It's great to hear that you are coming to the Kamloops match.  It is a pile of fun.

With heavier bullets they'll drift a little less in the wind which can be useful.  When I used my .45-70 for silhouette I was happy with the Buffalo Arms 459535 money bullet.  You will start to gain significant advantage at the turkey and ram lines.  The turkey targets are pesky.  If your off on the wind reading a little bit you'll have a lot of close misses .  A higher BC bullet will give you a greater margin of error.

If you want to see what sort of difference, play around with the free JBM Ballistics software. The money bullet has a BC of .5 or a little more.  I don't know about a flat nosed 405gr bullet, but I'm pretty sure it'll be well under 0.4.

Let me know if you have any questions about the Kamloops shoot.  I'd be glad to help.

Chris.

If you're going to shoot silhouette BPCR then you should move on up to the 500+ grs. My best (most accurate) bullet in the 45-70 weighed 560 grs. Load with black powder; Swiss, Kik, Goex. Determine your OACL when the bullet engages the lands, this is generally your best bet. Then determine how much bullet will be in the case. At this point, fill your empty, primed case with one of the above powders to the point where the base of your bullet will rest while the bullet nose will be touching the lands. Now depending upon which powder you're using, you can add anywhere from .030" to .25" more powder & then top it off with a wad. You'll now need to compress the powder charge somewhat to a depth that will accommodate your bullet. Seat the bullet.
You'll want to test different powders, charges, primers & bullets. You'll also need a good set of dies that'll give you proper neck tension. A good source of info & materials can be found at Buffalo Arms in Idaho.
Good shooting.

Quote:
Agree.  Might want to use the 457125 govt bullet (500gr) or the 457132 Postell (535gr)

If that barrel ends in a 20/1 twist you will be limited by bullet length. The 457125 lyman may be your best bet to be stable at the ram line.

Thanks for the replies guys.
I think I'll just "leave well enough alone for now" and shoot the commercial cast 405's I have now -- even if they might be a bit of a handicap.
"Boats" reply kind of struck a chord with me -- " a Trapdoor from X Sticks is brutal to shoot due stock shape" I built my rifle (including the butt stock) from the plans available through ASSRA and they show a Swiss style butt plate (I think its called) -- first load I tried was 35 gr of 4198 and from a bench, that thing was more than brutal -- it was downright painful. I quit at 18 rounds -- no longer fun. The Unique load is more tolerable and some have told me that "Black" shoots a bit softer ?
I'm not casting yet -- bought a mould off ebay (wrong one of course) have a bottom pour pot on the way but not here yet.
Chris, thanks for the offer but I wouldn't want to wreck your stuff.
I'll shoot the Kamloops match with what I have - call it a learning experience - no fear of turning in a low score. I have some previous experience at that.

I'm no BPCR shooter but from previous discussions there may be a conflict with using a Swiss buttplate at some organization's matches, hope not in this circumstance.

Cuslog, technically Swiss buttplates are not BPCR/BPTR legal, but don't worry.  The match directors use "loose NRA" rules.  I've never figured out what that means, but I do know that several shooters use rifles that are a little overweight for instance.  Like me for instance.  My .40-65 is a little over the 12lb 2 oz weight limit.

In addition to the standard match there is an original rifle silhouette match and trapdoors do well there.  There is also a gong match at 500m, 600m, 700m, and 800m.  The 500m target is offhand which is easier than it sounds.

Chris.