Reloading Mysteries

I managed to get to the range today to test some new reloads for my Bergara .357 magnum.

I've had a bit of reloading experience, but up until recently I've just followed common recipes. However, I now have some 200 grain cast bullets I want to shoot at subsonic velocities, and ADI (my powder supplier) has no tested recipes for these projectiles.... so this is new territory for me. Thanks to folks here, and elsewhere, I have data for 200 grain projectiles using other powders, so I carefully compared the powders and data and came up with my own loads. I figured that a lot of the published data would have been for revolvers, and I would be using a relatively strong rifle for my load testing so I should be fairly safe. I reasoned that if the same model of rifle can also be chambered in .308, 7mm-08 and 45-70, then it should be strong enough for experiments where the desired outcome was a modest speed with a lead projectile.

I am likely to get other powders in the future, but meanwhile I have APS350 (similar burn rate to 'Red Dot'), Trail Boss, and AP70N (similar burn rate to 'Unique'). I have been using CCI 400 small rifle primers.

All powders give me acceptable hunting accuracy with 125 grain and 158 grain lead projectiles when shot at subsonic speeds.

I don't know if it is permissible to post personal load data on this site, so if it isn't allowed, feel free to delete it or tell me to edit it. I should note here that my batch of powder, my scale calibration and my methods may be different to what other folks may have or do, so always consult the manufacturer's reloading data before deciding how much powder to use. And be aware that some firearms are stronger than others. Never make assumptions about the substitution of projectiles, primers or powder.

The 200 grain cast projectile is still challenging me. I figure that the 16 inch twist in the Bergara barrel should work with this bullet. I have cut a cartridge case off at the point where the base of the properly seated 200 grain projectile would sit, so I was able to see what the maximum capacity was for each powder. There was plenty of space for the APS350 and AP70N maximum loads, but it limited Trail Boss to 4.3 grains.

According to my Dad's old Chrony, 4.2 grains of Trail Boss gave me a velocity from 803 to 846 fps. This gave me a three shot group of 1.25 inches at 25 yards. 4.3 grains resulted speeds of 845 to 878 fps, but the group spread out to around 2.5 inches.

4.2 grains of APS350 propelled the projectiles at 911 to 932 fps but the 25 yard group was spread over 5.4 inches. Not good. The primers appeared to be slightly flattened with this load, so I wouldn't load more of this powder even if the accuracy had been promising.

5.4 grains of AP70N gave speeds of 1041 to 1074 fps. This gave me a 3 inch group at 25 yards. Although the Trail Boss loads gave me better accuracy, I want all the subsonic power I can get so I raced home from the range and loaded up some cartridges with just 5 grains of AP70N. The velocity of these ranged from 1023 to 1064 fps... and they gave me a 1.8 inch group at 50 yards, which equates to a group of 0.9 inch at 25 yards. This is getting better.

Oddly I load 158 grain cast bullets with 5 grains of AP70N also, and according to my notes these travel at 1036 to 1093 fps which isn't a heck of a lot faster than the 200 grain bullets with the same load.

I think my next step will be to load cartridges with the 200 grain lead bullets and try a slightly lower load of AP70N... maybe 4.8 grains... to see if accuracy improves. I know I could experiment with lead hardness and maybe use jacketed projectiles, but I want to use soft lead as it is commonly available and has the greatest chance of mushrooming when it hits (although I am not expecting great expansion at 1000 fps).

In case it is of interest to anybody, here is how I lubricate my cast bullets: At present I am happy with 'Fryxell Lube"... a 50/50 mix of beeswax and Sta-Lube Moly-Graph grease (which I think I bought from Mitre 10). I mixed the ingredients carefully on a stove outdoors (it smells pretty bad)... then I poured some into an old Elastoplast tin. I load the cartridges with powder, then start the bullet into the case with the lower grease ring still showing. I then pack the lube into the grease ring (and often the crimping ring) using a painter's plastic palette knife. I remove excess lube with the edge of the palette knife, followed with a careful wipe with a bit of paper towel.... taking care not to remove lube from the rings. I can then seat the bullet knowing that the powder cannot come into contact with the lube.

I know that tumble lubing or sizer lubing would be quicker... and better for someone shooting a heap of bullets, but I don't shoot a lot, I don't like the stickiness of Alox lube, and I have no desire to own a bullet sizer. I've tried pan lubing but I have come to prefer my current method.

Applying the lube:
https://i.imgur.com/E4fp6qT.jpg

Excess lube removed prior to seating to correct depth:
https://i.imgur.com/6x9JGUO.jpg

The loaded 200 grain bullet next to a 125 grain bullet. The big bullet sticks out too far to feed through the action of my Rossi lever action... but it still fits the chamber without jamming in the rifling.
https://i.imgur.com/2WRiL6H.jpg

I'd like to be able to have a load for the 200 grain projectiles that will consistently give me a group of under 1.5 inches or smaller at 50 yards at a velocity of between 950 and 1050 fps. My .22 rimfires and my .223 will shoot much better than this, but I don't yet have the experience to know what a reasonable expectation of accuracy should be from a .357 with slow soft cast bullets. I might get to try some new loads this week.

Heavy projectiles need fast twist rates to stabilize. What have you got?

The twist rate in the Bergara is 1:16 inches. Hopefully that should be suitable. At least I haven't had any bullets hit the target sideways during the tests.

One thing I find intriguing is that my heavier bullets (going at a similar velocity to my lighter bullets) tend to group to the right. I had hoped that the big heavy Bergara barrel would keep things fairly constant. But no... it is all quite mysterious.

