Hi All , I have a newly acquired Martini in 8.15 x45 ,. I have read up in that above Schutzen loads to use a Lyman. Mold. # 313260 that drops .315 dia. 165 Grain bullets but it seems to be discontinued . I've searched E- bay without luck. I was able to order a set of dies from Amazon . I have found a close mold from Midway ,a saeco 175 grain but it won't ship until 3/25 I won't wait that long .,next I' look elsewhere for a Saeco ,but prefer the right Lyman one.
  It also appears I'm going to need  Breach Seater . I was hoping someone may be able to point me in the right direction . Thank you in advance ., Bruce

PITA to do it but it'll be a BIG help to get an accurate chamber cast as well since while the chamber might nominally be right for an 8.15x46mmR CASE, but ahead of the case mouth the throat shape is critical for getting the correct "stop ring" bullet.

AccurateMolds.com has a wealth of good molds for that cartridge and they can be tweaked to fit the stop ring to the throat.    

The stop ring is comonly thought of as 'stopping" the bullet from going down too deep in the case by most modern American shooters. 
  But it ALSO has an important accuracy function, if used as originally designed.  At its forward edge it sort-of "sets the headspace" of the bulleted round.  I think it needs to be just long enough and fat enough to fill the space between the leading edge of the case mouth and the tapered beginning of the rifling  (throat or leade or whatever term you want to use) Too short, the bullet can get off axis as it "jumps" from the case into the rifling.
 
I have tried to order my SR (stop-ring bullet) moulds so that the loaded bulleted cartridge has a bit of a slight resistance/crush fit as the closing block pushes the leading edge of the SR into the beginning of the rifling. (But not so much that it forces the bullet back into the case and shears off the SR band.)  Ideally I like to see an ejected test bullet showing a bit of rifling engraved into about a third or half of the SR band.  
With an accurate chamber/throat casting you can determine what that should be; and Accurate can adjust the size of the stop-ring band to fit your rifles needs.

SR=StopRing in my vernacular.  

I have 3 or 4 Euro-schuetzens on "martini" actions.  Breech-seating bullets is possible, but getting a workable mechanical breech-seater can be difficult. I have only run into 1 good design and it is a fabrication nightmare. One could drill holes and add pins to hook a breech seater device to the action but I could not do that to one of these fine antique works of the guncrafter's art
A push-seater with a dog-leg bend works but it can be a pain in the hand if not in the extreme lower back----then there is the issue of working around a scope.

The technique used in Europe, as I understand it, was to carry a rifle, and a shooting case containing empty primed cartridge cases, a quantity of premeasured packets of powder, and a quantity of purchased pre-lubed bullets to the range--often on the town trolly or bicycle.  At the range the powder was dumped into the case, and the bullet was carefully inserted into the case mouth with finger pressure, the cartridge inserted, and when your number came up, step to the shooting point and make your shot. 
  I doubt that their shooting style involved many 100 shot matches,  spending a whole day or weekend shooting off one's "personal" bench etc.   My guess it was more a matter of: step up to one of a limited number of firing stands, making your shot, and then stepping back. Then waiting for others to shoot before you took your next turn to shoot.  Of course most if not all was offhand, and I think most of the shooting done with these originals was with iron sights.  

Our style of shooting them is significantly different now.

I have seen a few old German bullet catalogue pages that listed hundred of different designs and sizes of bullets----most with SR--stop rings.   They are a lot like our old Lyman mold catalogues---but you were usually ordering the bullets, not normally the mold to cast your own.  Seeing them like that was a real "AH-HA"  moment for me.
Just the availability of almost identical bullets with the only variance being the size of the stop-ring band itself seems to evidence that that little band was much more than just to keep the bullet from going too deep in the case.   

