perform a lock back check. Perform tests using MagPul Gen III mag to remove as many magazine induced variables as possible.
Jamessdp115
09-16-21, 14:32
Thanks for the feedback MistWolf....1st round fired and cycle the 2nd round into the chamber and cycle out...BUT the 3rd round jammed at the top and bolt pressed against the 3rd and same time the 4th round pinned under the 3rd.... i'd know, it confusing without the pic's!!! This happened 2 or 3 times in the roll!!! I'd had to released the mag and removed the jammed ammo's(3rd & 4th) from the chamber
Thanks for the feedback MistWolf....1st round fired and cycle the 2nd round into the chamber and cycle out...BUT the 3rd round jammed at the top and bolt pressed against the 3rd and same time the 4th round pinned under the 3rd.... i'd know, it confusing without the pic's!!! This happened 2 or 3 times in the roll!!! I'd had to released the mag and removed the jammed ammo's(3rd & 4th) from the chamber
I think I'm getting the picture.
Start by installing a new Colt extractor spring. If you can't find a Colt spring, install the Sprinco extractor spring. No O ring. Don't bother with any other brand extractor spring.
Jamessdp115
09-16-21, 14:47
Hmmmm... Why would the brand new Geiessel AR extractor spring goes WRONG??
Jamessdp115
09-16-21, 14:54
hMMM..., Why would a brand new Geiessel extractor spring goes WRONG...?? I am just a junior level on these AR kind of things.
so, the colt AR15A4 extractor spring will fit the SDP Geiessel/11.5/556??
Q. Why would a brand new Geiessele(SDP) AR extractor goes WRONG? Also, the Colt AR15A4 extractor spring fit the Geiessele?
so, the colt AR15A4 extractor spring will fit the SDP Geiessel/11.5/556??
Yes, the Colt or Sprinco extractor springs will fit just fine. Just make sure you install it correctly. Youtube is your friend here.
Q. Why would a brand new Geiessele(SDP) AR extractor goes WRONG? Also, the Colt AR15A4 extractor spring fit the Geiessele?
It happens. I had a new upper from a very reputable manufacturer fail to extract once. I changed the extractor spring with a new BCM spring, and it never happened again.
sidewaysil80
09-16-21, 16:45
What ammo, specifically, are you using?
Jamessdp115
09-16-21, 16:53
can't remember the ammo brand or type BUT it is 556/55G... i'd just ordered the Colt extractor spring, should be here ~ 7 or 9 days!!!
sidewaysil80
09-16-21, 16:54
can't remember the ammo brand or type BUT it is 556/55G... i'd just ordered the Colt extractor spring, should be here ~ 7 or 9 days!!!
Was it reloaded ammo? Before ordering and replacing parts, I would throw another bolt carrier group in the gun and see if that fixes it. Then you can pass that on to Geissele and they look into your bolt (for example).
Jamessdp115
09-16-21, 17:46
Hmmmm. That’s good idea. I have a DD/M4, would that fit into geissele??
No, I didn’t not cleaned & lube the AR when I was shooting very 1st time…. It’s was my fault
Q. Why would a brand new Geiessele(SDP) AR extractor goes WRONG? Also, the Colt AR15A4 extractor spring fit the Geiessele?
Why it could go wrong... Because shit happens. I doubt "G" makes their own springs. Chances are good that they have the same source as Colt. The difference between a good rifle and a bad one is pretty much QC and customer service. Almost without exceptions AR parts are interchangeable between manufacturers.
Jamessdp115
09-16-21, 18:13
Far as the customer service… the geissele tech guy told me to run few more tests with different ammo’s & mags…if they knows the answer, they should said, send it back and we will take care of it!!! BUT no!!
Far as the customer service… the geissele tech guy told me to run few more tests with different ammo’s & mags…if they knows the answer, they should said, send it back and we will take care of it!!! BUT no!!
At some point they probably figured out you were not qualified to diagnose the problem. No offence but it doesn't sound like you are. Why would they tell you to send it back without trying what they advise if they think it is their problem? Not a lot of cred when you don't remember what ammo caused the problem.
Jamessdp115
09-16-21, 20:58
I think that would be a fair statement… I’d already said that I am a junior on the AR field of expertises and that is why I would be on this kind of “net” networking to find out that I am going crazy!! 😎
...what ammo caused the problem.
