250Z Message from Barra Airguns on Accuracy

[Billm]

Scope it, and if youre choked, id contact barra and rts the whole thing. Let them know you are going to continue inspecting every rifle they send until they send out one that meets their advertised rifles specs of an unchoked rifle.

You honestly think that you can see if the bore is choked with a bore scope?

 

[PestPlasteringPlinker]

You honestly think that you can see if the bore is choked with a bore scope?

I would imagine you could see the curvature of the light picking up the transition. Bowed shiny surface should(should is the key word) be noticeable with light, while being magnified.

 

[Billm]

I would imagine you could see the curvature of the light picking up the transition. Bowed shiny surface should(should is the key word) be noticeable with light, while being magnified.

You’re talking .002” or .0508mm. Highly unlikely any human eye looking through a bore scope is going to pick that up. I’m just trying to point out that a better way is to slug the barrel twice. Chamber a slug and push it in a few inches with a dowel etc. and then push it back out from the muzzle. Then pass another one from the breech out through the muzzle. The measured difference between the two will be the choke. The second slug will also tell you if the bore is uniform for the full length of the barrel. I’m starting to believe SPA barrels start out tight, go loose in the center and then tight at the choke. Not really a good sign lol. You can feel the choke.

 

[PestPlasteringPlinker]

You’re talking .002” or .0508mm. Highly unlikely any human eye looking through a bore scope is going to pick that up. I’m just trying to point out that a better way is to slug the barrel twice. Chamber a slug and push it in a few inches with a dowel etc. and then push it back out from the muzzle. Then pass another one from the breech out through the muzzle. The measured difference between the two will be the choke. The second slug will also tell you if the bore is uniform for the full length of the barrel. I’m starting to believe SPA barrels start out tight, go loose in the center and then tight at the choke. Not really a good sign lol. You can feel the choke.

See, mine didn't have that problem. The original did for sure. No doubt. This replacement I ordered, has only the slightest, and I mean the slightest hiccup right at the crown, which, I am positive will be taken out with a crown polish.

Im pretty simple on if its choked. I put a slug down the breach, get past it, and ease the thing down. If it catches about 2 ish inches, yeah, thats enough of a tell tale that its a choked barrel.

Like I said, should. I would think a bore scope would pick up on the transition of the light on the lands and flats, but Im not gung ho like that, nor do i need to be. If my replacement barrel would have been any worse than it is, it would have gone back instantly, because I paid for what they advertised.

I had the absolute slightest chatter(which i knew i could get out easy)about half way down, but after the second bore mop, completely gone.

I polish breach to crown. Not incrementally. Polishing like that, a barrel like my original, would never get the choke out. I agree, their breach on my original, get real, and the lock up(on my stock one) at 2 inches with a 36g zan was unreal.

Absolute lazer with pellets though, I don't know why, buuuuut, then I started trying slugs, then I had to inspect what was going on. Then me being me, had to pull out the compounds, and different grit papers, and micrometer. And put more work into the stock barrel than anything else.

As stated originally though, if I was you, I wouldn't lay a finger more on it, because it doesn't meet your standards, or what they say it is. Get at them, and flat out tell them, what it is, and to send an actual, un choked, tested, qc'd barrel.

Realistically, if their stringent qc was stringent, I could do the same. I paid for it as advertised. But 10 minutes on a crown, for me, is not worth splitting a hair. If it was more than that, nah. My barrel i fixed is the chefs kiss right now, but I certainly would not go that hard in the paint on a second one.

 

[Billm]

See, mine didn't have that problem. The original did for sure. No doubt. This replacement I ordered, has only the slightest, and I mean the slightest hiccup right at the crown, which, I am positive will be taken out with a crown polish.

Im pretty simple on if its choked. I put a slug down the breach, get past it, and ease the thing down. If it catches about 2 ish inches, yeah, thats enough of a tell tale that its a choked barrel.

Like I said, should. I would think a bore scope would pick up on the transition of the light on the lands and flats, but Im not gung ho like that, nor do i need to be. If my replacement barrel would have been any worse than it is, it would have gone back instantly, because I paid for what they advertised.

