NEW SPR TROUBLE ON FIRST RANGE TRIP. UPDATE IN OP.

[georgeib]

THANK YOU.
After posting this- I saw the excellent thread here on springs. I liked the reviews of the 42 coil Tubb spring, and was considerng it already when I saw your fast response. Should I try the 36 or 42?

My take away from lysander's posts in that thread is that buffer weight has MUCH more influence than spring weight. I would experiment with Tubb's Carrier Weight System, if I were you.

[sinister]

I think the 42-coil is for AR-10s/SR-25s. Maybe the short ones are for 300 Blackout? I don't remember specifically, but don't over-spring.

I used the Tubb weight for years in my National Match (yes, to shoot at Camp Perry) M16s. The two-piece set-up wasn't so much a pain in the backside as it was annoying to have the tungsten insert, then the steel sleeve fall out when stripping the rifle for cleaning. I solved that by using an XH buffer.

[Straight Shooter]

I think the 42-coil is for AR-10s/SR-25s. Maybe the short ones are for 300 Blackout? I don't remember specifically, but don't over-spring.

I used the Tubb weight for years in my National Match (yes, to shoot at Camp Perry) M16s. The two-piece set-up wasn't so much a pain in the backside as it was annoying to have the tungsten insert, then the steel sleeve fall out when stripping the rifle for cleaning. I solved that by using an XH buffer.

Yes sir- I knew the 42 coil was to be for .308, but several here & elsewhere report using them in 5.56 guns to great effect.
Wondering while at Camp Perry- did you see any using the NM bcg? Thoughts on that?
I am def gonna order a Tubb Spring. When I do & can get to the range to test, can I safely assune that if it will workk with M193, its good to go with the heavier stuff? Dont want to have to use my Match ammo for testing too much if possible.

[sinister]

I saw one or two, but people normally put the extra money into ammo, barrels, spotting scope, travel and accommodation, and match fees.

I don't see the advantage of a zoot carrier when I can get a few for the same price (i.e., back-up gun, uppers, or spare).

[Straight Shooter]

I saw one or two, but people normally put the extra money into ammo, barrels, spotting scope, travel and accommodation, and match fees.

I don't see the advantage of a zoot carrier when I can get a few for the same price (i.e., back-up gun, uppers, or spare).

I appreciate your response, thank you again.

[Todd.K]

Extra power recoil springs are mainly used to bandaid over gassed carbines. I’m not a fan there and there just shouldn’t be any need with a rifle.

The longer the gas system the more potential for different powder burn rates to impact bolt speed and function. PMC bronze way back in the day is a great example if you want to dig in the archives.

A test for good cyclic rate test that doesn’t take a lot of ammo:

1) Keep your ammo as cold as you will be shooting. If you are building a coyote gun in the summer to use in the winter, put your ammo in a cooler with dry ice.

2) Do a lock back test (one round in each mag), but hold the gun loosely and an inch or two off your shoulder. Repeat a few more times and if it reliably locks back you are good with that ammo.

[MistWolf]

...I've never heard a complain about BCM extractors, or extractor springs...

You haven't been paying attention to all the "double feed" with "my new BCM upper" posts. We haven't had any in a while, but some time back, there were quite a few. When the extractor spring was replaced, the problem went away. Anecdotal, yes. But a noticeable pattern that would be foolish to ignore.

I believe the development of the M4 spring is talked about in the book Black Rifle II. In the evolution to the AR family of weapons from the first AR15 to the M4, the extractor spring had to be upgraded twice. Once when they changed to a higher energy powder and again after the M4 began having extraction issues when used for duty beyond its original intent as a simple PDW.

Years ago, I came across a forum thread discussing the extractor spring and O ring. One post came up by someone who was involved with correcting issues with the AR FOW said the O ring was an interim fix. It was only necessary because of the difficulties of getting the .mil to add the then new Colt spring to the system. The reason given for not adopting the new spring was to avoid adding a new NSN for what is essentially the same part. They finally resolved the problem by approving the new spring for use in the M16 as well as the M4 and obsoleting the old spring from the system. I don't recall who the poster was and I believe the thread was on ar15.com and was old when I stumbled across it.

What I do know is, I've personally replaced several failed extractor springs and advised others online to do the same using the Colt M4 spring. The failed springs were sourced from PSA, generic brand BCGs, BCM and Colt. Only one of the springs needing replacement was a Colt M4 spring and it was in my personal AR. The rest were PSA, BCM and generic.

[AndyLate]

I remember it as a suspected bad batch of BCM springs and I swear I also remember the "o-ring" being an interim fix.

I know for a fact you better eat your Wheaties if you want to use the o-ring with the updated Colt or Sprinco spring.

Andy

[ViniVidivici]

I have a newer BCM extractor spring kit, still in the bag...spring, insert, AND o-ring.

What's the consensus on using the o-ring with it off the bat? Why is it included?

[MistWolf]

I have a newer BCM extractor spring kit, still in the bag...spring, insert, AND o-ring.

What's the consensus on using the o-ring with it off the bat?

If an extractor spring needs an O ring, the spring needs to be replaced.