Accurate Load for AR 15?

[jdschwass]

Hey, I have been reading through this forum for a few years now, but never posted before. Recently I have been faced with a challenge, and hoping for some advice/suggestions.

I have recently begun casting bullets for my AR15. Despite many good discussions on the matter, I haven’t really been able to find any true accuracy tests that ended in success. My goal is that I can develop a load that is accurate enough for 3-gun training.
My rifle is chambered in 5.56, 14.5 inch barrel with a 1:7 twist rate, carbine gas system. I have the Lee 55gr. Mold.
I have been casting out of wheel weights, and water dropping the bullets for hardness. Then installing a gas check, and sizing to .225.
I have tested with both lubed, and powder coated bullets.
As a baseline, my rifle will shoot a 55 gr. Jacketed bullet at sub MOA.

I don’t keep a lot of powders on hand, but I have been experimenting with what I have. Any pistol powder loads I tried would not cycle the action within a safe pressure, so I wont comment on that.
I worked up some loads using 4166, and I also worked up some loads with 4895, since it worked well for reduced loads. Using both powders, I did some testing and determined the exact charge that would just allow the action to cycle 100%, I used that as the base line for my accuracy testing.

My first accuracy tests were using cast bullet, lubed with LLA and copper gas check. At 50 yards I couldn’t get groups tighter than 8 inches with either powder. If I used a slower load, I could tighten it up, however the action would not cycle while still being accurate. No leading of the barrel was observed with any of the loads that I have tested.

Next. I made up a batch of bullets, and then powder coated them. Using a gas checked bullet with powder coating, I was able to get the group down to 3 inches at 50 yards, with the action cycling 100%. I did this using a 22gr charge of 4895. A grain more or less than 22gr of powder resulted in the groups opening up to over 6 inches. The 4166 would not group.

I then did a comparison with 15 rounds loaded with gas checks, and another 15 without. There was a significant improvement in accuracy with the gas check installed, using identical charges. I was hoping that I could save myself the time and cost of installing a G/C, but have now proven that it is required for accuracy.

So currently the best I can do, is 3 inches at 50 yards, which is 6 inches at 100 yards. Shooting 8 inch steel plates is doable, but not ideal at 100 yards.

I have measured my bullet weights, and found that they range from 56-58 gr. I could probably tighten up the grouping a bit by segregating by weight, but this would be very time consuming.
Otherwise, I think my only option is to change my powder, or to find a heavier bullet.

So this is where I am at. I know I am at a bit of an uphill battle trying to get a 55 gr cast bullet to stabilize from a 1:7 barrel, but I feel I have made some good progress so far. I would really appreciate any advice or things to try that might allow me to tighten things up. Since I don’t keep a lot if powders on hand, I would just be guessing if I go out and buy something else.

Thanks for any info. Much appreciated.

[runfiverun]

weight sort.
before you get that far visually cull after casting.
look at them like they owe you money and your in line right behind them at the bank on payday.

you could also try a harder alloy, I run a 4/6/90 alloy in my 8-9 twist rifles.
I weight sort and use 22.3grs of IMR-4895 [which is slower than H type] in Lake city brass.
you could also try some varget or 4064.

[Gewehr-Guy]

I think runfiverun is right about harder alloy. Do you use a separate neck exp. die, like a lyman M- die or Lee? Loading a too soft small boolit in a neck sized tight for a j-bullet can really scrape them up. If you ever once use the Lee die with NOE's expander plugs you will get an assortment for every caliber.

[jdschwass]

Thanks for the replies. I agree with the inspections... I should start sorting bullets a bit better. With a powder coated bullet, is the hardness of the lead going to have the same importance? I'm not sure. I have a lee universal expanding die that I use to open the brass before seating bullet. Then a light crimp to close it back up.
I'm glad we are on the same page for powder. This is interesting stuff. Your input is appreciated.
Cheers.

[bruce drake]

I run a hardened alloy for my 223 Rem cast loads as well with water-dropped wheel-weights. I lube with Lars 2500 lube when I size and gas-check the bullet and then coat with a light coat of Alox Tumble lube to ensure everything is coated to help prevent any leading. I'll take a little extra smoke over the chance of leading my barrels.

