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Joined: 06 Jan 2012 Posts: 4 Location: Northeast Ohio

I find myself getting more and more interested in full bore slugs and round balls for shotguns. I have decided to start this journey with my Ithaca M37 16 ga shotgun. It was handed down to me by my father when I was 14 years old (getting close to 50 years ago) for rabbit and pheasant hunting and it was the first gun I ever used for deer hunting (with Foster-type slugs). All that with a 26" barrel equipped with a PolyChoke. Then in the late 1960s (or so) I got it equipped (by the factory) with a 20" Deerslayer barrel (smoothbore) for more deer hunting. Then those shotgun deer hunting days faded away as I "discovered" rifles". Now, as mentioned above, I have come full cicle and want to experiment with full bore round balls and "Paradox-like" slugs.

So...some information I have managed to gather: I slugged the barrel with a 16 ga Brenneke slug (a real snug fit...the slug had an OD of about 0.671") and determined the barrel had an ID of about 0.650". This is close to the comments made about these barrels in Snyder's book on the Ithaca M37...that these barrels were made with an ID about a thousanth or two greater than the SAAMI maximum OD of a rifled slug (0.651").

In studying a number of posts on this and other forums forum I understand that a properly fitted full bore round ball ought to be a bit larger than the bore's ID...say up to 0.005" larger. If correct that means I could use a round ball with an OD of up to say 0.655". How does this sound to those of you with experiance in this matter.

Next...round ball alloy: Again in studying a number of posts I am seeing at least two differing opinions. On one side in the alloy 30:1 lead:tin. On the other hand I see either air-cooled or water-quenched WW alloy. Again, I am asking for recommendations.

My next step in this journey is to buy a custom mold. But to do this I need your recommendations to guide my decision of round ball diameter and alloy. Then I will approach Brooks, Old West, and/or Jeff Tanner about a mold.

Thanks in advance for any and all help and guidance you can provide.

Joe

Hello JosephG
And welcome on your first post
I would say pure lead is perfect
and 30/1 will help fill out the mould cavity.

The full bore round ball and slug will not cause an issue
in lightly choked guns

Many are finding that round balls in plastic wad cups do well

I was wondering if the Lee 12 guage in the wad slug mould
could be used as a full bore 16 gauge slug??

http://leeprecision.com/xcart/Bullet-Slug-Mold/

also look here
http://www.16ga.com/forum/viewtopic.php?t=12213

Mike

The lee bullet slug is designed for rifled barrels, not smooth bores. I think it best to stick with pure lead for round balls if you are going to use one that tightly fits the bore. However, you do not want one so tight it deforms. Round balls fly best out of smooth bores if they fill the bore and remain perfectly round. They often prove to be more accurate than Foster slugs. The muzzle crown must be square and smooth though. This is very important.

Keep the velocity under 1200 FPS too. The faster you push a round ball, the more any slight surface deformities will affect its flight. a pure lead .65 caliber ball does not need much speed to fly straight, hit hard and kill cleanly. That is why most smooth bore muskets were at least .62 caliber. The heavy mass of the ball and the big wound canal did everything needed if the ball was placed through the vitals.

I'd also recommend not using a plastic one piece wad for the load either. The shot cup petals tend to interfere with the ball as it leaves the muzzle. Not needed either. All you need do is grease the ball with some bee's wax or TC bore butter to limit fouling the bore, then seat the ball on a felt card wad or two over a plastic gas check to limit any blow by. You can buy these plastic gas checks or cut the base off a one piece wad. Either fold crimp or roll crimp the hull closed. You should be good to go.

Joined: 26 Apr 2010 Posts: 3178 Location: NCWa

I have no experience with bore size round balls from a shotgun; however I have shot a loaded/shot a lot of cast bullets from rifles/handguns, and I think the physics would be similar. Best performance/accuracy was obtained in rifled bores if the bullet was .001-.003" larger than the bore. It seems this would be accomplished by having a slight degree of choke in the barrel. The angle of contact between the ball and barrel would be very acute so I'd expect the increase in pressure due to the decreased space to be workable.

Joined: 06 Jan 2012 Posts: 4 Location: Northeast Ohio

First of all...thanks to you all for your replies...they are appreciated.

skeettx: Two problems I see with the Lee 12 ga slug. (1) As 16gauageguy says it appears to be designed for rifled barrels (my barrel is a smoothbore). (2) I believe its cast diameter is about 0.675"...but my Deerslayer barrel has an ID of about 0.650". Even if I go with a a sized slug diameter of say 0.655", I would have to size that slug down by 0.015"...that's an awlful lot. On the other hand I agree with your recommendation of pure lead or 30/1 lead/tin alloy.

