I pretty much exclusively shoot black powder in my single shots but have decided to give SR-4759 a try in my .32-40.   I can see why schuetzen riflemen made the switch.

I shot one target a while ago to get my feet wet, using 14.3gr of SR-48759 and placing a wad at the case mouth.  The resulting 200m target was pretty embarrasing.

Today I decided to try again, based on recent advice on this forum to ditch the wads.  I started with a lower powder charge of 13.0gr and the results were less than impressive, but much better than my earlier attempt.  I then moved to 13.5gr and the group improved significantly.  There is still considerable work to do, but this resulted in a 9 shot group of 1.8" high and 2.1" wide at 200m.   I'm pretty happy so far considering that this is only the 3rd target I've shot with smokeless using this rifle.  The results are on par with my best black powder load using Swiss 1.5.   

The one thing I found puzzling was that there was a large difference in elevation between the 13.0gr and 13.5gr loads.  The lighter load was well centered on the 25 ring, while the heavier load was about 5" higher.  Is this normal with smokeless to see more than 2 moa of sight change with a 0.5gr charge increase, or maybe just indicative of poor combustion at the lower charge?   

For those interested in the details:
Rifle is someone else's old Ruger #1 bench gun in .32-40 with a Ron Smith barrel.

The target was shot with a single case, CCI BR2 primers, pre-weighed charges, a Hoch 20:1 200gr bullet lubed with SPG.   

Chris.

Make a case scraper from a nail. Scrape your case occasionally. Without a wad on 4759, might get soot buildup in the case. The lower the powder charge the heavier to soot will be. 

Nice looking group. If centered on the target would post 245 5c, maybe?   

Not bad at all. 

       Joe.

Very nice shooting. I use 4759 In my 8.15x46r rifles and have found that having powder forward in the case improved accuracy but lowers velocity, maybe powder position caused you impact change.

Dale

Craigster, I do know about 4579 being discontinued, but I've got a can and a half here that I used to shoot in .45-70 lever guns but figured it'd be more fun to shoot it up in the .32-40.

Chris.

Old standby advice is 4227 for 32/40 and smaller 4759 for 38/55 and larger

Few years ago I went away from that formula using 4227 in the 38/55 just because it measures better.  No real reason 4759 won't work in the 32/40 if you get it right. Rule of thumb is just that, can be pushed if need be

Most 32/40s work best supersonic all the way to the target about 1450 fps at the muzzle.  Might need to boost your 4759 loads up to that level. Other old advice is 4759 works well until it gets overloaded then spikes,  pressure increases faster than the charge weight would indicate.  Guessing that’s not an issue with 1450 fps 32/40 loads but keep your eyes out for pressure signs anyhow

My take only somebody else probably knows more about it.

Boats

Reading your old posts on 13.6gr as a good load was what made me try 13.0gr and then up to 13.5gr.  I'm going to try my Brooks bullet ( which is not too far off from the Hoch one in shape and length ) and see what I can get out of it. 

Chris.

Relative quickness charts don't agree on 4227 & 4759 some put one faster others the reverse. I have found different lots may be faster than others.  In 32/40 cases either one about 14.5 grs is a standard 200 yard charge.   

Go slower long bullets want to tip. My rifles sometimes I go half a grain higher if the target shows oblong holes.  Bullet is going subsonic at about 200, some ranges are measured in yards others in meters most not measured with any precesion.  200 one may be 210 or 190 another.  Little tipping if it's the bullet going subsonic  just before impact won't hurt performance. I bump the charge up anyway. Oblong bothers me round does not.

Boats

gunlaker wrote on Dec 10^th, 2014 at 10:17am:


How long have you been trying?