22 caliber shooting requires very careful bullet screening. You can't get the same amount of accuracy with a 2-3gr variance in a small 55gr bullet than you can with a 150gr or larger 30 caliber bullet with the same 2-3gr variance in bullet weight.

I found a good load for both my 1-7 and 1-8 twist 20" barrelled ARs when I went to a heavier cast bullet (69gr mold from Mi-Hec molds. NOE runs that same weight but with a different profile.) Your barrel's twist may be an issue with that lighter cast bullet as I never got better than 4MOA at 100 yards with a LEE Bator 55gr cast bullet with either the 1-7 or 1-8. With the heavier bullet and a nice slow powder, I get 2MOA at hundred yards which is on par with my Highpower Match Loads with 68gr Hornady HPs. My Powder? 24gr of IMR 4831 at 2100fps. Another good load is 19.4gr of H380 at 2100fps but its about 2-3MOA. With these two loads, I can practice for NRA Highpower Matches without the expense of shooting premium jacketed all the time.

My 1-9 twist AR shoots the LEE Bator 55 with decent accuracy but I haven't really built an accuracy load for it yet. It runs fine with 22gr of H4895 but its mostly for plinking with that stock AR rifle.

[jdschwass]

This is great info. Thanks for your time.
So i sounds like if I want to work with what I have, I need to be more diligent with sorting bullets by weight and inspecting them better.
I guess I really should look into finding a mold that will drop a heavier bullet.

I think I could likely improve my plain cast bullet accuracy with the harder alloy. This is evident by the effect of powder coating, which increased accuracy with the same charge.

At the end of the day, if I can get 2-3 MOA, then that is good enough for 3 gun training. I will begin looking at molds, and in the meantime, break out the scale and start sorting.... ugg... got my work cut out for me.

Thanks again guys, much appreciated feedback.

[bruce drake]

first sort by eye. You can quickly see which bullets have incomplete fill-out or rounding of the driving bands and bases. Than go to the scale. Save your eyes and sanity in weighting out several hundred of them. There are stickies on alloy hardness on this forum. You can go TOO HARD as well.
http://noebulletmolds.com/NV/index.p...gusvaf7kvo6jg3
NOE had 60, 62, 68 and 70gr molds on hand
Bruce

[aspangler]

I noticed that noone has welcomed you to the forum yet. Let me be the first to do so. I have limited experiance with the AR and cast but I get acceptable accruacy from my 1-7 twist with WD linotype/WW in 80/20% over 20.5 grains H4895. (new Lee 55 gr.) Good lick and I'll be watching this thread.

[jdschwass]

Thanks for the welcome!

I did a bit of sorting last night, at least enough to put together another round of testing. I would say that ¾ of all the bullets were almost right on 57gr. A few were slightly heavier, but I would say that 95% of all my bullets were within one grain of each other, which I think is pretty good. As for visual inspections, I will typically throw away anything obvious during the sizing process, but I rarely drop bullets with imperfections. My larger 30cal and large bullets are more commonly defected, but the little 22’s seem to be much more consistent.

Like I said before, I do expand the case before seating the bullet, however I am thinking this round I will try going a bit lighter on the crimp, in case I am shaving a bit of material off the bullet when shooting.


I did take a look at the NOE molds online. Those heavier 68/70 gr molds look excellent. However, none seem to be in stock currently. Are there any alternatives? They are also fairly pricey given my doleful Canadian currency.
Looks like I will have to start saving, but certainly the heavier bullet may be the answer.

Not sure when I will get a chance to test the next batch, we got 3 and a half feet of snow in the past 48 hours, so much of my time has been spent cleaning up that mess. My range is outdoors, so during the winter months, which means strapping on the snowshoes.

Ill report back once I have some results.


Thanks for the support.
Cheers.

[runfiverun]

remember we are talking weight sorting into .1-.2gr windows.
I don't even run my 166gr boolits at a 1gr variance when I'm spinning them quickly.
for the ones I'm pushing hard I break them down into .3gr windows and toss anything outside the 166.9 window back and anything below the 166.0gr window goes back also.
the rest go into 3 separate groups.
I do the same with my fast 22's they go into .1g weight cups .4-.5-.6 are my go to weights.
above and below go back or are used in the bolt gun at lower velocity's.

