COMMON KNOWLEDGE ???

[OLDNAVYMCPO]

At the range recently, a close friend asked me to spot for him and help him zero his AR-15. Brand new rifle with an inexpensive red dot.

I agreed and set up my spotting scope while he loaded his magazines and settled in at the bench. Like I said, he was a close friend, Vet and frequent shooter.

Following my suggestion, we started at 30 yds. He got on paper but the groups weren't anything to brag about. We moved to a target at 100 yds.

He was shooting from a bench with a rest and yet couldn't get on paper at 100 yds. I asked if he had properly torqued his scope mount, thinking it might be wobbling. He said it was installed at Cabella's where he had bought the rifle

We moved to a target at 50 yds. He was on paper but poor groups. Finally got to center and 2 inches high with several shots in a row. Moved to 100 yds, still erratic but he was satisfied.

He had collected all his brass with a brass catcher. He doesn't reload and insisted I take his brass which I didn't particularly want since I use the same headstamp from the same lot for my reloads. He more or less shamed me into taking his brass.

Several days later, I was loading 5.56 and checked his brass thinking I would use it for plinking. Checking his headstamps, I was totally floored. He had tried to zero his rifle using an assortment of brass from different manufacturers, some .223 and some 5.56. Just stuff he had collected. I couldn't believe my eyes. He had tried to zero that rifle with an assortment of ammo, almost a 100 rnds.

I had assumed he would have had a clue. You never know.


I apparently didn't make myself sufficiently clear, the problem wasn't a matter of different headstamp but rather different brands of different commercial ammo altogether.

[zeke]

While I segregate all my 223 brass, the problems he was having appear to be much more than just using mixed brass. Would bet the inexpensive red dot, who mounted it and the bullet/powder combination may be in play.

Excellent suggestion to move up close to start. Another consideration when having these type of problems is to have someone else shoot the gun for another variable check.

[LVSteve]

This page shows how varying ammo can kill accuracy. Note how far the POI moves between the different types. Educational Zone #8 - 5.56 Military Ammo Accuracy - The Box O' Truth

[DWalt]

Segregation by case headstamp is much over-rated and unnecessary. I find that segregation by weight is better, and I always trim necks to the same length. That is more important than most shooters think.

[hoc9sw]

This is not a surprise to me. I had an old handgun guy who had purchased an AR in 556 as his first rifle of any sort. The shop sold him 30 round mags. So he shows up with 20 round boxes of everything you could imagine between 223, 556, bullet types, weights, $6/20 to $30/20 ....

He proceeds to load a box of 20, then open the next (very different) box. I asked him to stop, and just load that 20. He got riled at me, and we had to go out to the waiting area to have a discussion. After a half hour, it finally dawned on him why I have mainly 20 round mags (besides the fact that I don't like mags hanging down, I learned to shoot with an M1).

As well, I keep a detailed log of ammo fired, so I get crazy when it is mixed. The only time I mix is while teaching someone new.

I can't imagine how much waste there could have been.

[old bear]

I never realized that different makes of ammo would make that much difference in Accuracy, when mixed together. As much as I hate to admit it, I got no clue about that.

[TOM BECKWITH]

Although not really comparable, when setting up a new .22 rifle or scope on one, I do use mixed ammo. Once settled in, I stick to a specific lot for results and future use.

[H Richard]

When I bought a DPMS AR a couple years ago I bought 500 rounds of Fed. 50 gr. FMJ and zeroed the rifle. I then bought 500 rounds of Winchester brass and the Midway Dogtown 50 gr HP and developed my load. The handload groups in about 1 1/2" at 100 yds and the FMJ groups closer to 2" at 100 yds. There is an elevation difference of about 2" with the FMJ grouping lower than the HP load. Both loads chrono at about 3150. I only shoot one type at any time, the gun sits in the rack with several loaded magazines handy for the SHTF situation. I may never fire the gun again.

