20 gauge SxS project

[bcp477]

Started a project a couple of months ago. Namely, turning a cheap side by side 20 gauge shotgun into a short range slug gun. I am not yet ready to report everything yet, as I have some test loads yet to shoot, but I did find a good load the other day, using a homemade slug. I also confirmed that, absolutely NO surprise, my shotgun barrels are not regulated well. That is, the LEFT one is badly out - shoots about 8" left and 14" low with the "good" slug load. Mind you, it actually shoots tight groups, so the barrel is not "bad"...just out of regulation. The right barrel, however, shoots right to point of aim - and good, tight groups. I have installed a fiber optic front sight on the centre rib and use that in combination with a u-notch rear sight machined into the receiver. No surprise about the barrel regulation...I almost expected it...because that is so common on cheap side by sides. The gun is a Stoeger Uplander 20 gauge, with barrels cut to 20".

Anyway, more later when I finish a few more test loads.

[richhodg66]

Similar things have been done on here, there was a thread a few years ago of a guy making a double rifle like you're doing and I remember him having to do some things to regulate the barrels. Look around, sounds like fun.

[6pt-sika]

FWIW , I fool with SxS’s in all gauges and anything from a 28 gauge up I’ve made decent slug loads for my parameters . Being as ALL the guns I use are older what would be called guns by classic makers I don’t do anything to the guns to change them . And usually one barrel will be pretty much on the POA and the other barrel if off by a noticeable distance I use a buckshot load . I’ve got several the both barrels are deer capable with slugs inside my preferred distance , but that’s not typically the norm .

[bcp477]

I've actually been toying with the idea of using long barrel liners (18" barrel "adapters") to convert this shotgun into a sort of double rifle. A double rifle is really what I've always wanted - but will never have, due to the cost. I find them fascinating, though. However, a smooth bore double (shotgun) is also fascinating to me...so there it is. With the barrel regulation issue on this Stoeger, I will most likely leave it as is and see what I can get out of it. I am on the way, anyhow, with finding a good load for it...and especially with figuring out a good way to make slugs, custom- sized for this shotgun.

[bcp477]

While I am thinking about it...here are the slugs I have been making...and my "custom" sizing die for them. The one on the left is using a cut-off CB1078-20 Claybuster wad...and the one on the right uses a wad of unknown manufacture (but which fits very nicely in my barrels). The "sizing die" is, of course, merely the cut-off barrel section I removed from my Stoeger, when I shortened the barrels and eliminated the chokes (to have cylinder bore- size barrels). The business end of both slugs is provided by a Hornady .53" swaged lead ball.

Making these slugs is very simple. I use hot glue ( I prefer the 3 minute, slow-setting type). Place a good-sized dollop of hot glue in the wad...then in goes the ball, which I roll around with my finger, to make sure the glue is spread around on the inside...especially on the inside of the wad petals (to ensure they are glued to the ball). Then, while the glue is still soft, I insert the slug into the cut-off barrel "sizing die", pushing it a couple of inches in with a push stick I made. Let it cool, then push it out. Voila ! A perfectly sized slug for my shotgun barrels.

The balls themselves average about 225 grains (just over 1/2 ounce)...and the completed slugs average about 258 grains. Quite light for a shotgun slug, I know, but I only use them for punching paper, or ringing steel targets, anyway. The load with these has about the same muzzle energy as a solid mid-range 44 magnum load, but with much less perceived recoil (firing them through a 6.7 lb shotgun with a shoulder stock, instead of a 2.5 lb handgun).

[bcp477]

The other thing that I do...which is outside of the box...is that I do NOT crimp my loads. I HATE the idea of crimping a shotgun hull, because it essentially destroys the hull. The crimp will just ensure that the hull will split within a few firings - and thus must be cut down to be used again, or thrown away.

Instead, I place an overshot card on top of the slug, then seal the shell with wax. Ordinary paraffin wax. I dribble in melted wax, then tilt the shell over and spin it, so that the wax is distributed in a concave shape - higher on the edges than in the middle. Thus, a relatively small amount of wax forms a pretty strong seal. I have run tests on this...and it requires an amount of force only a few ounces different (sometimes less, sometimes more) than required to push open a star crimp from the inside. Of course, most everyone uses a roll crimp on slugs...but I couldn't get conclusive test results when I tried a comparison test with roll crimps (and my wax seals). I get clean burning of the powder in the shells and good accuracy. So, my wax seal method does work. The wax releases cleanly from the inside of the hulls, with no partial blockage, as with an opened crimp...so the passage of the payload from the hull to the forcing cone in the barrel is smoother (and I'd like to think) more forgiving, than with a crimp. No bloopers and a clean powder burn indicates that the pressure build inside the shell is acceptable. Also, I often use 3" hulls for these loads, to give the slug a longer "head start" inside the shell and put the transition point between the hull mouth and the forcing cone closer together. I don't know if this helps...but it certainly doesn't hurt.

