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Posted: 8/31/2007 1:38:49 PM EDT
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I just recently bought a new BCG (LMT) for my SBR, and decided to install the BCM spring upgrade. First off, it took me a good thirty minutes to get the pin through the holes (the extractor and bolt holes) after I installed the new spring. The spring is so damn strong it was hard as all hell to get the holes to line up correctly. Once I put the rifle back together and charged it, it was hard to do. The problem is in the beginning of pulling it back, it seems it gets stuck on something. I just though that maybe it needed to be broke in. I then decided to cycle through a few rounds and see how it felt. It was even harder to charge. And it was "stuck" at the same place. Once you get past the actuall "sticking" it is fine. I was just wondering if all of this is because of the Upgrade kit or the new bolt maybe needs to be broke in. Honestly, I have no idea. And it is not really a huge problem unless you are trying to charge it with support hand then it takes a quick jerk to get it moving. Since I have not shot it yet I was also wondering if this will effect anything which may cause damage or realiability issues. Thanks for the help. |
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I just discovered the same thing, having gotten the same kits that you did. I gave up attempting to get the extractor pins in because I feared that if I were successful, they could never be removed again. This was attempted on two Bushmaster bolts and a spare bolt purchased through Bravo Company. I also tried it with the original BM/BC spring inserts because they looked smaller: No Go. I then tried the new springs with out the insert: No Go. |
| doesn't anyone use these ?: www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=242478 |
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Not at $12.50 a piece. The "o" ring in the upgrade kits that Bravo Company and others sell is made of VIton whcih is pretty bullet proof. They cost about .$60 cents each in gross. These are not to be confused with the cheap hardware store O rings that are silicone based. I have about 90 of them, but thay don't provide an advantage in barrel lengths less than 16" or so sys LMT who made my MRP upper. They'rre right. When i put the upgrade kit in my 16"LMT I went from 100% functionality to one FTE every 10th round. Still don't know why, just know it's so. Tackl Tack |
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You guys with problems assembling the extractor after replacing the spring. Are you installing the new BCM extractor spring and seating it fully into the extractor? The best method is to lay the spring upside down on a hard flat surface, drop in the extractor insert, place the extractor on top of the spring, and with thumb pressure press the extractor down onto the spring. You should hear or at least feel a light “snap” when the spring is correctly seated. ETA: Forgot to add the extractor insert. 
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I understand what you are saying about fully seating the spring. I ensured that it was. Pin wouldn't go in even when the extractor was held to the bolt wit a pair of vise grips, also ensured that the extractor was level in it's pocket on the bolt. I may try snipping a bit of that spring off, little by little until it works. |
| It may take a mike or two, but you just have to depress the extractor with a lot of pressure from your thumb & the retaining pin should slide right through. The tip of your thumb will be sore for half a day but it worked for me in the 7 bolts I installed the BCM upgrades in one day. |
I'm thinking hydraulic press, am reading up on what Archimedes had to say.
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It just has the O-ring not the "upgraded" spring. The new spring is much stiffer and has 5 loops in it not just 3. ETA: so after any of you actually got it all together and charged the weapon did you have any problems with it being unusually hard to charge?? |
You have some other problem here.... The setup works as designed. I think you are doing it wrong. Take your durometer, put it in the fat end of the spring. Put that spring in the hole on the extractor and snap it into place (this is a pain). It will seat down in the hole. Then put the O ring around the spring. Then put the extractor with O ring and spring on it into its slot on the side of the Bolt. Press it down with your fingers and look through the holes that the pin will go through. See where they line up. Now, put the pin in... It works as designed. |
| When i installed mine,i didnt get the spring fully seated and pulled it out and renstalled as Quib suggested,snaped into place and with a little more force the pin went in fine.But with the oring in place it was getting squashed when i tried to install the extractor.I left the oring off and it installed easier and works fine. |
Actually, it is the longer barrel lengths that does not need them. Shorter barrels need stronger extraction. |
| Pardon my ignorance, when you all are talking about BCM sping replacement, are we talking about the same thing as the Larue extractor spring upgrades. I just received mine but haven't tried to install them yet. Just curious if this thread pertains to what I'll be taking part in....... |
Basically, yes, with the exception that the BCM kit comes with insert and o-ring. Looks like the LaRue is just the spring. Not sure if you'll experience the same difficulty as some experience with the BCM kit. Again, I had no difficulty. ETA: The kit from LaRue even notes to seat the extractor spring fully as I mentioned earlier.   |
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Update With manipulation, was able to test spring in spare bolt made by BCM, moved on to doing two Bushmasters. Task swiftly made twice as easy as spring #1 went into orbit while trying to seat in pocket: MIA. Move to spring Set #2. Got it into a BM bolt eventually, comparing BCM and BM bolt ectractors, looks like the BM spring pocket might be a tad shallow. 
