CZ 452V T4 Trainer: Post-Bedding with new results

[shooterman_zero17]

So I recently took the plunge to bed the CZ 452. I've bedded a 700SA before, so bedding wasn't necessarily something new to me. However, the CZ action was a totally different experience. I bedded only the rear tang, the front of the action/back of the barrel (up to the barrel screw lug) and in front of the barrel screw lug. I stopped the barrel 'pad' at the Balance Point (in which the barreled action (sans scope/rings) balanced at). I saw that Anchor Zero Six and jaia (both users here) had experimented with this and their rifles (CZ 455s) had yielded promising results, which pushed me to try doing so with my rifle.

Another big difference in the setup of this rifle is in the optics department. I decided to go with what I originally wanted to do for glass, which was an MRAD-adjusted SS 12x or 16x. Shoutout to Knife here on the Hide, he was selling a basically-new 16x on the PX, which I purchased. I also wanted a higher-quality set of rings, and here SWFA/Seekins gets the nod. Purchased a set of low 30mm Seekins through SWFA (as well as a sunshade for the SS). More input on the glass later.

Another change that is still in the works for this rifle is adding a rail section from Accushot (via Triad Tactical) for my Atlas V8.1 (which came from the PX here back in March or so). Still waiting on the bits to come in (the ones 427cobra has generously and perpetually lent out for a while).

The rifle as it sits now:

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

These results shown here are from a previous range trip, PRIOR to bedding, just for the sake of comparison.

The two images showing 5-shot groups of under an inch were the best two from that day. The others showing groups larger than an inch are not all of the 5 shot groups, but represent what the average the rifle shot that day (give or take) in the other groups.

These groups were shot with Remington Eley Target Rifle, the same as is shot in the following post.

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

These groups are from today 9/28/2012, post-bedding and with new glass. Again, the same ammo as is shown in previous groups (post above), is used here; Remington Eley Target Rifle. First image is the whole target just to stay honest. Before moving onto the box, I walked it in using bulk ammo, and then tweaked it with the higher quality stuff.

Next shows the first 5-round group I punched (one round, reloaded, and four from the reloaded magazine), so I did entirely break my position to load the mag again. With the leftover from the second mag, I punched the top of the diamond in the bottom target. Above, is a 10 round group from the same lot of ammo.

Of note, I had two different (although sequential) lots of ammo. Lot A was used for the zero and 10 round.

Next, a trio of 5-round groups from Lot A. I didn't bother measuring the bottom group here. This was coming from a cold range (more on that to follow).

And another trio of 5-round groups, but these from Lot B. I played with the zero up and down a couple clicks here, which accounts for the up and down in the groups.

Finally, two more 5-round groups, one from Lot A and B. The 1" sticky was not there while I was shooting, I put it there as a reference for OnTarget and as a visual aid. My points of aim were using the holds on the reticle over different targets on the box. I experimented with using the diamond by itself (which worked well for me with having the dot inside the hollow diamond body) on the group on the left, and with using the .5MIL hash-marks and holding the reference target between them on the group on the right. Using the hash-marks wasn't as solid of a reference point for shooting a group to me, which I think is reflected in the group size.

Now, I'm not approaching these numbers from a completely scholarly point of view, but I'm trying to keep the range of data I'm drawing from close enough to one another. The groups I have posted in pre-bedding are the 4 best 5-shot groups from that day of shooting. I averaged those together. Then I took the 4 best 5-shot groups from shooting today (post-bedding) and averaged those.

Pre-Bedding over one range trip, best groups:
1) .871"
2) .884"
3) 1.129"
4) 1.139"
Average: 1.055"

Post-Bedding over one range trip, best groups:
1) .624"
2) .688"
3) .833"
4) .881"
Average: .756"

Post-Bedding over one range trip, two largest and two smallest groups:
1) .624"
2) .688"
3) 1.223"
4) 1.441"
Average: .994"

This isn't averaging in shooter error

As far as shooting from a cold range, it seems now that the rifle shoots more consistently now that it is bedded when shooting a longer string of fire. Shooting fewer rounds, or waiting longer between shooting groups seems to open things up, and takes a couple rounds for it to settle back in.

Couldn't ask for anything else from this rifle. This is what I envisioned owning and shooting when I first set out a year and a half ago purchasing the rifle and ordering the stock from Manners in the Group Buy here.

 

[ggmanning]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

That looks good in the stock. I bedded my 452 varmint a little different. I bedded the action and drilled out the stock for the forward lug to have clearance and then island bedded the lug. I used a set screw to attach the lug to the barrel and solidly keep it in place. It has worked out well but your method sounds like an easier job. CZ really should build these with 2 action screws and no lug....maybe the weight of the varmint barrel made them use a lug??

 

[armorpl8chikn]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

try some Lapua Center X in it, I am betting it will shoot better still.
Very nice rig.

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armorpl8chikn</div><div class="ubbcode-body">try some Lapua Center X in it, I am betting it will shoot better still.
Very nice rig. </div></div>

I have limited myself on ammo selection, but now that it is at the point it's at, it's time to start really branching out.

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DFOOSKING</div><div class="ubbcode-body">What are the type and height of your rings good sir?

