MPA BA22 with novice precision shooter

[David T]

I know there is some interest in the MPA BA22, and after unexpectedly hijacking a different thread, I decided to make my own.

I'll tell you what I have, and answer any questions if I can. First of all, details on the rifle. Barrel is 18", Area 419 rail, trigger was set at the factory at 1 lb, 7 ounces, and an Athlon Ares 4.5-27 MOA scope on top held on with Burris Xtreme rings. I have an Atlas bipod holding it up. I learned that the trigger has a YoDave spring, but the trigger and surfaces themselves were polished at MPA for a better feel.

The bolt was a bit rough from the factory but has worked in nicely since I've been using it. I have shot between 1200 and 1500 rounds out of it.

The trigger had a slight grating feel to it, but seemed to break cleanly. I actually polished it up a bit and eliminated that for the most part.

Adjustments to the stock are done by loosening set screws, moving the cheek piece or butt plate to the proper position, then tightening the set screws. There are no dials to move them. There is no beveling on the magwell to seat magazines quickly, but I've gotten somewhat used to where they go, and for the most part, I'm able to get them in fairly easily. That being said, this is probably not be ideal for competitive shooting.

I did put on an Anarchy Outdoors swept bold handle with one of their oversized bolt nobs, and it fits great. Initially, I had some concerns it was not machined correctly on the outside circumference, as it seemed to be binding up in the receiver. However, I recently took the rifle apart and checked the torque on the two inward set barrel screws, receiver screws, and scope ring bolts. When I put the rifle back together, the bolt functioned much better. Something moved around somewhere.

One of the problems I noticed with the internals when I took it apart is that the mag well was broken just forward of the rear screw. As a result, I wound up purchasing a new aluminum mag well from DIP. While I was on their site, I also purchased one of their adjustable sears. I just put the sear in tonight, so I have not yet had a chance to shoot it, but while dry firing it, it seems to feel very nice.

Probably the most annoying thing about this rifle (and I can NOT say this is a problem caused by MPA) is that they bolt will unexpectedly come all the way out when cycling the action - as in, pull the bolt back, and it entirely separates from the receiver. I'm not sure if this is a problem with all CZ 455's or not, but it would be nice if there was a fix for it. (This is my first experience with a CZ rifle.)

As for myself, I'm new to the world of precision rimfire shooting, and this is my first higher end precision rimfire rifle. I don't consider myself to be a bad shooter, but I don't consider myself a total newbie, either.

I'm working on finding that perfect ammo/position/contact combination, but this is a group I shot today. As a result of a reply on the prior thread by Seymour Fish, I tried to take out as many variables as possible. Barrel was cleaned by running a snake down the barrel, and I cleaned up the chamber with a bore brush. I then used Wolf Match Target in the prone position, first from the bipod (with the steel cleats inserted, not the rubber feet), and then off a sandbag. Prior to shooting the groups, I reset my zero, since the rifle had been taken apart to be retorqued.

Again, I am new to the precision rimfire world, and I'm hoping the scatter of the shots is something I can fix (whether me or finding the right ammo. I'll post more group pics later. Average overall velocity was 1061 FPS (averaged across the 100 rounds).

 

[David T]

I know I left a lot of details out on what the rifle comes with, but the MPA site is pretty clear on what comes with it, I was just listing what I have specific to my rifle.

 

[Hellbender]

First, understand I am not familiar with your exact rifle/combo of parts, but several things you mention raise some concern and need to be looked at closely.

"I recently took the rifle apart and checked the torque on the two inward set barrel screws, receiver screws, and scope ring bolts. When I put the rifle back together, the bolt functioned much better. Something moved around somewhere."

This sounds like you have a screw intruding on the bolt raceways somewhere....remove the bolt and slide your finger over all the internal surfaces the bolt can touch. ALL screws must be slightly BELOW the surface. Remove the offender and shorten it.

The CAUSE of the broken mag well needs to be determined, if possible. It may have been a simple incorrect assembly, but may be something is in a bind in the chassis, may be as simple as a spacer or washer was put in the wrong place/order.

