5.56 ammo for sighting in

[RRomig]

Exactly
What good is it to sight in with one ammo when your planning on shooting something else. Don’t confuse sighting in with working up groups. I’ll buy several different boxes of ammo and shoot groups. Then when I choose the ammo I’m going to buy in bulk I sight in (zero) with that.

 

[Ponder_MD]

So I've been testing out this thing I built. 16" 1x7 twist, chrome lined barrel. Using iron sights at 100 yds. The trigger is kind of heavy and it's single stage. I know I could improve that.

I'm not sure if my eyes are old now or if I've forgotten my fundamentals or what but I cannot seem to get consistent with this rifle. Mechanically it functions perfectly. It fits comfortably. I have a sling. It has an A2 front sight and YHM flip-up rear sight. I don't want to resort to optics yet.

I've tried M193 55gr
X-TAC M855 62gr (is this junk ammo?)
Hornaday Superperformance Match 75gr

At 100 yds, I'm on the paper. Sometimes in the bull, but I have no grouping, really. No consistency. It's not the ammo, it's me and/or the rifle.

Should I start this process on a bench or do it as I plan to shoot (prone)?

 

[E.Shell]

Are you "sighting in" or are you "performance testing"?

If sighting in: Use the ammo you will be shooting.

If performance testing: If your rifle wont' shoot appropriate FGMM into one hole, there's probably something wrong with it.

 

[E.Shell]

So I've been testing out this thing I built. 16" 1x7 twist, chrome lined barrel. Using iron sights at 100 yds. The trigger is kind of heavy and it's single stage. I know I could improve that.

I'm not sure if my eyes are old now or if I've forgotten my fundamentals or what but I cannot seem to get consistent with this rifle. Mechanically it functions perfectly. It fits comfortably. I have a sling. It has an A2 front sight and YHM flip-up rear sight. I don't want to resort to optics yet.

I've tried M193 55gr
X-TAC M855 62gr (is this junk ammo?)
Hornaday Superperformance Match 75gr

At 100 yds, I'm on the paper. Sometimes in the bull, but I have no grouping, really. No consistency. It's not the ammo, it's me and/or the rifle.

Should I start this process on a bench or do it as I plan to shoot (prone)?

Ditch the "M-xxx whatever", use good ammo and let another skilled person shoot it. IME, Hornady Superformance is decent hunting ammo, but not necessarily match grade. Try some FGMMs.

 

[mauser58]

If using as a hunting rifle I would sight in for that weight of bullet for size of animal. Varmint hunting lets say then 55 should be ok. I hunt Deer sized so use 75 or 77 grain. Some like the 68 or others but use proper grain for type of hunting and sight in for that. If just target then dont use heavy grain

 

[Ponder_MD]

Ditch the "M-xxx whatever", use good ammo and let another skilled person shoot it. IME, Hornady Superformance is decent hunting ammo, but not necessarily match grade. Try some FGMMs.

Yes, I've been thinking that another skilled person would be a good first step.

 

[outrider58]

Maybe try and find a heavier bullet/cartridge?
55g is a bit light for that rifling. Something 62g and up would probably perform better out of that barrel.

 

[Ponder_MD]

Maybe try and find a heavier bullet/cartridge?
55g is a bit light for that rifling. Something 62g and up would probably perform better out of that barrel.

I did. I've got 62 and 75gr as well.

 

[RRomig]

If you’re trying to determine the accuracy of your rifle / ammo I’d mount a scope and have a very good rest. You don’t need a sled or anything special you just need to know where the cross hairs are when the shot breaks. I keep a ten power scope with a fine reticle just for testing. If you need a loner let me know.

 

[Bountied]

Are you "sighting in" or are you "performance testing"?

If sighting in: Use the ammo you will be shooting.

If performance testing: If your rifle wont' shoot appropriate FGMM into one hole, there's probably something wrong with it.

One hole at 100yds with an AR? With FGMM ammo? I know you know your stuff but I'd love to have a rifle that could do that. Any rifle.

 

[Russ D]

Chrome lined barrels aren’t known for producing tiny groups. Couple that with only shooting irons and I can understand why you are having trouble. If you have a flat top rifle and aren’t highly skilled at using irons then you most likely are going to need a scope and a stable shooting platform. Like E. Shell said FGMM is proven quality factory ammo so use that as your benchmark. If one hole groups are your absolute goal then order a White Oak SPR barrel and save yourself a lot of time and wasted ammo.