[Wyo]

My Granddad used an old Model 70 Winchester in .270 Win. for elk. When we headed out for a day on the mountain, he would grab a handful of loose cartridges from an old cigar box. Some would be 130 gr., some would be 150 gr., some were of unknown weight, some were spitzer and some were roundnose. A few were slightly green. He would stick them in the rifle in random order and away we would go. I don't know how they would have done on paper as he seldom shot paper, but he always managed to get an elk with that mess of old ammo. Better to be lucky than good, I guess.

[johnbeaver]

Having a bunch of kids, I ended up with several hunting rifles of the same brand and caliber.
I still don't understand how one will shoot a different brand of ammo, same bullet weight, so much different. But it will.
I always shoot three types in a rifle to see which groups the best. And never mix.

[LVSteve]

Originally Posted by old bear

I never realized that different makes of ammo would make that much difference in Accuracy, when mixed together. As much as I hate to admit it, I got no clue about that.

It can get really ugly if you mix in one type of ammo the gun REALLY dislikes. My education in this came without even having to mix the ammo.

I was trying to zero the scope on a heavy barreled .308 at 50 yards using some German battlepack 7.62x51 ammo. Absolute shotgun patterns followed. Tried some Winchester hunting ammo of the same weight and the groups shrunk to what I expected. The punchline is that the battlepack ammo is laser accurate and consistent in a converted Chilean 1912 Mauser. Go figure.

[ExRanger714]

I only shot M-193 til you couldn't find it and tried some Wolf. Fed allright but hit 6" low at 31 yards which is my favorite zero range. Zeroed at 31 yds. it's back to zero at 310 yards and never rises more than 6" midrange.

Now that you can get 193 again I'm stocked up and sticking with it.

[vonn]

You can lead a horse to water but you can’t make it drink! Hopefully they use the proper caliber!

[Ogandydancer]

I don't shoot rifles but I guess the same would hold true for a handgun. I would have never thought of it. I have shot mostly all the same brand and Wt. ammo from my pistols every time I go to the range. However the pistol I am most accurate with is an old import P6. Which I have done NO mods to.

[Wise_A]

I've shot bullseye with a few different guys that showed up with a different box of ammo every week. Then they'd be sitting there complaining about their guns, their 'dots, etc, while adjusting their zero's in the middle of the match.

[susieqz]

my handguns are very ammo sensitive.
for my 15-4, i bot a box of every ammo i could find.
i spent more on test ammo than i did on the gun.
out of all that ammo, the gun only likes one type.
there is no second place.
had i not done the testing i would never have known that i had a match quality gun.

[F75gunslinger]

The other part of that as well is what round the gun is chambered for ? I have a 5.56 chambered upper that will shoot both .223 and 5.56 acceptably. Not the best but acceptable. I have a long medium barreled upper with a good scope chambered in .223. With the right ammo that upper will hold under an inch at 100 yards. Put some 5.56 in it and it goes all over the place and half the time becomes a single shot.

The two rounds aren't interchangeable. The 5.56 chambers are generally a little more toleranced for reliability.The .223 chambers are generally a bit tighter. YMMV

[gregintenn]

Originally Posted by Ogandydancer

I don't shoot rifles but I guess the same would hold true for a handgun. I would have never thought of it. I have shot mostly all the same brand and Wt. ammo from my pistols every time I go to the range. However the pistol I am most accurate with is an old import P6. Which I have done NO mods to.

It actually works backwards. Generally, a heavier bullet fired in a rifle will impact the target lower than a lighter bullet. A heavier bullet in a handgun will usually shoot higher than it's lighter counterpart. I blame this on a combination of a lighter gun, slower bullet exit, and more dwell time to cause muzzle rise in the handgun.

[britbike1]

I had a similar problem with an ar with a nikon 223 scope I was trying to sight in until the gun next to me said to check the mount. Sure enough I had put in on the nite before and forgot to fully tighten the mount. Goes to show, go back to step one basics and check everything over.