I had the absolute slightest chatter(which i knew i could get out easy)about half way down, but after the second bore mop, completely gone.

I polish breach to crown. Not incrementally. Polishing like that, a barrel like my original, would never get the choke out. I agree, their breach on my original, get real, and the lock up(on my stock one) at 2 inches with a 36g zan was unreal.

Absolute lazer with pellets though, I don't know why, buuuuut, then I started trying slugs, then I had to inspect what was going on. Then me being me, had to pull out the compounds, and different grit papers, and micrometer. And put more work into the stock barrel than anything else.

As stated originally though, if I was you, I wouldn't lay a finger more on it, because it doesn't meet your standards, or what they say it is. Get at them, and flat out tell them, what it is, and to send an actual, un choked, tested, qc'd barrel.

Realistically, if their stringent qc was stringent, I could do the same. I paid for it as advertised. But 10 minutes on a crown, for me, is not worth splitting a hair. If it was more than that, nah. My barrel i fixed is the chefs kiss right now, but I certainly would not go that hard in the paint on a second one.

My barrel was very accrete pellets, but fell apart with slugs

 

[PestPlasteringPlinker]

My barrel was very accrete pellets, but fell apart with slugs

That was 100% the issue with my first barrel. Drove me to the point of going bananas

 

[Bladefin]

I'll try to push a slug from the crown to the breech when I get home. Actually, I'll run some patches through them and lightly lube the slugs and do the whole thing over. But both were extremely tight the last 2-2.5" and yes the slugs both measured out to 0.253". My caliper will not do ten-thousandths individually, it's zero or 0.0005.

I'm going to reach out today and see if there's a possibility that my shipment was pulled from the wrong stock. I'm also not going to do anything other than running some patches through them and reslugging until I hear something one way or the other on these from Barra.

You’re talking .002” or .0508mm. Highly unlikely any human eye looking through a bore scope is going to pick that up. I’m just trying to point out that a better way is to slug the barrel twice. Chamber a slug and push it in a few inches with a dowel etc. and then push it back out from the muzzle. Then pass another one from the breech out through the muzzle. The measured difference between the two will be the choke. The second slug will also tell you if the bore is uniform for the full length of the barrel. I’m starting to believe SPA barrels start out tight, go loose in the center and then tight at the choke. Not really a good sign lol. You can feel the choke.

Looking closely at the barrels, I believe the way it starts out tight after the breech is the leade transition where the rifling starts. It's a steep rough transition. After that it's a smooth easy push until those last couple inches, where a considerable amount of force was needed to finish. Maybe part of that was due to no lube, I don't know.
The leade can be fixed. The choke? Not so much.

 

[BSJ]

I'll try to push a slug from the crown to the breech when I get home. Actually, I'll run some patches through them and lightly lube the slugs and do the whole thing over. But both were extremely tight the last 2-2.5" and yes the slugs both measured out to 0.253". My caliper will not do ten-thousandths individually, it's zero or 0.0005.

I'm going to reach out today and see if there's a possibility that my shipment was pulled from the wrong stock. I'm also not going to do anything other than running some patches through them and reslugging until I hear something one way or the other on these from Barra.


Looking closely at the barrels, I believe the way it starts out tight after the breech is the leade transition where the rifling starts. It's a steep rough transition. After that it's a smooth easy push until those last couple inches, where a considerable amount of force was needed to finish. Maybe part of that was due to no lube, I don't know.
The leade can be fixed. The choke? Not so much.

Back in the May-June time frame they told me they were sending me an inspected barrel. It was still full of the factory gunk, and just as bad as all the others. Prior to that, I ordered three at one time hoping to get at least one good one. All hand mangled lands on both ends.

I doubt they have a borescope or anyone that knows what they're looking for during this so called inspection!

 

[Bladefin]

Back in the May-June time frame they told me they were sending me an inspected barrel. It was still full of the factory gunk, and just as bad as all the others. Prior to that, I ordered three at one time hoping to get at least one good one. All hand mangled lands on both ends.