 

[calicojack]

At 100 yds, I'm on the paper. Sometimes in the bull, but I have no grouping, really. No consistency. It's not the ammo, it's me and/or the rifle.

Should I start this process on a bench or do it as I plan to shoot (prone)?

With iron sights you probably have about a 3 MOA rifle. I have a copy of Colt's AR-15 Sporter Rile Operation and Maintenance Manual from the 1960's. It states:

"Every Sporter is fired for group form in a bench rest. Acceptance specifications call for 5-shot groups with an extreme spread of less than 3 inches at 100 yards"

I would say that's still true today for an AR15 rifle not specifically built for competition.

If you shoot 5 shots from a bench rest, using match grade ammo if possible, is your group larger than this upside down Magpul sticker?

 

[Ponder_MD]

OK, now we're getting somewhere.
Let me try from a bench with this match grade stuff and report back.

 

[brianns]

A rep from Berger Bullets once told me not to expect the best accuracy with ammo that had a penetrator in it. So pick some regular or match ammo with a homogeneous lead core.

Then practice or have another person test it out. I think you’re on the right track though. With practice you’ll start to see what’s consistent with your skills and various ammo/equipment.

 

[calicojack]

A rep from Berger Bullets once told me not to expect the best accuracy with ammo that had a penetrator in it. So pick some regular or match ammo with a homogeneous lead core.

Yes! I can vouch for that. I got TERRIBLE grouping with green tip ammo and then someone pointed out to me what you just said.

OP did you use penetrator ammo? If so I missed that. That's a big part of your problem then.

 

[Magnumite]

I generally use whatever I have to get a rifle/carbine sight setting close then use my go-to ammo…which is usually Federal. What I pay attention to along with group size is the approximate POI of the other loads I may have around for practice considerations.

 

[E.Shell]

One hole at 100yds with an AR? With FGMM ammo?

Yes. Not a feat.

I know you know your stuff but I'd love to have a rifle that could do that. Any rifle.

The ammo (Federal Gold Medal Match) will indeed shoot one-hole groups at 100 yards. Anything less is some sort of problem back at the firing point.

Not all rifles are capable of that sort of precision, but as a test medium, you can get an idea what you and your rifle ARE capable of by shooting FGMM as a control group.

If you haven't shot a precision rifle lately, you might be surprised at what is possible these days with good equipment and solid technique. I'd bet most of my students will tell you they were overlapping bullets at 100 before we went to long range.

An AR doesn't have to be magical (or mythical) to shoot that well. A well built AR-15 or even an AR-10 will equal all but the very finest bolt gun. Properly handled, why would they not?

We've shot 11" 5-shot groups at 1,200 yards with a 16" AR-10 using 7.21x51 FGMM 175s. I built a 24" heavy Krieger barreled 5.56 rifle for a friend that was so consistent with FGMM chewing one ragged hole at 100, he ended up getting bored and sold it. I have a 20" HBAR style Krieger barreled 5.56 upper that shot just about as well last time I had it out. I used it for a student loaner when they couldn't tolerate the recoil of a .308.

A well built bolt gun will shoot 1/4 MOA groups all day long, using FGMM or good handloads. I have a what is basically an off-the-shelf Remington LTR (20" .308 bolt gun) that will shoot 3/8 MOA with FGMM 168s. The only thing I've done to it is mill the stock to accept Badger/AICS bottom metal, then epoxy bed the bottom metal and action. An off-the-shelf Savage target rifle will typically shoot 1/4-3/8 MOA with factory ammo (FGMM for 5.56 + 7.62, Hornady for 6.5 ManBun Creedmoor), as will many of the Ruger precision rifles.

 

[outrider58]

OK, now we're getting somewhere.
Let me try from a bench with this match grade stuff and report back.

To do it any other way is only testing your ability, not the rifle's.

A side question; when you built your rifle, did you true the receiver face, and if the barrel was not a "thermal fit", did you seat it using Locktite 620 on the barrel extension?

Even with an inherently accurate rifle, the above can improve accuracy.

 

[Ponder_MD]

OP did you use penetrator ammo? If so I missed that. That's a big part of your problem then.

It was one of 3 ammos that I tried. It's a commercial reproduction of M855 by X-TAC.
I do have some Hornaday Superperformance Match grade stuff.

 

[Ponder_MD]

We've shot 11" 5-shot groups at 1,200 yards with a 16" AR-10 using 7.21x51 FGMM 175s.

That's amazing with a 16" barrel.