Just started building my new CZ457 today and ran into a problem. I am using a Bscar scope base. After I installed it I put a pair of Leupold Mark IV rings on it. The problem is I can't cycle the bolt. The place where you screw the bolt handle to the bolt is striking the base of the ring. I can get it to work with Burris Signature Zee rings because the base of the ring is not as wide. What rings are you guys using that will clear. From their website it says the Area 419 scope base sits higher. It seems that might be a workable solution. I don't need a lot of room to clear the rings. Just a little bit.
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Need help with scope base.
- Thread starter ronnielee54
- Start date
I have already changed out rings so a picture would not help. I will try to explain better. On the bolt, there is piece sticking out that is threaded to screw the bolt handle in. The base of the Mark IV rings are wider so they stick out more. The piece on the bolt is barely making contact with the front right corner at the base of the rings. This blocks the bolt from opening.
I've used a BScar 15 moa and now a 35 moa rail without issue on my 457. Generic 1" rings on the 15, now using Warne Mountain Tech 30mm medium (#721M) along with the BScar 35 moa rail. You can see the clearance here:
A friend ran into that exact issue with the bscar 0 MOA and his 457. Vortex precision, Seekins or other rings that are narrow on the bottom and have an upward angle work better than stuff that is wide and squared off.
The 419 does sit higher so has a wider choice in rings.
I also am using the 0 MOA base. I have a 25 MOA base that I might try. The Mark IV rings are kind of like you described. They are wider and squared off at the base.
I love high quality, expensive toys...... given the utilitarian nature of scope rings, I tend to spend under $60.00 bucks on each set.
In the case of post number 8, given that the rings are likely aluminum, and the steel fastener probably has some sort of knurling to
prevent rotation, I would probably add a 1/2"x 45* chamfer to clear the bolt. Then hide it with Alumi-hyde or black Sharpie. On the Bergara
you can see that the base stops where the bolt lifts. The V22 is the same way. The first thing I do is decide where my scope needs to go for me to shoot from the most ergonomical and comfortable position.
Then I find mounts to get me there. In photo #3, you can see the base clamp screw.
It is flush mount. None of my mounts have big, manly, 1/2" hex nut to snag things or cause another interference. A couple of years ago,
my two Anschutz 64s had mounting issues. The existing DIP mount stopped where the bolt handle started. I spoke with Bob at DIP and showed him my mounts and clearance condition. A short time later, he sent me special ANS 64 bases. With my narrow scope mounts with flush screws
that also had a very narrow foot-print, allowed Bob to simply extend his existing product. His next step was to make it a standard DIP product. I believe it's called a Scout.
Often I need to go from dovetail to PIC mounts. They make a $10.00 pinch block to achieve that. UTG??
The AREA 419 rail is robust and clamps to your CZ. The DIP or many other use flat tip set screws to push on the top of the receiver.
They also have very little cross section once you machine away the PIC slots and the underside dove tail. I have had them flex while torquing the screws. I highly advise that you put #8 shot under the set screws to preserve your guns finish. Brass tip screws exist.... I know..... they will
also leave witness marks on your bluing.
Worst case.... design a mount and have your local shop make it for you. Shown in photo 5 and 7. The Dove tail to PIC rail pinch block is
shown in photo #7 in black.
Your clearance issue will show up again and again. Every gun you own will have it's own unique mounting needs. I can only suggest that
you find the optimal location for your scope based on the needs of your body and build up the base and mounts to get there. IE: If your LOP puts your head, grip and trigger finger in a great position but the rail prevents the use of straight up mounts..... Spend $37.00 on UTG offset mounts. They may look flimsy but they are plenty ridged. Even if they do vibrate like a tuning fork by .005" during the shot, they will return to their mounted position. Just like a guitar spring while at rest. Nobody shoots with a 3" gun barrel to stop all vibration.
The very FIRST thing I would get over is the entire idea of getting your scope bore as close as humanly possible to the barrel bore.
It's my opinion that if the clearance to the objective bell is 0.10" or 1"... it will have no influence on your shooting. Conversely,
If you have your scope mounted as close as possible and then you find yourself contorting your body to fit the gun, your shots are going to suffer!! Your eye won't be in its best position, your cheek will be pushing against the rest, and only god knows what other forces you will
be putting into your gun to disrupt your shot.