" is that they bolt will unexpectedly come all the way out when cycling the action "

This may be rectified by fixing the problem/s above, (again, I am not familiar with your CZ) but is probably a sticky part, either a burr somewhere or maybe just gunked up. The bolt release MUST move freely and fully through it's entire travel range with the bolt removed.

On your prone technique, cleated feet are not needed (unless shooting on ice or very slick, hard surface like ice), you are probably overloading your bipod and this causes inconsistencies, slight forward pressure is enough, the legs don't have to bend. I've found an ATLAS is much more forgiving, with a larger "sweet spot" than a Harris, but many disagree.

You are using a rear bag, correct?

I recco you buy some cheap ammo (CCI SV) and shoot at 25 yards until you learn to keep ALL shots touching. Make EVERY SHOT count, THINK about every step in your position/cheek pressure/bipod loading/sight picture/trigger pull. When you can do that, move to 50 yards, then the higher priced ammo, when you can out shoot the cheaper stuff.

There's absolutely NO REASON to waste money on 1/2 MOA ammo when YOU can only shoot 2 MOA.

DRY FIRE is actually MORE important than shooting. Put up a tiny dot at 25 yards (make sure you know how to check and adjust parallax properly, it's NOT just the clearest focus on your scope). and watch your crosshairs closely when you break the shot, ANY crosshair movement requires fixing, adjust until you figure it out.

 

[David T]

Well, I took a look at the rifle a bit more closely when I changed out the mag well with one from DIP, and I put a new adjustable sear in as well. I took Hellbender's advice about looking at the internals and couldn't find anything wrong with the bolt or raceway to allow the bolt to pull free. I did do an online search of the problem, and seems I'm not the only one. Best guess is that the bolt release is fairly tight on tolerances, and if the recess on the underside of the bolt in any way rubs the release as the bolt is being cycled, it MIGHT drop the release out of the way just enough to allow the bolt to be released.

As to the broken mag well, I think it had more to do with overtorquing the screw on the plastic part than anything else.

I was able to shoot the rifle today, hoping to have some positive result from the changes I made, and some groups were very nice. Unfortunately, there was still inconsistencies. (I couldn't bring myself to drop the range down to 25 yards just yet.) Ammo was Wolf Match Target again.

I disassembled the rifle and receiver from the chassis one more time, and noticed something I hadn't before. Stupid me, I took for granted that the chassis would allow the barrel to free float. I found the two screws holding the spigot mount to the forend were impinging on the barrel enough to leave marks on the barrel.

I'm hoping that this is the cause of the problem. If not, the rifle is going over to my friend's place so he can test drive it.

 

[Hellbender]

The screws hitting could cause a mess of stuff to happen as the chassis flexes under bipod load and barrel harmonics.
That should fix it....or at least help!

 

[JoeB]

If I was you I would be having a serious talk with the people that built that rifle. That is not acceptable for the kind of money you spent .
I would expect to find that type of shoddy work from Ruger at their price point.

 

[DownhillFromHere]

Probably the most annoying thing about this rifle (and I can NOT say this is a problem caused by MPA) is that they bolt will unexpectedly come all the way out when cycling the action - as in, pull the bolt back, and it entirely separates from the receiver. I'm not sure if this is a problem with all CZ 455's or not, but it would be nice if there was a fix for it.

Putting a YoDave trigger kit in a CZ-455 can, and does, cause this issue. In my experience with my CZ-455, the lighter I set pull via the spring/shim combination, the more likely the bolt will occasionally pull all the way out. At present, my trigger breaks cleanly at about 24 ounces. If I insert the bolt and cycle it several times, holding the trigger back as I close the bolt, I find the pull-out issue to be significantly reduced.

I have not tried to ascertain exactly why this happens.

