Ar-15 cast velocity

[silverjay]

Been working on a load for the ar using 4064 and the NOE 55 grn boolit. Have good function and groups between 1 and 1 1/2" at 100 with a five shot group. Average velocity over the chrono is 1968 plus or minus 25. How does that velocity compare with what others have seen?

[Larry Gibson]

Seems about right. What barrel twist?

Larry Gibson

[silverjay]

1/9 twist

[Wayne S]

Good results, Have you tried any other powders ?

[Larry Gibson]

1/9 twist

That is about right then.

Larry Gibson

[Gunnut 45/454]

Your runnin a little faster then I do. But I also shoot them out of my 1:7" twist and any faster then 1900 fps accuracy goes to hell! I get the same accuracy from my 1:9" as you do can easily get 10 rounds on a 9x11" target at 200 yards as well usually about a 6" group.

[silverjay]

Good results, Have you tried any other powders ?

I have not. Was trying to stay with powder that I already have a use for.

[cmdrted]

Try any medium burn rate rifle powder ie 2230 3031 4895 and a little slower 2520 and cfe 223. start at a magic number of 18.0 grains. tweak it up or down to accuracy. The fastest I can drive them with a noe 62 grain linotype boolit is about 2100 +/- 50 fps. accuracy starts falling around 2200 and leading with this boolit starts to build. groups measure @ 1.25 or less from a bench and a old handle scope mount and tasco 3x 10. I size to 225 with a lyman 450 and any gaschecks. copper seem to be fractionally better than aluminum. My twist is 1-9

[cmdrted]

Also the range is at 100yds! The gun is a franken ar standard A2 heavy barrel bushmaster LOWER. no muzzle break. Full length sized and lee dies.

[TCLouis]

Wonder how that would work with an old slow twist barrel?

How much 4064 have you been stuffing behind that boolit?

[Larry Gibson]

With 10 shot groups at 100 yards out of the 20" barrels of my 3 ARs using 60 gr cast over medium and slow burning powders accuracy runs 2 moa out of the 12" twist at 2200-2300 fps and at 1900-1950 fps out of the 9" twist. I do not expect other than usable accuracy out of 7" twist ARs above 1500-1600 fps which is where functional reliability with medium - slow burning powders is usually found as with my 7" twist AR. I've found 60 +gr cast bullets work best.

Larry Gibson

[Boolseye]

I'm pushing them harder than that–same boolit, 22 grains of VV530, over 2500 fps (one chronoed at 2725). No significant leading and good accuracy after about 30 rounds. My home-build AR seems to like it, 1-9 twist barrel. staying accurate at 50 yds, haven't tried 100 yet. Just havin' fun.

[Larry Gibson]

What is "good" accuracy at 50 yards with fast twist ARs can be poor at 100 yards and atrocious at 200 yards.

Larry Gibson

[runfiverun]

little girl routinely shots her 1-9 twist at a tick over 2700 she shot several 1.7-1.9" groups at the Nevada cast boolit shoot in front of everybody over the week end we were there.

measuring stuff and making it fit closely isn't that hard.
I get better [much better] groups in my 1-8 twist but only at 2600 fps with a different boolit.
I do actually have a scope on mine.

[HARRYMPOPE]

my M4 profile 1-7 Mossberg melonite lined barrel and 17g of Surp 4895 and my 62g Eagan looks like it will be OK at 50 (2" or so) I loaded it for the kid to save money as he shoots too fast.This is with a 4MOA dot sight.

George

[Nickle]

What is "good" accuracy at 50 yards with fast twist ARs can be poor at 100 yards and atrocious at 200 yards.

Larry Gibson

There's a lot of folks out there that just don't understand the truth in that statement.

[Larry Gibson]

Ain't it the truth. ........

Larry Gibson

[Gunnut 45/454]

Speed isn't the biggest factor that I've found to getting accuracy with these little Boolit's! The number one factor to accuracy is the boolits can't, I repeat can't have any defects! So one must get the alloy just right in temp and mix! Cause they must fill out the mold prefectly. Correct sizing goes along way, both my AR's are tight bores so .225" works for me , slugging a .22 bore sucks. But if your not getting good groups you may have to slug your bore. Mine are also chromed bores. A non chromed bore would probably work better .

[Boolseye]

Seeing the wisdom (not to mention the powder savings) of loading my AR rounds at the previously suggested velocities.
15 gr. of Reloader 7 seems to be right in the ballpark (1900-2000 fps). Good thread, thanks.