It's not the ammo.
I agree that if factory ammo was used, then that’s not the cause.
I’m surprised that Geissele didn’t provide an RMA, since it’s a factory gun that hasn’t been modified. It shouldn’t take long to perform a lock-back test, and if it fails, then that’s all Geissele should need to know. Swapping the DD bolt carrier group would be an easy test.
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Why it could go wrong... Because shit happens. I doubt "G" makes their own springs. Chances are good that they have the same source as Colt...
Colt developed the spring design they use. If G is using Colt extractor springs, they have to buy them from Colt.
Jamessdp115
09-16-21, 22:33
I’d also think is NOT the ammo…. It’s factory ammo and had NO issues when I ran on the 1st the run…. I will do a lock/back test soon I can.
Thanks
Geissele's product page indicates that the gas block is pinned (bombproof installation), so I'm comfortable stating that a gas block mis-alignment didn't occur after it was in your posession.
sidewaysil80
09-17-21, 20:15
I’d also think is NOT the ammo…. It’s factory ammo and had NO issues when I ran on the 1st the run…. I will do a lock/back test soon I can.
Thanks
Factory from say federal or hornady…or factory from say freedom/lax? Have you at least tried different ammo since this incident…to rule that out? That is your easiest option, do these in the following order:
1. Look into upper receiver and check to make sure the gas tube isn’t damaged/obstructed, post a pic if need be
2. Take your handguard off and post pic of gas block, check to see if loose
3. Try different ammo to simply rule it out
4. Try different bolt carrier group (yes your daniel defense is fine)
What state are you in? Perhaps someone can recommend armorer or gun store if you have difficulty with anything above.
Jamessdp115
09-17-21, 20:28
Thanks “sidewaysil80…. I will do the following your recommendation 1,3, 4 soon. I’m not going take off the handrail til the geissele tech guy said “okay”…. I’m in the PNW(Oregon)
Identify the problem by isolating variables.
Changing only one at a time.
Bolt, ammo, mags, gas system.
If I understand your explanation correctly, my mk18 would do something similar, unsuppressed with Barnaul, so my guess is ammo (since you still can’t say what you’re using) or the gas system.
As long as your troubleshooting skills are better than your grammar. [emoji1787] If not, at least make sure it’s not mags or ammo and just ask for an RMA and let them sort out.
Jamessdp115
09-17-21, 20:44
Ha! Can’t wait for an RMA!!
Dan1612…. How did you fix or solved your issue with MK18??
Dan1612…. How did you fix or solved your issue with MK18??
To run crap steel case lacquered ammo in a 0.070 unsuppressed Mk18 with a carbine spring and H2 buffer, you can drop the buffer weight to compensate for the lack of pressure, or you can suppress it, or run the type of ammo it was designed to run (mil 556).
Wait. You’ve got a 0.068 gas port with a Super 42 H3. I demand to know what kind of ammo you’re running. Watch it be PMC bronze. Lol
The failure to eject due to extraction malfunction is NOT due to ammo, mags or short stroking. It's due to a bad extractor spring.
When a fired round and a live round are jammed in the action, it's because the extractor didn't hold the fired round.
Replace the extractor spring before troubleshooting for short stroking. Use a Colt spring.
The failure to eject due to extraction malfunction is NOT due to ammo, mags or short stroking. It's due to a bad extractor spring.
When a fired round and a live round are jammed in the action, it's because the extractor didn't hold the fired round.
Replace the extractor spring before troubleshooting for short stroking. Use a Colt spring.
Is that what’s happening? I honestly couldn’t tell what he was on about.
Jamessdp115
09-17-21, 22:41
Colt spring is ordered and should be here within 5-7days. Meanwhile I’ll run different kinds of testing, by putting a DD bolt into geissele
What’s happening is now after I’d clean the AR…. 1st shot in the chamber and fired and it cycled the 2nd round—-> fired, it would ejected the 2nd round BUT 3 rd would pinned on the top of chamber and pressed by the bolt, same time the 4th round is jammed underneath the 3rd!!! Only way I can clear out the messed is to released mag and pull the charging handle or use my fingers to removed the jammed rounds…. Does it make any sense
If the DD bolt fixes the issue, then MistWolf is almost certainly correct that the extractor spring is the problem.
