12g diameters

[hollow-point]

whilst viewing mid-south,s site inoticed lyman round ball mould for 12g in two sizes. .662 and.690. why the difference? . then went to nei site. their 12g is listed at .732-.735. i want to use in a 12g sxs fabarm with 24 inch barrels. rifled and plain bore. what does all this mean? hoping some kind soul can set me straight.

[hollow-point]

i also have 28inch barrels with screw-in chokes. can these be used without the chokes in.

[crowbeaner]

Mfgs. rarely have the same diameters for any 12 ga. moulds. I just measured 5 different barrels/guns and got 4 different diameters for the barrels. From .700 modified to .730 slug barrel on a Win. 1300. Evidently the mould mfgs. want people to guess at what they need. If you check Midway's site you see a .705 diameter for the Foster slug mould. I have 2 older 12S moulds, and the diameter is .690 to .691. I myself wish that somebody would make a slug mould of .730 so it would fit my barrel of .710 and shoot as well as the factory loads do. FWIW I measured the Lee key drive slugs and they mike .675 so any barrel over extra full (.660) should be fine. Hope this helps. CB.

[45 2.1]

I myself wish that somebody would make a slug mould of .730 so it would fit my barrel of .710 and shoot as well as the factory loads do.

You don't want a slug over groove diameter in a rifled slug barrel. Rapine used to make two slugs like this though. You might be able to find one. Or have someone make you one like below.

[Red River Rick]

45 2:1

Would you be able to post a drawing of the lubed grooved slug shown in your picture. It would be much appreciatted.


RRR

[crowbeaner]

45 2.1 - I want a slug that will obturate in the backbored part of my SMOOTHBORE barrel and then squeeze down. If the slug is pure lead and tin the squeeze won't make that much difference in pressure, especially if I roll crimp the loads. The factory load HAS to be able to be fired in ANY barrel, and not necessarily the best fit in all barrels. I'm sure shooting the factory load in a .660 extra full Hastings barrel won't make for a KB. I want a full caliber slug. The BPI AQ slug mikes .735 and the base plastic is .740. No problem there. CB.

[scb]

The modern standard for a 12 gage bore is .729. One has to be certain to get past the choke when measuring the bore. The choke is of course the constriction of the bore at the muzzle that is either bored or swaged into the barrel to improve shot patterns. This is the main reason for undersized balls and slugs. A .730 dia. ball being fired thru almost any choke would quite probably at least cause the barrel to split. Steve

[crowbeaner]

Do you have the link or website info for Rapine? All I could get to come up was bovine scat. Even a phone # would be good. Thanks,CB.

[turbo1889]

Okay first off, some slugs are wad-slugs and are designed to fit inside a shot wad and thus must be slightly smaller then bore size so that (Slug Diameter) + ( 2 x (Shot-Wad Petal Thickness) ) = (Internal Bore Diameter or a Little Less). Other slugs are instead full-bore slugs and are sized so that (Slug Diameter) = (Internal Bore Diameter or a Little Less). The lee slugs are wad-slugs along with the Lyman slugs that are hour-glass shaped, and the other Lyman slugs are full-bore slugs. Other slug molds of both types from various other makes.

Secondly slugs are usually a little on the small side so that if they are fired through a choked gun bad things don't happen.

[45 2.1]

Do you have the link or website info for Rapine? All I could get to come up was bovine scat. Even a phone # would be good. Thanks,CB.

Sorry, I don't have that info. Rapine is supposed to still be in business, maybe someone else has his phone number. I would pay particular attention to not sending an oversize slug thru a choked barrel. Very good advice has been given by the other posters. The pictured wadcutter slug is for rifled barrels only.

[crowbeaner]

I got frustrated last night and finally found the contact info on Rapine. Rapine Bullet Mould Mfg. Co. 9503 Landis Lane East Greenville, PA 18041 (215) 679-5413 Fax (215) 679-6442. Hope this helps. CB.

[longbow]

Here's my two cents worth too.

I certainly don't claim to be an expert on shotgun slug shooting but have shot several different styles.

I have loading book recipes for .660" and .690" diameter round ball, Lyman wasp wasted slug, Lyman Foster slug, several of the Ballistic Products slugs - I have used their AQ slug which while expensive is excellent from a smootbore and Brennekes. I have also made moulds that produce slugs of equal weight to Lyman styles and loaded using the Lyman Foster slug data.

The .660" and .690" round balls are to be loaded in Winchester plastic wads though the .690" ball can be loaded over fiber/felt/card wads. The Lyman wap wasted slug is also to be loaded in a plastic wad as are several other types of "undersized" slugs - so not really undersized.

The Lyman Foster slug is grossly undersized at .715" (but too big to fit in a plastic wad) and does obturate to fill the bore but in my experience does not do it consistently. Shooting slugs into soft snow then recovering them showed quite uneven expansion to fill the bore - and no I don't think it was distortion from impact because the slugs still fit the bore.

The choke issue is a real concern as a round ball or other solid slug will not easily compress and so may damage the barrel or choke section. Having said that I have never understood why manufacturers of hollow Foster style slugs make then so undersized if they obturate to fill the bore anyway! They still have to squeeze down to get through the choke.

My view is that the slug should fill the bore and if to be shot even accidentally through a choke then designed to squeeze through without damage to the gun. If you are shooting cylinder bore or fully rifled only then that is not an issue and a full bore round ball of about .730" should work well.

