MDT Chassis VS More Ammo / Practice (CZ455)

[kermit the monster]

Hey guys. I wanted to get into PRS/NRL Matches so I picked up a CZ455 as a trainer rifle recently. I'm currently using the original polymer stock it came with. Duct taped a vertical grip and cheek rest on it. Sanded the for-end a little to "free float it" (but unsure how free it is when the polymer flexes ever so slightly).

In your opinion, how important is it to get a chassis? For the same I have the option of either picking up kitted out MDT chassis for the 455 or getting ~6,500 rounds of CCI Standard Velocity.

Which would be most beneficial in the short term? Will I have to buy the chassis eventually?

Would appreciate any input, thanks. Included a target I shot today in okay conditions. Little bit windy, but not excessive.

 

[littlepod]

How well does that rifle group in better condition? Are you shooting off a tripod or prone? You should get the rifle to consistently shoot at least .9moa at 50 yards.

For PRS and nrl22 to type stuff you can do majority of it just dry firing. Don't need to shoot 6500 rounds of ammo.

It looks like you have your set up pretty comfortable for yourself. Get a few boxes of SK+. Stop using CCI SV.

 

[kermit the monster]

How well does that rifle group in better condition? Are you shooting off a tripod or prone? You should get the rifle to consistently shoot at least .9moa at 50 yards.

For PRS and nrl22 to type stuff you can do majority of it just dry firing. Don't need to shoot 6500 rounds of ammo.

It looks like you have your set up pretty comfortable for yourself. Get a few boxes of SK+. Stop using CCI SV.

This was in prone with a sticky brick rear bag. I usually shoot USPSA/IDPA so this rifle shooting thing is new to me.

I've been able to squeeze out quite a few 9.9-1.1 MOA groups with CCI SV, however not consistently. Lots of the bad shots in these groups were operator error. Either fatigue, eyes not focusing properly, forgetting to squeeze the trigger properly.

I've only put a box of STD+ in this gun, got some groups of 0.8-1.0. It's a comfy setup, but I'm just worried not using a chassis is preventing me from squeezing all the accuracy I can out of the rifle.

I know you mentioned 0.9 MOA as a standard for 50 yards, is that what's necessary to be competitive in PRS or NRL? Appreciate the input, thanks!

 

[littlepod]

NRL22 generally has 1/4" targets at 35yards. That's where they stretch the most out of the rifle. .5" at 50 is common. 2" at 100yards is common.

If you strap your rifle into a vise, and shoot it, you can check it's potential if you don't trust yourself as a shooter. The chassis isn't going to make the rifle shoot better, it might make you shoot better if it makes you feel more comfortable. Things that I had issues from the base stock that you seem to have modified -

No cheek rest - you fixed that.
Rounded bottom that made it wobbly on barricades - you seemed to have filed/installed an arca rail so you're fine.
Vertical Grip - you fixed that.

Learn to shoot a heavy trigger, then get a lighter one. Don't jump to a lighter trigger if you can't properly shoot a heavy trigger, just bad fundamentals.

So if I was in your spot, what a chassis lends me would be -

I can throw weights on there to get a better balance. That's about it tbh, I got a chassis because I'm not handy and didn't want to engineer my own cheek rest, arca rail, vert grip. But you seemed to have solved almost of that, except the balance. Also your rifle is pretty light which makes it a bit more unstable on barricades. You could solve that by just filling the stock and foreend with lead too.

CCI SV can shoot well... it's just not consistent. It's hard to shop for lots. You're constantly rezeroing and redoping every brick you buy. Lot test some SK+ from goodshootinginc, buy a case. Call yourself good for a year.

 

[tsovern]

Not sure how helpful this is, but I know from recent experience that going to a chassis doesn't guarantee to improve or (in my case) even maintain the rifle's shooting qualities. It wasn't an MDT chassis, but is a 455.

