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.

Before you trash your barrels,you might try loading your own shells first. It's a small investment compared to sacrificing the gun.
There are wads that will tighten up your patterns and along with lower velocities and larger shot just may give you what you want.
Besides its a hell of a lot of fun
Justin

Justin is dead on right. I can't imagine not reloading for these guns. And if kept basic it's darned economical. A MEC 600 Jr press, a bag of wads, a can of powder, a sack of shot, and a few primers and you're ready to load a flat.

Do you recall how your hammer Richards was smacking clays at Whittington? I was using my reloads with your gun--7/8 oz #8 running about 1150 fps in 2 3/4" Federal hulls. And I think it was close to cylinder choke. Great gun!

Justin & Joe:
Yeah, you're both probably right about reloading. I used to reload, but the necessities of life got in the way. The gun in question is my under-lever Harkom hammer gun. Just stunning engraving, barrels and wood. I don't want to mess with the bores.
Mark

I totally agree with you, Mark......not with a gun like that. I'm sure it will amaze you how far you can reach out shooting one ounce of #7 sub 1200 fps. Slow 1 1/8 and #5 or #6 for big birds.

A nice roll crimped paper hull would compiment your Harkom beautifully. If you are thinking about getting back in to reloading a good used scale, a Mec sizemaster and a good used Pacific or MEC press to deprime/prime with and drop your powder and shot charges plus an old manual BGI roll crimp tool and you are in business. 12 gauge Federal Gold Medal paper hulls are still available.

As Joe said, .005 jug choke would help a lot, and no one but you would ever know. Besides, who's to say someone in the distance past didn't do it seeing how gun owners have many, many times altered their guns. Good luck - Paul

I am not a reloader but I have a guy that can load anything and we are loading black powder mostly but he said he has never seen any data on roll crimp vs pie crimped . Where can I find this info?

You mean on pressure and velocity, Monty? I think some of the stuff put out by Ballistic Products has some information.

Gough Thomas states it as fact in one of his later books. Says the overshot card gets in the way of the shot and spreads out the pattern.

Best,

Mike

http://www.youtube.com/watch?v=k3M46XVfVOU

Roll crimp is what I was curious about mainly. We are shooting these older guns some without any choke.I will wrap the tubes in tin foil if it will tighten the choke for ducks.
Thanks

BPI has a technical brochure on roll crimping from 2005 that provides pressure and fps info for sample loads. But they do not offer a direct comparison between star and roll crimp loads.

"We are shooting these older guns some without any choke.I will wrap the tubes in tin foil it it will tighten the choke for ducks."

What "tubes" do you wrap in tin foil?

There are pretty serious limits to what you can do to cylinder bore vintage guns to tighten chokes. Newer guns that will handle steel or Hevi-Shot, that will tighten chokes. Buffered loads will tighten chokes. But I don't know of any low pressure, buffered loads for vintage guns.

Has anyone loaded lead shot in a steel shot wad? I'm wondering if the tightening effects of shooting steel shot shells is due to the wad design.

muchatrucha
Sorry do not review my post.Stupid job I have gives me little time to blog. I grew up better than this. Heard that statement from a table next to me last week.

Chuck
That utube is past cool. We did this as a kid but we shot cans so we had no Idea of the pattern. I have joked about it in recent years but I had no idea it worked.