Heavy slow bullets will group to the right with right-handed shooters (or to the left if you are that way inclined). It is caused by the longer barrel time allowing your body to pivot slightly with the recoil before the bullet exits the muzzle. In pistols, slow heavy bullets shoot higher than lighter, faster bullets for the same barrel time reason, allowing the shooters arm to rise a bit with the recoil before the bullet exits the muzzle. It confuses the hell out of people because it is the opposite effect to what they expect.

At first look I thought they looked like .22LR.......Especially in the middle pic. I think you are on the right track with the AP70N. Sounds promising.

Smith & Wesson 38/357 mag barrels have 1:18 3/4" twist so your 16" Bergra is fine your 200 gr bullet really has the wrong shaped nose for good terminal performance
at subsonic velocity a HP is the best then a FP take a look at the Lyman Keith designed 358429 it performs well on animals, make your lead as soft as possible 50/50
Wheel weights and pure lead is as hard as you should go even then you may not get much expansion at full power loads, Don't try hot rodding your loads .357 mag
max pressure is 42.000 C.U.P Rifle and Pistol it is not the strength of the firearm it is the case, If you want high velocity look at Winchester 296 powder.

Thanks for the responses. I appreciate the very useful and encouraging information. I'd never thought about rifle 'twist' during recoil. When I shot the heavy bullets that grouped to the right, I was resting the rifle on sandbags with virtually no grip to counter the torque. I must try holding the rifle tight next time to see how much of a difference it makes. That info certainly helps to dispel some of the mystery.

I like the look of that Lyman 358429. Thanks for the suggestion. I will keep my eye out.

I am using what I believe to be fairly soft lead. I got a lot of leadlight 'came' scrap which I made ingots from. I do add a little tin in the form of skinny leadlighting 50/50 solder, but I suspect it doesn't always mix in well.

Yep, those .357 cartridges with lead projectiles remind me of .22 cartridges as well. I like the look of them.

Here is a picture showing three of the projectile types I have. On the left is a Speer swaged lead semi-wadcutter hollowpoint. I bought these from Reloaders. They didn't group consistently for me when using Trail Boss powder, but the one group I recently tried with APS350 grouped well enough for close-range subsonic hunting. I haven't taken them hunting yet. The middle bullet is the home-cast Lee 358-158-RF. This performs well. On the right is the new Lee c358-200-RF. The meplat isn't so big on this, but it should be better than a pointed nose.

https://i.imgur.com/8qwXGo9.jpg

Here is another question related to accuracy. Why do some powders seem to work better with certain projectiles at similar velocities? Can a faster powder sometimes deform the back end of a bullet before it gets underway maybe?

Yesterday I received my cute little muzzle forward suppressor from Waitaki Engineering and I was keen to try it out. The thread in the suppressor was perfect, and it screwed straight on with no hassles. I fired a few shots with the scope still on the Bergara and was happy enough with the accuracy. I then removed the scope and adjusted the open sights as best I could. I found that the rear sight was loose and could move from side to side, so I took it right off... cleaned it up... then refitted it with a big squirt of acid-cure silicone between the mating surfaces. It was secure after that. Although I would not generally be comfortable about shooting game at over 75 yards with this rig, I tried shooting a group at a five-inch paper disc set up at a hundred yards using my subsonic 200 grain cast bullets. I got a group of about 3.7 inches... which was satisfying enough considering the coarse, fluorescent open sights and the fact that I was covering the target with my foresight to allow for the distance. I shot an even smaller group with the Rossi Puma and 125 grain slow cast projectiles, but for some reason the point of impact was several inches to the right even though at 25 yards it hits centrally. It was getting fairly late at this stage and the light wasn't marvellous... and perhaps i had the gun on a cant. Dunno. Earlier in the day I made a video recording the sound of a shot through the suppressor: https://www.youtube.com/watch?v=-2tezDd8ty4

I've never had much luck with trailboss in small calibre, shotgun powders like blue dot, red dot and 700x or n 320 have always given better groups for me in 303, 3030, 310 cadet, 38 s&W and 38/55.
Old books pretty much all recommend unique, and 6 to10 grains seemed the default setting for rifle 3 to 5 for pistol. No filler needed, I suspect the sharp shove in the back got them to engage better with the rifling. I ran out of unique but have buckets of the others. Blue dot is best for supersonic loads there is a little unburnt powder below 1200fps.

When I first got interested in subsonics it seemed that Trail Boss was a simple and safe powder to manage... which it is. I started using pistol powder when I couldn't fit enough Trail Boss into my .357 case to give me 1050 fps. The pistol powders are cheaper per shot too. If I had to choose just one powder for reloading .357, I'd pick AP70N. I'll have to get some W296 or AR2205 if I want more velocity. All I really want to have is the ability to get an animal for the freezer occasionally, and I am well equipped for most common hunting scenarios. But there is a tempting array of calibres, powders and projectiles crying out to be experimented with. And when I go to the range it is easy to shoot off all the cartridges I have with me.

I use AP70N in 9mm, meters well and cleaning burning.

What is the velocity of those 9mm bullets Tikka?

Around 1020fps with 124gn (across the Lab Radar). Can go quite a bit faster but we wanted closer to minor PF.

Hmmm. That load with a good bullet in a short rifle might be a great choice for a subsonic hunting tool

I used AP70N in my 11.5" AR circle 10 before the govt confiscated it. 9mm too.