View Full Version : BCM extractor springs?
I need a dozen extractor springs and usually use Colt springs, but BCM has them substantially cheaper.
Should I spring for the Colts or are the BCM ones a good alternative?
Sprinco 4-coil (https://www.rogtac.com/tactical-springs-ar15-m4-m16-triple-kit-26403/) has ground ends like the Colt spring, unlike the BCM spring.
I didn’t even think about Sprinco. I would consider them too.
Sprinco 4-coil (https://www.rogtac.com/tactical-springs-ar15-m4-m16-triple-kit-26403/) has ground ends like the Colt spring, unlike the BCM spring.
Any reason to go with the 4 coil over the 5 coil?
the AR-15 Junkie
11-04-21, 19:18
Colt Extractor springs on gunbroker for $3 a piece. Nothing better.
https://www.gunbroker.com/item/913700215
The Colt spring is regarded as the standard and the 4-coil Sprinco appears to be more similar to it; the 5-coil was reported to be stiffer than the BCM spring (https://www.m4carbine.net/showthread.php?230800-Extractor-spring-strength-ranking), which itself was reported to be stiffer than the Colt spring (separate post, can't find it). The ground ends are important for the spring working optimally according to one post here though I have no knowledge of the matter myself.
BCM is good to go as always.
The Colt spring is regarded as the standard and the 4-coil Sprinco appears to be more similar to it; the 5-coil was reported to be stiffer than the BCM spring (https://www.m4carbine.net/showthread.php?230800-Extractor-spring-strength-ranking), which itself was reported to be stiffer than the Colt spring (separate post, can't find it). The ground ends are important for the spring working optimally according to one post here though I have no knowledge of the matter myself.
Thanks. I think I remember that now that you say it.
I found a baggie full of Sprinco extractor springs in the shop this morning. None of them have ground ends.
Order placed for Colt springs and opinion of Sprinco lowered another notch.
the AR-15 Junkie
11-05-21, 08:35
I found a baggie full of Sprinco extractor springs in the shop this morning. None of them have ground ends.
Order placed for Colt springs and opinion of Sprinco lowered another notch.
Sprinco is marketing hype pushed by the SOTAR Snobs.
Sprinco is marketing hype pushed by the SOTAR Snobs.
The Sprinco extractor spring was reccommend by Iraqgunz and is used by Sionics and I believe SOLGW on his recommendation. IG knew a lot about the AR FOW (and others as well).
I would choose a Colt or Sprinco extractor spring over BCM.
I found a baggie full of Sprinco extractor springs in the shop this morning. None of them have ground ends.
Four coil, or five coil?
But I cant imagine BCM would make a shitty spring. I dont know shit about extractor springs but I do have confidence in BCM. Cant go wrong with Colt either.
PB
https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-extractor-spring-assembly-prod4840.aspx
But I cant imagine BCM would make a shitty spring. I dont know shit about extractor springs but I do have confidence in BCM. Cant go wrong with Colt either.
PB
A few years ago, a batch of bad extractor spring slipped past their QA.
In this day and age, a company offering a extractor spring upgrade kit with an O ring needs to update their extractor spring.
Four coil, or five coil?
A few packages of 5 coil and some loose ones that I think are 4 coil. They’re from SOLGW is all I know.
the AR-15 Junkie
11-05-21, 13:55
https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-extractor-spring-assembly-prod4840.aspx
Those are $6 each, you can get the exact same ones in the same brownells baggies for $3 each on gunbroker, I provided the link a few posts above.
There is no reason to use anything else. Why bother trying to decide if you need a 4 coil or 5 coil, if the ends are ground or not, if you need the o ring or not lol?
Simple, Colt Gold. 3 bucks a pop.
^Yep.
I’m not in the mood for aftermarket enhanced AR parts and all the hilarity that inevitably ensues.
I have 4 due for their second buffer spring replacement and while I’m at it an extractor spring, hammer spring, and gas rings. They’re Colt uppers and will be getting all Colt springs.
The Sprinco extractor spring was reccommend by Iraqgunz and is used by Sionics and I believe SOLGW on his recommendation. IG knew a lot about the AR FOW (and others as well).
I would choose a Colt or Sprinco extractor spring over BCM.
If IG said it was good to go, that’d usually be enough for me. Not saying he was the be-all-end-all, but I would have trusted his lies over most people’s “knowledge”.
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Yes, the colt gold and sprinco 4 coil are very much alike and both have ground ends.
The Colt spring is regarded as the standard and the 4-coil Sprinco appears to be more similar..
What is the purpose, value, benefit of ground ends?
bamashooter
11-06-21, 07:30
What is the purpose, value, benefit of ground ends?
Supposedly a truer travel (compression) along the spring's axis. I wouldn't be too concerned with the claim. Easier on the fingers. lol
Y'all need to do a blind shooting test; Colt / BCM / Sprinco 4/5 coils.
If you can't tell by ejection and overall feels, you don't know ARs.
Just sayin.
the AR-15 Junkie
11-06-21, 10:28
If IG said it was good to go, that’d usually be enough for me. Not saying he was the be-all-end-all, but I would have trusted his lies over most people’s “knowledge”.
Sent from my iPhone using Tapatalk
Its called business relationships.
The Colt spring is regarded as the standard and the 4-coil Sprinco appears to be more similar to it; the 5-coil was reported to be stiffer than the BCM spring (https://www.m4carbine.net/showthread.php?230800-Extractor-spring-strength-ranking), which itself was reported to be stiffer than the Colt spring (separate post, can't find it). The ground ends are important for the spring working optimally according to one post here though I have no knowledge of the matter myself.
I think it is correct to say the BCM springs are stiffer than the previous generation of Colt springs.
Andy
Are you implying that the BCM springs are NOT stiffer than the current copper/gold Colt springs?
Adding complication there are reportedly two BCM spring designs.
There are two different BCM extractor springs. The original ones are five coils and the more recent ones are four coils. Somewhere there are posts explaining the change.
The five coil springs restrict extractor travel in some bolts. I have both of them here. After trying many after market springs I have settled on the Colt "gold" spring for all of my rifles. The differences among springs are very subtle but real.
I tried O rings when they were popular but IMO they restrict extractor travel to much and place to much stress on the pivot pin.
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