Jamessdp115
09-18-21, 09:45
i'll wait til PNW rain storms goes away.
Based on his last response the first and second round both are ejecting (which would mean this is not an extraction issue) and he is getting a double feed on round 3 with round 4. At least as far as I can tell.
Jamessdp115
09-18-21, 18:59
YesÂ… thatÂ’s correct. My thought is this. Is it possible that 1st &2nd rounds fired and cycled out, during that time, could cause the over gassing out??
Or mag feeding issue??
Based on his last response the first and second round both are ejecting (which would mean this is not an extraction issue) and he is getting a double feed on round 3 with round 4. At least as far as I can tell.
First, the number of rounds fired before the malfunction is irrelevant. This malfunction is intermittent which means it doesn't manifest 100% of the time. What is relevant is the malfunction itself. This malfunction is caused by an extraction issue.
Second, the malfunction isn't a double feed. A double feed is when two live rounds pop out of the magazine. Double feeds are caused by an out of spec mag.
Yes… that’s correct. My thought is this. Is it possible that 1st &2nd rounds fired and cycled out, during that time, could cause the over gassing out??
Critical thinking time- How could the first two rounds cause over gassing of the third? The gas in the system doesn't blow down instantly but it does blow down fast enough there will be little to no residual pressure in the system before the shooter can trigger the next shot. If the residual gas could cause overgassing, why isn't it a problem in full auto ARs?
Next, even if the AR was over gassed, it wouldn't cause the extractor to lose control of the empty unless the extractor is worn or the spring is weak.
Or mag feeding issue??
Don't start second guessing or over thinking the problem. That leads to time wasting and down unproductive rabbit holes.
First, the number of rounds fired before the malfunction is irrelevant. This malfunction is intermittent which means it doesn't manifest 100% of the time. What is relevant is the malfunction itself. This malfunction is caused by an extraction issue.
Second, the malfunction isn't a double feed. A double feed is when two live rounds pop out of the magazine. Double feeds are caused by an out of spec mag.
Read what he said again. He said that rounds three and four both come out of the mag at the same time and round three is blocked from chambering by round 4. I agree, which round the failure occurs on is irrelevant, but from what I can surmise from his albeit poorly formed explanation (and he agreed with me) this is what is occurring. Now, that being said, I am certainly not planting my flag on this hill mostly because of a lack of a clear explanation from the OP as to what is really happening. We are all guessing at this point.
Jamessdp115
09-20-21, 17:56
Mistwolf is correct…. It’s bold ejector spring issue!!
Today, I went out and shots some more. I’d bought new mags; pro mag, MFT, Hexmag, DD. New ammos; wolf/55g/fmj and IMI/55g/fmj and original ammo(pu 2.0)?can’t read the ammo print/55g
Just to proof is not the mag or ammos or over gassing/under gassing or buffer/buffer spring issues.
On the 1st test, I used my DDm4 V7 on different types of combinations….5rounds each set…. NO issues, it would fired/cycled and bolt locked on last rounds!!
On the 2nd test, I used same set up on Geissele… again the malfunction happened as earlier. This is exactly what “MistWolf” said the malfunctioning is intermittently.
Finally, I removed the DD BCG and replaced into Geissele and used 3 different types of ammos with 5 different types of mags combinations…. NO issues; fired, cycled and locked the bolt on the last round.
I contacted the geissele tech person… they want me to ship the BCG and they look at it and maybe they will send me a replacement part.
Thanks
Nice job guys!!
I’m sure G will take care of you.
Jamessdp115
09-20-21, 18:06
They want me email to them with exactly what I did todayÂ….
A beer 🍻 on MistWolf!!!
Lesson learned—-> clean & lube dammed AR !!
If I had a dollar for every time MistWolf came along and recommended a Colt extractor spring and ended being right...
They want me email to them with exactly what I did todayÂ….
A beer [emoji482] on MistWolf!!!
Lesson learned—-> clean & lube dammed AR !!
It could still be the gas key, which you could figure out quite easily, you could still just put in what you ordered and be running much faster.
But if it were me, I’d make them fix it out of principle.
Assuming it’s the spring, I just wondered how a bad spring got in there.
Jamessdp115
09-20-21, 19:00
Me——> impatient!!! I’d had to wait 3days to clear the PNW weather!!!
That “G” gas ran perfectly with DD!!