I shoot them to enjoy the experience of using them the way they were intended.  I know I am self-imposing limits by using them in the original way but that is the choice I make. 
This is all based on my own interpretation of the catalogues and design/function/and shooting customs.

all of the Accurate Molds bullets have a small meplat (flat tip) so the point  is kind of moot. if you look at the accurate molds catalogue pages you'll see a few stop ring bullets that have been created with the critical dimensions listed.      Now I'm sure some of our better educated and technically informed members have a great scientific description pf all of this. 
So basically you want one that the base of the bullet will fit into the case with the back edge of the band against the case mouth with the bullet not protruding back into the case beyond the base of the neck.  the leading part of the nose behind the taper to the meplat should be "bore riding" on top of the lands so that it self-centers in the bore.  If it tapers back and gradually engages the rifling lands until it gets to the actual stop ring thats good.  IN MY OPINION!!
The stop ring should be wide enough to fill to the bottom of the grooves plus maybe a 1000th or two.  The length of the band should be such that the back edge of it is solidly against the case mouth and the front edge engages the beginning of the rifling and begins cutting into the band.  With my bullets the stop ring itself is almost as thick as the case brass at the mouth so that the inserted bullet feels like continuation of the case---- almost like the heeled bullets of rimfire cases--except they are not crimped in place
  This sort of sets the bullet solidly into the lands and the oversized band helps seal the bullet from any high pressure gas escaping forward.   

obviously case length has to be consistent and trimming probably is a good idea to keep them square. 
  once you get the rifle and get a good chamber cast you can look and see where the mouth of the case ends in the chamber---sometimes it's hard to see and has to be found by measuring the case length for comparison----and where the beginning of the rifling starts----thats the critical measurement --to my way of thinking.

I don't think I am explaining this very well  and its all based on my own conjecture and experimenting.   
I'm not winning matches so it may all be off-base.   and I try to remember that these guns were created for offhand shooting not sub-MOA benchrest group size competition

I very seriously doubt that the small meplat flat will make any difference at those ranges,  and probably not enough to accurately measure and isolate from other factors at 200 either.   again   JMHO

There are any number of powders that will work.  Some seem to work a little better with cast bullets that others. I know that the 108/109 powders are used a lot in the small-capacity high-intensity modern cartridges.  Taking a look at Lymans Cast Bullet handbook might give some help.   

One of the standbys for the schuetzen-shooting crowd using traditional cases and bullets has been 4759.  It appears to have been discontinued by the mfg. but is still often available at gun-show tables, some gunshops, shooters estate sales, and a "event" swap meets. 
I have acquired several smaller cans and a couple of the 8# canisters that way.  Differing "lots" of powder will vary slightly of course, but I have taken to "boxing" them together to average out the lot-to-lot variations. I do this with other powder as well.   
  However it is a larger tubular grain powder that does not meter well through todays ultra-precise powder measures that lack the ability to cut through the grains.  Most of the real "precision" bench rest shooters prefer the fine-grained easy to meter "ball" grained powders because of that.

Blue dot, might be a good load. I've had good accuracy with it but, in a much smaller case.

Another one to consider is 2400, it's between 4227 and #9. Also 4100 (about #9 speed), MP300 is the slowest that I would consider. Try both rifle and pistol primers, also.

If you don't have any that are referenced, you'll be on your own in working up a load.

Frank

Mike, I'd really LIKE to see some pictures of your breech seater.

Maynard, I thought your description quite understandable, well done sir!!   

I can't speak to the 8.15 in my Original Haenel/Aydt Schuetzen rifle as it's chambered in some oddball of a cartridge I suppose that either a gunsmith or target shooter had an idea for.  I call it an "8.7 X 55R" as that's the dimensions and no one on 3 continents can find it listed anywhere. 

My Bartles stalking rifle is in 8.15 and it settled on 12 grs. of SR-4759.  It also liked Reloader 7 but I would have to check for the charge.  Just for grins and giggles and because I am a black powder junky I even worked up a load with straight Fffg and a similar duplex load with SR-4759 as a kicker.  Surprisingly they both shot quite well!!!  I don't use or have a stop ring bullet mold but it is something I'd like to try.  Maynards description shed more light on that than I'd considered.  I shoot an ancient Ideal 32 cal. bullet sized to .319 and it works great.  50/50 lead/lino for smokeless and 25-1 for black or duplex.  Neat old cartridge chambered in some fabulous rifles.