Accuracy question. (.22lr in a 5.56)

[JFrost]

I have a DPMS 5.56 with a CMMG .22lr conversion kit shooting CCI Stingers. With the .223 rounds the rifle is very accurate, but when shooting the .22lr they literally spray all over the place. At 50 feet while bench rested the pattern looks to be about 4 feet across. Is this because of the 1:9 twist? If so, is it even possible to be accurate with such light rounds? Or is it something else? Thanks.

 

[EdC]

I've got the CMMG myself, and have used it on a Colt LE6920. Very inaccurate, although I wouldn't say as bad as a 4 foot pattern at 50. Bad enough though. I'd say 8-9 inches at 50 ft. My guess is the twist. Tried CCI, Wolf subsonics and other ammo that work great in every other .22 rifle I have. Maybe it needs a 20" barrel to work well.

 

[dom1104]

50 FEET its 4 feet long?

I would quit it with the hyper velocity low grain rounds.

Try some normal old federal bulk pack or cci mini-mags.

They shoot fine in my 1/7.

 

[JFrost]

Hmm. So, is this right? "High twist rate for light and/or fast rounds and low twist rate for heavy and/or slow rounds." And somewhere in there should be a sweet spot? Is there a formula or graph for this? I'll try 'normal' velocity .22's next time and see what happens.

 

[melensdad]

The diameter of a 22lr is slightly smaller than the diameter of a 223. Essentially bullets from a 22lr bounce down the barrel of a rifle that is designed for 223/5.56. Some have good luck and others spray their bullets around.

Best bet is to try different brands of 22lr until you find one that your rifle shoots reasonably well. Then stick with that brand.

 

[Mr. Habib]

Hmm. So, is this right? "High twist rate for light and/or fast rounds and low twist rate for heavy and/or slow rounds." And somewhere in there should be a sweet spot? Is there a formula or graph for this? I'll try 'normal' velocity .22's next time and see what happens.

The ideal twist rate for a particular bullet depends on the caliber and length of the bullet. Here's a link to the formula. Greenhill Formula.The standard twist for .22lr is 1:16. Also as was previously mentioned, .22lr bullets are smaller diameter than .223's.

 

[dom1104]

You should be getting 3 - 4 inch accuracy at 50 yards, not 2 feet at 50 feet.

People will make a big deal about the .001 difference in the bore, but the soft lead 22 expands not unlike a shotgun slug.

I have shot 22lr from a 1/12 twist A1 barreled AR15, with amazing accuracy.

Nothing is "bouncing down the barrel", its a twist rate issue.

Find bullets that work in your gun, most likely it will be the 40 grain and longer hollow points.

1/7 doesnt work very well at all
1/9 works better than 1/7
1/12 works fantastic.

All the barrels are the same bore size.

There is no mystery here, the issue is the twist.

 

[SmileDocHill]

I have a 24" 1/9 twist HBAR that I use a CMMG .22 conversion in and I get 4MOA at 25 meters (within an inch).
I have a lot of people that don't believe that so I may have a generous memory of my range trip. I'll have to go take pics next time but I'm pretty sure I was getting that.

I did this little test after attending an Appleseed one time. I didn't use the conversion for the seed but used it and the targets and techniques in my next couple trips to the range. The range trip was more for a followup refresher so I didn't take pics.

 

[thompal]

I guess I just fail to see the attraction of these conversion kits. By the time you buy an AR AND a conversion kit, you end up with a VERY VERY expensive, horribly inaccurate .22LR. What's the advantage that I'm missing?

 

[dom1104]

Super simple Thompal.

If you already have an AR, that you cant shoot at many of the ranges around indy, you buy a kit for $150 bucks, and you can shoot thousands, and thousands, and thousands of rounds thru your AR15.

Then when you get to your match, range, SHTF event, you have thousands of rounds of ammo thru the gun you otherwise couldnt shoot very much.

 

[thompal]

Super simple Thompal.

If you already have an AR, that you cant shoot at many of the ranges around indy, you buy a kit for $150 bucks, and you can shoot thousands, and thousands, and thousands of rounds thru your AR15.

Then when you get to your match, range, SHTF event, you have thousands of rounds of ammo thru the gun you otherwise couldnt shoot very much.

I guess I still don't see the attraction. I could spend $150 and have a horribly inaccurate .22 rifle, with the added attraction of being able to put thousands of rounds of wear on my AR, OR, I could spend $200 or so and have a tack-driver .22 and not put any wear on my AR.

 

[IndianaGTI]

The diameter of a .22 LR bullet is .222 while the diameter of a 5.56 is .224. You guys keep talking about rifling. How much does the rifling matter if the bullet is small enough that it is not firmly engaging the rifling. It doesn't matter if you have 1 in 1 or 1 in 20 if the bullet is just ping ponging down the barrel.

Yes, I know it isn't quite that extreme, but the bullet is smaller than the barrel.

 

[mettle]

I have a DPMS 5.56 with a CMMG .22lr conversion kit shooting CCI Stingers. With the .223 rounds the rifle is very accurate, but when shooting the .22lr they literally spray all over the place. At 50 feet while bench rested the pattern looks to be about 4 feet across. Is this because of the 1:9 twist? If so, is it even possible to be accurate with such light rounds? Or is it something else? Thanks.