 

[David T]

So another update on this one.. I shaved the tips of the screws off to clear the barrel. Took it out today after torquing the chassis back to the receiver. I DID check the clearance with a piece of cardboard about the thickness of a business card. It was a bit close at the forward end of the receiver, but felt it was clear enough. I shot CCI Standard to get back on target and then fired for groupings. I'll be damned if it didn't look about as bad as before, if not worse in some cases. I checked the forend again by eyesight, and it was CLOSE to, but wasn't, touching. Took the rifle apart and tried to get some shimming in the chassis, and really only found a good spot just forward of the receiver. So, about 1" of the rear of the barrel has a shim on it. Shot some more of the CCI with it, and didn't really do anything for it.

Just before calling it a day, I shot the remainder of the SK Standard Plus, and Thank Goodness, found an ammo that seemed to shoot well. So, in other words, my rifle doesn't seem to shoot CCI Standard, which seems to be a fairly common go-to ammo for a lot of people. Now, I need to wait for more ammo, since now I only have CCI Standard LOL.

Whether the shimming did anything for accuracy with the SK, I don't know. I DO know that the forend has much better clearance now than before.

When looking at the pictures, you'll see that under the SK, I also shot RWS and Fed GM Target that didn't shoot well either.

 

[David T]

Putting a YoDave trigger kit in a CZ-455 can, and does, cause this issue. In my experience with my CZ-455, the lighter I set pull via the spring/shim combination, the more likely the bolt will occasionally pull all the way out. At present, my trigger breaks cleanly at about 24 ounces. If I insert the bolt and cycle it several times, holding the trigger back as I close the bolt, I find the pull-out issue to be significantly reduced.

I have not tried to ascertain exactly why this happens.[/QUOTE

Thank you for the info, it's annoying!

 

[David T]

On a note for the aluminum mag well that I purchased as an aftermarket piece. When I got that, I also purchased the extended mag release and aluminum spacer block to go along with it. The mag release is nice, but it's harder to get the magazine in the well with this set up. It seemed to me that the fully enclosed plastic OEM mag well was much easier to get used to putting the magazine in quickly.

 

[David T]

Another note (problem) on this rifle. I found that the screws holding the barrel into the receiver were protruding out of the receiver and were contacting the chassis. Ordinarily, I think the MPA chassis was designed to accommodate this with two small pockets machined into the chassis that can be seen in the picture above. But what I saw were marks on the chassis behind those pockets which to me showed the pockets may have been misaligned.

The chassis is designed with one raised section left and right of the centerline of the length of the chassis that are about 1" long each. The receiver is centered in and resting on the chassis with these sections. The dimples are machined at the forward edge of these sections. These two points and where the rear tang rests on the receiver are the only points on the chassis where the receiver rests.

I found machine screws at the local hardware store that are a bit shorter than those supplied by MPA and have since changed them out.

Now with the front of the receiver sitting lower in the chassis, there is JUST enough room to slide a thick piece of paper between the barrel and the chassis. I know the aim of freefloating a barrel is to achieve at least that amount of clearance, but for this system, I would like more, especially since when I apply pressure to the two, I can achieve contact between them.

I sent the bolt action rep for MPA a message detailing the issues I've noted in this post, along with some others I haven't, and the reply was quick, but lackluster.

My friend told me of another thread in the bolt action section regarding MPA's customer service. After reading those posts, I'm hesitant to send the rifle back for a thorough check and to increase the clearance of the barrel from the chassis.

I attached 3 pics. One shows the barrel screws, another is a not great pic of the clearance at the front, and the third is a close up of the dimples and the protrusions the receiver rests on.

 

[sharpdoug]

Not exactly the same issue, but: picture 1) was a Vudoo 22 in a MPA chassis. Picture 2) was switching to a Manners stock at 100yds, Picture 3) was same setup at 50yds.

Turned out the issue was interference with the magazine, once we figured that out the MPA was as good as the the Manners. Little things make a difference. Don’t give up on the MPA.