Anyway, those who think I am crazy...go ahead and let me have it. Here is a photo of a couple of completed shells. Maybe I am crazy for stepping outside the box a bit...but my methods DO seem to work. I will post photos of my targets, after my next range trip.

[kens]

I have heard, but have not tried, to move the point of aim of a shotgun barrel by toying with the squareness of the muzzle.
dress the muzzle off-square and it supposed to move POA because of gas escaping one side first.

[dverna]

Barrel regulation is possible but not easy. One reason a double rifle is expensive.

I know a guy who had a custom choke tube made to change the POI. It worked. And it is not silly expensive. A lot of trail and error work is needed.

[bcp477]

Yes, lots of trial and error needed to regulate the barrels - especially if one is off as far as mine. That is why I did (temporarily) install sights on EACH barrel...to get around the regulation problem. That is, a front bead sight on each barrel. However, I found them difficult to use...and the stock didn't help, either. The easiest and most consistent results occurred with the centre rib sights. The only good way to get sights on the individual barrels to work, I think, would be to include a REAR sight, in addition to the front one....and possibly modify the comb of the stock a bit. Not sure I want to go that far. I am still thinking the matter over. At least I have ONE barrel that shoots right where I want it. I can always just treat the shotgun like a single shot - with a backup barrel loaded with buckshot. Hate to "waste" a good barrel, though, so to speak. Since the left barrel shoots tight groups - at least as tight as the right one it seems, it certainly would be great to have use of both for slugs.

In any case, I'll work it out. Just another little challenge to keep me interested...

[centershot]

The other thing that I do...which is outside of the box...is that I do NOT crimp my loads. I HATE the idea of crimping a shotgun hull, because it essentially destroys the hull. The crimp will just ensure that the hull will split within a few firings - and thus must be cut down to be used again, or thrown away.

Instead, I place an overshot card on top of the slug, then seal the shell with wax. Ordinary paraffin wax. I dribble in melted wax, then tilt the shell over and spin it, so that the wax is distributed in a concave shape - higher on the edges than in the middle. Thus, a relatively small amount of wax forms a pretty strong seal. I have run tests on this...and it requires an amount of force only a few ounces different (sometimes less, sometimes more) than required to push open a star crimp from the inside. Of course, most everyone uses a roll crimp on slugs...but I couldn't get conclusive test results when I tried a comparison test with roll crimps (and my wax seals). I get clean burning of the powder in the shells and good accuracy. So, my wax seal method does work. The wax releases cleanly from the inside of the hulls, with no partial blockage, as with an opened crimp...so the passage of the payload from the hull to the forcing cone in the barrel is smoother (and I'd like to think) more forgiving, than with a crimp. No bloopers and a clean powder burn indicates that the pressure build inside the shell is acceptable. Also, I often use 3" hulls for these loads, to give the slug a longer "head start" inside the shell and put the transition point between the hull mouth and the forcing cone closer together. I don't know if this helps...but it certainly doesn't hurt.

Anyway, those who think I am crazy...go ahead and let me have it. Here is a photo of a couple of completed shells. Maybe I am crazy for stepping outside the box a bit...but my methods DO seem to work. I will post photos of my targets, after my next range trip.

Ingenious! Just another example of why I love this site so much!

[kens]

What about sights on the center rib, the rear is a 2-leaf fold down, and you sight in each leaf?

[bcp477]

What about sights on the center rib, the rear is a 2-leaf fold down, and you sight in each leaf?

Holy Moly, kens !!! I had not thought of that. Sounds like a very workable and efficient idea, not to mention relatively inexpensive. Right in my wheelhouse ! Thanks !!! I will definitely give it a look !

[bcp477]

What about sights on the center rib, the rear is a 2-leaf fold down, and you sight in each leaf?

