.22lr that mics out to .221

[Ninety]

Can some of you mic out your ammo? Or do you know of a readily available source to find out this information?

I have looked at a couple of manf. websites but they didn't seem to state what their bullets mic out at, unless I missed it. . .

Thank you ..

It's for a 22lr conversion on a 5.45 rifle

We mic'd some out the other nite and some were .223 some were .221

[Bastard]

externally lubricated - more than likely the cause of the variations

also you would probably have better luck in the rimfire section

[thenodnarb]

Why on earth are you measuring? .22lr is perfect for that bore, even better than .223 or 5.56.
Even if its 1 thou or 2 thou over, that should be fine. lead bullets swage down just fine.

[rg1]

Not precise measurements since 22 RF bullets are coated with different lubes:
Winchester Super-X 36 gr HP----.223"
Remington Thunderbolt----------.224"
CCI Green Tag--------------------.224.5"
CCI Mini Mag 36 HP---------------.224"
Your measurements on your .22's may differ from mine.

[Ninety]

Ty rg1
We measured some cci and it was .221..

I was a little worried that there might not be enough powder behind the 22lr..
Also found this

The nominal bore diameter for .22 rimfire, be it short, long, or long rifle (exclusive of .22 WMR which is
.224") is .222". However, it is not uncommon for barrels rifled at different times in the life of the button to
measure in excess of that by almost .001".

It is unlikely that CMMG would intentionally choose a barrel with a bore of .223" as there is no economic
advantage to doing so and would result in negative feedback from the shooting community over poor accuracy.

Of even greater concern to a rifleman is the chamber. Ruger offers a 10-22 with a tight chamber (like
a Bentz) that is slightly longer than a tight European match bolt chamber, but is shorter than most
general purpose semi-auto .22lr chambers. This gives a boost to accuracy and yet will allow for the extraction of a live round.
CMMG prides itself on the live round extraction feature, which tells you something about their chamber.
I suspect the CMMG barrel uses the standard .22lr semi-auto reamer that will enable the gun to run in rapid fire
without jamming using a wide variety of ammunition.

If your reason for asking the dimesnion is driven by a desire for accuracy or merely as a curiosity I can see no harm in it, but be
aware that .001" one way or another is not the end all when it comes to rimfire accuracy as many other factors go in to the mix
of variables which make or break an accurate firearm.

Hope you get your answer,
Ted
AFSC2W171Z [Member]

From Ar15.comhttp://www.ar15.com/archive/topic.ht...f=145&t=202866


I had asked in another thread and was surprised no real responses.. also a little surprised it hasn't come up before.. I'm just trying to avoid building a dedicated 22lr or another 223. as the one 223 AR I have I really don't want to shoot 22lr out of it. The idea is to mill down a conversion kit to work with my 5.45 build. Would make it a cheap shooter but who knows.. Haven't really received any feedback on it.



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[thenodnarb]

a conversion kit for a 5.45 AK sounds awesome. Wikipedia says the standard twist rate for a 5.45 is 1 in 10. That's still too fast for .22 but the smaller groove diameter should still lead to much better accuracy than that in AR's in .223

Of course the other inherent problem with conversion kits is the long unrifled lead caused by the conversion chamber.
Don't worry about bullet diameter just yet. It shouldn't be a problem.

[rsrocket1]

I believe the SAAMI specifications are .217 bore diameter and .222 groove diameter for the .22 long rifle, and .219 bore diameter and .224 groove diameter for the 223 remington. A .221" 22LR will likely bump up in a 22LR gun. It may or may not bump up to completely seal the gases in a SAAMI spec .223 barrel, but it will very likely engage the rifling and spin so you should get fairly accurate shots. Will you get 1MOA accuracy? Only you can test that out. Will it lead the barrel? Again, only you can test that out and even if you do, you can clean it out in 1 minute with a bore mop and Chore Boy strand.