Subsonic blackpowder

[JonnyReb]

I just kinda made the jump back to BP from airgunning, and enjoy both for the main reason of being capable of low noise as compared to supersonic rimfires and centerfire rifles. .50 cal airguns and .50 cal BP rifles are far from silent but are quiet enough and meet local requirements so they're my choice for target/hunting behind the house. No sonic crack at least. Not to mention the uniqueness , challenge and cool factor. I've been chronying the patched .50 (178gr)roundball at 920fps using 10 year old triple seven in my CVA bobcat at a measure of 40gr's. Seems accurate. Will be my typical load for everything except designated deer hunting, in which case i'll use a different rifle. Anyone else purposely shoot subsonic for noise reduction, to allow use of softer more pure lead, be more accurate,to save powder or for less kick? Any favorite low charge loads? Look forward to your input,.   Jeff

[keith44]

Nope,
I load for accuracy at power levels appropriate to the task of the rifle.  I would guess most are sub-sonic as there is no "crack" at the shot.  My .54 likes 425 grain projectiles launched by 85 grains of 2F.  Plenty of boom, but no crack.  Definitely not quiet.
My .32 likes 25 grains of 3F pushing a .310 round ball, still no crack, but again plenty of noise.

... to allow use of softer more pure lead, ...

umm, how do you get more pure lead??  Either you are shooting pure lead, or you are not getting the best accuracy from your muzzleloader.

[JonnyReb]

 Hey keith, thanks for the reply. The approach of loading for accuracy makes lots of sense of course and i'll take it into consideration as I try different loads and projectiles. I'd expect the most accuracy is obtained by lead that never goes above the speed of sound or deals with the instability that jumping the barrier is said to have. Of course the RB's i'm using are close to being pure lead, or however hornady sells them. All slugs i've ever molded for ag's were pure lead but only because they were shooting subsonic. I believe some folks increase bullet hardness in order to keep their slug intact when shooting hotter loads. Seems like i've read 1600fps or above is a no-no when shooting pure cast ammo. If your slinging 400gr slugs however, i'm sure 1600fps will never matter. Would be interesting to know what your rounds are averaging in fps/ftlb. BIG medicine for sure:-) J

[necchi]

I don't think a shpere is as effected by the sonic shift as many of the bullet shaped projectiles are. I mean a ball is a ball.
 
Just like CF loading, many rifles will have two or more accuracy ranges, one around 20-40grns and another at the higher end,
and theres always the magnumitis crowd that needs and claims "Max" loads are the most accurate,,
 
I know plenty of folks that are quite happy with lower recoil accuracy.
 
Most of my rifles run the best accuracy above the sound barrier, they "crack" when fired and my loads don't "seem" accurate they are,, ragged hole type accuracy at 50 and 3-4" at 100 with open iron sights. The rifles shoot better than I can.

[keith44]

Hi Ya JonnyReb,
I think the 1,600 fps and faster loads have no place in traditional muzzleloaders.  This is just my line of thinking, no rule, nothing to quote from, just me and my little broke thinker.


  At any rate those velocities were reached with black powder cartridges, both here and "across the pond".  The Buffalo cartridges benefited from a bit of tin mixed into the lead when it was cast, so did the even bigger Black Powder Express cartridges.  Still the velocity at impact with the target was the major factor.  Pure lead bullets do not typically fracture, hard lead alloys can but the velocity must be very fast.  Pure lead expands rapidly when driven much beyond 1,400 fps this limits penetration.  Harder alloys penetrate better, but may not expand.  It is a balancing act.

[coyotejoe]

Hi Ya JonnyReb,
I think the 1,600 fps and faster loads have no place in traditional muzzleloaders.  This is just my line of thinking, no rule, nothing to quote from, just me and my little broke thinker.

Most hunting loads with round balls will exceed 1600 fps, your .32 with 25 grains of 3f is probably pushing 1800 fps. Personally I would consider 1600 fps as a minimum to give a trajectory flat enough for a 100 yard point blank range. Black powder cartridges are another matter entirely since they are pushing long heavy conical bullets and can't be compared to round balls in any aspect.
With a .50 caliber round ball as little as 40 grains of 3f will crack the sound barrier and 30 grains will beat your high power air rifle which probably doesn't do 1,000 fps.

