SR556 22lr Conversion?

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cbzdel

Bearcat
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Would the SR556 take oneof the AR15 22lr conversion kits? One of the kits that comes with a new bolt/carrier.

I am starting to not want to get the SR22 after seeing one in person, I didnt like the feel, but the SR556 is a whole new beast :)
 

Snake45

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I don't know this for a fact, but I'm having a hard time thinking of why it wouldn't.

Does the SR556 use a standard AR-type charging handle? If it does, my guess would be that a .22 conversion kit would fit.
 

wetidlerjr

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I have been told by a member on another board that the gas piston rod in the Ruger 556 is very difficult to remove and it must be removed to use the bolt conversion. I can easily remove it on my Bushmaster (Adams Arms gas piston conv.) so I can use one in it.
I have no experience with a Ruger 556 so I can't confirm this info.
 

SIGWatchman

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As far as I can tell, it will not work. As stated, Ruger chose to make the op rod inaccessible to the end user and it sticks out too far into the receiver.
 

Snake45

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Anyone have a cutaway of SR556, and/or a photo of the charging handle out of the gun? I'm trying to picture where the problem is, and how you might be able to modfy something to get it to work. :?
 

SIGWatchman

Bearcat
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Snake45":zdf8pgu2 said:
Anyone have a cutaway of SR556, and/or a photo of the charging handle out of the gun? I'm trying to picture where the problem is, and how you might be able to modfy something to get it to work. :?

The operating rod sticks further out into the upper receiver than a DI gas tube does, about the length of a gas key tube. The SR556 uses a standard charging handle.

What I would like to see is how those ciener type .22lr conversions actually fit into the upper. My concern is the conversion will not seat fully due to the op rod sticking out. If there is nothing about the conversion that rides up into the charging handle then maybe they would work. I'd hate to see someone dump the $200 into one of those conversions only to learn it doesn't fit due to an operating rod that cannot be removed.
 

wetidlerjr

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SIGWatchman":1hexpfs4 said:
Snake45":1hexpfs4 said:
Anyone have a cutaway of SR556, and/or a photo of the charging handle out of the gun? I'm trying to picture where the problem is, and how you might be able to modfy something to get it to work. :?

The operating rod sticks further out into the upper receiver than a DI gas tube does, about the length of a gas key tube. The SR556 uses a standard charging handle.

What I would like to see is how those ciener type .22lr conversions actually fit into the upper. My concern is the conversion will not seat fully due to the op rod sticking out. If there is nothing about the conversion that rides up into the charging handle then maybe they would work. I'd hate to see someone dump the $200 into one of those conversions only to learn it doesn't fit due to an operating rod that cannot be removed.

That IS the problem. I have an AA conversion in one of my Bushmaster ARs and unless you take out the rod you can not seat the conversion bolt properly. Apparently, the SR556 does not make it easy (or even possible) for the end-user to remove it without major disassembly.
 

SIGWatchman

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If there is anyone around Pittsburgh that has one of those Ciener type .22lr conversions for the AR, I would be happy to see if it fits and works in my SR556.
 

wetidlerjr

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SIGWatchman":27e3xcov said:
If there is anyone around Pittsburgh that has one of those Ciener type .22lr conversions for the AR, I would be happy to see if it fits and works in my SR556.

It won't unless you get the rod out. 8)
 
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So, two questions as a side note:

On a standard AR15 you have to remove some part... besides the obvious bolt, to put in a 22lr conversion kit?

How accurate is the rifle shooting 22lr after the conversion?

What is the best conversion kit for the money?

Okay, I know that's 3 questions.
 

Snake45

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blume357":qlw1bjqs said:
On a standard AR15 you have to remove some part... besides the obvious bolt, to put in a 22lr conversion kit?
You remove the 5.56 bolt carrier group and replace it with the conversion. Push pull click click, it's back together just that quick.