As an update, I've done the math on a double leaf Express sight. The angles of correction needed are quite small...namely about 0.65 degrees on the windage and about 0.75 degrees on the elevation (for the left barrel). Of course, there are more calculations needed for the basic setup. As well, to state the obvious, developing a zero with such sights will ONLY be correct at ONE specific distance... and with ONE specific load. But, I only intended this project to be accurate to about 50 yards, anyway. So, the overall "Kentucky windage" needed for OTHER distances within that envelope is not large.

So, in conclusion, a double leaf Express sight WILL work. It will require some work to set up. But, not many other ways to get a simple solution that will work with BOTH barrels. Just adding an ordinary adjustable rear sight to the center rib would only allow a zero for ONE barrel - so that is not really a useful solution.

[longbow]

You are not so far outside the box as you might think. Another fellow that used to post here used beeswax melted and poured into the hull mouth just as you are doing with paraffin and he said it worked well.

The Kodiak double rifles apparently use a double leaf site systems for the the reason discussed... regulating a double rifle is time consuming and expensive. My understanding is that the Kodiaks are laser aligned at assembly which gets them reasonably close but to save the trial and error of shooting and repositioning/re-soldering rib and barrels to get same POI they just use a leaf sight for each barrel. That keeps the price down to affordable amounts (for us peasants).

I have also read of but not tried the dressing of muzzles to change point of impact. I wouldn't do it to a classic gun but a modern inexpensive side by is a prime candidate and if it doesn't work just re-square the muzzles. You won't have removed more than a few thou of metal to try it out.

I too dream of a double rifle or preferably a Paradox gun but I will never be able to afford an H&H Paradox gun! I have to accept window shopping and dreaming (fantasizing?).

Longbow

[lar45]

I vote for 45-70 liners
A few years ago, I decided that I needed a double rifle, but found them to be abit cost prohibitive. So I found an old Belgian 12 ga double SxS with the Greener cross bolt and started cutting.


I ordered some .475" barrel blanks from Pac-Nor and turned them down to fit inside the 12 ga barrels.


I found some NECG Express sights at Brownells and mounted them to the rib.








Everything that I had read about regulating said that the gun was shot from a standing rest. I took some 2x4s and built a triangle that I C clamped to the 4x4 upright at the range. I put a sand bag on it and would rest my left forearm on it, get the sights lined up just below the target, lift up slightly to center on the target and shoot.
The gun moves differently when shot standing vs sitting at a bench. The left barrel will tend to shoot up and left, the right barrel will tend to shoot up and right.

To regulate my barrels I left the muzzle end the full inside diameter of the 12ga barrels, then turned the next 12" down to a smaller diameter with a gradual taper. I'm not sure if I'm describing this very clear or not, it's almost 6 AM and I haven't had any coffee yet.

Okay, I'm back now and have Coffee.

After mounting the Express sights to the rib, I shot the right barrel and left barrel to see where they ended up. Then I used a small sharp chisel to put a verticle witness mark on the right barrel. I pulled the right barrel and filed one side down slightly while keeping a rounded contour to match the inside of the barrel. Then I cut some thin brass shims to wrap around the other side of the barrel. I reinserted the barrel and then pushed/hammered lightly, the brass shim into place and fired the right barrel again. I would rotate the barrel some and shoot it again. This way I could point the end of the barrel, up/down right/left until it shot to the sights.
Once the right barrel was on target, I cleaned everything well and silver soldered the insert into place.
I then did the same to the left barrel.
Ideally you want the right and left barrels to shoot about 1.5" apart so that they are both shooting parallel to each other no matter what the distance is, they should be about 1.5" apart. If you steer both barrels to shoot an overlapping target at 50 yds, then at 100 yds the left barrel will shoot right and the right will shoot left.

Once you have both barrels soldered into place and cleaned up, take the barrel assembly off and mill out the breech end of the liners so you can make a new extractor to slide the smaller diameter shells out when you open it.

Sorry, didn't mean to get so long winded.

[longbow]

I had a similar idea but using eccentric collars at the muzzles so they could be turned to offset the muzzle of the liners. Haven't got to the project yet and may not but it is doable. There was a Russian double in .45-70 done more or less that way too so it is a valid way to go.

I guess once you have yours regulated and soldered in place it is solid and can't move so that's good. Are you getting consistent accuracy from both barrels?

[Kosh75287]

All of this is just SO cool...