 

[DownhillFromHere]

As has been said, CCI SV is not the ammo you want to buy for accuracy. It's not "bad" for what it is - I have a case of it I use for positional practice under 100 yards, but for matches I use Center-X (in a Vudoo which was lot-tested at Lapua's Arizona facility). SK Std+ is at the lower end of "serious" ammo and you should try some of the other SK labels such as Rifle Match. Call Good Shooting Inc. for help in assembling samples for lot testing.

When you tried the SK Std+, was your bore clean or was it fouled with CCI SV? The lubes on these two cartridges are very different, and you would have had to fire at least half a box of Std+ to "season" the barrel with SK lube. From a clean bore, it takes maybe 10-15 rounds for velocity and accuracy to settle down.

You can greatly improve the trigger on a CZ with the YoDave trigger kit. The biggest aggravation is the shipping cost from Canada is outrageous - it's customs, not the vendor, that forces the cost. Given you've already set up your rifle with an ARCA rail and an Atlas bipod, you probably already know about the trigger kit.

Wrt a chassis - well, mine helped a bit in terms of accuracy (CZ-455 "Tacticool" in MDT LSS-22) but mostly in adjustability and consistency. Fifty-yard groups around 0.6" were the norm with SK Rifle Match. I have a hard time imagining a chassis making things worse. Which chassis is available to you? Cost? Unless you want a pile of plinking ammo - not necessarily a bad thing, but I'd invest in better ammo - I'd be looking at the chassis. Here's a photo of my rig, which is going up for sale pretty soon (will probably put the rifle back in the factory Boyd stock and sell separately).

 

[kermit the monster]

NRL22 generally has 1/4" targets at 35yards. That's where they stretch the most out of the rifle. .5" at 50 is common. 2" at 100yards is common.

If you strap your rifle into a vise, and shoot it, you can check it's potential if you don't trust yourself as a shooter. The chassis isn't going to make the rifle shoot better, it might make you shoot better if it makes you feel more comfortable. Things that I had issues from the base stock that you seem to have modified -

No cheek rest - you fixed that.
Rounded bottom that made it wobbly on barricades - you seemed to have filed/installed an arca rail so you're fine.
Vertical Grip - you fixed that.

Learn to shoot a heavy trigger, then get a lighter one. Don't jump to a lighter trigger if you can't properly shoot a heavy trigger, just bad fundamentals.

So if I was in your spot, what a chassis lends me would be -

I can throw weights on there to get a better balance. That's about it tbh, I got a chassis because I'm not handy and didn't want to engineer my own cheek rest, arca rail, vert grip. But you seemed to have solved almost of that, except the balance. Also your rifle is pretty light which makes it a bit more unstable on barricades. You could solve that by just filling the stock and foreend with lead too.

CCI SV can shoot well... it's just not consistent. It's hard to shop for lots. You're constantly rezeroing and redoping every brick you buy. Lot test some SK+ from goodshootinginc, buy a case. Call yourself good for a year.

1/4 "? That's nuts, y'all are literally shooting at flies. I'll try to find a vise locally, that'll definitely be on the to-do list.

I started with the stock trigger, which was about 3-4ish pounds I believe. I had about 700 rounds on it before just switching over to a Flyweight just yesterday. I have that one down to 1 pound with a little take up for safety.

I learned the heavy trigger, but now I'm forgetting to press well once in a while with the new one just because it's so easy to use. Should I continue with the new trigger or go back to practicing on the factory? With the heavy one, I press very deliberately, but with the new trigger, I forget maybe 1/10 the time.

Jerking the trigger around isn't causing problems for me, I think it's more of my arms and grip. I'm pulling the stock into me very hard, causing fatigue.

For balance, I'll probably attach some blocks of steel or lead on it if need be. Where should the center of gravity be sitting?

I thought I could edge by with CCI for matches haha, looks like I'll be trying the SK lineup instead.

 

[kermit the monster]

Not sure how helpful this is, but I know from recent experience that going to a chassis doesn't guarantee to improve or (in my case) even maintain the rifle's shooting qualities. It wasn't an MDT chassis, but is a 455.