Look at Olympic shooters with sights intentionally positioned 2.5" above the bore. They put spacers under the front and rear sights to
get that high. I'm guessing they know more than me.
Post #6 say's "Vortex precision, Seekins or other rings that are narrow on the bottom and have an upward angle work better than stuff that is wide and squared off.
They are your rings...... there for you can make them suit your needs. If you wanted those rings on a custom build and they wouldn't fit
your brand new toy you had on order, the builder would call you, give you the option to ad the chamfer and you would say..... Sure... that
sounds like a great, simple solution. They would machine it, tape it and Cerakote it.
LOOK at the last FWB 65 Olympic pistol..... It still puts the pellet in the same hole at 10 meters just like the straight bbl. 65s guns do.
It was made to prove a point.
Just food for thought.....
In the case of post number 8, given that the rings are likely aluminum, and the steel fastener probably has some sort of knurling to
prevent rotation, I would probably add a 1/2"x 45* chamfer to clear the bolt. Then hide it with Alumi-hyde or black Sharpie. On the Bergara
you can see that the base stops where the bolt lifts. The V22 is the same way. The first thing I do is decide where my scope needs to go for me to shoot from the most ergonomical and comfortable position.
Then I find mounts to get me there. In photo #3, you can see the base clamp screw.
It is flush mount. None of my mounts have big, manly, 1/2" hex nut to snag things or cause another interference. A couple of years ago,
my two Anschutz 64s had mounting issues. The existing DIP mount stopped where the bolt handle started. I spoke with Bob at DIP and showed him my mounts and clearance condition. A short time later, he sent me special ANS 64 bases. With my narrow scope mounts with flush screws
that also had a very narrow foot-print, allowed Bob to simply extend his existing product. His next step was to make it a standard DIP product. I believe it's called a Scout.
Often I need to go from dovetail to PIC mounts. They make a $10.00 pinch block to achieve that. UTG??
The AREA 419 rail is robust and clamps to your CZ. The DIP or many other use flat tip set screws to push on the top of the receiver.
They also have very little cross section once you machine away the PIC slots and the underside dove tail. I have had them flex while torquing the screws. I highly advise that you put #8 shot under the set screws to preserve your guns finish. Brass tip screws exist.... I know..... they will
also leave witness marks on your bluing.
Worst case.... design a mount and have your local shop make it for you. Shown in photo 5 and 7. The Dove tail to PIC rail pinch block is
shown in photo #7 in black.
Your clearance issue will show up again and again. Every gun you own will have it's own unique mounting needs. I can only suggest that
you find the optimal location for your scope based on the needs of your body and build up the base and mounts to get there. IE: If your LOP puts your head, grip and trigger finger in a great position but the rail prevents the use of straight up mounts..... Spend $37.00 on UTG offset mounts. They may look flimsy but they are plenty ridged. Even if they do vibrate like a tuning fork by .005" during the shot, they will return to their mounted position. Just like a guitar spring while at rest. Nobody shoots with a 3" gun barrel to stop all vibration.
The very FIRST thing I would get over is the entire idea of getting your scope bore as close as humanly possible to the barrel bore.
It's my opinion that if the clearance to the objective bell is 0.10" or 1"... it will have no influence on your shooting. Conversely,
If you have your scope mounted as close as possible and then you find yourself contorting your body to fit the gun, your shots are going to suffer!! Your eye won't be in its best position, your cheek will be pushing against the rest, and only god knows what other forces you will
be putting into your gun to disrupt your shot.
Look at Olympic shooters with sights intentionally positioned 2.5" above the bore. They put spacers under the front and rear sights to
get that high. I'm guessing they know more than me.
Post #6 say's "Vortex precision, Seekins or other rings that are narrow on the bottom and have an upward angle work better than stuff that is wide and squared off.
They are your rings...... there for you can make them suit your needs. If you wanted those rings on a custom build and they wouldn't fit
your brand new toy you had on order, the builder would call you, give you the option to ad the chamfer and you would say..... Sure... that
sounds like a great, simple solution. They would machine it, tape it and Cerakote it.
LOOK at the last FWB 65 Olympic pistol..... It still puts the pellet in the same hole at 10 meters just like the straight bbl. 65s guns do.
It was made to prove a point.
Just food for thought.....
