I have ordered a Spikes 545x39 upper to use with my Plum Crazy lower. I am concerned about possible problem with light strikes...With this concern; I contacted tthe people at PCF, who were very helpful....they were against changing the hammer spring because it changes the trigger dynamics (trigger pull ect).  They indicated that if the light strike problem did occur; they would suggest replacing the firing pin with a titanium one and this should correct the problem....Has anybody done this and does it work....also anyone used this upper/lower combination and how did it work and did you have to replace the hammer spring...any imput would be appreciated.

Just checking in to see how the build came out.  Any soft strikes?  I built a varmint gun with a PCF lower and so far so good.  I don't plan to use any Wolf, or Tula, however I might use one of their lowers on a budget carbine build in the near future.

UPDATE: I got my Spikes 545 upper a while back and it looks good...In the mean time I spotted a cmmg muli caliber lower at a good price. For an economy AR build I had a PCF lower mated to a Rguns 556 upper and I think it will work out great.  Thinking about it; I felt that the cmmg lower might be more suited to mate up with the Spikes 545 upper...with that in mind; I purchased the cmmg lower.....I have installed the wolfe heavy hammer spring and the buffer that were supplied with the upper.  It mated up great and looks good...I hope to get to the range soon and try the Spikes 545/cmmg lower plus try the PCF lower/rguns upper...now I have one problem...and extra PCF lower....I have to think up another project...

use the spring that came with the Spikes upper if you have any problems, mine works flawlessly, its a PCF lower on Spikes 5.45x39mm upper as well
you can also replace the PCF internals with a Spikes LowerPartsKit or any LPK for that matter
i ended up ordering a Spikes "stripped" lower, PalmettoState buttstock and RockRiver LPK to go with this Spikes upper... nothing wrong with the PCF im gonna put an AdamsArms 5.45 piston on it

as far as "other project" go 6.8 (if you can afford the ammo)  



http://i140.photobucket.com/albums/r32/ginsusars/100_0629.jpg

titanium.. break easy ????

I have a 7.62x39 upper on a PlumCrazy lower and have had zero problems with light strikes on the Russian ammo.  On the aluminum lower I previously had the upper on I had to run a much stiffer spring to get consistent strikes.

I have two of these lowers inbound that I plan to use for various projects.  Anyone else have any comments; good, bad or ugly?