[bcp477]

By way of an update on this project... I checked the muzzles again, very carefully. They were both off by a small amount (that is, not quite perfectly perpendicular to the bore axis). Evidently, I did not do quite as good a job with them initially as I thought. I usually don't mess that up, as I have cut and crowned bunches of barrels, over the years. Oh well, egg on my face ! Interestingly, the left muzzle was "off" more than the right one...and in a direction that was conducive to the left barrel shooting left and low (which is exactly what it did in testing). I have since re-worked both muzzles - making them as perfect as I can. So, likely BOTH barrels will change POI now, but the right one should not change much. I've been too busy to get to the range since, but I have a large batch of test loads ready to go. I should be able to give it another test soon.

Once I have a proper "baseline" from which to work (which I would already have IF I hadn't messed up)...then I will explore the possibility of moving the POI via the muzzle.

I'll report back as to the results.

The double rifle idea still holds much fascination for me. Nice job, lar45. Not sure what I'll do , in the end...but for the time being, I want to see what I can get out of the barrels as is. Also, one of the cartridges I might like to try would be 45/70...but alas, that won't work with 20 gauge (existing) barrels.

Oh and kudos, lar45, as to your barrel regulation method. I thought of doing essentially the same thing, if I ever make this project over into a double rifle of sorts. I agree...and most people don't realize...that double RIFLE barrels are NEVER supposed to "cross". They are supposed to be set up to shoot parallel- just as you have done. SHOTGUNS (that is, using SHOT loads)...are set up to cross...so that the shot pattern will overlap. Of course, a dedicated slug gun, even if smooth bore, should shoot parallel, as well. And that IS what I am going for...

[lar45]

I had a similar idea but using eccentric collars at the muzzles so they could be turned to offset the muzzle of the liners. Haven't got to the project yet and may not but it is doable. There was a Russian double in .45-70 done more or less that way too so it is a valid way to go.

I guess once you have yours regulated and soldered in place it is solid and can't move so that's good. Are you getting consistent accuracy from both barrels?

I saw a setup like that, I think it was the Baikal 20" 12ga double. The shotgun had external superficial hammers and the muzzle was threaded to be able to tighten down the lock nut after you turned the offset insert into place. It came with an extractor that was operated by the 12ga extractor. What I really wanted was one of their 45-70 doubles. I had one on order for several years, but they were so slow on getting them out, that I took a nap on the project and missed it when they were finally released.

I am getting consistent accuracy from both barrels. Each barrel will shoot about 1.5" with a cast 500 at 2150fps from the standing bench. I had Mountain Molds cut the mold with a .4" nose, thinking that I might be able to use them in a 475 Linebaugh. It was a 2 cavity mold. One cavity had a 70% Meplat and the other a 90%. Both of them shot about the same.

[longbow]

Might have been Baikal but certainly Russian double with liners and eccentric collars. I heard they were a bit crude... but also affordable, so I am guessing a guy could clean up and smooth action if required. Can't say I have seen any info on them for some time but then I haven't been looking.

Your shim and solder idea is simpler and once soldered solid should be just fine. Did you fill in all around the liner to make for a smooth muzzle then crown liner and shotgun barrel together?

More recently my "plan" such as it is, is to go the same sort of route as the OP... so back on track... I've been wanting a poor man's Paradox gun and so far have not had the slug accuracy I wanted out to 100 yards. Decent accuracy to 50 or 60 yards doesn't seem to be too difficult to achieve with home cast and loaded slugs but, for me anyway, decent and consistent 100 yard accuracy has been elusive from smoothbore and that is single shot. So, I decided that what I should do is to make a slow twist deep rifled choke tube to suit round balls and "square" slugs. Several years ago I made a small rifling machine to do that and rifled a piece of 3/4" pipe as a test. it worked pretty well but life got in the way and it was left foe about 3 years. Then I bought a blank choke tube, bored it to 0.690" and proceeded to rifle. Well, it is stainless steel and rifling was slow going with a multi tooth cutter so I changed the cutter to single tooth which was working better but... it cut too well, grabbed and pulled the tube a bit making it out of time with me not realizing it so the rifling got messed up. It may be salvageable but I'll likely start over in the future.

Even if my slow twist, deep rifled choke tube works, I will still have the same issue as the OP pointed out ~ cheap side by regulation issues. It may be possible to make the choke tubes eccentric with longer thread than factory and a lock nut so the tube can be turned to correct regulation then locked down. Not sure if it is worth the effort.

The other option is forget slugs and go with Tri-Ball loads or 2 large balls. Effective range should be similar as for full bore slugs and regulation shouldn't be an issue unless way off.

We'll see how the "plan" goes I guess.

I'll be interested in the OP's results and any other info along these lines too.

Longbow