Just for reference, which chassis are we talking about? At least style, like stock and aluminum block? Blink twice if it's a KRG or MPA. What kind of stock did you start with? Wood, polymer, boyds...

 

[kermit the monster]

As has been said, CCI SV is not the ammo you want to buy for accuracy. It's not "bad" for what it is - I have a case of it I use for positional practice under 100 yards, but for matches I use Center-X (in a Vudoo which was lot-tested at Lapua's Arizona facility). SK Std+ is at the lower end of "serious" ammo and you should try some of the other SK labels such as Rifle Match. Call Good Shooting Inc. for help in assembling samples for lot testing.

When you tried the SK Std+, was your bore clean or was it fouled with CCI SV? The lubes on these two cartridges are very different, and you would have had to fire at least half a box of Std+ to "season" the barrel with SK lube. From a clean bore, it takes maybe 10-15 rounds for velocity and accuracy to settle down.

You can greatly improve the trigger on a CZ with the YoDave trigger kit. The biggest aggravation is the shipping cost from Canada is outrageous - it's customs, not the vendor, that forces the cost. Given you've already set up your rifle with an ARCA rail and an Atlas bipod, you probably already know about the trigger kit.

Wrt a chassis - well, mine helped a bit in terms of accuracy (CZ-455 "Tacticool" in MDT LSS-22) but mostly in adjustability and consistency. Fifty-yard groups around 0.6" were the norm with SK Rifle Match. I have a hard time imagining a chassis making things worse. Which chassis is available to you? Cost? Unless you want a pile of plinking ammo - not necessarily a bad thing, but I'd invest in better ammo - I'd be looking at the chassis. Here's a photo of my rig, which is going up for sale pretty soon (will probably put the rifle back in the factory Boyd stock and sell separately).

View attachment 7359637

Locally, I have access to SK Pistol Match, Flat Nose, STD+. For Eley we've got Sport, Club, Force and Subsonic/High Velocity hollow points. Would any of these be acceptable alternatives to Rifle match?

I didn't know better regarding the fouled bore stuff, I shot the groups and noticing it tightened up later on. Will need to buy some more to try that again.

In regards to trigger, I picked up a Flywieght and man I've never felt a trigger that good. So easy to adjust everything too, it's like a dream.

Chassis wise, I'd be looking at a MDT LSS with the skeleton stock and machined for a Flyweight + arca rail and barricade stop for 450. Note that I paid 330 for the gun new, so I'd have a little justifying to do with myself haha.

My main concern is still flexing of the forend, and the pillars for the current stock. Thinking of just dremeling the channel more. to ensure free floating.

 

[tsovern]

Just for reference, which chassis are we talking about? At least style, like stock and aluminum block? Blink twice if it's a KRG or MPA. What kind of stock did you start with? Wood, polymer, boyds...
[/QUOTE]

I started with and am back to the Manners w bed and pillars. The chassis in reference is all alloy and nicely constructed. It's not MPA , however I'm not willing to disclose the manufacturer as they aren't aware of the issue at this time.

 

[DownhillFromHere]

Locally, I have access to SK Pistol Match, Flat Nose, STD+. For Eley we've got Sport, Club, Force and Subsonic/High Velocity hollow points. Would any of these be acceptable alternatives to Rifle match?

I didn't know better regarding the fouled bore stuff, I shot the groups and noticing it tightened up later on. Will need to buy some more to try that again.

In regards to trigger, I picked up a Flywieght and man I've never felt a trigger that good. So easy to adjust everything too, it's like a dream.

Chassis wise, I'd be looking at a MDT LSS with the skeleton stock and machined for a Flyweight + arca rail and barricade stop for 450. Note that I paid 330 for the gun new, so I'd have a little justifying to do with myself haha.

My main concern is still flexing of the forend, and the pillars for the current stock. Thinking of just dremeling the channel more. to ensure free floating.

