So, I went down to the range yesterday to finish breaking in a Cz 550 in .404J. Had been doing it piece meal over the course of months and not attempting to shoot for accuracy. Just a shot or two in the direction of the target and clean the rifle when I got home. Finally figured it was time to mount a scope and get serious.

First shot was using an old hand load that came with another .404J I'd bought. Hawke bullet, 350gr IIRC. Perfect for a fouling shot before zeroing the scope with old 400gr RWS solids. Fouling shot a bit low but no problem, after all it was a quick off hand shot with a boresighted scope. Switch to the RWS loads. Off the rest I don't even touch the paper. WTF? Check that all the screwws are tight and try again. Still not on paper. Walk out to target and see that I think are tumbling .404 bullets on the badly shot up board. No one else being at the range, I grab the rifle and walk out to the target and fire a couple of shots from 20m. Finally hit paper and yep, the bullets are tumbling.

What do you think has happened? First shot with the light handload normal. Next 4 shots with old, heavy factory loads tumble. Hadn't noticed this before, but wasn't paying attention either. Just firing a couple of offhand shots into used targets at the end of sessions. I'll load up some hand loads and see what happens with them, but I'm of course worrying that I've some how managed to wreck a barrel.

Dean

CZ factory 404?

barrel is oversized, call CZ

jeffeosso,

Thanks for the reply. The shop I bought it at has been eaten by a major retailer who are a major PITA to deal with. Getting firearms related stuff to and from the US is a major PITA nowdays. Hope the problem is an oversized barrel, but this is sounding like getting it fixed without spending much of my own cash will be a minor epic.

Dean.

First, measure the RWS bullets. If they measure .423" or within a thousandth or so, contact the Canadian importer of CZ rifles, which just happens to be...CZ-USA. Their number is 1-800-955-4486.

If they agree that the barrel is out of specification, they should be able to assist you in getting it to a service facility.

George

I got the calipers out when I got home from work today. The RWS factory loads have a very consistent .421 bullet diameter as do the stock of Woodleighs I picked up (which is what I think RWS used). The Swift A-Frames were also remarkably consistent at .422, the Hornaday DGX was less consistent, averaging a bit less than .4225. Smells like it is an oversized barrel as suggested. Next call will be to CZ-USA (thanks for the number).

Dean

Use the inside calipers to measure the bore at the muzzle.

George

Maki,I had the same experience with two CZ's.One was a 458wm and the other a lott.Both of their bores were shotgun like from the beginning and it did not take long before they were tumbling bullets(100rds-200rds or so).My Ruger in 458Lott proved that this was the case.I have fired over two thousand rds with my Ruger lott and it still is accurate out to 100yds and beyond without tumbling bullets.I've said this before and that is CZ barrels are really poor in that there is nothing there to begin with.So far from my experience,tumbling bullets are caused by an oversize or shot-out bore.Also,the CZ's would only shoot the A-frame or Woodleigh softs-they would never shoot any solid or monometal accurate,even from the begining.I am very satisfied with Ruger rifles that my next target rifle will be a Ruger 308.

Yeah, I am betting older ammo, undersize bullets. My PacNor M70 in 404j shoots like a varmint rifle w/ current manuf bullets; NF, Hawk (although I have had them shed jackets), Barnes, Woodleigh. They all mic 0.423".

Being dense, I never thought to mic the barrel until it was suggested here. The result was .4235. I'm guessing that is within manufacturing tolerances. For some reason I wouldn't have guessed that .0025" would have been that critical. Just how much can you expect a barrel to expand anyway?

Dean

Dean

Try a few North Forks.

quote:

Originally posted by lawndart:
Try a few North Forks.

Would love to. Know a Canadian distributor?

Dean

quote:

Originally posted by maki:

quote:

Originally posted by lawndart:
Try a few North Forks.

Would love to. Know a Canadian distributor?

Dean

Current Woodleigh or Hornady should be the proper size, 0.423". I think RWS even made them as small as 0.418"?

For the .404 Jeffery, bullets and barrel groove diameters are supposed to be .423 inch, right?

Maki,

We do have a Canadian distributor - Prophet River Firearms. Their website is www.prophetriver.com. For ordering inquiries please contact Clayton Smiley at csmiley@prophetriver.com or by phone at 780.875.0575 or 780.872.2865

North Fork Technologies
www.northforkbullets.com

.423 or .424.. but if you can mike it at .423, its probably to big