That “G” gas ran perfectly with DD!!
Yes. With the entire BCG, but it could still be the gas key rather than the bolt itself. However, if I understand the malfunction correctly, it does seem to point to an extraction issue.
Easy to figure out. Stick the G bolt in the DD carrier and fire a few rounds.
Jamessdp115
09-20-21, 19:05
Dan1612—> give up the “gas” issue. It’s BCG!!
Thanks for your inputs anyway.
🙌🏼
Dan1612—> give up the “gas” issue. It’s BCG!!
Thanks for your inputs anyway.
[emoji1373]
So, the gas key, IS part of the BCG.
Your thread Sir, and you’ve got it all figured out.
Best of luck.
Over and out.
Dan is correct here. The correct way to troubleshoot is to make 1 change at a time. Take the bolt out of the DD carrier and see if it runs in the Geissele carrier. Or better yet, swap the extractor springs between the bolts.
Jamessdp115
09-20-21, 19:18
DD bolt into “G”—-> fired/cycled/ejected & locked on all 3 different brands of ammos into 6 different set of mags…. NO Issues
I didn’t swoop the extractor springs from each others . I’m afraid the “G” tech guy won’t cover the warranty issues by taking the spring out into other brand
DD bolt into “G”—-> fired/cycled/ejected & locked on all 3 different brands of ammos into 6 different set of mags…. NO Issues
DD bolt, or DD bolt carrier group was swapped?
By swapping bolt carrier groups, the bolt, carrier (including gas key) cam pin, firing pin, and firing pin retainer were all swapped. I’m no math expert, but adding up these items doesn’t give me an answer of 1.
Jamessdp115
09-20-21, 19:54
Oop… just the DD bolt switch into “G”
Oop… just the DD bolt switch into “G”So you took the bolt out of the DD carrier and put into the Geissele carrier before inserting the carrier into the Geissele rifle? Or you took the entire DD bolt carrier and installed into the Geissele?
Jamessdp115
09-20-21, 21:29
Took the entire DD bolt carrier(when you pulled out the charging handle, whole bolt) into “G”….everything worked.
Took the entire DD bolt carrier(when you pulled out the charging handle, whole bolt) into “G”….everything worked.
Right. We're telling you to take the bolt out of the carrier and just swap the bolt only, not the whole bolt carrier group.
sidewaysil80
09-21-21, 02:51
I think we’re beating a dead horse to satisfy our curiosity for exact cause of malfunction. While second nature to us, it seems swapping bolts is outside OP’s skill level. We narrowed down the issue and isolated it for him, Geissele is aware and offering to help, sounds like case closed for now.
I think we’re beating a dead horse to satisfy our curiosity for exact cause of malfunction. While second nature to us, it seems swapping bolts is outside OP’s skill level. We narrowed down the issue and isolated it for him, Geissele is aware and offering to help, sounds like case closed for now.
And we will never know for sure........ I still can't surmise what he did to solve the issue. Of if he solved the issue. I feel dumber for having participated in this discussion and apologize to my fellow forum members for even commenting here :D
Yes. With the entire BCG, but it could still be the gas key rather than the bolt itself. However, if I understand the malfunction correctly, it does seem to point to an extraction issue.
Easy to figure out. Stick the G bolt in the DD carrier and fire a few rounds.
Dan1612—> give up the “gas” issue. It’s BCG!!
Thanks for your inputs anyway.
����
James, it's hard to translate your posts, they look like code on my screen. Dan makes a good point. I had one AR that started with short stroking and extraction issues. The upper was a test bed, so it also had an adjustable gas block.
After a very frustrating series of troubleshooting tests, the following problems were uncovered-
- Gas block adjustment locking spring lost tension leading to the gas block adjustment constantly changing
- Extractor spring failing leading to extraction issues
- Piston rings completely worn
- Gas key leaking where it mates to carrier
- Gat tube worn were it fits in gas key
Each problem had to be identified and repaired individually. Each time one was fixed, the next reared its ugly head at test firing, starting the troubleshooting tree again. While it's possible the extractor spring solved your malfunction, it is cheap insurance to make sure there isn't another problem waiting in the wings.
James, if understand the gobble dee gook your posts show up as on my screen, you did the lock back check using a completely different carrier. What Dan is suggesting is, install the known good bolt (DD?) in the G carrier and perform a lock back check. Dan has made an excellent suggestion. Installing a known good bolt, you can test to see if there is a problem with the gas key of the G carrier.
