The stock CMMG spring allows the bolt to cycle very hard with high velocity rounds.  It shoots subsonic reliably, tossing the brass to about ten feet and 4 o'clock.

I ordered and installed the Taccom spring HP spring.  It was no heavier.

Does anyone make a heavier spring for this application?

Talk to Tim at TACCOM. He is our resident expert.

I got mine from Lakeside Machine.

It appears that Lakeside Machine doesn't make retail sales, but urges one to contact a distributor.

I put in an order at Delta Three Tactical for the kit of four recoil springs.  I'd never heard of them before this search for springs, but I am not 100% confident that they are still operating since I can't get confirmation for my order.

Does anyone else have a retailer they would recommend?

Black Dog Machine sells the Lake Side Spring kit.

http://blackdogmachinellc.net/ciener-lakeside-spring-kit.aspx

BDM sells one version of the kit.  I just ordered that one from BDM, but it isn't the one I would have preferred (but I thank you for the courtesy of giving me the link).


I cancelled my order with Delta Three Tactical.  

I placed it two weeks ago.  I tried to call to confirm that he had Lakeside ST-22 kits in stock.  The telephone message instructs one to contact him by email or fax.  I did both over the last two weeks, and never received a response of any kind.  Don Thomas may be a fine fellow, but his refusal or inability to disclose whether he actually carries the items he advertises seems evasive.

Get the reliability kit from TACCOM. Has everything you need.

Dave N

Taccom describes its recoil spring as "High Performance" rather than heavy or "extra power".  I read in one of these post that the Taccom spring is even lighter than the stock CMMG spring.

I'll report on the Lakeside springs when I get them.  Black Dog Machine confirmed my order and sent shipping info within an hour of my order.

I recently bought a replacement set of springs (two recoil springs, an extractor spring, and a firing pin spring) from CMMG.  The new recoil spring is 9 3/8" long.  The old spring, circa 2009, is 9" long.  I'm not seeing the replacement pack set, but here's a link to just the recoil spring:

https://www.cmmginc.com/shop/spring-recoil-22arc/

Best of luck.

MHO, YMMV, etc.

Yesterday, I received the spring kit I ordered from BDM on Friday.  It only has two heavy recoil springs, but they are conspicuously heavier.  They measure at 11 inches rather than 9 and change and are a slightly different color.

If you go too heavy you will lose reliability.
There isn't much in .22LR I haven't shot through the AR .22's from Spikes, DPMS, Ciener, Nordic, and TACCOM in testing for them.
I never needed to change a recoil spring shooting anything from Mini Mags to Subs with CMMG, DPMS, or TACCOM.

Good luck. Let us know.

Dave N

One of those outfits, the one that had a rubber sleeve around the recoil spring that functioned as a buffer, was onto something, I think.  The leg on the CMMG only permits a small o-ring; anything mote and the BHO won't work.

I acknowledge and expect that the heavier spring will not permit some loads to cycle.  My plan would be to trim the spring until the heavier loads work.  Reliability with the stock weight currently suffers with Remington GB and TB, but sometimes I will get hammer follow with mini-mags as well.

I noticed that accuracy improved when I added an o-ring buffer to the BCG.  My suspicion is that the very hard cycling has an adverse effect on accuracy with heavier loads.

Thanks, I will.

Another thing that comes into play with 22 LR AR-15's is the hammer spring and fire control group.  A milspec hammer spring is heavier than some other FCG's on the market.   When I first started using a Ciener 22 conversions with a milspec single stage trigger I broke several Ciener firing pins.  When I switched to RRA NM FCG I quit breaking firing pins.  The reliability also improved because it required less recoil momentum to cock the hammer.   All my dedicated 22 LR builds use either RRA NM or Geissele G2S FCG.   RRA does not recommend using thei NM triggers with 22 LR conversions or dedicated uppers.   I personally have had good luck with RRA NM but YMMV.

We used to warn against Remington anything in the AR conversions.

Dave N

Shadowcop, I can understand that warning if a stock spring or weaker is used.

I've read those RRA warnings too, which I thought was a shame because I can tune an RRA to my preference very easily.  I use my favorite RRA for a couple hundred rounds in early testing, but then took ti out because I was afraid it would break.  I have a Larue in it now.  I find the Larue second stage heavier than I prefer, but it is reputed to be robust.

FWIW, I also tested a regular New Frontier plastic FCG, which is reputed to be a problem in blowback designs, but I had perfect function with it.

First my thanks for the help and knowledge shared here.  I leave the following in the event anyone else pursues this solution.

I installed the Lakeside 11 inch recoil spring.  The effort involved in retracting the charging handle was noticeably greater.  I thought I should try it before attempting to trim it to function with a HV load.  I loaded Remington golden bullet (RGB) into a magazine. after the first shot, I expected to have to charge manually, but it wasn't necessary.  The RGB cycled without incident until it didn't.

Four shots in, I pulled the trigger, but there was no bang.  My initial thought was "Shadowcop was right!".  I looked at the bolt which was sitting half way between locked open and closed, and moved with little effort.  I assumed the spring had broken.

Upon disassembly, I found that the end of the spring was a bit larger than the spring-stop ring on the CMMG recoil rod.  It had snuck beyond that shelf and jammed itself and the recoil rod inside the spring guide channel at the top of the bolt..  After much effort and swearing and thinking I had put spring on backward, I clipped off the mangle end and reversed the spring.  Three shot later, It had jammed the same way.  This time, I used a small pair of pliers to reduce the diameter of the last coil at the end of the spring so that it was difficult to get back on.

RGB functioned and the bolt locked back on this essentially unshortened Lakeside heavy duty spring.  Then the surprises came.

CCI mini-mag functioned and the bolt locked back.

Aguila HV functioned and the bolt locked back.

Aquila standard velocity functioned and the bolt locked back.

Winchester 45gr subsonic functioned and the bolt locked back.


Lessons I drew from this:

1.  Before using a new spring on a CMMG recoil spring guide rod, inspect the rear end of the spring and be sure that it is tight around that end of the rod.  If the spring slides onto the rod easily, it's too loose.

2.  Standard springs seem to be calibrated either for quite short barrels or for heavier single stage FCGs, or maybe both.  That the Lakeside kit comes with a lighter hammer spring seems nuts, but it must work for someone.

Good job and report!
The problems we experienced with Remington was due to the profile of the bullet and the stuff is filthy, gumming up the chamber asnd feed rsmp in a short time.
The copper wash rounds always worked best during testing, leaving less residue.
I averaged about 700 rounds asn outing while testing for these companies.

Dave N

zuki here's a trick I've used after cutting a spring.

File the head of a 16 penny nail smooth and then heat it red hot with a propane torch. Quickly touch the clipped coil to the nail head and watch the coil draw up tight against the next one. Now your spring looks like an original uncut one.

It seats squarely now when installed and won't gouge up the surface it bears upon.

Thanks.  I don't think I've ever gone more than 500 rounds in a session with this one, and that took me all day.  Maybe I'll stop cleaning it to see if I can induce a problem.

I appreciate the tip.  I haven't a torch, but I do have a stove.  I'll give it a shot.