I just ordered a 3 position frt from Rare Breed. I already have a Parker Mtn trip bar that I have not yet installed on my Sig Rattler (mine is the 5" non-lt earlier version). Does anyone else have an frt in a Sig Rattler? If so, did you have to remove the firing pin safety? did you have to change springs to cure any bolt bounce? i'm trying to decide whether to install my first frt in a CMMG 9mm Banshee or the Sig Rattler. I feel confident I can get the frt to run properly in the CMMG (I have plenty of bolt weights, buffers, AR springs, etc) and am inclined to put it in that one versus the rattler just because I don't want to go to a lot of trouble with the Rattler. Any thoughts?

Haven't tried an FRT in anything, but unless the hammer has the geometry to actuate the FPS lever you will need to remove the FPS or better yet get the G-lever which should work.

Proven Outfitters usually has the G-levers but they aren't cheap.

Thanks for the info. Still waiting on frt to arrive, then I will try it in the MCX with the firing pin safety lever removed. I think I recall a post somewhere that said the G lever does mot work on the FRT but I need to look for that again.

Can confirm that FRTs work great in the CMMG Banshee 9mms. Works best with an H2 buffer in my experience.


I have no experience with the Sig Rattler.

Any updates from JimACP? I have an MCX Gen 1, have rare breed on order but need to get a trip bar. PMM says I need a slightly different "legacy" version of the trip bar for the gen 1 MCX and say out of stock. Anyone else installed the rare breed on an MCX? Preferably a Gen 1 which supposedly needs a slightly different trip bar???

Rare Greed is for boomers.

Rube, yes, I can confirm that the RB frt works well in my Rattler with a Frankenstein trip. Although I was prepared to remove the firing pin safety, I tried it initially without removing same and, on my fairly early model Rattler at least, the frt works without removing the firing pin saftey. And Mars, yes, I'm a proud boomer.

Edit to add: I forgot to mention, I am using my Rattler upper on an Ar-15 lower with the adapter Sig sells for installing a Rattler upper on an AR lower. I decided to try that first because I also wanted to use a CMMG Banshee upper with .22 conversion on the same sbr registered lower that now has a folding stock. While I assume the frt would work just as well in the Sig lower receiver, I cannot confirm that. I can confirm that both the Rattler upper in 300 Blackout and a CMMG Banshee upper in .22 work very well on an AR-15 lower with a RB frt and a Sig adapter to delete the buffer tube. Although I mentioned in my first post I was planning on using a PMM trip, I ended up ordering a trip from Frankenstein due to reports that it worked better for other people versus the PMM. I still have the PMM trip and may try it in an MPX although I have heard mixed reports on using an frt in an MPX.

Finally, I also mentioned in my first post that I was trying to decide whether to put the frt in the Rattler or in a CMMG 9mm Banshee. After putting my first frt in the AR lower dedicated to the Rattler and .22 uppers, I ended up ordering another RB frt and put it in the 9mm Banshee with standard buffer tube and H3 buffer. After adding bolt weights to both the 9mm and .22 bolt carriers, they both work very well in their respective lowers with no misfires due to bolt bounce. I did not have to change any springs on the Rattler and I have not had any bolt bounce with the Rattler in its stock (upper) form.

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