.223 1-9" AR with 50gr V Max and 4198

[Southwind]

As title states, I am trying to find a good load for my 16" AR with a 9 twist. The IMR site says for a 50gr bullet, the range is 19.9 to 21.9 grains of 4198 powder.

I ran a ladder test today and went all the way up to max and the load would not throw the bolt back far enough to grab a live round from the magazine. It ejected every round, just would not load a live round. I did not get a decent group until I shot the 21.9gr group. I also did not have any signs of pressure with any of the rounds.

I read another post on an IMR thread where a guy swore by loading 22+ gr of powder with a 50/52 bullet and got great accuracy. After I shot my reloads, I fired 10 rounds of factory Remmy UMC ammo and they cycled perfectly so I don't think I have a gas issue.

Is it safe to keep going up in small increments to see what cycles this gun and groups well. Was thinking about 22.0, 22.1 and 22.2gr to start off with.

thx, Steve

 

[smschulz]

You might need to try some other spring and or buffer combination.
I can't say you did anything wrong with your load but this happens sometimes with light loads.

 

[Engine 22]

Before you go and throw $ at new parts for your rifle, are you seeing any pressure signs with that published "max" load?
In my experience, the "max" load found in most manuals are considerably conservative. IMO, manuals and charts are a great resource in determining a general range for loads. Keep in mind that every chamber/barrel is different. If it were my rifle, I would continue in .2gr incriments until I find a desireable load or I see signs of over pressure.

 

[milo 2.0]

I'm with Engine on this, keep going up. You state IMR data, Hodgdon owns IMR, I'd use their site for data, but man did they recently screw that up????

One thing not realized when searching data for 223, most is for bolts guns, not semi. Sierra's manual is about the best for service rifle, except most don't shoot their bullets until you get up in the 69gr range. There's a difference between the 2 rifles.

By Hornady's manual, bolt gun data your light loads should have been in the 2900 fps range??

4198 really is on the upper end of fast burners, personally I like the slower end myself. A midrange like 3031, or Benchmark might suit you better? With 4198 your pressure spike will be fast and definitive! And remember it's March, it's going to warm up.

I hate to say this, but in recent years, new powders like AR comp, CFE 223, IMR 8208 xbr, are the future.
I do realize there's quite a glut for these offerings, but powders like 4198, Win 748, H335, etc.. are going by the wayside.

 

[briang7511]

What AR are you using? I have a bushmaster ORC with a 16 in barrel 1in 9 twist. I have found excellent results with varget. I am using 26 gr with a 52 bthp and either sierra or hornady and the 52 gr amax. No problems cycling. No mods to the rifle other than the JP trigger springs. I know its not 4198 powder but thought it might help. Just looked in the lyman manual and it doesn't show the pressure for a 50 gr bullet but it does list it for a 45 gr bullet and 4198 pressures are a lot higher than varget. You would think that the higher pressure would help things cycle. I have also tested with cfe223 but my groups were better with varget.

 

[8AteEight]

one thought I had: has your scale/measure been double checked lately.. When I got mine, I checked with a 105gr. bullet, and it read about 3full gr. high. Quick modification, and I was in Bidness.
YMMV, but its something to think about.

 

[Southwind]

Thx for the replies. I also have some H-335 I will be trying in this gun. All of my other 223's really like IMR 4895 with both 50 and 69 gr bullets. I just have a couple lbs of 4198 and H335 I need to use up. Was hoping to find a good load for this gun with 4198, but not sure I will be able to safely.

Out of my other ar15, an 18" Mk 12, I tried the same load with a 50gr Midway Dogtown soft point with a OAL of 2.210". I started at 20gr, but it did not cycle the action fully until over 21gr of 4198 and I found the best accuracy at 21.2gr (all of this still well under the published max). I am going to try these Midway bullets with the AR in question and see if they work. They are not as accurate at the V Max's, but maybe with a shorter OAL than the V Max they will generate enough pressure to cycle this ar too.