Cz600 lux short throat

DGY

DGY

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Well looks like my new to me cz600 lux has a really short throat, when measuring distance to lands or max coal with 2 different bullets it’s way shorter than the 2.2600” sammi length .
One bullet is a Speer 70gn varmint and the max to jam is 2.0940” and with Hornady 50gn ECX it’s 2.168.
Magazine is long enough for long bullets, twist rate is 1:9 so should be able to stabilize 69-70 bullets, so I wonder why bother with a 1:9 twist if the throat is too short for longer bullets?
Who can lengthen a 223 throat?
Is it a simple procedure?
 
The throat is an integral part of the reamer. Chamber throats don't just accidentally end up short. If the chamber headspace is correct then the throat will be correct. The manufacturer made dozens of barrels with that reamer. Yours didn't end up different from all the others.

I'm gonna suggest you are either measuring something wrong or using an unsuitable bullet shape. You are also measuring COAL which is HIGHLY subjective to bullet shape. You have no idea what bullet shape was used to determine the SAMMI OAL. Stop measuring COAL and start measuring to the lands and ogive.

Once the seating depth is suitable for the throat, the COAL is completely irrelevant.
 
Yes I totally agree! I read a bit and sounds like cz is not using sammi specs but the European equivalent CIP(?) and from what I could find online they have a tighter chamber and shorter throat and the sammi specs, so you think that could be true? I’m a bit sceptical since 223 rem is so widely used. But I read that tikka chamber are also in some chambering tighter chambers. I will be meeting with a friend this week that has done lots of gunsmithing for himself and is a avid reloader and wildcat relaxer as well, he has thousands of 223 bullets of different weight and shape so I will go there with my rifle and I’m sure he will be able to straighten me out 😂 .
Thanks for the reply!
 
Ok went to my friend place and we tried a bunch of different bullets like the nosler custom competition 69gn, and year the bullet with its slender longer ogive sits better in the case, but bullet seated as far out as the lands would permit still has its base past(not much but still) the bottom section of the case shoulder.
Anyway I will start shooting it as soon as the cold snap goes away, -45c this morning at my place. And will shoot some lighter shorter bullet that I will be getting and I will develop a load using those 69gn nosler custom competition one too!
My friend is ordering a new reamer for him self and he will be ordering a thrower for the 223, so maybe I will get the throat lengthened a few thousands…
 
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