How accurate is the rifle shooting 22lr after the conversion?
This can vary widely depending on ammo type, barrel twist rate, phase of the moon, the Dow-Jones average, etc. Some have reported accuracy as good as a stock 10/22 or even a bit better. My own experience is that if you get groups under an inch at 25 yards, you're doing okay; if you can consistently get under 3/4" at 25 yards, you're doing pretty well, and if you have a combination that will consistently shoot under 1/2" (or even 5/8"), that's a real gem.

You'll prolly be able to stay on a beer can at 25 yards without much trouble. At 50 it's likely you'll have some shots that won't hit the beer can, though most will.

What is the best conversion kit for the money?
I think most of them available now are copies, more or less, of the Ciener. The Ciener's been around a long time and is a known entity. The downside is that Ciener has the worst customer service in the whole firearms industry. The good news is that there are many people at Rimfirecentral.com and AR15.com who have a lot of experience with Cieners and can help you get one broken in and running smoothly. They sometimes take a little tuning but they almost always run well eventually.
 

wetidlerjr

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I have a dedicated 22LR AR upper (Tactical Solutions) and a conversion bolt from CMMG. I had a minor problem with my CMMG conversion which they corrected in less than a week. The dedicated upper is more accurate but not as much as you might think. The CMMG conversion bolt worked fine in both of my Bushmaster uppers but I had to install a hammer without a notch in the lower I use with my 22LR AR upper. I used an old style hammer from DPMS. This is a common thing that VERY often must be done as the notch hammer will not re-cock after the first shot.



AR Hammer wo/notch

ar15_hammer.jpg


AR Hammer w/notch

Hammer.jpg
 
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Yes, I saw that little potential problem on the CMMG sight... at least they tell you about it and also say use round nose ammo and I think they recommend 36 grain high velocity ammo too

the issue I now wonder about with a conversion kit is shooting 22lr ammo through a barrel with a 1/9 or even 1/7 twist? Sounds like it may be okay out to 25 yards but anything beyond and you might have a round tumbling instead of twisting?
 

Snake45

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blume357":1f2fcfae said:
the issue I now wonder about with a conversion kit is shooting 22lr ammo through a barrel with a 1/9 or even 1/7 twist? Sounds like it may be okay out to 25 yards but anything beyond and you might have a round tumbling instead of twisting?
Tumbling doesn't seem to be the problem. I've never heard of anyone getting keyholes at 50 yards (or even 100, for that matter). The problem might be that the too-fast spin (normal .22LR twist rate is 1:16) tends to accentuate any off-center weight in the bullet. In other words, if there's a tiny little "bubble" or air pocket in the bullet (and I believe .22 bullets are swaged, not cast), or a dent or scratch on the surface, or a tiny little extra bit of lead, say on the base, then the bullet is going to behave a bit like an unbalanced wheel/tire on your car. The too-fast twist exaggerates this effect.

And then there's the matter that most .22LR bullets are undersized for a .22 centerfire bore. And the fact that in the drop-in conversions, the bullet flies for a short distance down a smooth bore before it engages the rifling at all.

I have one 1:12 AR barrel that will shoot Winchester Dynapoints into tighter groups than either of my 10/22s. But two other 1:12 barrels I tested won't shoot them (or anything else) nearly as well.

Accuracy of drop-in conversions in ARs is very hit or miss. Some people have gotten very, very good accuracy (if their postings are to be believed) but this is the exception rather than the rule and is not to be expected. No one can tell you how YOUR conversion will shoot in YOUR rifle, you just have to roll the dice and see what you get. I will say that the lower your accuracy expectations, the happier you are likely to be.

FWIW, I shoot my conversion (not a Ciener, but a USGI M261 unit) at 1/6 scale Mil E silhouettes at 50 feet, which is like shooting fullsize targets at 100 yards. I shoot them from standing or offhand position. This is a challenging target but the rifle is accurate enough to "clean the course" if I do my part (as they say). Interestingly, there's not much difference in group size (offhand, remember) between the converted AR and other, more accurate .22 rifles in my hands. A better shot might be able to tell the difference. :wink:
 
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