Are there any reasonably accurate ways to determine how much powder will burn in a certain barrel length?
Here is my situation:
I made a smokeless muzzleloader out of a Savage 110 action and added a #7 .458 barrel with a breechplug that uses a 45 acp case for the primer.
I am trying to work up a load for a 150 grain 30 cal SMK/Accubond/SST/A-Max
The sabot weighs 42 grains bringing the total weight to 192 grains.
My main problem is with choice of powders.
1) I need a stick powder so that it does not fall through the hole in the breechplug;
2) the bullet/sabot offers VERY little initial resistance;
3) 22 1/2 inches of usable barrel length, this INCLUDES the powder area;
4) I would prefer to not duplex powder. It has worked well but if one powder will work I prefer that.
5) 50,000 psi working load would be preferred (55k max)
Now the problem:
When I get a powder to a meaningful load the muzzle blast becomes excessive and the accuracy goes to heck ( presumably due to not burning the powder soon enough).
60+ grains of H4198 is about max
65 grains of N120 the same( I thought that this should be a good range of powder).
N110 was still good @ 60 grains but I ran out of time.
So my real question is, do I just proceed by trail and error in figuring if a powder will burn completely in this short tube?
Thanks for the concern, I have been shooting a Savage Muzzleloader( 50 cal)since 2001. Most loads use N110, 4759, RL-7, 2400, 5744
I was not really happy with the light barrel and that is why I beefed it up to a #7 contour with a 1 1/4 inch diameter.
Yes, a heavier bullet would make things easier, but would also reduce range too. I am limited by a 1:14 twist.
I can get to 1000 yards, but just barely, and would like a little more cushion.
when you say offers very little "initial" resistance,are you saying that it gets tighter as it goes down the barrel? if this is the case,by that i mean the bore diameter is smaller at the breach end than it is towards the muzzle,that barrel will probably never shoot very well.
other than that, i would also say you need a bigger bullet.get a sabot that would shoot the 338 bullets, a 225 accubond might work in a 14.maybe it wouldn't but a 168 or 165 in 30 cal would.
What I meant is that since the bullet does not get swagged into the bore, which takes 1,000 or more pounds of pressure, the bullet starts moving quicker and at a lower pressure.
Duplex may be the best way to get much past 3,000 fps without raising the pressure beyond my comfort zone. N110 would seem to be the fast side to reach 3100, but N120, which I think should be ideal, may need more pressure than a 192 grain sabot/bullet can provide.
Edge, i understand now. you're simply comparing the difference between a conventional jacketed bullet with a sabot in a muzzleloader.i thought you meant the bullet started easy and got more difficult as it went down the barrel when you were seating it.
if i understand this right,you're using a pistol primer, rifle powder and bullet.might be a little easier to get a 30-06 and some reloading dies! [img]/ubbthreads/images/graemlins/smile.gif[/img]
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