I was reading my shooting bible last night "THE MODERN SCHUETZEN RIFLE' and came across the chapter on shooting sub-sonic. Sounds almost too good to be true is anyone doing that these days? I have'nt read much about it other than in the "BOOK". Seems like a lot of good ideas there, I know that I have shoot some very good groups with a .22 rimfire at 200 yards and have shot with a few people that shot sub-sonic in the BPCR game out to 500 meters and they did well, very well at times. I'm presently shooting a 32-40 with a 14" twist and at this time trying to push them about as fast as possible trying to beat the wind maybe I'm going the wrong direction? Anybody have any thoughts on this?

Richard

Sub sonic has always been out there and few people have done well with it. Our Club 200 yard Single Shot offhand matches one good shooter uses Trail boss in 38/55's sub sonic.  In fact the club record was with his sub sonic 38/55.  I shoot all the time with a super sonic 38/55 load and when the sub sonic load beats me it's the shooter not the load that did it.

Personally I don't think sub sonic is any advantage. Show some solid results in bench rest matches may change my mind.  Schuetzen 32/40 I want the bullet to stay super sonic all the way to the target.

Boats

Mike 
Wayne Schwartz's friend Garet Garrett was shooting his everyday rifle in 30 Schwartz with a 1-14 twist Douglas barrel with breach seated bullets of 1-30 alloy, Emmerts lube, a 204gr bullet 1.160 in length at 1025 fps using 7.4grs of AA-9 of which the Greenhill formula does not support and he shot his smallest group to date at 200yds with 6 shots in the 25 ring that could be covered with a quarter and it does not mention if he did or did not shoot any additional shots other than those six mentioned in his first round of testing. 

J.Louis

I've had some reasonable results shooting subsonic loads in .30 caliber rifles and pistols. This mostly with Unique, wad/no wad, 314299.
Mike Barret says that SR4756 is the powder to use, that he and friends have been shooting very small groups with it. I recently got a bottle and will work on it.
314299 at 200 gr. in 12 twist guns does not keyhole down to very low velocities-shooting 12" below normal 1400 fps loads at 100 yards.
We think subsonic is good because of the wind drift effect and because of reduced recoil. But velocity variation is the enemy of this thinking.
Experimentation continues.
joe b.

I have a #2 Ballard in 32 Ballard long which is pretty accurate at 1070fps just off the muzzle, checked with a shooting chrony.  I'm still working at it, but subsonic speeds are supposed to keep one away from the buffeting that ocours when supersonic bullets enter the transonic zone.  So, if you can keep it supersonic all the way out to two hundred yards, you're good to go.  If not, the theory goes, you're better off to go subsonic all the way.  The Postell bullet is pretty popular amongst the sillywet guys because they can't stay supersonic all the way out to the rams.  And those guys almost all use black powder.

Sub-sonic was a fad that ran for a while. I know that Wayne and Garrett played with it I also remember Dean Popma fooling with it. The reason that it is not more popular today, I think, is a combination of a couple of things.
First it is counter intuitive after centuries of pushing the envelope looking for more speed we are somewhat conditioned to think that speed is the answer and experiments with less speed are quickly dropped when a lack of results confirms a preconceived notion.
At roughly the same time period people were making semi-spitzer bullets work consistently for the first time. I can remember when I first started being told that only those flat pointed bullets of the "Pope type" would work in our rifles. Guys like Jerry Barnett were at that proving them wrong. Tighter twists, and faster speed along with the semi-spitzer were proving a success. 
Wayne's account of the subsonic experiments doesn't mention bullet shape, but I strongly suspect that a more traditional flat point bullet was used. When others tried sub-sonic loads with the semi spitzer bullets they were already having success with and didn't get what they expected they soon dropped the idea and returned to speeds that maintained super-sonic levels till impact. I just think they failed to consider the effect of point shape on stability and when initial experiments showed poor performance, instead of exploring all the options they stopped and went back to what was giving them success in their preconceived direction.
For a better understanding of the point shape to velocity relationship re read Harvey Donaldson on the subject. I know Harvey can be a gas bag but that doesn't mean that sometimes he isn't right.

40 Rod

I have seen some amazing targets shot at 200yds with a rimfire rifle in varied shooting disciplines utilizing sub-sonic ammunition and the majority of them were shot in the prone position. In days gone by we used to shoot some 200yd rimfire Schuetzen bench rest matches of which were a hoot to shoot with the exception of trying to locate the bullet holes especially in the presence of mirage and the scores were remarkably high.

J.Louis

Subsconic will work but, you have to approach it in the right way to take full advantage of it. The wind drift advantage can only be maximized with the right bullet shape and the load has to have a very low extreme spread. The rifling has to fully stabilized the bullet. If you have those three thing under control you'll be successful. Sounds easy but, it's not! You have to dedicate a rifle and barrel to it, that's number one. The greenhill formula comes closest to predicting a twist rate for any bullet that you want to shoot in the subsonic range but, don't use the upper limit on it. i.e. if it says that a 1.03 long bullet is the max length that will stabilize in a 15 twist, .321 barrel, go 5% under that. Not all 15 twist (or any other twist rate) will be right on the money (Douglas only guarantees within 1/2 inch), when your working on the limit, you have to be sure so, I'd either go with a 5% reduction in length or 1" faster twist
 
In my case, I used a 1.19 lg spitzer bullet (430 gr) in a 20 twist, 1.15 full octagon 31" long Douglas barrel mounted on a Sharps Borchardt. I did not buy the barrel to do subsonic work or I would have ordered a 18 twist. My best load was 10.0 gr Unique, 971 fps, 19 ES, 6.9 SD, no wad. I got a .84 group with that combo @ 100. It's a comfortable load to shoot in my 15 lb gun

The old style flat point bullets will handicap you, a lot. You need a aerodynamic shape, similar to the modern spitzer shapes that we use but, with a radius nose of at least .030R. That with a 4 to 6 caliber ogive will get you a bullet like you need. Sectional density will then be a factor of the length of the bands and of course, the higher the BC the better but, you have to increase the twist rate to match the overall length. The two things you don't want in a subsonic bullet is a flat or a sharp point. A .060 to .080 flat (32 cal) is better than the larger flats of nose pour bullets and may be better than a sharp point but, you need a radius for best results