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Tuning an AR with different springs in a JP captured recoil spring


EngineerEli

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So I had some weird issues with my AR at my last 3 gun match. It was running great all day, then during one stage I kept getting a dead trigger. I would rack the gun, and a live round would get chucked out, then it would go off the next time, then again a dead trigger this happened something like 8 times. I changed the mag, and the gun started working again. I'm pretty sure I went from the cheap PPU 55gr .223 stuff to a more powerful 55gr 5.56 factory load. My though was that the bolt carrier was coming far enough back to chuck the spent case and chamber a new round, but not quite far enough to completely cock the hammer. Is this even possible? The gun has a complete Adams Arms 16" piston upper with a mid length piston system, which I admit does seem to need a little more gas to cycle. It has given me some problems in the past with cheap steal cased stuff that was known to be weaker powered. I am also using my Hyperfire 24C trigger which was new for that match.

My questions to you guys are the following. If my gun was in fact just slightly short stroking on the weaker stuff, but I would like it to run reliably with whatever is on sale, can I just try clipping a half a coil off the recoil spring at a time and see if I am then able to run it reliably? I know JP offers a kit of 5 reduced power springs, so that is another option, albeit a slightly more expensive. Also, I have read some places that people have successfully used 5" 1911 springs in the 18-24 lb range on their JP captured recoil systems. Can anyone speak to actually doing this and what weight spring you ended up with? Were you able to figure out the equivalent to what the factory one is that comes with the JP system?

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I bought the set of 5 JP springs, and currently use the lightest one. I'm using the 24C trigger as well, but I'm using DI, not piston. I simply installed the lightest weight spring, then tuned the gas block for the ammo I'm running. That, in combination with a Voodoo Low Mass carrier, make this rifle VERY smooth.

FWIW, I would never use 2 different types of ammo in a match unless absolutely necessary.

On another note, I would give the trigger another look. Slowly cycle the bolt by hand and figure out where the ejection point is vs. when the trigger resets.

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So is the JP springs same size as the 1911 recoils springs?

They are not the same as 1911 springs from what I was told.

Unfortunately, I have not had the chance to try the Hyperfire trigger. I only use Geissele and JP triggers. Even with powder puff loads and using rifle length gas systems, my guns have been running fine on the stock spring.

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So is the JP springs same size as the 1911 recoils springs?

They are not the same as 1911 springs from what I was told.

By whom were you told, not that I don't believe you I was just hoping for some first hand experience.

I think it may be a combination of factors, the fact that my piston system seems to need slightly hotter rounds to run reliably in it's current state. Lighter springs may help this. And, that the hiperfire trigger has those toggle springs. I currently have the strongest ones in there which give you the lightest trigger pull, but past half way the hammer actually exerts more force to the primer, also meaning it takes more force to cock the hammer. It may be time to just get the spring kit from JP...

About using multiple kinds of ammo for a match, yea, I would probably agree it is not a great idea. Thing is though, that 3gun falls in a very distant second in priority to USPSA so I really just shoot it for fun. I buy whatever ammo is on sale, so I would like to have a gun set up to handle all types. The change in feel during the match is not enough to cause any problems as long as the gun goes bang every time.

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Well cr@p I really was hoping I wouldn't hear that. I haven't had the chance to tear it down and check things out closer... New question, how is hipper fires customer service???

Explain. I am running two of the HF triggers w zero issues. What did you find?
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His hammer was getting caught on the disconnector, which is what it is supposed to do but when you release the trigger the hammer is supposed to come off the disco and onto the sear. It was getting hung up. Pull the upper off and pin the trigger push the hammer down until it catches on the disconnector the ease the trigger out and see if it comes off the disco and onto the sear on its own.

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So is the JP springs same size as the 1911 recoils springs?

They are not the same as 1911 springs from what I was told.

By whom were you told, not that I don't believe you I was just hoping for some first hand experience.

I think it may be a combination of factors, the fact that my piston system seems to need slightly hotter rounds to run reliably in it's current state. Lighter springs may help this. And, that the hiperfire trigger has those toggle springs. I currently have the strongest ones in there which give you the lightest trigger pull, but past half way the hammer actually exerts more force to the primer, also meaning it takes more force to cock the hammer. It may be time to just get the spring kit from JP...

About using multiple kinds of ammo for a match, yea, I would probably agree it is not a great idea. Thing is though, that 3gun falls in a very distant second in priority to USPSA so I really just shoot it for fun. I buy whatever ammo is on sale, so I would like to have a gun set up to handle all types. The change in feel during the match is not enough to cause any problems as long as the gun goes bang every time.

I asked the question by email last year to their parts department.

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Well I looked more closely at it last night and you guys are right, the hammer hits the disconnector way before the case would ever be cleared from the gun... So the bolt may be cycling fine. Problem is, I am unable to replicate the issue on the bench I tried doing it fast and slow, rough and gentle, it worked perfectly every time. I am currently running an Billet Omega Armory lower, that I won from the price table at the IL sectional last year, and the pins are just from a standard parts kit, I want to say Bushmaster, or DPMS or something. Should I just change my lower back over to the original one I had in the gun? That was just a Supirior Arms lower, another probably not very well known manufacturer. The HF trigger was installed at about the same time as the lower being switched over, but I did go to the range with some friends and ran 40-60 rds thorough it in it's current configuration with no issues. My biggest question now is if it is really the trigger malfunctioning, how could changing the magazine, or type of ammo make the problem go away???

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I have one doing something very similar to that with the jp captured spring and a geisslle super dynamic 3gun trigger that I still can't figure out

Sent from my LG-D850 using Tapatalk

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