 

[JG26_Irish]

David,

I shot a PRS rimfire match in 2017 with a fellow who scored in the top 10 that day using a CZ455. He was hitting 6# steel plates at 290y with it. He was having the same issue with the bolt pulling out when he cycled it quickly during the time stress of those timed stages. Since we each shot one at a time on our squad, I observed this happening many times during the course of the day and asked him about it. He claimed that with the trigger set very light as he had done it was a issue. Apparently one of the parts in the trigger mechanism is also the bolt stop?

Looking at the accuracy you are getting and if I understand correctly you were firing at 50y, I cannot help but think that something is still affecting the rifle to hurt the accuracy. Shooting from a solid bench off of a front & rear sandbag or prone off of your bipod with a rear bag on a calm day, using the Wolf ammo you should be able to see groups at least as small as 1/2" at 50y and if it is with an ammo the gun likes, even down to much less. I don't see that and there is enough vertical stringing to make me wonder if perhaps there is still not enough clearance between the bbl and the forearm of the chassis? Could be that when you fire, the recoil is sufficient to be causing the bbl to contact the chassis at least on some of the shots which can foul up the harmonics as well as bump the barrel upward in a random manner. I would suggest shimming the chassis to gain more clearance and test it. If things improve then you can look for a more permanent means to open it up. This is total guesswork so take it with a grain of salt. Most of the CZ's I have seen shoot better. Another possibility, is if you know anyone with a CZ455 who would let you bolt your action into their stock and test fire it. If it makes no difference, you will at least have eliminated that possibility. Be methodical and try to change only one thing at a time.

Something I did with a Savage once was to bed the action using JBWeld. There was only a tiny amount used on the rear of the action but a big gob just at the front of the receiver and the first 1" or so of the barrel ahead of the receiver. This will raise the barrel in the chassis and increase the clearance as well as provide a solidly fit contact patch for the action, but it is something of a permanent fix. I used pam cooling spray on the metal bottom of the receiver and barrel as a release agent and roughed up the stock using a dremel tool so the epoxy would not fall out. Before going that route, I would try gaining clearance with a shim of some sort. i.e. rubber pad, aluminum, even carving out a small piece of wood would do the trick, etc. Stay mindful of the variables and recognize that one of the big ones is ammo. Don't alter the chassis mount and then also change ammo and expect to learn much. The ammo change will overshadow most other changes. Pick one ammo and get the gun working well and then go out and test different ammo to find what it likes. I am assuming that you bought this gun new and know for a fact that the barrel has not been damaged by somebody improperly cleaning it with a metal rod or poor quality jags. A proper vinyl coated one piece rod such as from Dewey is a must with any precision rifle. A damaged crown can cause all sorts of issues with accuracy. A good rod guide is a must also. These are small investments to protect your big ones. Good luck and let us know how it pans out.

Irish

 

[David T]

I like the MPA chassis and really would prefer to keep it under the CZ action. However, MPA really screwed it up with my setup. I did buy the rifle new, so I'm not sure how the chassis to action fit got screwed up so badly. In addition to the raised screws I had to shave off and the barrel retention screws that I had to change out, I found today that the barrel was bouncing up and down on the spigot mount (the black anodizing of the mount is worn off ever so slightly, and there is a corresponding mark on the barrel). As to shimming the action, I did that once already, and it shot the Wolf Match Target well, but I raised it up quite a bit and didn't want to torque the action much. To get that much of a lift away from the chassis again, I would only feel comfortable bedding the action, or shaving off some of the chassis section that it was close to.

I am going to send MPA another letter, and see if they'll ship out a new chassis first, with a return label for mine - I don't want to send this one back when the question of their customer service is in doubt.

I attached a pic of the spigot mount, and I found some wearing on the section of the chassis where it's closest to the barrel, now, as well.

 

[David T]

Not exactly the same issue, but: picture 1) was a Vudoo 22 in a MPA chassis. Picture 2) was switching to a Manners stock at 100yds, Picture 3) was same setup at 50yds.

Turned out the issue was interference with the magazine, once we figured that out the MPA was as good as the the Manners. Little things make a difference. Don’t give up on the MPA.

