'length of pull'
 

dear elders, may I know the ideal length of pull
for a dbbl shotgun with 30 inch barrel.i am 6.1.

I'm also 6-1, my Browning Citori O/U has 30" barrels, my Browning BT-99 has a 32" barrel. The LOP of both of these guns is 14-3/8" which fit good enough to get me classed A or AA, and 27 yd in all classes of registered Trap and Skeet.

It is not a set formula. Arm length, general build, clothing, etc. all come into play. Not many of us have a shotgun fitted special for us (like Holland & Holland does), but try to get someone that shoots clay birds to help by watching your mount to determine if the fit is close enough. My buddy and I are the same height and he needs a LOP a full 1/2" shorter than mine.

bend your finger like your pulling the trigger, measure from the crook up the forearm to the elbow joint,subtract 1/2-3/4" for clothing, your most probably around 14" I'm 5'10 and my LOP is 13 5/8's
RR

Ridge's measurement is a good starting point. Some folks prefer a little more or a little less pull, but in general, that "elbow to bent finger" trick works.

I've always heard a shotgun should have a bit more pull than a rifle, although I don't follow any of it religiously.

As a general rule (which also works with how you are dressed); put the butt of the gun in the "crease" of where your forearm and bicep meet.

Place the pad of your fingerprint on the trigger = length of pull.

As we all know; body types vary.

Hold your arm bent at the elbow, with your trigger finger bent like it would be on a trigger.
Then measure from where the trigger would fit in the bend of the first joint, to the bend in your elbow up against the bicep.
That will be your length of pull.
I know it sounds weird but it works.