IMR 4166 .223 Rem Test in AR

m&p45acp10+1

New member
I will make a long story short. I bought an AR a couple of weeks ago. I did the initial testing of it with factory ammo, as my .223 Rem I have reloaded are neck sized for my bolt action. I used up the last of my H335 for them. Though I will not have to reload for my bolt action for a good while as I loaded up a whole lot of them for that reason.

I have been watching the shelves around here for H335. They seem to have everything but H335 it seems. It is my go to for 55 grain VMax. Well I took a trip to a place that is a bit over an hours drive away. They had no H335, and only had 100 count boxes of VMax. The VMax I will not buy in smaller than 250 count as the price jumps up there when you are getting 1K at time.

The manager is an old friend of mine from back in my days of working with a couple of charities that he is a big supporter of. He tells me if I want it he will set me up with a manager's special. (I am a sucker for a good deal.)

The deal 500 count box of Hornady 50 grain ZMax (ZMax is VMax with a green tip.) and a pound of IMR 4166, and 1K Sellier & Bellot primers. Price $75 out the door tax included. Needless to say I took the deal.


I was busy with vacation, and things at work for the past 3 weeks so stuff was waiting on my bench for me. I at last had the time to load up some test loads for work up. I was able to shoot them on Friday. The results are everything worked. I have only iron sights on the AR so test groups were at 25 and 50 yards. Once I get optics for it I will stretch it out farther. I did test a few with my Savage Model 12 against my pet load in it.



Ok first things first this powder from what I understand is pretty new. The only data I could find for it was from Hodgdon.com. It list a starting load of 23.9 grains. Max load of 26.2 compressed. The powder is a stick powder. It is medium short length, and very uniform. With test with a few dippers, and a ProAuto disk. It seemed to meter great. Variance was less than .2 grains. Most were on the money. I for the sake of work up use a Hornady LNL Auto Charge digital dispenser.

The compressed max loads may not be possible for those that trim the brass shorter as some of it would be spilling out of the case. With a max of 26.2 grains I decided to check a few cases to see if it would hold more. None held more than 26.8 Most it was overflowing the neck at 26.5 Some of my short trimmed brass it was overflowing the case at 25.9 grains. So I doubt too much of an overcharge can be put into a case as it will not fit.

Test with both rifles was done. The end results using round robin test for me showed the max load was the most consistently accurate. In fact as the charge weight increased in this case. The groups seemed to get better.

Now in the bolt gun at 100 yards compared to my pet load with a 55 grain max loaded with H335 it was not as good as the pet load. Though I would not sneeze at it either as it gave a group of less than 3/4 of an inch at 100 yards for a 5 shot group.

In the end. I may end up getting some more of this powder as I like the fact that I will be able to make a nice dipper for it to speed things up at the bench.
 
Mrs. M&P removed the bull's eye from the target today with the load. She went through 120 rounds in short order. The barrel looked pretty clean after a few pulls through with a dry bore snake. Several patches showed minimal copper fouling after 200+ rounds.
 
Sounds like you have found a usable solution, congratulations. I have used various powders for my 223/5.56 loads including CFE 223 and 8202 XBR, but my go to powder is still H-335 and I still have a couple of pounds of it.

For my bolt action 223, I like and use the Hornady 75 grain BT A-Max (#22792) and find that H-4895 works extremely well for that size bullet.

Thank you for sharing your findings with us and giving us another solution for our 223/5.56 loads.

Good luck and stay safe.
Jim
 
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