I have had some decent accuracy in a smoothbore using paper patched Foster slugs so they are brought up to bore diameter. Also, the AQ slug has given very good accuracy out of my Browning BPS with smoothbore slug barrel as have Brennekes.

Using anything but proven loading book recipes is dangerous though as shotguns do not give pressure signs like rifles do. I had an unpleasant experience where I was using Foster slugs in shortened hulls in a 3" chamber - after all they are mostly full of wad right? Well, I was using the book load but shortened hull reduced wad column and I blew up a gun! All I could figure was that the slug left the hull and obturated in the chamber then hit the forcing cone and had to swage down creating a high pressure. The remains of the barrel showed lead streaks up to the forcing cone.

All of my shotgun reloading manuals say exactly the same thing - do not change anything from the recipe given. Even just a change of wad type can produce dangerous pressures. A change in primer brand can also result in high pressures. Winchester 209 is not the same as Federal 209 is not the same as CCI 209!

Just a word of warning.

Since I don't have large funds for shooting expensive factory slug loads or even large quantities of AQ slugs I will be casting my own but being very careful with loads, hulls, wad coulmns, primers.etc.

Paper patching doesn't bother me as I don't think it can have a negative effect - no noticable increase in weight and a slippery surface added. Adding grease grooves and increasing mould diameter by a few thou also wouldn't worry me unless the slug weight increased significantly.

In fact I will be adding grease grooves to my Lyman Foster slug mould to bring it to bore size but I will also be boring the core pin opening and altering the core pin so weight remains the same.

I believe I saw a post where Buckshot added grease grooves to a mould for someone on this site. So you might look for that.

Another project that may be worth while is getting or making a .730" ball mould or stubby wadcutter type mould with a core pin and adding a skirt similar to the Ballistic Products AQ slug. The hollow center allows swaging through a choke and the skirt adds stability. As long as diameter and weight match an AQ or .690" ball, same wads, etc. the load should be safe.

Good luck and shoot safe.

Longbow

[crowbeaner]

Just for grins today while I was waiting for the mag 20 to get up to temp I cut open a 25 year old Federal slug shell. I found a plastic gas seal that looks a lot like a BPI BPGS, a 1/2 " hard card wad, and a 1/8 inch hard card under the slug; the same components listed in the data from the 4th ED. Lyman shotshell handbook for the Fed. High Power hull. As near as I can measure (because the slug was oblong) the diameter of the slug is .675. Therefore, the .690 slugs I have are actually BIGGER than the factory slug. The only difference is that the factory slug has the little shallow grooves to impart spin. SOOO the loads I have will look just like the factory one. If I roll crimp they will be identical except for the powder, which looks suspiciously like SR 4756 but bigger rounded flattened balls. I didn't weigh the charge because I don't have my scale here. At any rate I couldn't get the same powder anyway. Hope this helps all who have been following. I'm going to try and lube my slugs with bowl wax, so if accuracy is in the toilet you know why. CB.

[scb]

The thought that hollow skirt slugs obturate to fit the bore I think is somewhat misunderstood. These slugs are given the hollow skirt so they fly like a badminton birdie. At least that's what Lyman calmed. That is also why they say that the rifling on rifled slugs serves no purpose except from a "sales" point of view. If you think about it there are wads between the slug and the powder charge. The gas from the burning powder can't get into the skirt to expand it like it does in say Minnie ball or a hollow base wadcutter. I suppose that there could be some expansion due to inertia as happens with a maxi ball. Just some food for discussion. Steve

[crowbeaner]

That is why I'm looking for a source of little plastic balls for the base of the slug to act as an expander like the factory loads and help the badminton birdie fly straighter. I was surprised that the factory slug is as small as it is; the lead is REALLY soft and can be squeezed into shape easily. Even my pure lead slugs aren't that soft. CB.

[scb]

I haven't gone back to check, but it seems to me that Corbin (the bullet swage folks) had some of these balls. The thing is I don't know if they have them as big as you may need. Steve

[longbow]

scb

I have recovered 12 gauge slugs cast from pure lead in a Lyman slug mould and they do slug up to fit the barrel. In fact it is one of the problems I think with "undersize" Foster slug designs used by factories and Lyman.

All of the slugs I recovered were shot into soft snow and went many yards before they stopped and all were bore size after starting out at 0.715" (if memory serves - I'd have to mike one to be sure but they were definitely well under bore size when they started) and each one of them was bore size, distorted with uneven expansion and nose off center when recovered.

The distortion was not caused by impact with the snow because they all fit the barrel after recovery. The rub marks on the skirt were quite uneven, showing either uneven expansion or tipping as the slug entered the bore.

Paper patching to about bore size helped accuracy noticably.

Another trick to help keep distortion to a minimum as well is to fill the base with hot melt glue. This adds negligible weight but does help keep the slug from distorting unevenly.

I have to conclude that the slugs do expand even when loaded over hard card wads per book recipes and so have to squeeze through a choke, if one is present, anyway. They may as well start out either bore size or sized to fit a plastic wad as the Lee and Lyman wasp waisted slugs do so they fit the bore to begin with.

This has been my experience anyway.

Longbow

[hollow-point]

thanks fellers, this is the info i need ! thank you very much.