Cast in AR

[Gunnut 45/454]

Well as you know I got my Lyman 55 gr mold awhile back now that I have GC's I've been working on a load for my AR's. Already had this load made up for some comercial Cast I bought. It function the action well and is fairly accurate to about 50 yards in my 16" DPMS carbine. But you can forget 100 yards! This load is pretty good in my Sav Hunter 11 at 100 yards about an inch group normally! Well I loaded some of the Lyman cast at 19gr IMR4895 like the others! I didn't take in to account for diffferent design- loaded them to long and first range trip was a bust -action wouldn't close! So got back and seated them shorter and actually function checked them this time! Since I have to seat them deeper I think I can get away with a lighter charge -only fired 8 rounds as it was cold out. Next load is going to be 18.5 grs hopefully with better group.

[Andrew Quigley]

I wondered if anyone casted for AR rifles. What kind of velocity can you expect?

[garym1a2]

I want to get into cast also. I just worry my carbine twist is too fast. Its hard to find 1:12 twists barrelels.

[Calamity Jake]

Here's a cople of groups I shot out of my heavy barrel 1 in 12 twist Rock River AR15

15 rounds per group.

[Gunnut 45/454]

My DPMS is 1:9" twist, my next AR is a 1:7" the Colt MT I had was 1:7" and it actually shot cast better then the DPMS . My Savage Hunter 11 is 1:9" as well. Though a slower twist should be better for cast thats not to only factor for accuracy. Unfortunately my chrony bit the bullet-literally! These are probably 2000-2100 fps range. As you need to be going around that speed for function purposes in an AR. I'd say in my non expert opinion you need 40000 plus PSI to get proper ejection/loading. For close range plinking/hunting/target shooting is my goal. I'm a cheap bastard so if I can get it done with a cast bullet all the better! Now I'm going to reduce the charge to see 1. can I still get proper fuction. 2. improve the accuracy some. If I can get it to about 1-1.5" at 50 than it should be good for some 100 yard or so target/ hunting. A nice close range yote /jack bunny round!

Jake
Nice groups! What cast bullet you using?

[Dschuttig]

I've shot thousands of cast bullets out of my Rock river 1:9 standard a2. I had originally bought the lyman 225646 (tapered bullet with 2 grooves in nose, I think that # is right). Behind anywhere from 18-21 grs h4895 it shot Ok, but always had fliers. I got a used lyman 225462 which shoots much better with very few fliers. I can get around 1.25" at 50 yards with 20-21 grs 4895. Dan

[400short]

new guy here, trying to learn about casting. Why would a lead bullet respond differently to twist rate than a jacketed bullet? I see mention here that twist rate is a concern. It seems to me that a J bullet will operate in all twists mentioned above, whats different about lead?
Thanks

[Calamity Jake]

Lead can be shoot with all twists just the fast ones require shooting them slower as the boolit will try to skid the rifling instead of being grabbed by it, if it skids accuracy suffers.

Read some of the archives here for cast in a 96 Swede for more info.

[400short]

OK, Thanks Jake. That makes sense. I shoot quite a bit of 223 for NRA hi-power. I use a 75 gr. bthp at about 2770 fps in a 1/8 twist barrel. Somewheres I've seen a statement that lead can be pushed to about 2700fps. I'm assuming this is the hard stuff, BHN what, 20+? It would be great to be able to shoot practice cheaply. I'll chase down the thread you mentioned.

[Gunnut 45/454]

400short
Yep you have to run straight Lino probably to get them that fast. Good luck in finding a heavy mold!

Anyway did my test with 18.5gr IMR 4895 and the Lyman bullet- again 16" DPMS at 50 yards temp 32 very little wind and I'm quite pleased with what I got for a group ! I figured the first ones were going to fast -they were ! Dropped the .5 gr and as expected the group tightened right up. I had two shooter induced flyers as it was shot fairly rapidly to ensure fucntion! I really like the thought of reloads for under $.10!

[trench]

CAn I ask why the trouble? If not full power/range, why not just use the .22lr conversion unit?

[Larry Gibson]

new guy here, trying to learn about casting. Why would a lead bullet respond differently to twist rate than a jacketed bullet? I see mention here that twist rate is a concern. It seems to me that a J bullet will operate in all twists mentioned above, whats different about lead?
Thanks

Cast bullets are not as well balanced as match jacketed bullets and during accelleration to high velocities they become even more imbalanced. They do not "skid" or "strip" in the rifling at HV as some believe. Bullets from faster twist barrels at a given velocity will have a higher RPM rate. The centrafugal force of the higher RPM causes the inaccuracy above a certain level of RPM. That "level" of RPm depends on numerous things but you can't push it to much or inaccuracy is the result.

Easiest way to get accuracy at HV with cast bullets is to control the RPM by using the slowest twist which will still provide rotational stability to the chosen cast bullet. With fast twist ARs in 223/5.56 the best accuracy will come with medium or slow burning powders at functional reliability. You'll get higher velocity with better accuracy the 12" twist or better yet with a custom 14" twist barrel. I push the 225462 to 2350 - 2400 fps out of my 12" twist AR and maintain 3 MOA or less accuracy with 20 shots which is equal to many lots of M193 type ball ammo.

