First try with .223 Rem CB Load

[avan47]

This was my first try casting boolits for my .223 rem. The rifle is a Rem M700 Light Varmint, and is more accurate than I can shoot it. The boolit is the new BATOR mold with Gator gas checks seated while sizing in a Lee .225 die. I tumble lubed, sized, and tumble lubed again using the 45/45/10 Xlox lube as posted on this site. I was surprised at how easy it was to size and seat gas checks with the Lee die, as my old fingers don’t pick up small items very easily. The BATOR mold is not broken in yet, and I had a lot of trouble casting good boolits. About two-thirds of them went back in the re-melt can. A boolit that small is difficult to cast with a bottom pour pot. I may have to adjust the flow rate down a bit. The alloy was about 50/50 ww and pure lead, with a small piece of bar solder to add a bit of tin. I do not have a .22 M-die, but I had no problems seating the boolits with my RCBS seating die. I used the same seating die setting that I used for the Sierra bullets. The picture shows how they compare better than I can explain it. Rifling engraves the nose of the boolit on chambering, but the seating depth is not affected by chambering, ejecting or recoil (not much of that) while in the magazine. After shooting 9 rounds, there was no trace of leading. The load was 11.6 grains of Rx7 for about 1900 fps. There was a lot of variation in the velocity. The first 4 rounds produced about a 9 inch group. I shot the last 5 rounds from a more stable shooting position, and an image of the target is attached. The weight of a sample of the boolits was from 52.9 gr to 53.9 gr. I don’t know if this is the cause of the vertical stringing. Is Reloader 7 a position-sensitive powder? I will try another load with weight sorted boolits to see if that makes a difference. I am also interested in trying other powders for a more accurate load, and to try to push the velocity up to about 2100fps. Any suggestions?30842

[avan47]

Here is the target. The grid is quarter inch.

[stubshaft]

Looks like you have the big nose version of the Bator (Bator v3). If you seat it off of the rifling the GC will be protruding into the case. I would suggest you get yourself an "M" die as you are probably also swaging the boolits down when seating it into the case. Use a faster powder, RE 7 is on the slow side. I have had better results with 2400 and small PISTOL primers. Unique is also a good powder but have switched to AA#5 as it has the same burning rate in most cartridges and meters well.

[Larry Gibson]

avan47

What is the twist of your M700 barrel?

Are you using a chronograph or guestimating the "about 1900 fps"?

I concur with getting the M die.

Larry Gibson

[avan47]

I think the twist is 1 in 12. I think that is the standard twist for the Rem M700 in .223. Chronograph. Mean = 1909, Hi = 1975, Lo = 1806, St. Dev = 59.70

Midway USA has the Lee Universal Cast Bullet Expanding Die on sale. Does anyone know if that tool is worth buying? I shoot a lot of different cast boolit diameters.

I don't want to seat the boolit deeper. I think having the rifeling engrave the nose of the boolit is a good thing as long as I work up my loads. I don't want the top of the gas check protruding below the neck of the cartridge.

Will the case neck swage a gas checked boolit? I would think the gas check would prevent that.

[NHlever]

I have a Remington SPS in .223 that I've been shooting cast boolits in. I've been using Unique, Red Dot, IMR 4227, A-2400, and AA-1680 with good results to the velocities you are looking for. I actually did more work with a CZ 527, but have since sold that gun. In the Remington, 9.0 grains of A-2400 with the Lyman 225415 55 grain boolit, 6.0 Grains of TiteGroup with the 225415, and light loads (3.0 to 4.5 grains) of Red Dot have worked the best producing sub 1" five shot groups at the 50 yard range I can get to in the snow. I also have the obsolete Lyman 22596 55 grain mold, and that hasn't produced quite the same groups, but they are close. Good luck with yours! The .22 calibers are sure fun to play with using cast bullets. I had a Ruger 77/22H in .22 Hornet that I shot a lot, but eventually got talked out of it by a friend at the range that thought I was having way too much fun, and he needed to share it.

[Larry Gibson]

avan47

I think the twist is 1 in 12. I think that is the standard twist for the Rem M700 in .223. Chronograph. Mean = 1909, Hi = 1975, Lo = 1806, St. Dev = 59.70

I've been shooting similar bullet, the Lyman 225462, for many years in my 12" twist M700V. You should be able to sneak up to 2200+ fps with very good cast bullet accuracy if yours is a 12" twist also. The chronographed velocity is telling you that the ignition is not consistent. The vertical spread was saying the same thing. If you want to use RL7 I suggest a 1/3 - 1/2 gr tuft of dacron over the powder to keep it positioned uniformly over the primer. Try that load again and work up in .3 gr increments and see if accuracy doesn't get better before it gets worse again (above 2200 fps. I use H4895 in my .223 with that twist and bullet. Start at 17 gr and work up the same way. Use the dacron filler also.

If you don't want to shoot that fast then many faster burning propellents will give you very good accuracy in the 1500 - 1800 fps range. The reduced charge of RL7 just isn't doing that in your present load.

Midway USA has the Lee Universal Cast Bullet Expanding Die on sale. Does anyone know if that tool is worth buying? I shoot a lot of different cast boolit diameters.

The Lee tool only flares the case mouth where as the Lyman Mdie will uniformly size the inside of the case neck and with put a nice step just inse so the bullet can be started there and will seat straight. That is important, especially trying to put that little bullet in that little hole.

I don't want to seat the boolit deeper. I think having the rifeling engrave the nose of the boolit is a good thing as long as I work up my loads. I don't want the top of the gas check protruding below the neck of the cartridge.

That's the best, don't change.

Will the case neck swage a gas checked boolit? I would think the gas check would prevent that.

Depending on the hardness of the case necks the neck can size the GC or spring back down after the Gc passes and swage down the softer bullet. That's another good reason to use the Lyman M die as it will uniformly expand the inside of the case neck for a proper neck tension on .224/.225 bullets. The Lee does not.

Larry Gibson