Jamessdp115
09-22-21, 10:12
MistWolf…
I did the final testing by installing DD bolt into “G”…..NO issues / function without any issues.
Yesterday, the “ G” tech guy ordered the RMA and I’m send it out the Geissele today.
Again, thanks for sticking with me
Jamessdp115
10-01-21, 09:51
The Geissele replaced the REBCG due to the some tolerance stacking issue between the BCG and the upper. They are shipping my baby “G” back today.
The Geissele replaced the REBCG due to the some tolerance stacking issue between the BCG and the upper. They are shipping my baby “G” back today.
Good news. Let us know how it functions.
Jamessdp115
10-01-21, 10:22
So why would they stacking together??
sidewaysil80
10-01-21, 11:16
So why would they stacking together??
Google tolerance stacking.
Jamessdp115
10-01-21, 11:30
Great…more homework
I tend to think "tolerance stacking" is used as an excuse for out-of-spec parts, since according to lysander properly specified and manufactured parts prevent it.
If the design is properly toleranced on the drawings (and the M16 is), and the parts made to the tolerances specified, then stacking of tolerance will have no effect on operation. The only time "tolerance stacking" causes problems is if the tolerance are not designed correctly, or the parts are not made correctly.
That's the whole point of interchangeability. A rifle made from parts all at one end of the tolerance band should work just as well as ones made at nominal, or a random mix.
Jamessdp115
10-01-21, 11:48
They said everything checked out… they are replacing BCG
They said everything checked out… they are replacing BCG
Did you send the upper back with the Colt extractor spring installed?
Jamessdp115
10-02-21, 07:58
No. I sent everything upper & lower original “G”. The colt extractor spring was not replaced.
Jamessdp115
10-13-21, 14:44
I got the “G” back from Geissele yesterday…I will get it out next week & test it out.
I got the “G” back from Geissele yesterday…I will get it out next week & test it out.
Did you try it with the new replacement Geissele BCG? Is it working?
Jamessdp115
10-25-21, 01:25
Not yet with this PNW rain storm this week and more rain coming. I’m going to try get out this week when the weather hold out.
Not yet with this PNW rain storm this week and more rain coming. I’m going to try get out this week when the weather hold out.
Ok, please let us know what happens. Would really like to see how the new Geissele bolt functions.
Jamessdp115
11-01-21, 17:11
Cane55…
I’d had 2 days of sunshine here in PDX…yesterday ran ~ 90 rounds, the G ran perfectly!!! I m very happy now!!!
Glad you got your gun working.
I’d have just sent back the BCG for replacement to save hassle and shipping an entire rifle.
Something to consider if stuff like this pops up for you in future rifles.
Jamessdp115
11-01-21, 17:35
Yes.. thanks the “G” wanted the whole “G” shipment to them…. It cost me $180 ship out by FedEx(surprisingly it got to them overnight). But that “G” is a sweet AR.
Yes.. thanks the “G” wanted the whole “G” shipment to them…. It cost me $180 ship out by FedEx(surprisingly it got to them overnight). But that “G” is a sweet AR.
I thought that might be the case, which I find only mildly ridiculous since they asked you to troubleshoot the problem.
They didn’t pay return shipping?
Yes they are very nice rifles and one is on my list at some point. I enjoy assembling them too much right now to spend the money on a factory rifle.
I like mine set up with certain components and would just end up changing stuff out regardless of how good the factory components might be……….
Jamessdp115
11-01-21, 19:14
I think their factory “G” stuffs is very good… I’d just don’t have a time & effort to get different components for the “G”. The “G” is more beefier than DD. I’m just a beginner shooter but I like the “G” very much.
I think their factory “G” stuffs is very good… I’d just don’t have a time & effort to get different components for the “G”. The “G” is more beefier than DD. I’m just a beginner shooter but I like the “G” very much.
You chose wisely for a beginner. Most people end up with a DPMS or Delton as their first rifle.
Everyone starts somewhere and I am still learning good stuff every day.
Cane55…
I’d had 2 days of sunshine here in PDX…yesterday ran ~ 90 rounds, the G ran perfectly!!! I m very happy now!!!
Glad to hear it’s working. That’s great news!
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