Will, since you appear to have the wide-spaced Schuetzen-style DSTs, I have another suggestion. It's A Good Idea to polish all trigger/sear mating surfaces where the top side of the kicker (rear trigger) contacts the bottom rear of the main sear, because it's possible that you're experiencing too much friction there. I have encountered a condition similar to a hangfire, when the kicker kicks the sear but doesn't kick it quite hard enough to trip it completely out of the notch. It seems to hesitate for a millisecond before finally disengagng, just enough to throw the shot. This can happen with any of the three types of wall set triggers although I've found it to be rare. I've experimented with two of the wide-spaced DSTs, four of the close-coupled DSTs and about eight of the SSTs over the years, just to give you an idea of where I'm coming from on this.

I've found that it's important to adjust the parts relationship so that the kicker moves as little as possible, both when it's initially set against its spring tension and also when it's tripped to disengage the main sear. This will reduce lock time & increase the force directed against the main sear, helping to ensure a clean trip with minimal disturbance of the rifle.

I never reduce the thickness of the main sear nose but I do reduce the sear notch depth on the hammer. Another way to do this is to install a pin or spacer on the hammer to reduce the main sear engagement, then if you go too far it's easy to cut down on the pin or spacer to restore some travel. Please PM me for details if necessary.

I've been trying for many years to get RF walls to shoot well, with only indifferent success. My friends KelleyO and xxgrampa tell me that they've had good results with negative headspace and minimal extractor cutout. They do this by essentially converting the double-leg extractor to a single leg one so that the case rim is supported in a much more positive manner, and then chambering shallow so that the case rim is pinched when the breech is fully closed. That will be my next effort.
Please keep us informed, good luck, Joe

While I do not have any specific low wall speed lock experence I have some Speed lock time.

In modern rifle Silouette when I switched from a 03 Springfield to a Remmington 700 the faster lock time was noticable and my scores did improve.  I further speeded up the 700 striker with a titanium firing pin and stronger spring. Not so noticible and I doubt if it was much faster than factory stock.

I had a Eric Johnson Ballard that was speed locked. The rifle had been converted to a smallbore prone gun,  The conversion was just like the ones mentioned on the board It worked OK. The rifle went off everytime and no acidental discharges..

I had my two CPA's  speed locked a couple of years ago.  Paul Shuttleworth  changes the hammer and it's a lot shorter in throw and ligher too. On a CPA action the spring tention is screw adjustable from the outside and I lightend it up.

I found the rifles worked well with Rimfire barrels but would not pop the Rifle primer when using either the 32/40 or the 38/55 barrels.  Even going back to max spring tension it would not fire reliably. I changed to large Pistol primers and now It works  fine. 

Overall it's a worthwhile conversion. For offhand it surely improves performance.

Boats

One thought that has occoured to me that might help the problem. If the action comes to full cock when it is closed. Take out the half cock notch and get rid of the fly. The fly could be the problem. I fixed a highwall that was grouping badly that way. It is an easy project and you can do it yourself if you are careful.

40 Rod