TacSol Uppers and Custom triggers

[GPalmer]

OK, here is the new bolt. On the last bolt the portion labeled A didn't come forward as far, it cut off before the face of the bolt. On the old bolt the section labeled B had a radius to it instead of being squared off like it is in this pic. Hope this helps!

[rman43]

Interesting! My first upper was an M4. It wouldn't work with my RRA NM trigger. Sent it back and they radiused the bottom surface of the bolt you have circled as B. My second was an LT. It was already radiused like the modified M4 bolt. It won't work on my RRA lower with an RRA NM, but works on my Spike's lower with an RRA NM trigger. Go figure... (Neither work with my DPMS lower with a Geissele SSA but my Nordic .22 upper works fine with it.)

[GPalmer]

Hmmm, I wonder if the newer bolt would let it work with the SSA. My personal experience was that my original problematic bolt worked better with the SSA than the stock GI trigger that was there to begin with. It wasn't a big difference but ignition did become more reliable. The biggest difference I noticed was that timing on double taps improved greatly, they were very touchy and had to be timed very closely with the GI trigger. With the SSA I could use my normal timing.

[rman43]

I don't have any idea what generation either of my bolts are, but both seemed to work OK with stock triggers/hammers. I'm beginning to thing that each one is a separate and individual case. I wish someone would explain to me why the LT upper won't work with the lower that the M4 uses. The LT hasn't had any modifications, but works fine with the Spikes lower. Both lowers have RRA NM triggers.
I'm sure there is probably a logical explanation, but it escapes me.

Tom

[TonyM]

Thanks GP for the pix. I looked at my bolt and it looks very similar to yours. I have the stock trigger group and have had a lot of trouble with my unit. The biggest problem has been the TS upper does not fit my lowers. I have 7 different lowers and the TS only fits one. TS wanted me to send the complete gun to them for tuning but I wanted the upper to fit all my lowers not just the one they tuned. I decided to modify the upper to fit my lowers not the other way around. I have had to change the front lug radius, to get the upper to pivot. The rear lug retaining hole to allow the pin to go through. I have removed metal from the bottom of the upper receiver to let the two parts mate without being in a bind. I have ran about 5K of .22 through the unit just to make it work. At this point in time it runs about 97% of the time, and will work with just about any .22 I feed it. I have only got it to work reliably with 2 lowers so far but I am happy with it. I think they have the potential to have a great product just too bad they have not perfected it yet. When they can make it truly a drop in unit they will have a great alternative for a .22 plinker.