452 17 hmr just can t get dialed in

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cliffmcc

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Like it says I can't seem to dial in a 452 17 hmr American.
Have free floated the stock.
You Dave at 1 lb
Torqued 20 to 25 lb.
Switched scope and rings.
One group of ten with cci tnt 17 can get .5 at 50 yards.
My 452 .22 and 455 .17 do circles around this.
Where to go from here is the question.
 
torque both screws to 5 inch pounds, shoot five and increase the torque another 5 inch pounds, shoot 5 and repeat until the group shrink to your liking
 
I shot the gun before free floating the barrel the group were so that s why I did it, I will try he 5 lb torque and work up, I had done this starting at 15 with no significant change. Bedding is an option I have never done it and would like to find some gun smith that has on the CZ s.
I m going to redo the trigger with a different shim and spring to make it crisper. The bore is so small it s hard to get a good look. Some say these can take a brick to break in was nt the case wit the 452 .22 or the 455 in 17 hmr. Definitely a learning process.
 
I'm no expert on the topic...but having owned a 452 Varmint in 17HMR, I thought I'd chime in.

1. Scope vs. distance~are you shooting @ 100 yards? If it's less than that, does your scope have SF or AO? Parallax issues alone can make for wonky results.
2. 452 "American"..meaning standard-weight barrel? Even 17HMR has the potential of warming the barrel enough to throw-off accuracy. I trust you're letting the barrel cool a bit between shots?
3. When I had a 452 Varmint in 17HMR, the only ammo it shot impressively was Hornady 20gr. HPs. That was with a bone stock, modified-nothing rifle. Everything else...it was an effort to keep around 1". Those could shoot under 1/2 MOA if I did my part.
4. I trust you trust your rest(s) front and rear to be steady?
 
Thanks for the reply, I m shooting 50 yards with a 14 power AO vortex scope, tried 2 different ones, and rings. The American is a heavy barrel . I bench shoot quite a bit and have been using the same set up I use to shoot 200 and 300 yrds.
I would like to look at the bore but I m not sure they make camera that small.
The funny thing is I can get a great group .3 /.5 with 5 rounds and then for ten others it can go to 1 to 1.5 at 50 yards. Trigger is set at 1 lb.
 
.22LRGUY said:
I'm no expert on the topic...but having owned a 452 Varmint in 17HMR, I thought I'd chime in.

1. Scope vs. distance~are you shooting @ 100 yards? If it's less than that, does your scope have SF or AO? Parallax issues alone can make for wonky results.
2. 452 "American"..meaning standard-weight barrel? Even 17HMR has the potential of warming the barrel enough to throw-off accuracy. I trust you're letting the barrel cool a bit between shots?
3. When I had a 452 Varmint in 17HMR, the only ammo it shot impressively was Hornady 20gr. HPs. That was with a bone stock, modified-nothing rifle. Everything else...it was an effort to keep around 1". Those could shoot under 1/2 MOA if I did my part.
4. I trust you trust your rest(s) front and rear to be steady?
Click to expand...

My 452 american will put em in the same hole at 50 with a 3-9x40 vortex viper non adjustable.

cliffmcc said:
Thanks for the reply, I m shooting 50 yards with a 14 power AO vortex scope, tried 2 different ones, and rings. The American is a heavy barrel .
Click to expand...

The american is a sporter weight barrel. The varmint is the heavy barrel.
 
The gun I m working on is an 452 American but has a heavier barrel than my regular American, I figured I d get better accuracy at 100 yds bench shooting. That's what is frustrating.
Saw an article where they free float the barrel by placing a washer between the magazine well and front screw, seemed questionable to me .
 
cliffmcc said:
The gun I m working on is an 452 American but has a heavier barrel than my regular American, I figured I d get better accuracy at 100 yds bench shooting. That's what is frustrating.
Saw an article where they free float the barrel by placing a washer between the magazine well and front screw, seemed questionable to me .
Click to expand...

A while back there were CZ's that had heavy barrels but whose receivers were stamped "American". The heavy barrel, together with a barrel lug, would make it a CZ 452 Varmint, despite the stamp "American".
 
cliffmcc said:
That defines this gun. Alot to ask for a single lug. I assume the accuracy should be good as a model?
Click to expand...

There is no reason to believe that the CZ 452 Varmint is any less accurate than any other CZ model. Individual rifles of any given model may shoot better or worse than another, but it doesn't matter between models. Torque the action screw to the receiver around 20 inch pounds and the barrel lug screw the same. This should be a good place to start. Test with good ammo such as SK Standard Plus.
 
You can also try an epoxy "shim" between the barrel and forestock. Not all CZs shoot well with a floated barrel. Both of mine have a shim added. If you're using a bipod or a rest near the front of the stock, it's easy to get enough stock flex to cause vertical strings in your groups, particularly with a heavy barrel.
With my 452 Varmint 22LR, I added the shim directly above the swivel stud the bipod attaches to. The vertical element in my groups was reduced noticeably.
If you wax the barrel channel first, removing the shim is easy if it doesn't work.
You can try a search on Rimfire Central for "CZ barrel shim", there should be some results.
 
Very confusing. I have 2, 452 s clearly marked American.
One is a thin barrel the other a heavy barrel. No doubt about it.
 
grauhanen said:
There is no reason to believe that the CZ 452 Varmint is any less accurate than any other CZ model. Individual rifles of any given model may shoot better or worse than another, but it doesn't matter between models. Torque the action screw to the receiver around 20 inch pounds and the barrel lug screw the same. This should be a good place to start. Test with good ammo such as SK Standard Plus.
Click to expand...

where does one get SK Standard Plus 17 hmr ammo? I need some....

OP, have you given the bore a good cleaning? ( I am assuming you have.... however it can't hurt to ask)

The other consideration is, there are times when CZ sends out a rifle that just not accurate. You do have option of sending it back.
 
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