Home Forums Reloading Bullet Casting Bullet instability

Interesting phenomenon I’m trying to work out. Been shooting a lot of 38 special lately. Standby load is the 358429 at about 10bhn, sized .357 and lubed with RCBS green, on top of 5gr of Unique. Bullets are filled out fine and I haven’t been able to find any odd weights indicating casting flaws. No leading after a couple hundred rounds leads me to believe bullet fit is pretty good.

Shooting them last weekend out of my 6.5” 38/44, 6 shot groups at 30 yards had no problem staying on a 3” plate from sitting. When I’d shoot at 75 yards from the same position with the same sight picture I’d get 3 or 4 out of a cylinder on the 8” gong and have a couple that would be wide of the target by up to 2 feet! Thinking it was me I proceeded to put 10 out of 12 on the same gong from my Single Six and all but one of an 8 round magazine from my 1911 .45. I shot 100 rounds of that load and it was always the same, not even near enough misses for me to suspect my shooting.

I know Keith talked about some cast bullets becoming unstable as the range increased with unpredictable wide flyers. But of course this doesn’t happen with his bullet designs! I’ve tried different hardness and slower as well as faster loads with no change. I have a RCBS 38-150KT mold coming and I’ll give it a go as soon as it shows up.
Anybody have any bright ideas?

The 358429 will become unstable in flight. The 358439(same bullet with hollow point) will shoot a long way. Is interesting to test various bullet designs. Still air or at least a light breeze can let a bullet be sccurate at long range. Try the same bullet/load quartering into a stiff wind can show instability.
We have turned samples on a lathe, loaded and shot until we got accuracy at 375 yards. That happened to be the distance to a ram target south of the house.

I’ve got a 358156HP but it’s pretty slow work making them plus fiddling with gas checks, too slow for shooting rocks and plates on a Sunday afternoon. Is the 38-150KT going to be any better or more of the same?

The 358156hp is a good bullet i think. I killed a trophy doe antelope with one. Shot was under a hundred yards , through the shoulders and exited.
The rcbs 150 kt might be ok, try it. Most of what we’ve tested has been in 45 colt and bigger.

Kid , I shoot all 3 of those designs and don't have any instability problems. I think they are the best cast designs out there. I've shot thousands of the RCBS 150 KT which with the alloys I use weigh close to 158 grs. 800 -1100 fps no problems. Last year at a gun show I scored a new Arsenal Mold for #358429 5 hole gang mold. Slick and very productive. Last Saturday I ran over 1000 of them in about 4 hrs. I have the 358156 molds in solids and the HP version Skeeter Skelton swore by them as much as Keith swore by the 358429 bullet. If a person makes them too hard and they are too undersize I guess one might get leading and stability problems. MB

Like Skeeter and Keith too IIRC, I’ve started sizing my bullets .357 and I don’t cast anything harder than straight WW. I get almost no leading in a half dozen 38 and 357 revolvers and have always gotten good accuracy. It’s just when the range increases that I’ve noticed the flyers lately. Joe average handgunner would never notice since most guys don’t shoot much past the 25 yard line if even that far.

I like to use my revolvers for utility guns and always have one with an extra speed strip or two in the truck. I’ve shot a bunch of snakes and coyotes, pigs and other vermin with them. Sometimes you don’t have a rifle and you just can’t get inside the 25-30 yard zone.

Sounds like we do things about the same.... Although I prefer speed loaders and usually have a small coffee can of loose ammo on the floor for an adequate supply of course. I do size and lube mine at .358 sometimes .359. I have went thru a pile of loads in the past years with Unique powder both 38 & 357 . Right now I'm working on a case of HP-38 I got cheap at a gun show couple years back. Gonna do some 357's with the Thompson bullet (358156) gas checked with a good dose of 2400 and see how that works out, warm but not hot. A good revolver is a joy to use, accuracy and the speed is only controled by the skill of the user what's not to like ? Simply one of the better things in life that is not financially beyond the means of an ordinary guy kinda like good plain food and a cold beer. MB

There are numerous iterations of the 358429 and there are also sizing factors that can unbalance a bullet (even perfectly good ones before they're sized). They could also be garbage right out of the mould and if they are out of a Lyman, they are suspect in my book, especially newer moulds.

Handgun bullets should be sized nose first if one is looking for extreme accuracy at long range. Keith bullets especially, since misalignment with those designs is difficult to see, but they are surely there. Bullets going from .360-.359 sized in most .357 dies are going to exhibit nose yaw when sized based first, even if they "look" good. Round driving band designs are easy to spot unconcentric sizing and even block misalignment. Square bands are a lot harder to detect.

I routinely use the NOE version of the 360429 at 100 yds. in an 8in. Model 14 and a 38/44 Outdoorsman with moderately heavy Longshot loads. Bullets are sized .358, but I use a Star sizer.

It might be a bit much, but check your bullet run out on the nose. It might surprise you....

Or use a Lee push through sizer for sizing and installing checks and lube in an oversized die in a lubesizer. I don’t shoot handguns much but it works very well for my rifle bullets.
Good luck,
Rick

ever considered the twist rate and length of you bullet? Try a shorter bullet and see if you still get the same results.

Try to recover some fired bullets and examine them. My guess is that you will find some residual lube on them. I had this happen with rcbs lube and it will cause flyers. I switched to a soft lube for my pistol bullets and accuracy is much better.

Try a little hotter load. 5.0/Unique is warmish, but most 358429s I've worked with have worked better with fairly hot loads. You're still below 38/44 levels right now. The earlier post about all 358429s not being created equal is dead on. Lymans fiddled with this design so much over the decades that nobody really knows what an original 358429 is supposed to look like.