Larry Gibson

[45 2.1]

Everbody seems to have a reason they can't get as good of accuracy after a certian spot. One excuse is as good as another I guess. Don't believe much of what you read or see if you hear such excuses. The choices you make determine what happens to your load......... it's your fault if it doesn't work.

[Dschuttig]

Cast bullets are not as well balanced as match jacketed bullets and during accelleration to high velocities they become even more imbalanced. They do not "skid" or "strip" in the rifling at HV as some believe. Bullets from faster twist barrels at a given velocity will have a higher RPM rate. The centrafugal force of the higher RPM causes the inaccuracy above a certain level of RPM. That "level" of RPm depends on numerous things but you can't push it to much or inaccuracy is the result.

Easiest way to get accuracy at HV with cast bullets is to control the RPM by using the slowest twist which will still provide rotational stability to the chosen cast bullet. With fast twist ARs in 223/5.56 the best accuracy will come with medium or slow burning powders at functional reliability. You'll get higher velocity with better accuracy the 12" twist or better yet with a custom 14" twist barrel. I push the 225462 to 2350 - 2400 fps out of my 12" twist AR and maintain 3 MOA or less accuracy with 20 shots which is equal to many lots of M193 type ball ammo.

Larry Gibson

That's about the same accuracy that I'm getting with my 225462 in a 1:9 twist. I could obviously get better accuracy out of match grade bullets, but at 9 cents each, how can you go wrong? I save good steel cases, load them with the 225462 and shoot tin cans while camping with my buddies, it's cheap and I don't have to chase brass. Dan

[ebner glocken]

I've never tried cast in any of my ARs. What does your gas system look like? How many rounds roughly does it take to foul it?

Ebner

[runfiverun]

so far about a billion.
seriously the rifling and chrome bore give me more accuracy/velocity issues than the cleaning.
i like shooting lead in the ar but if you buy in bulk you can get fmj's for about 9-10 cents each.
i keep the lead in the bolt gun and keep the accuracy along with the velocity.
i can actually shoot better groups in the bolt gun with cast than i ever could with jaxketed.

you don't need super hard lead to make things work i actually found better accuracy after cutting lino down to my 4/6/90 alloy.

[Larry Gibson]

Everbody seems to have a reason they can't get as good of accuracy after a certian spot. One excuse is as good as another I guess. Don't believe much of what you read or see if you hear such excuses. The choices you make determine what happens to your load......... it's your fault if it doesn't work.

Yup...that's my "excuse" for such accuracy with the short sight radii and my tired old eyes and I'm stinking to it By the time I get enough lens to see the front sight clear on the AR the target is pretty blurry...........

Now in my M700V with 12" twist the same load does 1.5 moa or better (talking 20 shot groups here 45 2.1) but then it's got a 20X scope on it. I suppose I could pick 5 of those shots or even 10 of them and claim some pretty darned good sub moa accuracy. But the truth is it's a 1.5 moa load all day long so I just call it that......

Larry Gibson

[Idaho Sharpshooter]

45 2.1,

possibly, if those "choices" you refer to do not include twist rate, and the accuracy potential of most commercial AR-15's commonly encountered. Most are built to the .125"+/- tolerance level.

Rich

[garym1a2]

I have done a few internet searches and cannot find a 1:12 twist in a 16 or 18 inch barrel, any hints.

Cast bullets are not as well balanced as match jacketed bullets and during accelleration to high velocities they become even more imbalanced. They do not "skid" or "strip" in the rifling at HV as some believe. Bullets from faster twist barrels at a given velocity will have a higher RPM rate. The centrafugal force of the higher RPM causes the inaccuracy above a certain level of RPM. That "level" of RPm depends on numerous things but you can't push it to much or inaccuracy is the result.

Easiest way to get accuracy at HV with cast bullets is to control the RPM by using the slowest twist which will still provide rotational stability to the chosen cast bullet. With fast twist ARs in 223/5.56 the best accuracy will come with medium or slow burning powders at functional reliability. You'll get higher velocity with better accuracy the 12" twist or better yet with a custom 14" twist barrel. I push the 225462 to 2350 - 2400 fps out of my 12" twist AR and maintain 3 MOA or less accuracy with 20 shots which is equal to many lots of M193 type ball ammo.

Larry Gibson

[45 2.1]

Yup...that's my "excuse" for such accuracy with the short sight radii and my tired old eyes and I'm stinking to it By the time I get enough lens to see the front sight clear on the AR the target is pretty blurry...........
Larry Gibson

More of the same............. Where's your flattops in this. Dschuttig just posted his results with a 9 twist. Seems he is doing a lot better than you are.

45 2.1,

possibly, if those "choices" you refer to do not include twist rate, and the accuracy potential of most commercial AR-15's commonly encountered. Most are built to the .125"+/- tolerance level.

Rich

Rifle and load choices are all included. Seems you would realize this since you have custom too. Commonplace ARs do very well now and are quite accurate........ 7 to 9 twist especially.