I doubt they have a borescope or anyone that knows what they're looking for during this so called inspection!

If I have to clean up the barrel, smooth out the leade and even work on the crown, that's fine. No issue with those things. I'd just like to get unchoked barrels that will shoot slugs as accurate as the initial batch of guns. I didn't pay a crap ton of money for a high end gun and I expect to have a little work to do for the $430.00 I spent on them. Just send me the same thing that they sent to all the Youtube reviewers.

 

[BSJ]

If I have to clean up the barrel, smooth out the leade and even work on the crown, that's fine. No issue with those things. I'd just like to get unchoked barrels that will shoot slugs as accurate as the initial batch of guns. I didn't pay a crap ton of money for a high end gun and I expect to have a little work to do for the $430.00 I spent on them. Just send me the same thing that they sent to all the Youtube reviewers.

FX won't even do that...

 

[PestPlasteringPlinker]

FX won't even do that...

So is it a common theme im assuming of sending out super qc'd guns to reviewers or something?

 

[BSJ]

So is it a common theme im assuming of sending out super qc'd guns to reviewers or something?

I got two Crowns when they were supposed to be the hottest thing ever. Sent the first one back because it shot like crap. Should've sent the second one back too...

 

[PestPlasteringPlinker]

I got two Crowns when they were supposed to be the hottest thing ever. Sent the first one back because it shot like crap. Should've sent the second one back too...

I actually had no idea that pcp companies did that. It would make sense though. Mass money grab with the least amount of true to spec production units.

That's such a shady, thing to do. Imma hope for my homies sake the pre orders are as decent as the barrel i got. If they're not, thats going to be so disheartening. Ill tell em to rts it, and borrow mine, so I have motivation to work on my sl30.

 

[Bladefin]

Ok, so, I may have been wrong. I cleaned the barrels and wow were they dirty. After 10 ballistol'd patches there's still dirt coming out. I pushed more KO MKII's that I hit with some silicone and they still came out at 0.253 but less effort at the end, but still more than the main body. After some texting with a buddy I decided to measure a before on the MK II's and they are coming out at 0.260! And yes I trust the calipers, Mitutoyo digital from the 90's when quality was better.

H&N 30gr are measuring 0.250 to 0.251 before and roughly the same after pushing. The difference is they seem to snag at several points mid body, where the MKII doesn't. They just get harder to push the last couple inches.
I'm going to really clean them this weekend and push some more slugs. The best of the two will get the leade cleaned up, polished, and touch up the crown. Then I'll reassemble and see how it shoots.

More to come...

 

[PestPlasteringPlinker]

Ok, so, I may have been wrong. I cleaned the barrels and wow were they dirty. After 10 ballistol'd patches there's still dirt coming out. I pushed more KO MKII's that I hit with some silicone and they still came out at 0.253 but less effort at the end, but still more than the main body. After some texting with a buddy I decided to measure a before on the MK II's and they are coming out at 0.260! And yes I trust the calipers, Mitutoyo digital from the 90's when quality was better.

H&N 30gr are measuring 0.250 to 0.251 before and roughly the same after pushing. The difference is they seem to snag at several points mid body, where the MKII doesn't. They just get harder to push the last couple inches.
I'm going to really clean them this weekend and push some more slugs. The best of the two will get the leade cleaned up, polished, and touch up the crown. Then I'll reassemble and see how it shoots.

More to come...

Yeah, mine took about 10 minutes to clean.

I had what I consider to be chatter mid body, came right out after polishing.

.260 is massive starting! Makes sense why it would for sure signal even the slightest of choke. My original barrel loves the 2505 h&n, this one, just finished reassemble with airing up. Letting things cool down for the night, and stabilize pressures. Tomorrow I'll be running the .251 33.49 knock outs, and .2505 32 grain h&ns, compared to 33 grain Apollo.

Ideally id prefer the heavier 33.49, to group the best and be the most consistent, but target time will tell.