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I think he is doing it correctly just some bolts, I guess are, different than others, because mine was nothing but a huge hassle. I ended up getting the new insert, spring and o-ring in it just took me awhile and I had to use a few tools to get enough pressure on the extractor in order to line up the holes. Anyway, I went and shot about a hundred rounds through it and it worked fine. It got easier to charge also. Like a bunch of you said it just needed to get broken in a little. |
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+1 on a mutha to reinstall. I use pliers to put pressure on the extractor (and hence spring) and push it into the bolt so the holes line up. I also can use a roll pin punch at the same diameter to hold everything in place while I locate the pin that actually holds the extractor in the bolt. Insert pin and push out roll pin punch. Do it fast enough nothing moves out of place. |
Exactly HeavyMetal...I run CRANE O-Rings + Colt HD "gold" Extractor springs in my 14.5's Colts and they run perfectly. Tack, you sure you know what you're doing?
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No, charging was fine; could be problems if the pin isn't centered though, I suppose. Now my cheap ass has to conduct a search so I don't have to pay another 5 bucks to replace that spring that shot off. Damn, I heard it bounce off of several surfaces like a cartoon too. 
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Absolutely! The upgrade lit wasn't designed for the 16" and longer barrels, and that's why LMT said I was having the issue. Others have had the same problem trying to add the upgrade when it is not needed.. A lot of trial and error went into this before posting the findings. Tack |
I dont know why it would effect a 16" barrel when the gas system is the same legnth as a 14.5 or shorter.A midlegnth gas system is one thing but standard carbine legnth..I dont know if that 2" longer would effect a rifle like that causing an FTE..with an xpower spring the extractor shouldnt be slipping off a rim Besides dont the A4 fullsize use x power springs and black inserts as well?
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The upgrade is for the Carbine system only! |
From what I understand on the 10.5 inch barrels the gas tube has to be opened up and that the shorter the barrel the more "violent" the rifle operates. I am guessing that because it is more violent then it needs a stronger extractor spring so it wont slip off the casing. In the 16" barrel, I am assuming, it is a softer action therefore doesnt need such a strong spring. This is just what I thought, I am not sure if this is correct or not, someone will correct me shortly if its wrong. |
| The gas system for a 10.5,11.5,14.5 and 16.5 is the same legnth..to Kyoshi..16" legnth is a carbine legnth just a 2" longer barrel unless its a midlegnth gas system wich im not referring to.So on a 16" barrel with CARBINE legnth gas system I would think that its not a factor.I have x power springs in all 5 of my carbines..ones a 16" HBAR and its fine..no malfunctions.Its the gas hole drilled in the barrel and not the tube that needs opening right? |
I was under the impression that the tube had to be enlarged...but that could be and probably is wrong. |
| Hmm, I run the CRANE O-Ring + Colt "Gold" spring in ALL of my AR uppers including rifle length gas systems and I haven't a single problem. If it's not an installation problem, maybe it's a problem with something else in the gas system (or the rifle) that the O-Ring and/or Spring is just enhancing? |
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