doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Tightening a pattern

Question: How to effectively increase pattern density by using 2 different shells.

I have a Damascus hammer gun choked .004 and .004. Probably had some choke in one barrel reamed out at one time. However both barrels still have .733 bores. Both barrels remain in proof for 2 1/2 inch shells.

I'd like to tighten the pattern in one barrel by using a different shell in the second chamber. I've been using a variety of manufactured low pressure shells.

Does a larger shot size accomplish this to some degree, or is there another factor?

Thanks in advance.

Things that tighten patterns:

Plastic wads
Shot cups
Larger shot
Buffering (also increases pressure)
Pie crimped shells shoot tighter than roll crimped shells
Low velocity
Longer forcing cones (when used with plastic wad/shotcup)


Things that open Patterns:

Fiber wads
Plastic inserts in the shot charge
High velocity

Bob Brister wrote an excellent book on patterns. Also Gough Thomas (GT Garwood) and Burrard have much on patterning although almost all of it was written before plastic wads and shot cups.

If I'm not mistaken, Zutz reported that simply changing powder to green dot tightened up his patterns.
My copy of "Shotgun Stuff"�is on loan at the moment, so I can't verify that, but, it is what I seem to recall.

Best,
Ted

I've often wondered if using a steel shot cup (extremely stiff shotcup pedals) would noticeably tighten a pattern.

good list AmarilloMike

I would add the following:

too tighten:
-harder shot
-unslit wad
-fewer slit wad (two slits instead of four)
-scotch tape around wad (two or so wraps)
-line shot cup with a wrap

too open:
-irregular shaped shot - flattened shot - (I don't like this on game as it creates ugly wounds that draw in fine feathers
- disperser wads/scatter masters wads

changing powders can affect patterns because of a change in the pressure curve - however one must experiment to determine the actual effect as individual bores behave differently

Okay, since I'm using commercially available modern shot shells, it appears that the easiest means of tightening a pattern would be to use a shell with larger shot size in the second chamber all else being equal.

yes on larger shot, also consider harder shot if available without having to go to a faster load like the fiochi golden pheasant

I believe rst will provide you some good options

1150 fps should be tighter than 1350 fps.

Yes on the larger shot but consider there will be less pattern density due to fewer pellets so probably wouldn't gain much, if any.

Mark, you could gain a lot by having the left barrel jug choked. Five thousandths off the wall thickness would give ten thousandths additional choke, making fourteen total. That would be a solid modified. I have had great experiences with jug chokes.

Two of my favorite "long range" guns are choked about what you have right now and they do reach out and touch 'em. Once I got over worrying about numbers and observing the kills I gained a lot of confidence in having little choke.

You're probably right Joe. I should just pattern it and see what I really have. If I'm two feet behind and over a target, it doesn't really matter what choke I'm using, right?
I'm reluctant to remove any metal on this particular gun.