Mechanical Vs Inertial Triggers

Dear Technoid,

Please give your view of benefits & shortcomings of inertia & mechanical triggers especially as they relate to skeet.Also,are there any disadvantages in using 2 3/4 inch shells in 3 inch chambers?


Dear G.,

I have B-25s with both the Mark 1&2 inertial triggers and also some FNs with the Mark 3 mechanical triggers. I have never had a trigger related failure to fire on either gun. That said, I prefer the Mark 3 triggers as they are a later design and a bit crisper.

Mechanicals are NOT by nature any crisper (Perazzis excellent trigger started as an inertial unit), but they are on the Belgian Brownings.

The mechanical trigger has two obvious advantages:

1) In pigeon shooting and hunting, where no malfunctions are permitted, you get a second shot if your first is a dud. 2) In skeet shooting, if you use a tube set, inertial blocks will normally not set with the small amount of recoil generated in the .410 bore. The makers of skeet tubes are quite accustomed to converting inertial triggers to mechanical when installing a skeet tube set.

In theory, the inertial trigger is supposed to be less likely to double. In practice, they have both seemed to be about the same to me as far as reliability is concerned.

I prefer the mechanicals as they come in handy in dry fire practice with snap caps.

2 3/4″ chambers vs 3″ chambers when using 2 3/4″ shells? There has never been any difference that I could measure. In theory, there is a small opportunity for gas blowby and loss of velocity, but I have never been able to detect it on a chronograph. Stan Baker used to sell .800″ bore barrels (the Baker Big Bore) and he claimed increased velocity. .800″ is 12 gauge chamber I.D.

Best Regards,

Bruce Buck
Shotgun Report’s Technoid

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