I.D choke tubes

[rev]

Anybody mic the I.D of their choke tubes, just to see if a .670 is a ,670 or a .690 is a .690
Just messing around last night and I thought I would check 4 different brand new,never been shot thru chokes. They ranged from .003 to .008 from the marked sized. I just thought with the machining tools we have these days that they would beable to cut a .670 a .670 not a .678. So does .008 going to make that big of different in 40 yards, As you might guess, I`m a newbie, and the season doesn`t come in until april 27th here in Indiana and I`m bored to death waiting with nothing to do but mic my chokes, I have found this forum a great help and jelious of the ones alreading bagging the birds, Will it make a difference.

[Reloader]

I check mine.  They are usually pretty close to stated, within .003.  I measured a Rhino 660 last week that was .658.

I think it does make a difference.  Ever wondered why you can buy two of the same chokes and have diff numbers from each?  I have several duplicate choke tubes and some pattern differently than the "same" choke in the same gun.

If it didn't make a difference, why do so many get better patterns with say a JH 660 over a JH665 or a IC 665 over a 670...

You may have a 662 that's supposed to be a 660 and it outshoot a 664 that's supposed to be a 665 at only a whopping .002 difference. Of course you may have two 665s that shoot diff even if they measure a true 665.   It's a weird deal and one reason I always suggest for guys to sight in their gun with the very choke they will use and the same lot of ammo if possible.

On that same note, My cousin borrowed a 660 JH for two seasons and liked it, so decided to buy hisself one.  I told him to just keep mine and give me the new one.  He wanted the new one, not my old one.  I told him he had better go shoot his gun again.  He did, POI was different.

Reloader

[rev]

I was wrong, I have a well known brand name choke that is marked .675 on the choke, Looked up the part # on their website, says it`s a .675.  I mic it at .690, If I had not have mic it, I would have pulled my hair out trying to figure out why it wasn`t shooting a tighter pattern then one that was .690. Now I have 2 choke tubes that are both .690 instead of 2 that are .015 difference. Glad I did before I started wasting a lot of shells. I guess when you are talking 1/1000th of an inch, I`m going to have to mic it to besure