5.56 ammo accuracy, or lack of

[Big Fred]

About 2 years ago I came into a new Ruger SR5.56 really cheap. I didn't do much with it till today. Took it to the range to sight it in, I put a Leupold 2x7 on it in a Burris PERP mount. It doesn't have the best trigger. And I have NO prior AR rifle experience, but I can shoot better than the results I got.

Here's the ammo I shot and the results at 100 yds:

Privi Partizan 55 gr. This put 10 into 1 1/2". This was acceptable to me.

Federal Brown Box XM193F 55 gr. This wouldn't do better than 10 in 3"

American Eagle Tactial Black Box XM193 55 gr. How about a 5" pattern !!!

I'm gonna load some of my own with 55 gr. FMJ and also try some different 55 gr. soft points I have around.

My question, has anyone else had bad results with either the Federal or American Eagle I listed above?

Thanks

[APS]

You're going to get those results from that class of ammunition, it's loaded as cheaply as possible. My M&P15 throws a pattern with the cheap stuff but is good enough for training and practice. The only "good" ammo I have tried was Black Hills and the difference was eye opening.

[Big Fred]

APS, Thanks for the reply. I've always liked Federal and I understand the cost factor, but that doesn't say much for them when ammo from Serbia cuts the groups in half or better.

I guess I'll use the Am. Eagle for blasting and practice with the Federal. At least shooting it up will yield me brass for reloading. I hope the brass is decent.

Thanks

[Pisgah]

Question -- did you clean between groups? Reason I ask, the last Privi .223 I had left copious copper fouling after just a few shots. It was accurate in the beginning, but accuracy fell off faster than with others I have tried.

[Big Fred]

Pisgah, NO, I did not clean between groups, thanks for the suggestion. I shot the Privi first then the Federal followed by the Am. Eagle. I was gonna clean the rifle tonight, but I'm gonna try out some .357 loads tomorrow so I think I will take the dirty rifle and run another 20 Privi through it and see if the groups open up in the dirty barrel. Then when I come home it will get a good cleaning. Then maybe another day this week I'll try the Am. Eagle again as it was the worst group, but was shot last.

Thanks

[MichiganScott]

M193 NATO ammo standard is 1.8-2.4 MOA or basically 2" at 100 yards.

Federal says that the "X" in the XM193 designation means it does not meet military standards in some aspect, but does meet commercial requirements. It could be as simple as not having a sealed neck or primer, or the accuracy could be poor.

[Doug M.]

I was thinking that the standard was closer to 4MOA. Is that for the carbine? When you consider that the standard is probably set in a test setting and not with a live shooter and real firearm, 3-4" is not all that bad. However, try good quality ammo - Black Hills or ASYM, and see how you do.
Remember that a service rifle will also have a more generous chamber if made correctly - 5.56 allows more room for a higher pressure loading. True 5.56 shot in a tighter chamber, like a .223 match cut, will pop primers.

[Lizardman_u]

What is your rate of twist in the rifling? At work we had M-16 and AR-15 A1s with a rate of twist at 1:7 which fed the 55 grain fmj (m193) with accuracy, but would keyhole the 62 grain fmj (M855). Conversely when we got the A2 with the 1:9 twist they would feed the M193 (55 gr fmj) but wouldn't keep tight groups (minute of coffee cup); good enough to hunt coyotes and plink, but not real accurate, but with the 62 grain fmj (M855) they were tack drivers. These are or were select fire weapons with the three posision safety (US Army civilian security).

Try some heavier rounds as I believe you have the A2 rifling or the 1:9 twist.

I also have a Bushmaster AR-15 without the select fire with a 24 inch bull barrel and 1:9 twist and it is quarter sized groupings at 100 meters instead of 1/4 inch groups with the 55 grain, but will get the 1/4 inch groups with the 62 grain rounds.

Dave

[Big Fred]

Well I took the dirty rifle out today and ran another 20 Privi through it and got the same results as before with the Privi, not bad at all. Then I ran 20 Am. Eagle and got about same pattern as before.

I'll give it a good cleaning in a day or two and hopefully by the weekend I'll get a few loads worked up to try. I have some 55 gr. fmj and some Hornady 55 gr. v-max [I think I do anyway] to try in the loads.

It does have a 1:9 twist, and somewhere in the reloading room is a 500 round case of XM855. I'll run some of them through it and see how it does with the heavier bullet.

Even though I'm somewhat disappointed with the accuracy of some of this ammo, I gotta admit the rifle is fun to shoot.

Thanks for all replys.