[JonnyReb]

When I chronied the 178gr roundball (.50)through my air rifle, I get about 700 fps. This equates to about 200ftlbs of energy, similar to a hardball .380. Using triple seven, 45 gr behind the same patched .495 roundball in a BP rifle gives me 920fps+/- and 65gr of T7 gives me 1300fps+/-. I'm guessing 55gr. Would approach the sound barrier and 90gr of powder would put me around 1600fps. Since the roundball isn't meant for 100 yard shots and the lowly .50 roundball from the 700fps airgun will penetrate a deer  vitals(broadside) and out the other side at close range, it doesn't seem like hopping  up a blackpowder ball much past the sound barrier is required for accuracy or killing energy. With a good shot of course. Not saying I intend to hunt deer with these low charges but for anything else the positives seem to outweigh the negative. J

[keith44]

Hi Ya JonnyReb,
I think the 1,600 fps and faster loads have no place in traditional muzzleloaders.  This is just my line of thinking, no rule, nothing to quote from, just me and my little broke thinker.

Most hunting loads with round balls will exceed 1600 fps, your .32 with 25 grains of 3f is probably pushing 1800 fps. Personally I would consider 1600 fps as a minimum to give a trajectory flat enough for a 100 yard point blank range. Black powder cartridges are another matter entirely since they are pushing long heavy conical bullets and can't be compared to round balls in any aspect.
With a .50 caliber round ball as little as 40 grains of 3f will crack the sound barrier and 30 grains will beat your high power air rifle which probably doesn't do 1,000 fps.

You are correct, I was thinking of my .54 x .54 double rifle that shoots 425 (ish) grain bullets nicely when pushed by 85 grains of 2F for aprox 1,400 fps (chrono'd 1,427 fps average)


My .32 with it's 41 inch barrel actually achieves 1,965 average with 25 grains of 3F Goex.
 
So...I guess it depends on the projectile...

[lakota]

You should try some real black powder. My buddy uses Triple 7 and I use Goex 3f. We bothe notice that Triple 7 has more of a sharp crack than the the Goex does.

[JonnyReb]

 Good advice thanks. I did read that T7 should be reduced by 15% to equal 2f BP. Makes sense it might be quieter. I was planning on trying some real BP soon as I locate it locally or worst case will end up ordering some. Appreciate that input.  J

[lakota]

I used to shoot 2F blackpowder. When I went to 3F blackpowder I noticed it also had a sharper crack than the 2F but I use less 3F per shot and it seems a bit easier to clean up after shooting. My buddy just found a can of 3F Triple 7. He has always shot 2F Triple 7. The 3F Triple 7 looks about like 4F blackpowder. The next time we go shooting I am going to try some in my flintlock just to see if it will ignite. Triple 7 sure seems to be a great improvement over Pyrodex.

[JonnyReb]

Hey thats good stuff too thanks. I was going to have to search out BP for a new flintlock myself and look forward to hearing of your results. I'll bet it (3F-T7)does pretty good. I'd use it in a heartbeat over the real thing if it were reliable. Think i'll google that and see what the consensus is. J

[coyotejoe]

Referencing the Lyman BP Handbook, 2nd edition, for the .50 caliber 28" barrel with a .490" ball they list no loads lighter the 40 grains With 40 grains Goex 2f they got 1196 fps, with Goex 3f they got 1332 fps, with Pyrodex RS it was 1190 fps and with Pyrodex P 1256 fps. So to be subsonic with any of those powder you would have to stay somewhere under 40 grains. To get a .50 caliber ball down to air gun velocities I don't know, I never tried loading that light. I recently shot my .45 caliber pistol with only 15 grains of 3f and clocked over 900 fps. Now that was only .45 caliber but also only a 10" barrel, I'd not be surprised if a .50 caliber rifle would do about the same.

[JonnyReb]

 Hey thanks Joe. Looks like my old powder may be the reason for my slow velocities, I can't think of any other reason. Look too, like when I buy new powder, I may have to switch to conicals/slugs to stay subsonic. This will hopefully increase energy signifigantly while allowing safe powder charges. Thanks for that info., jeff