PDA

View Full Version : Longbow, this is Jim, over.



Jim
11-27-2008, 11:24 AM
I recently aquired a Benelli Super Nova in 12 gauge 3.5" magnum chambering. I'd like to handload some .690 RBs in 3.5" mag shells for it and would like to get some feedback from you on this.
I've handloaded pistol and rifle ammo for years, but shotshell reloading is new to me. One thing I don't know about is reading the pressure signs in shotshells. Is this feasible?
Concerning RBs, I was thinking of the stack and how to build it. I figured a gas seal over the powder, X number of felt wads and a teflon wrap around the ball. Concerning the powder selection/charge, I have no clue. I would like to get the M/V up as high as I can.
Can you give me some starting pointers?

missionary5155
11-27-2008, 03:38 PM
Hello Good afternoon
I have been reloading RB for some yeras so I will pass on the little I understand.
Reloading RB in shotgun has alot in commmon with rifle cartriges. I would take one of your magnum shells and fire it noting in a loading book the case head expansion. Keep this for future observation and comparrison. As you increase your load use the visual and the case head expansion of your ORIGONAL factory cartridge as the MAX guide.
Your first task is to decide what choke size you will use. I am thinking your model has screw in chokes.. Personally I would look for the choke that would be about .005 more than the basic barrel diameter. If the barrel is NOT screw in type then you need to measure the tightest constriction of your choke and figure on about .005 total oversize of your choke.
I would use a poly type over powder wad as they do seal the charge gases very well. Do not bother with Unique to get the Max velocity as it gets real pressure sensitive. Bluedot looks great and I will be using some in my RB loads when I get back to Illinois.
Wads One thing I would try directly under and over the ball is a fiber wad with a hole cut in the center to help center the ball in the barrel. Dixie is experimenting with these. They look promising IF you are NOT using full length shotsleeves.
I have been shooting .685 RB for some years out of smooth bore barrels. I use full length shot sleeves. I will be experimenting using a rifled Mossy barrel on return to Illinois.

Jim
11-27-2008, 04:16 PM
Thanks, that's a lot of info right off the git go. As for centering the ball, I'm going to try something a little different. Cylinder bore is .725. The RB is .690. The difference is .035. 1/2 of that is .0175. I think I can roll 20# paper to that thickness and use it as a wrap to keep the ball centered.

longbow
11-27-2008, 10:20 PM
Jim, this is Longbow, over:

Not sure I can help a lot especially with 3 1/2" hulls but here is what I know.

As for pressure signs, I'm not too much of an experimenter with pushing the limits or developing loads from scratch. I use published loads for equivalent weight shot or slug and make as few changes as possible ~ maybe wad column or primer after checking several loads and components to cross reference for pressures so I can take an educated guess.

Hull design can have a large effect on pressure so be careful there. You don't want to be using a load designed for a straight walled hull in a compression formed tapered wall hull.

In fact about everything can and will affect pressure one way or the other so best is to get a loading manual or two as a start. "Reloading For Shotgunners" is good because it list several loads and pressures for each combination of components.

If I get sticky extraction I take that as a high pressure sign.

Mostly for any "experimental" loads I have used Blue Dot as it is slow and seems to be not finicky in a straight walled hull with heavy slug or shot loads. My basis lately for non-standard heavy slugs has been the Piledriver load info which was pretty basic: straight walled hull, plastic gas seal, hard card filler, 610 gr. full bore slug over up to 44 gr. Blue Dot. I have not exceeded 38 gr. Blue Dot with slugs up to 600 gr. so far. Recoil there is enough for me.

IMR 4756 has been recommended to me as better than Blue Dot but I have been unable to get any so am still using Blue Dot.

Missionary has a good system for his 0.685" RB's in modified shotcups. Check his posts.

Turbo1889 also has some good info if you do a search.

I think a few others have posted large RB loads on this forum too.

I do have some book loads for 0.690" RB's in 2 3/4" and 3" hulls but I don't think anything for 3 1/2". If you want me to look them up I will post them.

To be honest, I am not sure why a longer hull would make a difference to pressure since they are straight walled and the volume is taken up by filler wads but if you check the loading manuals pressures seem to rise in shorter, same design hulls. Since you are going longer it shouldn't be a problem but... I have no experience there.

Anyway, if the 610 gr. bore size Piledriver can be loaded over up to 44 gr. Blue Dot in a 2 3/4" hull, I would suggest cross referencing to some shot loads for 3 1/2" hull to make sure that is reasonable and start at 38 grs. and go from there. Check primer for those loads too. I generally use WW 209 which is not real hot.

I suggest a plastic gas seal and hard card filler wads with a teflon wrap or paper "patch" to take up bore slop but possibly a tough thin petal shotcup would work too. I have found that the shotcups I have used with 0.690" RB's shear petals even in my cylinder bore. Again, missionary gets good success with 0.685" RB in shotcups.

Not sure why but when I have used a plastic gas seal, 1/8" nitro card wad or even 1/2" hard card wad then a fiber wad I haven't gotten good performance so I use all hard card filler wads under the ball.

I have mostly gone to smaller 0.662" RB's in shotcups, which seem to do well, and 0.735" RB naked over hard card wads also does well.

Do get yourself a manual or two as shotshell reloading is not quite the same or as predictable as metallic cartridge reloading. The recipes are all worked up in a pressure barrel and some pretty small changes can create large pressure differences.

I hope that helps a bit anyway.

If you want to look at the 2 3/4" and 3" loads let me know.

Longbow

longbow
11-27-2008, 11:52 PM
Jim, me again:

Just in case you don't have any shotshell reloading info, here is a good place to start:

http://glarp.atk.com/2008/2008_Catalogs/AlliantPowderCatalog.pdf

http://www.alliantpowder.com/reloaders/index.aspx

and also:

http://data.hodgdon.com/shotshell_load.asp

Oddly, I don't see any slug loads in the Alliant info. I know I downloaded from Alliant before and have slug loads but they were limited recipes.

Anyway, I use the Lyman Shotshell Reloading Handbook vol's 2, 3 & 4, Reloading for Shotgunners, Alliant info, Hodgon info, IMR info, Ballistic Products Slug Loading Handbook and Ballistic Products Buckshot Loading Handbook plus whatever I have found on published loads or loads from trusted sources and some downloaded pprimer info. All for loads, starting points and comparisons. I don't deviate too far from listed loads.

Longbow