It sounds like you put the Vudoo back in the MPA and shot it after fixing the mag problem? And it shot well after the fix? How was the mag interfering? Great groups, BTW!

 

[EddieE]

Not exactly the same issue, but: picture 1) was a Vudoo 22 in a MPA chassis. Picture 2) was switching to a Manners stock at 100yds, Picture 3) was same setup at 50yds.

Turned out the issue was interference with the magazine, once we figured that out the MPA was as good as the the Manners. Little things make a difference. Don’t give up on the MPA.

Is this a common issue or was this an issue specific to this rifle/chassis combo? Was the inletting bad on the chassis? What I'm getting at is if I buy a vudoo with the MPA, will I have similar issues or have they addressed it? Thanks!

 

[sharpdoug]

No, the issue with that chassis -rifle combination was not resolved. Shooting it in the Manners.

The MPA is being used with a deviant 700 and absolutely no issues.

My thinking leads me towards a mag interface issue. I know folk that run the MPA with they’re Vudoo and have no problem. I have 3 AISC double stack 10 round mags for my 6 Creedmoor, 2 work fine the other doesn’t. Not so much of a chassis issue, but a mag issue.

 

[JPOPS]

No, the issue with that chassis -rifle combination was not resolved. Shooting it in the Manners.

The MPA is being used with a deviant 700 and absolutely no issues.

My thinking leads me towards a mag interface issue. I know folk that run the MPA with they’re Vudoo and have no problem. I have 3 AISC double stack 10 round mags for my 6 Creedmoor, 2 work fine the other doesn’t. Not so much of a chassis issue, but a mag issue.

Did you bring up this issue to Vudoo? Curious, I thought they tested all rifles before sending them out. Seems odd that this would miss QC

I’ve got one coming soon in an MPA competition chassis

 

[Tiger_Shilone]

OP what are your action torque values?

Reason I state this is that this is a big deal for the CZ455 action. I know a couple of aftermarket alum chassis mfgr's like to say to use 50-60 in/lbs and that is way, way too much. IT will cause bolt bind/movement issues and affect accuracy in a negative manner. The diameter of the action is smaller than a typical CF and will react a lot more to torque values, it will distort at higher values. I typically use between 20-30 in/lbs for CZ's in wood, chassis or fiberglass stocks with my go to value of 24 and 28 in/lbs rear/front. Use a torque wrench. I overtorqued to aftermarket chassis specs and the gun shot like crap, went back to lower values and things almost returned to normal.

Inadvertent 455 bolt pull out is caused by two things: Trigger weight too light, or sear engagement ramp bevel incorrect. The 455 uses the trigger mechanism as a bolt retainer (piss poor design, but it is what it is), pull the trigger to move the sear out of the way to remove bolt for maintenance. I had the bolt start pulling out when trigger weight was set below 2 lbs (I still use factory trigger) at 1.5lb or so. For me this problem went away when I went back up to 2lbs. Bevel incorrect is a known factory CZ problem on some 455 rifles, warranty it or replace the trigger. I've seen an incorrect bevel issue on 2 different buddies rifles, one sent it back and the other just put an aftermarket trigger in (IMHO the only good aftermarket is the Rifle Basix, the MR fly CZ and TImney triggers have had issues too). You may be able to stone the bevel yourself, it's pretty easy to see the engagement areas on the bolt and trigger. Do so at your own risk

I run the bolt pretty hard with an extended bolt handle, I have not had problems at 2 lbs trigger pull weight.

The cz factory magwell is plastic, it will break if overtorqued. They have replacements at CZ usa https://shop.cz-usa.com/SearchByKeyword?word=455

 

[David T]

I had asked MPA what the torque values were when I decided to tear it down after having all the issues. They had said 30-60 PSI, and I went low, 30 PSI.

I made contact with MPA and complained about the issues I was having, starting with all the contact issues between barrel and chassis. They gave me and RMA number and a shipping label to send it back. It is supposed to get to MPA on the 21st. Hopefully the issues will get corrected and I can have a rifle that should shoot better than me.