I watched my brother hit a broken clay pigeon from 105 yards last weekend with his cmmg .22 conversion in a Daniel defense rifle. He consecutively and consistently hit about 2" below it for 10 rounds before finally nailing it.

It is SURPRISINGLY accurate in my DD gun as well.

Sight your ar well and u can expect good things.

He was using Walmart federal bulk ammo too.

I'm not bragging, just saying it is eye opening accurate in a good rifle.

 

[dom1104]

The diameter of a .22 LR bullet is .222 while the diameter of a 5.56 is .224. You guys keep talking about rifling. How much does the rifling matter if the bullet is small enough that it is not firmly engaging the rifling. It doesn't matter if you have 1 in 1 or 1 in 20 if the bullet is just ping ponging down the barrel.

Yes, I know it isn't quite that extreme, but the bullet is smaller than the barrel.

You are simply incorrect in your thinking that the bullet stays the same diameter like it was made of titanium.

And yes, the rifling is what matters, not the bore size.

 

[dom1104]

I guess I still don't see the attraction. I could spend $150 and have a horribly inaccurate .22 rifle, with the added attraction of being able to put thousands of rounds of wear on my AR, OR, I could spend $200 or so and have a tack-driver .22 and not put any wear on my AR.

Some of us would rather "wear out" our AR in the pursuit of becoming a better shooter, than spending time shooting a 10/22.

The only route to the top spot on the score sheet is practice, and every minute, every round, and every dollar spent on "other guns" is working against you.

On the other hand, if your goal is just to not wear out your AR15, then of course you are 100% correct.

Because every minute you are spending time shooting that 10/22, you are "spending" time. Time you could have spent shooting the gun you are attempting to become expert with.

If the goal is to become an expert AR15 shot, well then son you gotta shoot AR15s.

 

[mettle]

Some of us would rather "wear out" our AR in the pursuit of becoming a better shooter, than spending time shooting a 10/22.

The only route to the top spot on the score sheet is practice, and every minute, every round, and every dollar spent on "other guns" is working against you.

On the other hand, if your goal is just to not wear out your AR15, then of course you are 100% correct.

Because every minute you are spending time shooting that 10/22, you are "spending" time. Time you could have spent shooting the gun you are attempting to become expert with.

If the goal is to become an expert AR15 shot, well then son you gotta shoot AR15s.

Not to mention the soft lead .22 rounds won't hurt the chrome anyways...

There are few on the planet, civilian speaking, that will fire enough of anything to wear out any barrel.

Let alone .22lr in an AR.

 

[U.S. Patriot]

I thought about a conversion kit or dedicated upper. I went with a 15-22 instead.

 

[.452browning]

My CMMG conversion in my CMMG M4 has been accurate enough for what i use it for. i dont shoot it beyond 50 yards really. i have but not very much. i can hit a 3" diameter resetting target all day at 50 yards from rest. but mostly i shoot it from closer with the conversion. working on transitioning on multiple targets. working on 2 chest 1 head drills and so on. just to make overall comfort level with rifle much better. once i go beyond 50 yards i drop my 5.56 BCG back in and shoot big boy bullets.

and mostly i have been using federal bulk pack ammo from walmart. probably 2000 rounds have been through it with minimal problems of FTF or FTE. i view it as a way to train for malfunctions.

 

[thompal]

If the goal is to become an expert AR15 shot, well then son you gotta shoot AR15s.

This I agree with 100%. Which is why, when I want to practice with my AR, I take it out and shoot it with actual correct ammo that is going to group as it should, have a correct POI at usable ranges, and have proper recoil characteristics.

An AR with a conversion kit may be fun to shoot, but if I'm going to shoot .22LR, I'd rather do it out of something that's going to be more ACCURATE, with a barrel that's designed to stabilize .22LR.

I'd be more inclined to go with a dedicated .22LR upper, although again, this is getting to be a pretty expensive .22.

If the object is to just get "trigger time" on your AR, why not just dry-fire it? The "recoil" is no less accurate than if you were running .22LR through it.

 

[dom1104]

This I agree with 100%. Which is why, when I want to practice with my AR, I take it out and shoot it with actual correct ammo that is going to group as it should, have a correct POI at usable ranges, and have proper recoil characteristics.

An AR with a conversion kit may be fun to shoot, but if I'm going to shoot .22LR, I'd rather do it out of something that's going to be more ACCURATE, with a barrel that's designed to stabilize .22LR.

I'd be more inclined to go with a dedicated .22LR upper, although again, this is getting to be a pretty expensive .22.

If the object is to just get "trigger time" on your AR, why not just dry-fire it? The "recoil" is no less accurate than if you were running .22LR through it.

I wont waste both of our time trying to convince you how much fun can be had with a 22lr conversion, you seem pretty set in your opinion, which is fine.

I have a dedicated upper as well, but honestly for most of what I do, the conversion kit works just as well.

steel plate shooting, sd drills, and teaching kids to shoot at close range, the conversion kit is plenty fine.