I patterned my old (new to me) Suhl sidelock SXS today and am happy with point of impact but not very happy with the pattern. I shot it at 40yds with 34gram No5 field loads. The pattern was pretty patchy with some areas getting heaps of pellets and others which would have missed a duck. How much benifit does back boring and lengthening the forcing cones provide with field loads. I,m not an olympic shooter or anything ,but is it worth the money to get these mods done? Will it show much benifit to pattern density? Do they reduce recoil or presure much?

LOng forcing cones will be the cheaper of the two and help with the recoil more than the pattern.

Back boring is a great way to lower recoil but by it self it dose little for the patteren.

What you may want to look at is choke work.
If the patteren is to tight or off to 1 side ,a gunsmith can hone the choke to either open the patteren .
If he only hones out 1 side the patteren can be moved.
Installing choke tubes can be a better way to go many times.

Now if the patterens are uneven , raged or has holes , what load or wad you shoot can fix most of those problems.

Johnch

I agree with lengthening the forcing cones, and agree that back-boring will not nessecarily help with patterns. Like a rimfire shooter that tries lots of different ammo to see what shoots best, try different factory loads if you are not a reloader, or try some different wad/powder combo's to see if they make a difference in the patterning. Lengthening the cones will help ease the shot load into the bore resulting in less deformation of the shot, and potentially better patterns due to the rounder shot pellets.

Try some diiferent loads.

That will IMO have more to do with the consistancy (eveness) of your pattern than chokes, forcing cones and/or backboring.

Unless there is roughness in the bore or chokes. the patchy pattern is probably due to the wads, shot or some other component being used in the shells.

It could be that the shotgun chokes were designed for shells without shotcups. (the chokes may be too "tight" for the "modern" loads) BPI has "brush wads that are designed for optimal patterning in these type of chokes.

Legthening the forcing cones might help some, as long as you are shooting lead shot. Choke tubes are the thing to look at, Briley make some long inside the barrel tubes that work great.

Trying different loads should be the first place to start.

Back boring you run into trouble with the wads sealing up. Cold weather hunting does not help with this.

I will definitly be getting the chokes reamed out to 1/2 and 1/4. While it is being done I will get the forcing cones reamed out to a more modern shape as well.