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New CZ 457 24" 1.180 Match Barrel from L3i
- Thread starter Mark_Dorman
- Start date
Got the barrel in yesterday. The new Grey Birch La Chassis 457 with the 16" forearm also arrived yesterday. I can say these two CZ457 upgrades are a match made in heaven. With everything mounted it balances perfectly on a shooting bag about 3-4 inches in front of the barricade stop with no extra weights. For my wife this makes a well-balanced competition rifle that isn't overly heavy for her. It weighed out at 15.2 lbs with an arca plate and bipod. It is 14.2 lbs with just the rifle.
I did measure the tenon to check headspace and I got 1.192. I ended up using the 0.004 shim. Personally, I think it was fine with the 0.001-0.002 shim, but this is my wife's NRL22/PRS rifle, and she wanted a slightly lighter bolt throw. We did cycle about 15 rounds through it just to test loading and extraction with no issues at all. All the rounds show signs of engaging the rifling nicely. The barrel has a nice clean finish. I don't see any machining marks or scratches in this one. We will test it at the range after work today for groups and break in.
I did measure the tenon to check headspace and I got 1.192. I ended up using the 0.004 shim. Personally, I think it was fine with the 0.001-0.002 shim, but this is my wife's NRL22/PRS rifle, and she wanted a slightly lighter bolt throw. We did cycle about 15 rounds through it just to test loading and extraction with no issues at all. All the rounds show signs of engaging the rifling nicely. The barrel has a nice clean finish. I don't see any machining marks or scratches in this one. We will test it at the range after work today for groups and break in.
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My wife shoots Norma TAC-22, Norma Match, and SK Rifle Match.
I didn't notice any contact with the chassis, but I will run the ol' trusty paper test.
As for the final headspace, if I measured everything correctly with my caliper it should be right at 0.044".
I didn't notice any contact with the chassis, but I will run the ol' trusty paper test.
As for the final headspace, if I measured everything correctly with my caliper it should be right at 0.044".
I'm mostly going to be running norma tac 22 for my son as well.
Although, I am thinking of letting him use my stash of Center-X. I guess I need to decide which ammo before I finalize on the shim
Did you measure rim thickness in order to choose the shim?
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TAC-22 is kind of that secret, not secret for NRL22. It shot great out of her stock 16" varmint barrel. For the price it is light years ahead of everything else at that price. The Norma Match isn't much more and we do see slightly better fps standard deviations. The SK rifle Match is my stash that my Bergara likes.
I didn't measure rim thickness. The barrel comes with 5 shims if I remember correctly. I fitted the barrel with no shim and the bolt close was very hard. So, I went one shim at a time really just checking based off the feel of the bolt close. I thought it was fine at 0.002 shim but I shoot a Bergara B14r which is known for a harder bolt close. The wife really wanted a lighter feel closer to how it was from the factory so, I kept trying shims until she was happy. We will test it at the range to make sure we are seeing good constant groups and velocities.
Now I'm confused?
Adding shims would make the bolt close harder for each step up in thickness.
But you're saying without any shims it was a tough bolt close and adding thickness made it easier?
That would be bolt shims. These are barrel shims. Each shim goes between the barrel shoulder and action face. This pulls the breach face away from the bolt face.
He is adding Barrel shims which moves the breach face further away from the bolt face.
To be honest I didn't read that part but with full confidence I can tell you they fit around the barrel tenon perfectly. So, if the barrel tenon is the same diameter as the inside diameter of the action there is no way they are meant to be bolt shims. I believe it is just a typo in the description.
You may want to look into the Grey Birch La Chassis. I don't know what his current setups weight is but at 14.2 lbs this one is fairly light. This is also with the Arken scope which Arken is known for making relatively heavy scopes.
you all need to watch his latest vid. It comes with barrel shims and he describes his thoughts on them and instructions. No bolt shims
go to about the 25 min mark
here
go to about the 25 min mark
here
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well thanks to your post I just placed an order with Grey Birch as well! How long did it take for your chassis to be delivered? I'm wondering if I may have the chassis for next weekend.
These are 50 yard 10 shot groups with Norma Match 22.
These are 100 yard 10 shot groups with Norma Match. Two ten shot groups in the bottom right, one at the corner of the white box and the other at the red dot. Not bad for budget ammo.
These are 100 yard 10 shot groups with Norma Match. Two ten shot groups in the bottom right, one at the corner of the white box and the other at the red dot. Not bad for budget ammo.
Got ours setup on Friday night (can't make it to the range until next weekend though).
Opened up the barrel channel on the Manners and it came out great IMO. I also did some light trim work on the scope rail so it lines up correctly with the ejection port.
Assuming my measurements were correct, I set the headspace to 0.043 and the barrel is nicely free floating.
Balance is spot on and the whole thing weighs in at 15.65 lbs.
Quick before and after:
Opened up the barrel channel on the Manners and it came out great IMO. I also did some light trim work on the scope rail so it lines up correctly with the ejection port.
Assuming my measurements were correct, I set the headspace to 0.043 and the barrel is nicely free floating.
Balance is spot on and the whole thing weighs in at 15.65 lbs.
Quick before and after:
30mm aluminum pipe I got off amazon for like $10 or so. 30mm is almost exactly 1.18 inches. I wrapped 60 grit sandpaper around it and went to town on it (finished with 120 grit). Took just under two hours going slow and doing a couple test fits along the way. If I was to do it again I could knock it out in an hour. If you're thinking about doing this, use a Dremel on the barrel pad in front of the action. It'll save 20 minutes as that thing takes a while to sand down by hand.
I plan to go back and do some extra finishing sanding on the edges and paint the channel black again. Probably will knock that out this week.
Hey Mark, which scope rail do you have that you had to remove some material to make room for the barrel size (so your port cut out in the rail would align)?
I wonder if there is any scope rail will be compatible without modifying it or if all rails that have a bit extended overhang (over the barrel) will need dremeling?
I have the MDT version, but if the Area419 one works without modification, I better pick that one up before their sale ends tonight!
I wonder if there is any scope rail will be compatible without modifying it or if all rails that have a bit extended overhang (over the barrel) will need dremeling?
I have the MDT version, but if the Area419 one works without modification, I better pick that one up before their sale ends tonight!
I have the Area 419 rail, but from what I know, there are only a couple rails that will work (ejection port line up perfectly) without having to grind them down a tad. This is purely a cosmetic issue as all the rails will function just fine without modification.
I'm almost 100% positive the following rails need modification:
- Area 419
- MDT
- DIP (Diversified Innovative Products)
- EGW (Evolution Gun Works)
- Any rail that doesn't cantilever over the barrel.
I think the CZ branded Weaver Rail might have enough clearance but it would be close:
There are some that I can't find picture of mounted and/or have never seen in person so can't say for sure if they'll require minor trimming like: Warne and Talley.
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Thank you @Mark_Dorman . Good info. I’m super busy right now, but that is exactly what I need to know to do mine. Might be after Christmas before I get to mine.
You can slide the area 419 rail back about a 1/16” and it works without modification but it looks a bit off on the ejection port. We have plans of doing a rail when we got get caught up on our current projects.
Yeah, I went back and edited my post to make that clear (my bad). It is just a cosmetic issue and not a function issue. Definitely worth pointing out.
You are doing the Lords work with all this thorough information you are providing!
