IMI ammo keyholing in my Sport I

[CVFD1433]

So i have the Sport 5r 1:8 twist and i bought 450 rounds of the IMI m855 62 gr on midwayusa.com. According to all of the reviews i was reading, it was a fairly good ammo for the price. Today i shot a box of it and at 25 yrds it couldnt hit a 10" plate. Weird because my rifle is sighted for a 62 gr bullet and normally drives tacks at 200 yrds. So i shot again at 10 yrds and I finally got it on paper but every shot was tumbling terribly. My rifle shoots the black box federal fine and accurate but this IMI stuff is terrible. I cant seem to find anyone else on the internet with this issue either. Only issue i see is the primer issue. Someone help please. Its not my gun i know, i just hate that maybe all 450 rounds i bought is bad. BTW i have about 1500 rounds through the barrel

[cyphertext]

Have you cleaned it recently? Any buildup in the barrel? I really have no other ideas...

[CVFD1433]

Yes i have

[Fishinfool]

If it's not a fouled barrel, and I knew the gun was accurate with other loadings, I would suspect the ammo. Something is seriously off if you can barely hit a target at 10 yards, and they are key holing. Your twist rate is plenty fast enough. Maybe pull a couple bullets and check them with a micrometer or caliper. Sounds like they might be undersize?

Larry

[agksimon]

I have the Sport 2, optics ready version, which has a 1 in 9 twist barrel. After doing extensive tests, with many brands and weights of ammunition, I found the IMI, 55 grain FMJ to hold the tightest groups of any that I tried. I can easily benchrest it to 1 moa and even less, with almost never a flyer. I also have the IMI 62 grain green tip and can benchrest into 2+ moa, also with rarely a flyer. I just bought several cases of the 55 grain, from Midway USA and it's now, all I use. I don't know why it's not working out for you.

[vonn]

Think I would use some different ammo and verify that the rifle works well with the new ammo. If it shoots ok I would contact Midway and go from there. Keep us posted as many took advantage of the sale and will be interested in your results.

[Kurusu]

The easy answer.

Do not use that ammo in that gun.

[M29since14]

Measuring the ammo is pointless if it won’t shoot in your gun at all and other stuff works fine. If you’ve done a side-by-side test and verified that, I’d be wanting to return the ammo and get my money back. That’s crazy!

I have a Sport like yours and it shoots acceptably with PMC green tip, but better with almost any decent quality 55 gr FMJ. I’ve never tried IMI’s green tip. If you get no satisfaction from Midway go directly to IMI.

[rtquig]

Do a search on this forum. IIRC there was a thread a few months ago concerning someone having keyhole problems. Good luck, I myself think it is your ammo.

[Racer X]

IMI is Israeli Military Industries and they use Winchester-produced machines. Olin has a strategic business alliance with IMI.

[vonn]

Wish that a reply had been posted as to the resolution of this problem.

[stwings]

M855 is tricky to manufacture. If the steel core penetrator isn't reasonably centered in the lead and jacket it will be wildly inaccurate. I would contact IMI about it. It may be a bad lot. IMI is a reputable company and if the ammo is faulty I'm confident they will make it right.

[BigBill]

The only time I had key hole ing was with my 30-06 I was shooting steel air tanks from diesel trucks. The fmj surplus ammo went through the steel sideways like a little rocket. Just a fluke round.

What size is the bore? What size is the ammo, diameter.?

[Pisgah]

Originally Posted by Kurusu

The easy answer.

Do not use that ammo in that gun.

This kind of simple, direct, sensible and factual reply has no business being on this board! ;-)

[bamashooter]

Originally Posted by vonn

Wish that a reply had been posted as to the resolution of this problem.

There are at least 5-6 conditions under which this phenomenon can occur. Time will tell (hopefully).

[CVFD1433]

Ok sorry for the wait guys. So my gunsmith did a few things to try to get my gun to quit keyholing. He said that it took two guys to get the barrel nut off because it was way overtightened from the factory and there was no barrel nut shims on the gun. So that didnt work so i had the barrel replaced. He ended up hooking me up with a 1:9 twist 223 wylde barrel with nitride finish and a yankee hill collapsible front sight. He said he took it to the range and was putting rounds in a dime at 100 yrds with iron sights. I asked him what caused my old barrel to wear out like it did and he asked if i shot tula ammo and i said yes quite a bit. He said if the barrel isnt chrome lined then dont shoot tula. It wears out a barrel extremely fast because the bullet isnt a true copper bullet. It has zinc in it. Sorry for the late resolution, i just got my rifle back today.

[agksimon]

Originally Posted by CVFD1433

I asked him what caused my old barrel to wear out like it did and he asked if i shot tula ammo and i said yes quite a bit. He said if the barrel isnt chrome lined then dont shoot tula. It wears out a barrel extremely fast because the bullet isnt a true copper bullet. It has zinc in it.

Zinc is a soft metal and shouldn't hurt the bore, but Tula is magnetic, as it has a steel jacketing, under the very thin copper plating. This is what's hard on the bore.

https://www.luckygunner.com/labs/bra...el-cased-ammo/

[Balright]

Sounds to me like your gunsmith needed to make a boat payment or something by selling you a new barrel being your other ammo shot just fine be interesting to see how the rounds you had problems with shoot now

[turbo38gn]

He was putting rounds in a dime at 100 yrds with iron sights ..... As for barrel shims ... more of this .. Even if your AR shoots fine ... I call BS.