Wrt which ammo brands/labels are "acceptable" - that's up to your rifle and your wallet. The reality is, .22s are just finicky odd creatures. You buy a few boxes of BillyBobsBlasterBullets for $2 - or $20 - per box and it shoots bugholes, so you go buy a brick - or a case - of it, it's a different lot, and it looks like #4 buckshoton paper. While that's obviously a huge exaggeration, there's truth to it, but you're also getting pretty deep in the weeds when you start worrying about lots. If you want to paddle around in the deep end of the pool, here's a good description of the difference lot testing can make. At long range - 100 yards or more, especially 200 or more - the more expensive brands usually provide more consistent velocity. When I had my Vudoo tested, I was fortunate to find a lot of Center-X ($10.30/box at GoodShooting) which performed practically as well as Midas+ ($14.70/box). It just depends on what your rifle likes and ranges you want to shoot. The SK labels at half the Center-X / Midas+ prices do just fine for most people.

With that said - if you can pick up boxes of all the different brands you mention locally, do so, and see which ones do the best. Don't worry about lots at this point (if ever). Stay away from high-velocity stuff (there is some discussion of HV vs standard in this forum; the strong consensus is standard velocity for accuracy). Same with hollow point - avoid it.

Ok, so you've seen for yourself how long it takes for groups to settle after changing ammo brands. The approach I use is run a bore snake through a few times (or a few patches on a cleaning jag), then at least ten rounds of the next brand before looking at velocity and group size.

Another factor in group size: it's amazing how far an almost imperceptible movement at the instant the shot breaks will toss that bullet away from point of aim. You'll see this for yourself with practice. It's that ssslllloooooww bullet that hangs around in the barrel 2.5-3 times longer than a centerfire bullet does.

Whether you want to spend $400+ for a chassis for a $330 rifle is up to you. The 455 is a capable platform which should get you pretty close to 0.5-0.7" 50-yard groups with the right ammo, but factory barrels are a bit of a coin toss. I have a buddy whose unmodified (except YoDave trigger) 455 consistently shoots 0.3" 50-yard groups with Eley Edge - as long as his Sparrow suppressor is mounted. I have another buddy whose Vudoo set a single-group (10 shots) record of 0.4" center-to-center at 100 meters (109 yards) at the Lapua AZ test facility, but performed relatievly poorly with his suppressor in place. It.depends.on.the.individual.rifle. You can read here all about all the things people have done with CZs. I have a very high regard for MDT products and for the way MDT supports their customers. My 3rd MDT chassis arrives early next week.

Good luck!

 

[kermit the monster]

Just for reference, which chassis are we talking about? At least style, like stock and aluminum block? Blink twice if it's a KRG or MPA. What kind of stock did you start with? Wood, polymer, boyds...

I started with and am back to the Manners w bed and pillars. The chassis in reference is all alloy and nicely constructed. It's not MPA , however I'm not willing to disclose the manufacturer as they aren't aware of the issue at this time.
[/QUOTE]

Did you do the bed and pillars yourself or did it come like that? Was there a perceptible increase in accuracy after you did it (if you did)?

 

[kermit the monster]

Wrt which ammo brands/labels are "acceptable" - that's up to your rifle and your wallet. The reality is, .22s are just finicky odd creatures. You buy a few boxes of BillyBobsBlasterBullets for $2 - or $20 - per box and it shoots bugholes, so you go buy a brick - or a case - of it, it's a different lot, and it looks like #4 buckshoton paper. While that's obviously a huge exaggeration, there's truth to it, but you're also getting pretty deep in the weeds when you start worrying about lots. If you want to paddle around in the deep end of the pool, here's a good description of the difference lot testing can make. At long range - 100 yards or more, especially 200 or more - the more expensive brands usually provide more consistent velocity. When I had my Vudoo tested, I was fortunate to find a lot of Center-X ($10.30/box at GoodShooting) which performed practically as well as Midas+ ($14.70/box). It just depends on what your rifle likes and ranges you want to shoot. The SK labels at half the Center-X / Midas+ prices do just fine for most people.