Ill throw a couple qd mags of hades through it first to get it leaded in. Then run a Big air mag of each of the following on a target to check out the groupings and make a decision

All the 33 grainers will get cronographed to see which of the diameters plays the highest, and lowest fps to verify.

Im hoping its a ringer for you! But yeah, if you check it and its still not right, I wouldn't go the route of polishing if that choke is throwing it off, but it'll be cool to see how you get it to turn out for you!

 

[Bladefin]

I got a bad tin of JSB KO MKII. They are measuring out to 0.259 to 0.261.
Another tin I have is 0.250.

 

[PestPlasteringPlinker]

I got a bad tin of JSB KO MKII. They are measuring out to 0.259 to 0.261.
Another tin I have is 0.250.

Yeah, that is what i was tripping about reading. Hard. That is so oversized, it sounds like a leshy size.

 

[PestPlasteringPlinker]

I got a bad tin of JSB KO MKII. They are measuring out to 0.259 to 0.261.
Another tin I have is 0.250.

I literally only just found knockout 1's at 2510, and those are big compared to my h&n 2505's.

Rule of thumb from what I have read, is if your barrel is reading 2504, .2505 is perfect, as far as slugs go.

My new barrel, all polished up, is just under the .2507. I really don't want to waste the air on 2495's, some of the deeper dish zans might flare to fit it, but the 251's really are sliding ideal in my barrel.

 

[BBGunn]

I literally only just found knockout 1's at 2510, and those are big compared to my h&n 2505's.

Rule of thumb from what I have read, is if your barrel is reading 2504, .2505 is perfect, as far as slugs go.

My new barrel, all polished up, is just under the .2507. I really don't want to waste the air on 2495's, some of the deeper dish zans might flare to fit it, but the 251's really are sliding ideal in my barrel.

I am not a proponent of automatically matching slug diameter to groove diameter for slug shooting. In my limited experience (3yrs) (35yrs PCP) shooting slugs I have not always found best accuracy with groove diameter fitting/filling slugs.

I'm not saying that tight fitting slugs won't be the most accurate in a given rifle, but rather that those tight fitting slugs have just as much chance of NOT being the most accurate. Put another way, from my experience, looser (not loose) fitting slugs have just as good a chance of shooting well out of a given rifle as do tight fitting slugs.

I know that AVS says that groove filling diameters are the 'key' to good slug accuracy..., but I have not found that to be true. Don't get me wrong, I've spent hundreds of dollars on AVS slugs and usually find one or two that are at the top of accuracy results in a given rifle. However, those that produce the best have not been the groove filling diameters.

Not criticizing, just sharing to help folks trying to find good slug accuracy from the 250Z.

 

[Pumacarl]

I am not a proponent of automatically matching slug diameter to groove diameter for slug shooting. In my limited experience (3yrs) (35yrs PCP) shooting slugs I have not always found best accuracy with groove diameter fitting/filling slugs.

I'm not saying that tight fitting slugs won't be the most accurate in a given rifle, but rather that those tight fitting slugs have just as much chance of NOT being the most accurate. Put another way, from my experience, looser (not loose) fitting slugs have just as good a chance of shooting well out of a given rifle as do tight fitting slugs.

I know that AVS says that groove filling diameters are the 'key' to good slug accuracy..., but I have not found that to be true. Don't get me wrong, I've spent hundreds of dollars on AVS slugs and usually find one or two that are at the top of accuracy results in a given rifle. However, those that produce the best have not been the groove filling diameters.

Not criticizing, just sharing to help folks trying to find good slug accuracy from the 250Z.

Bingo! Unfortunately, I think you're right. I respect the hell out of AVS, and Roachcreek and Knifemaker, all slug pioneers or makers, but I don't think that there is a definitive formula either. We're all still testing every time.

For my 250z I never would have tried the .216 JSB KO slug if @Dairyboy hadn't told me that it shot lights out in one of his guns that usually shot .217. Turns out it shoots great in mine too.

The way things have been moving in the past 10 years, I'm not going to make any predictions, but I would not be surprised if someone came up with a guaranteed slug fit for a particular barrel, ...but I'm not holding my breath either.