CZ 455

[chuck d]

Getting ready for my 1st SB match. My practice session at a 100 yards was poor. I was using same ammo I used in my 452, and the long range wasn't nearly as good. The 452 was 3/4" at 100 yards. So I benched the 455, same ammo and it looks about 2 1/2-3"! WOW. I have a match tomorrow and will go with it. Anyone seeing the 455's not shooting? I have a Yo Dave's trigger in it.
The ammo is a Eley practice that I got a case for a good price.
Suggestions? I have a bunch of Eley target and some Wolf Match.

thanks
chuck

[oldrifleman]

Rimfires can be a very finicky group, each will like different brands or even lots within a brand better than others. You will need to try what you have can get until you are satisfied ( or broke).

[jfaaa]

Just got a 455 Synthetic, not the same stock as the 452 silhouette, much cheaper feeling and looking. the trigger wasn't too bad, around 3# out of the box. I put a good Leupold 6.5 to 20 on and went to sight it it. Grouped good shooting off a benchrest grade rifle rest with CCI std vel at 40, 60, 77, fair at 100, but I could hit clay birds at 100 meters offhand no problem. Dialed it back to 40 meters, practiced offhand, and got lousy results. Sat back down at the bench and got a 4" group at 40 meters. The 4" group was the last of 100 rounds total. WHAT HAPPENED?? All shots were touching at 40 meters the first time around! I'm going to try the whole exercise again with some SK rifle match. Also put in an adjustable sear and adjusted trigger to 2.5#. Hoping the ammo is the issue on this one.

Jim

[chuckjordan2]

Jim,
Chuck,

You know that every time you take apart your CZ (action from stock) it can have a detrimental POI shift. I read that Jim just changed distances and came back to 40yds. It may have heated the barrel. Is your 455 barrel free floating? Without seeing the physical rifle, or reading more info, I can only provide a guess...

I found my 452 American likes a torque setting (action to stock) at 21 inch lbs. Hour's will likely be different. But I rarely (@2-3 years?) disassemble it. That was after I checked the barrel was floated.
Chuck, I would try another session with a cold barrel. And keep the barrel cool.

Also, where you bench the for end makes a difference. Try benching it where your supporting hand will be.

Chuck

[BCloninger]

Second on action bolt torque, but also check torque on the barrel retention bolts.

[chuck d]

Thanks guys

After a disastrous 1/10 on rams yesterday, I went home and back to my range. My ammo preformed as it had at 100- 3" or so. I tried the Eley target I had, had that was worse! I was using my benchrest gear. I then tried Wolf xtra match and that was magic. By bench groups went to 3/4 of an inch. Off hang I was hitting 5/10 rams.

Jim-
I am not a big cleaner, I had about 150 rounds thru my 455 and saw definite improvements after cleaning. Nothing aggressive- a few wet patches, a nylon brush and patch out.


Thanks for the feed back
chuck

[yankee]

Try just a dry patch for cleaning. If testing ammo a dry patch between brands. Then 10 or so shots to settle the barrel in then shoot for group.

[chuckjordan2]

3" down to 3/4" is a jump for not-bad ammo. Have you adjusted your bolts? I find that I'll tighten to a certain inch pound, then shoot 5 shots. Then either tighten or loosen and follow that pattern until that group tighten's up.

[jfaaa]

On the 455 synthetic: floated the barrel all the way back to the receiver. Did the same routine from 40, 60 , 77, 100 with SK match extra and CCI std.vel. 2 distinct groups 1 to 2 inches apart at each distance. The smaller groups were from CCI std vel, which surprised me. The final 40 meter target was the famous cliche~ one ragged hole- with CCI ! Originally the barrel was tight to the stock forearm about halfway out from the receiver.I think floating helped, also think more rounds down the barrel (about 250 now) are breaking it in.

Jim

[BCloninger]

What kind of lubricant is on the CCI Standard Velocity? 711B shot very well for me, but lead fouling would come out of the barrel in spirals unless the bullets got extra lubricant. It seemed more sensible to use Eley or SK in a lapped barrel, but if the 455 bore is a little rough, fouling may have smoothed it out.