Page 1 of 1

Lets test your diagnostic know how!!!!!

Posted: Sat Feb 27, 2010 2:55 pm
by Lenard
I recently bought a CZ 223 Varmint with a Kevlar stock. Here are some of the clues of what it was doing and later on an explanation of what I found.

Groups were 3/4" to 2". With a cold barrel, it would shoot smaller groups and when warmed, they increased in size.

The scope setting never changed and the initial poi was the same every time out.

Action and scope screws were always checked for tightness.

This particular model has a bedding block for the action and the barrel is floated.

I know the answer to this, but just want to see if anyone can come up with a diagnosis.

Lenard

Re: Lets test your diagnostic know how!!!!!

Posted: Sun Feb 28, 2010 6:25 am
by glenn asher
It sorta sounds like the bedding block may be warped. That's not uncommon, even with HS stocks, let alone B&C. OR, it could be the bottom metal isn't seating properly, not uncommon with CZs, I'm told (haven't had that issue on my three).

Which bullets are you using? The Kevlar Varmints are usually 1-9" twist, I'm wondering also, if you're twisting the bullets too much for their jackets?

This could go on all day..................

Re: Lets test your diagnostic know how!!!!!

Posted: Sun Feb 28, 2010 6:46 am
by Daniel Brothers in SC
the load is too hot.......

Re: Lets test your diagnostic know how!!!!!

Posted: Sun Feb 28, 2010 9:16 am
by Lenard
Glenn, you hit the problem first time. It was the magazine box and it was bottoming out before the action was securely seated in the stock. It could not be much, as the most of the groups were less than two inches.

I releived the top of the magazine box about 1/16" and it immediately started shooting under a dime consistently. I was pretty sure that something was loose as experience had shown me that.

None of the loads are near maximum.

Re: Lets test your diagnostic know how!!!!!

Posted: Sun Feb 28, 2010 12:31 pm
by glenn asher
I'm glad you got it worked out. Rifles can be frustrating, especially when the rig SHOULD be problem free. Bedding blocks are supposed to cure all ills, and they help a lot, IF they are perfect. If they aren't perfect, all bets are off. Bedding, in general, though, is one of the easier things to fix, a little sanding here and there, some epoxy in the right places, and things are peachy.

A mag box issue can be frustrating, too. If some rifle brands are bedded with the mag box too tight, it can really cause accuracy hiccups, too. Some rifles are meant to have the box snug, and others are meant to have them float. Flip that around, and it takes all kinds of cussing to get it figured out. IIRC, Remington mag boxes are supposed to float, Winchesters, too, but Rugers............... or is it the other way around? :wall: :wall: :wall:

Re: Lets test your diagnostic know how!!!!!

Posted: Tue Mar 02, 2010 2:19 pm
by Lenard
Glen I took the cz out yesterday to see what it would do with 40 Sierra Hornet bullets. To my surprise, it shot into .400 at 112 yards. On top of that, the velocity was 3800 fps with the above bullet. I really questioned if the 1-9 twist would over stabilize those thin jackets bullets and blow them apart. The load should sure put the stops on sage rats and rock chucks.

Only around 15 days to my first trip.

Re: Lets test your diagnostic know how!!!!!

Posted: Tue Mar 02, 2010 4:20 pm
by glenn asher
Good deal! The first Savage .223 I bought, had a nice smooth barrel and shot the Sierra Blitzes really well. It was one of the older long-action rifles. I eventually got a short-action .223 to go with it, and wouldn't you know it, it would tear those Blitzes apart midway to the targets. :(
That got me going on the V-Max, Ballistic tip kick. They are tough enough for a rougher barrel.

CZs have hammer-forged barrels, and they are usually nice and smooth, so they seldom rip bullet jackets into pieces. Luckily, yours seems to be smooth enough for those little bullets.
Have fun in the rat patches!