Expert gunsmith Jason Harris shows you how to adjust trigger-pull weight with this step-by-step guide

Jason Harris recently had a customer that had traded in a Beretta 682 Gold E and bought a Perazzi MX8. He thought that the new gun felt strange when in use. Basically, he said that when the top barrel was fired first, the second bottom barrel felt incredibly light.

The Perazzi, which was made in 1997, was in excellent condition, hadn’t really done that much work and would probably retail on the gunroom shelf at about the £3,600 mark. At current prices, a similar gun bought new would cost around £8,000, but when this gun was new it probably cost in the region of £5,000. With this sort of money tied up in a gun the owner obviously wanted it to be right!

The thing is, though, the Beretta would naturally have a heavier trigger-pull than the Perazzi – that’s how they’re made – so even a slight difference on the trigger-pulls would seem unnatural, especially as the customer had been using the Beretta exclusively for many, many years.

This step-by-step guide shows you how to adjust the trigger-pull weight of a shotgun:

1: The first task was obviously to check the trigger-pull weights on each barrel. To do this we use a simple spring-loaded set of scales – similar to those used by fishermen. There was a slight difference between the pull weights for each barrel, both were around the 3lb mark – with the top barrel being just over and the lower just under. The difference was “very slight” but, often these things come down to perception and what you’re used to.

adjust trigger pull weightGenerally speaking, at this stage I would normally tell the customer that there was absolutely nothing wrong with the gun and suggest he simply shot loads of cartridges through it to get used to it and develop a “feel” as to how the gun handled.

adjust trigger pull weight2: However, that’s easier said than done for a perfectionist such as me, so I decided to have a closer look at the action to check whether I could improve the pull weights. Fortunately, on Perazzis of this type the trigger mechanism can simply be dropped out, so it was easy to inspect.

3: First we removed the fore-end and barrels.

adjust trigger pull weight4: With the barrels removed, it only takes a moment to check for any blemishes inside. In this case, there were none. Incidentally, while we’re talking about Perazzi barrels, owners would do well to remember that unlike many other guns – the bores of the barrels are not chrome plated. Sure, the chambers are chromed, but the inside of the barrels are not. Try to ensure that the barrels are cleaned thoroughly and lightly oiled each time they’ve been used.

5: To complete our thorough inspection we removed the stock, leaving just the action frame.

adjust trigger pull weight6: With the stock removed I noticed the tiniest, smallest of cracks in the woodwork – the position highlighted here in the picture with the tip of a pen. The crack was hardly noticeable and showed no sign of moving when the stock was stressed (twisted and bent), so in all likelihood it was superficial. As such, my view was that this fault required no further remedial action at the time.

7: Continuing with our task of balancing the trigger weights I checked the main springs..

8: ..and then both the sears.

9: Close inspection revealed that the sear for the bottom barrel might have been slightly modified in the past as it was slightly rounded compared with the other.

10: The peg on which the cocking dogs pivot was knocked out using a punch and small hammer…

11: …and the sear was given a crisper edge using a fine diamond file.

12: The trigger mechanism was then reassembled…

13: …as was the rest of the gun.

adjust trigger pull weight14: All that now remained was to check the pull weights again. The bottom barrel was now similar to the top, with both being just over 3lbs. As far as I was concerned that was it. Job done!