16gaugeguy: Thanks for the guidance with respect to alloys, fit, loading, and velocity. As far as fit...you indicate the round ball should tightly fit the bore. For my barrel with an Id of 0.650" does this mean a ball of 0.650" or a ball greater than 0.650" by say 0.002 - 0.005"?

AmreicanMeet: I believe your experience with respect to bore fit is consitent with others. My barrel has no choke...it is a straight bore with an ID of about 0.650". So to do like you do with rifles i would have to a mold that gives a ball with a diameter of 0.651 - 0.653".

My next steps are to decide on a ball diameter and a mold maker. I am getting close and all your responses are helping me with my decision making process.

Joined: 26 Dec 2011 Posts: 54 Location: NW Tennessee

I did pretty good with a .690 roundball in a plastic shotcup fired from a muzzloading double 12. I worked up the load so that I could use the gun during primitive deer season as buckshot was illegal in that application.

This is not what you have asked ! But a friend wanted to hunt with a 16 bore that I sold them and ask if I had any slugs for it ?

I said no , but you could order some if you like , they said do you not have anything that would work ?

I really was intrigued with the question for I had been thinking along your lines as well for some time now .

I thought well I have several hundred cast up .50 cal REAL slugs that I had never used , pulled them out set one in my wad and thought back to my ole paper patching days and wala !

I took a .50 cal , "I think 250grain " REAL slug paper patched the thing placed it in my DR 16 wad put a bit of REX -1 behind her fold crimped the jewel and guess what this did out of a Mossberg Bolt 16 bore set on cyl with the poly choke .

The little gun would do under 3" all day long at 50 yards , now set the choke to any other setting and it opened up to better than a pie plate and my buddy said that later on they had tweeked it and it done better than we had gotten by going just a shade tighter than Cyl .

This individual took several deer in Tenn . with the gun this past fall , I played with it a might and found several guns did not like this combination but I have a few that done just as well if not a hair better , bullets were tumbling on the vast majority of the guns and loads shot but some did not , go figgure .

Best regards, Nick

I've a theory here Nick. The choke or choke/barrel combination on the Mossie is probably giving the .50 REAL ball just enough spin to stabilize it out to 50 yards. We both have enough experience to know that each barrel, be it a rifle or a smoothbore, is a law unto itself, even if we can't always figure out why. Perhaps changing the adjustable choke a bit on the Mossie disrupts things by de-stabilizing an already marginally stabilized slug.

In the past, I've used the same Lee REAL Balls in a .50 caliber Browning Mountain Rifle with excellent results out to 75 yards. The gun has a moderately slow, 1/62" twist barrel meant for patched round balls over stiff charges of FFG. Even so, REAL balls carefully loaded on top of a couple of .50 caliber card wads and max charges of FFG also seem to be stabilized enough to group very well. This is not supposed to be possible, but results don't lie. So perhaps these Lee projectiles aren't all that hard to stabilize, especially if they are being shoved along fast enough to gain the needed centrifical force.

We both know that most smooth bores aren't really smooth. Most have some surface irregularities which can and will cause a projectile to exhibit some spin. This might help a round ball or a slug. Even a bit of spin will stabilize a big round ball. Some bigger bore round ball rifle barrels have 1/72" twist or less. The .54 cal Green Mountain barrel on My TC Hawken has that much twist. The rifle groups properly patched .535 RBs over 120 to 140 grains of FFG into 2 inch groups from a rest out at 90-100 yards all day long (if I carefully swab between shots). Really big bores need no more than 1/90" to stabilize a round ball. That ain't much twist IMO.

Just the opposite for shot charges. Spin or rather, the lack of it is one of the main reasons why some smooth bore shotgun barrels pattern better than others with shot. Spin is never a good thing when it comes to tight, full shot patterns. I discovered years ago that evenly and thoroughly roto-polishing the bore of my trap guns end to end with a cleaning rod chucked up in an electric drill and tipped w/ a 20 ga. brush wrapped in #OOOO steel wool improves my patterns and my scores. The key words here are evenly and thoroughly. A half done job could occasionally make things worse. I think that any unevenness in the polishing job or unremoved residue tends to degrade the patterns because some spin results. I'm certain spinning a load of shot will dispurse it faster every time.

However, any projectile must leave the bore undisturbed once it is sufficiently spinning to remain stable in flight. A square/true muzzle or crown with no burrs etc is a must. Any irregularities here will degrade accuracy and the resulting groups. Same thing applies to shot columns. Both ball and shot need to leave the bore in a straight line to do the job IMO.