With that said - if you can pick up boxes of all the different brands you mention locally, do so, and see which ones do the best. Don't worry about lots at this point (if ever). Stay away from high-velocity stuff (there is some discussion of HV vs standard in this forum; the strong consensus is standard velocity for accuracy). Same with hollow point - avoid it.

Ok, so you've seen for yourself how long it takes for groups to settle after changing ammo brands. The approach I use is run a bore snake through a few times (or a few patches on a cleaning jag), then at least ten rounds of the next brand before looking at velocity and group size.

Another factor in group size: it's amazing how far an almost imperceptible movement at the instant the shot breaks will toss that bullet away from point of aim. You'll see this for yourself with practice. It's that ssslllloooooww bullet that hangs around in the barrel 2.5-3 times longer than a centerfire bullet does.

Whether you want to spend $400+ for a chassis for a $330 rifle is up to you. The 455 is a capable platform which should get you pretty close to 0.5-0.7" 50-yard groups with the right ammo, but factory barrels are a bit of a coin toss. I have a buddy whose unmodified (except YoDave trigger) 455 consistently shoots 0.3" 50-yard groups with Eley Edge - as long as his Sparrow suppressor is mounted. I have another buddy whose Vudoo set a single-group (10 shots) record of 0.4" center-to-center at 100 meters (109 yards) at the Lapua AZ test facility, but performed relatievly poorly with his suppressor in place. It.depends.on.the.individual.rifle. You can read here all about all the things people have done with CZs. I have a very high regard for MDT products and for the way MDT supports their customers. My 3rd MDT chassis arrives early next week.

Good luck!

I'll be picking up a variety and trying that out then, will pick up a bore snake, appreciate the tip! I don't think I have the ability to see a difference in lots yet, but that'll be something I keep in mind for the future.

Looks like I'll need to improve my follow through after the trigger's pressed then, never knew that would be such an important factor.

For the Vudoo, you mentioned that it squeezed out sub half moa groups in a vise, but what groups could your buddy shoot as a human? I'm just curious to hear how much error is applied by the human shooter. Something MDT is probably in my future, but likely not the short term. College student budget haha.

 

[tsovern]

The rifle was bedded when I bought it. It is a very poor job as the front pillar is misaligned and it was bedding hadn't been relieved for the barrel screws. After relieving the screw head area and playing with action screw torque ( which suggests action to bedding issues I suppose) the rifle shoots very well. Out of a 10x 5, with it's favorite lot of cx or sk STD+, I'll get 3 or 4 .5" to .65" groups, 2 or 3 hovering around .75" and remaining groups w fliers at 1-1.25". (@100yrds) This is w 12"/# of torque on the rear action screw and the front so light I can't measure it w my Fat wrench. Stick it in the chassis and all that doubles. Tried several different torque variations as well as using Al. tape for bedding to get the receiver to free span from screw to screw. No luck.

 

[kermit the monster]

The rifle was bedded when I bought it. It is a very poor job as the front pillar is misaligned and it was bedding hadn't been relieved for the barrel screws. After relieving the screw head area and playing with action screw torque ( which suggests action to bedding issues I suppose) the rifle shoots very well. Out of a 10x 5, with it's favorite lot of cx or sk STD+, I'll get 3 or 4 .5" to .65" groups, 2 or 3 hovering around .75" and remaining groups w fliers at 1-1.25". (@100yrds) This is w 12"/# of torque on the rear action screw and the front so light I can't measure it w my Fat wrench. Stick it in the chassis and all that doubles. Tried several different torque variations as well as using Al. tape for bedding to get the receiver to free span from screw to screw. No luck.

How do you keep the screws in at that kind of torque? Is blue loctite even enough? That's some great groups though

 

[tsovern]

I have reference marks on screws and bottom metal. It may or may not stay for the duration of a nrl match type situation, it hasn't been in that environment. Hasn't been a problem w many rounds prone and off bench. Not a good solution, but I'm more interested in finding a fix for the chassis because the adjustability is a pretty big deal for me.
Edit: I started using the loctite, but haven't renewed since going back to the manners.