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12/9/2010 4:10:53 PM EDT
i was just wondering this, i've always heard that little smooth space between the conversion kit and the rifled barrel degrades accuracy when it has to jump from smooth to rifled. Would rifling that space improve accuracy? Or would it even make a difference? Or is there some reason it cant be done. it seems to me that it wouldnt be that big of a deal to put grooves in that space other then a added step to the manufacture of the conversion kit. just wondering. Thanks
12/9/2010 4:14:35 PM EDT
[#1]
How would you have it match the barrel rifling?

Or would it even matter if it didn't "clock" correctly?
12/9/2010 4:27:09 PM EDT
[#2]
i agree, but im thinking wouldnt it be better if the bullet is already starting to turn instead of just jumping into the rifling
12/9/2010 4:48:31 PM EDT
[#3]
Interesting question. I'm no engineer, but I'm thinking that since there is no way of knowing what twist the upper it is used in might have, that rifling in the conversion kit might be detrimental to accuracy instead of helping.
12/9/2010 5:22:38 PM EDT
[#4]
Um, the Air Force conversion has a rifled chamber insert.
I'm money and months away from testing conversions in a rimfire barrel.
12/9/2010 5:54:09 PM EDT
[#5]
Were  the military barrels not all 1/12 when .22 conversions were being used?
12/9/2010 5:56:18 PM EDT
[#6]
I had heard that the Air Force Conversion has rifling. I've never even held one.
I wonder if it's 1:12" or 1:14". It should be one of the 2 to match up with early
M16's / AR's of the period. The Air Force actually bought into the original AR-15's.

IMHO the rifling may be more detrimental than having no rifling. It's assured that the
rifling in the chamber adapter won't line up with rifling in many of the rifles it's used in.
Even if they have the same twist rate. It may have been a key selling point for the Air
Force but we don't see anyone doing it on what they sell now.

At one time, I wanted to open the freebore of the 22 chamber adapter from 0.221 / 0.222
to 0.224. Federal and several other manufacturers 22's measure 0.223 / 0.224 when the
bullet is crimped in the manufacturing process. After really thinking the whole idea over, I
opened one up. It didn't make any difference or it was so minuscule that it didn't matter.

Just my thoughts,
Dave
12/9/2010 6:56:47 PM EDT
[#7]
I have often felt that it is a wonder that the bullet can shoot worth a crap after doing that 2" or so jump to a barrel that is all the wrong twist ????
Seems you would get lots of blow by with the unrifled portion being sort of loose

Best I can come up with is the bullet takes a leep and due to low friction gets a pretty good velocity so that when it slams into the rifeling it mashes down (obutrates?) and gets a real good grip on that nasty wrong twist rifeling ?
12/9/2010 7:24:12 PM EDT
[#8]
All we really need to know is that the conversions available to us are pretty reliable,
reasonably accurate and an absolute blast to shoot....

Spec
12/9/2010 7:30:17 PM EDT
[#9]
That's why dedicated uppers exist. No questions or concerns there.
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