[CVFD1433]

Originally Posted by Balright

Sounds to me like your gunsmith needed to make a boat payment or something by selling you a new barrel being your other ammo shot just fine be interesting to see how the rounds you had problems with shoot now

Well thats the thing, when i got the rifle back the 1st time with the tweaks done to it i shot 4 types of ammo all of which keyholed. I shot imi 62gr m855, federal black box, American eagle red box, and fedeeal fusion 62 gr and all keyholed at 25 yrds. As for the dime at 100 yrds it was on a led sled and the new barrel is a match grade barrel.

[Rastoff]

I've never had a gun that keyholed with one ammo and not with all others. This is a weird problem.

Originally Posted by CVFD1433

He said that it took two guys to get the barrel nut off because it was way overtightened from the factory and there was no barrel nut shims on the gun.

Not all guns require shims. In fact, the majority don't. At least I've never used one and I have no problems with my rifles.

Originally Posted by CVFD1433

He said he took it to the range and was putting rounds in a dime at 100 yrds with iron sights.

He was exaggerating; I hope. Because the alternative is he's flat out lying. You see the main problem here is the size of the front sight. It's much larger than 1MOA. A dime is .7" and at 100 yards is almost invisible to most people. Hitting a dime is hard enough. Shooting a group the size of a dime is...well...it doesn't happen.

I'm sorry to say it, but it sounds like he sold you a bill of goods. However, it also sounds like you got a nice barrel, forearm and sight. At the very least you now should have a good rifle. It would have been cheaper to send it to S&W.

[cyphertext]

I agree with the others... you need a new gunsmith.

Perhaps your barrel was over torqued from the factory, but it doesn't require shims. Barrel shims are typically used with free float hand guards and non standard barrel nuts to get the proper alignment for the gas tube under the proper torque, because some barrel nuts that come with free float rails have fewer alignment holes than a standard barrel nut (mil spec type). If you have to use a shim with a standard barrel nut, something is wrong and out of spec.

Bi-metal bullets are not what caused the wear. Yes, I have seen the lucky gunner test, but what that test doesn't take into consideration is the powder used. From other tests that I have read about, it appears that the powder used has more effect on the barrel than the jacket of the bullet.

As far as "putting rounds in a dime"... possibly was shooting dime sized groups, but agree with others that he was not hitting a target the size of a dime.

I also agree that I would have sent it back to S&W, as your round count seems to be way low for wearing out the barrel under typical range use.

[MichiganScott]

Depending on the amount of wear and overall condition, the OP could have sold the original 1:8 5r barrel for a decent price. I hope he got it back from the 'smith. Had he sent the rifle back to the mothership, they would probably have re-barreled it with a current Sport barrel for free. The 5r barrels are no longer available for the Sport.

The US military at Frankfort Arsenal in 1942 began producing an ammunition known as M2 Ball, Alternate. It was a soft steel jacket covered with gilding metal to conserve on copper. Testing done at the time showed no more barrel wear than regular M2 Ball with a copper jacket. My club has issued M2 Ball, Alternate for it's CMP high power matches since their inception 21 years ago. Last years high overall competitor used a club gun that has had probably 4k rounds of the clad jacketed ammo down it's tube. It wouldn't have happened if the barrel was shot out.

[cyphertext]

Originally Posted by MichiganScott

Had he sent the rifle back to the mothership, they would probably have re-barreled it with a current Sport barrel for free. The 5r barrels are no longer available for the Sport.

I don't know about that. They still have the barrel available, they just don't put it on the Sport anymore. Good customer service would dictate that they replace with like for like, or better... Would be a good question for S&W.

[CVFD1433]

Just to clear some things up, the gunsmith was putting groups the size of a dime at 100 yrds. Not actually hitting a dime lol. Im going shooting today. I will post results

[cyphertext]

Originally Posted by CVFD1433

Just to clear some things up, the gunsmith was putting groups the size of a dime at 100 yrds. Not actually hitting a dime lol. Im going shooting today. I will post results

I think most knew what you meant... groups that could be covered by a dime.

[Rastoff]

Originally Posted by CVFD1433

Just to clear some things up, the gunsmith was putting groups the size of a dime at 100 yrds.

No, what I said was what I believe; not even groups that size. The consistency required is almost impossible with iron sights. Especially with regular ammo.

Maybe he did, but I'd want to see it myself. And, if he did, he's a world class shooter.

I had a manufacturer tell me he shot this group:


I don't believe him either.

[cyphertext]

Rastoff, I agree with you that he was probably exaggerating a little bit. Perhaps he was shooting a 1950s dime group adjusted for inflation... Takes about a dollar to do what a dime did back then!

[CVFD1433]

Ok so i just got back from the range and had a blast. My rifle has never shot this good before. Kneeling at 25 yrds i put 10 rounds in the center ring on the target about the size of a quarter. Kneeling at 100 yrds i put 10 rounds on target within the size of a baseball. All this with the imi m855 62gr. I shot every other type of ammo that was keyholing before and it all grouped within a quarter while kneeling at 25 yards as well. I am extremely happy with my purchase and the gunsmiths work. Im sorry to all about the lack of details regarding the gunsmith and such. My wife complains that i lack descriptive detail lol. I was eventually going to get a nice barrel for it anyway, this just gave me an excuse to get it done.

[Rastoff]

Well, that is a good report. I'm glad you're happy. At the end that's all that really matters.

EDIT: Just for the record, I believe that gun CAN shoot dime sized groups. It just needs a rest, match grade ammo and a better sighting device.