</div></div>

Seekins Precision 30mm Lows. There is still a smidge of room beneath the objective bell too, a little more than I was expecting.

 

[TOP PREDATOR]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

that is a VERY nice rifle.

good data on the bedding job.

 

[JelloStorm]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Yes, very nice writeup!

I can't wait to do the same with my new 17HMR!

 

[armorpl8chikn]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Hey, now that thing is ready no excuse not to come up to TSC in Conover.

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

As much as I would like to make October happen, I can't swing it. Next year when the matches start is another story though...

 

[charlie_atlas]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

What cheek riser is that?

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: charlie_atlas</div><div class="ubbcode-body">What cheek riser is that? </div></div>

An XLR Industries cheekpiece. I had a fellow Hider (tmshot) PM me and ask if I was interested in the cheekpiece and the inserts that it screws into. I had wanted one since I saw a Group Buy on them here and ordered the stock. Works fantastically.

 

[charlie_atlas]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Thanks, Just picked one up for $25

 

[garey]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Nice build. that is definitely on my to-do list

 

[Early Cuyler]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Nice stick! I'm waiting on an AWC Ultra II based on the CZ452 action and already have the Manner's stock waiting here for it. How do you like the sock bolt knob? Have you thought about replacing it?

 

[pvtpyle]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Would like to know what stock that is. I shoot a CZ 452 Varmint and I want to upgrade from the factory stock. I agree with your optics choice. I shoot a SS 20x42. They are great scopes. I, along with armorpl8chikn, wholeheartedly recommend Lapua Center X. I, too, started out with Ealey and found it to be less than desirable past 100 yards (yes, Joe, you can gloat now)It has been the greatest at 210 yards. Really wish you could be there in October. It's a blast.

 

[Early Cuyler]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Pvt.Pyle</div><div class="ubbcode-body">Would like to know what stock that is. I shoot a CZ 452 Varmint and I want to upgrade from the factory stock. I agree with your optics choice. I shoot a SS 20x42. They are great scopes. I, along with armorpl8chikn, wholeheartedly recommend Lapua Center X. I, too, started out with Ealey and found it to be less than desirable past 100 yards (yes, Joe, you can gloat now)It has been the greatest at 210 yards. Really wish you could be there in October. It's a blast. </div></div>

The stock is a Manners T4. Just give them a call and see what they can do for you. Here's a link-
http://mannersstocks.com/mcs-news-announcements/506/#more-506

 

[justin amateur]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I stopped the barrel 'pad' at the Balance Point (in which the barreled action (sans scope/rings) balanced at). I saw that Anchor Zero Six and jaia (both users here) had experimented with this and their rifles (CZ 455s) had yielded promising results, which pushed me to try doing so with my rifle.</div></div>

My ears were burning.

I've gone beyond the balance point on my latest testing.
Epoxy shims all the way to the fore end. Before reassembling the rifle
a very tiny dot of hi-temp silicon gasket adhesive is applied to the center
of the front epoxy shim, so that the fore stock and Lilja barrel lock together.
No stock flex, no barrel shifting. To break the bond between the barrel
and adhesive, braided fishing line is worked between the barrel and shim
to cut the silicon adhesive loose so the barrel can be removed.
The silicon gasket adhesive dampens firing vibrations, which improved accuracy.
I know, it goes against free floated being the rule, but rules are meant to be broken.

 

[shooterman_zero17]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

Thanks guys.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Halcyon612</div><div class="ubbcode-body">How do you like the sock bolt knob? Have you thought about replacing it?</div></div>

It works. It isn't overly hard working the bolt, but with the glass in low rings now its a slightly tight squeeze. I've considered changing it, but more than likely will just keep it as is.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jaia</div><div class="ubbcode-body">
My ears were burning.

</div></div>

Your approach, its...

Hoping to see some results from that.

 

[bunsen27]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jaia</div><div class="ubbcode-body">My ears were burning.

I've gone beyond the balance point on my latest testing.
Epoxy shims all the way to the fore end. Before reassembling the rifle
a very tiny dot of hi-temp silicon gasket adhesive is applied to the center
of the front epoxy shim, so that the fore stock and Lilja barrel lock together.
No stock flex, no barrel shifting. To break the bond between the barrel
and adhesive, braided fishing line is worked between the barrel and shim
to cut the silicon adhesive loose so the barrel can be removed.
The silicon gasket adhesive dampens firing vibrations, which improved accuracy.
I know, it goes against free floated being the rule, but rules are meant to be broken.

</div></div>
My Win 52B has these little rectangular rubber pads along the bottom of the barrel chanel all the way out as well. Old school tech. I might have to try this with my CZ 452 Varmint to see if will tighten it up some.

OP nice stick, hope to see you in Conover next year. One word of warning though: once you shoot a few matches you start getting this burning desire to buy an Anschutz and shoot Lapua Center X through it. However it will be one of the best matches you ever shoot.

 

[J.Davis]

Re: CZ 452V T4 Trainer: Post-Bedding with new results

I'm in the middle of bedding a Rem. 597 right now. Hopefully I can get close to a .3" reduction in group size as well. That CZ looks great!