[jdschwass]

What are you using to measure the weight with?
I have a manual lee scale, which is slow for weighing 100's of bullets.
I also have a cheapo electronic scale that I use for setting up my powder measure. It is good, but only will measure in .2 Gr, so I cant really get enough accuracy to measure .4, .5, .6 like you are.


I now have 20 rounds loaded, all with 57.0gr bullets, so I am interested to see what happens with my grouping.

[Gewehr-Guy]

Sounds like you have an abundance of white fluffy backstop material! If you have a way to push it into a pile and catch your bullets you can examine them to see if your alloy is up to the velocity -twist rate. My range is my hay yard, I push all the snow from around hay stacks into a big pile , set target frames (old pallets) and shoot all winter. gather up my lead next spring and shoot it again next year!

[dverna]

What are you using to measure the weight with?
I have a manual lee scale, which is slow for weighing 100's of bullets.
I also have a cheapo electronic scale that I use for setting up my powder measure. It is good, but only will measure in .2 Gr, so I cant really get enough accuracy to measure .4, .5, .6 like you are.


I now have 20 rounds loaded, all with 57.0gr bullets, so I am interested to see what happens with my grouping.

I use a digital scale. So much faster

Don Verna

[runfiverun]

and within .1 gr.
I wouldn't trust the lee ball scale for much.
the little lyman 12 or 1500 scale is a pretty good one.

[Tmaloy]

Hi jdschwass. Welcome to the board. I too started casting for my AR rifles. I viewed all the topics I could on the subject and finally decided on going with the Mihec 75 gr. MP Nato mold. Gas checked and powder coated, I have pushed these up to 2500 fps with no leading. I also use the NOE expanders and use IMR 4895. All the AR rifles I load for are 1 in 7 or 8 twists and I find the accuracy acceptable for my use. I have shot them in 10.5, 16, 18, and 20 inch barrels with the same load and they function well. I have only been able to shoot them out to 120 yards where I am but they do consistently hit the 8" plate we tote out to the range. I pm'ed Mihec for the mold about a year ago and he still had some available. When I started using cast in my rifles all the shooters who saw it said I would ruin my guns. I have yet to see any problems and I saved some money while gaining much experience thanks to the suggestions and posts of the members here. Good Luck!

[jdschwass]

This Mihec mold sounds great. Is this a brand name? Or is this someone making them? What is the cost of acquiring such a mold??

I havent had a chance to do any shooting since my last post, but I did... (pardon the pun) bite the boolit and purchase a better scale. It is digital, and accurate to 0.000gr, which is much better than my 0.2 gr scale.
I sorted a handful of bullets out. So far I have just been sorting by grains. So far I have 56, 57, 58. Anything outside of that I chucked back in the pile for melting.
90% of the bullets are coming out in the 57gr category. Once I have done a bit more, I will start sorting each of those groups.

My plan here is to make "the perfect batch". Im going to do everything right, sort my bullets to .1, measure each charge, etc etc. Then I will see how I do for a grouping. Im very curious to see if all this work is going to pay off! Really hoping to get out this weekend to try some out.

Thanks again for the help so far.

[Tmaloy]

Miha Previc aka MP-Molds is a vendor here and can be contacted by PM. He might still have some molds available, I suggest contacting him if you are interested.

[jdschwass]

I thought I would provide a quick update on my progress, or lack thereof.
As I said before, I put together a batch of perfect loads. I weighed out all my bullets, and loaded only the ones that were 57.0gr.
I weighed each charge, used all similar cases, etc. Per my previous testing, 22 gr of IMR4895 was my load. The bullets were powder coated and gas checked. Everything was as close as it was going to get.
I fired off 20 or so rounds at 50 yards. My grouping was about 3 inches. I was shooting from prone with sandbags.

So overall, I think that my accuracy is mostly a reflection of the 1:7 twist barrel. It is the only factor that I really cannot change in my test. So as previously discussed, likely need to look into the heavier bullet weights.

Well i certainly learned some stuff, so thanks again for everyone's help.
Cheers.

[Tmaloy]

There is a group buy going on at NOE for a 100 grain mold, .22 caliber. I jumped on since I would like to try this mold out. I don't know if you'd be interested, but it shouldn't hurt to take a look.

[jdschwass]

100 gr sounds interesting. Where can I get more info on that?

Thanks.