Author Topic: BNM Bolt Probe Problems? (Read 22431 times))

ACZan · « **Reply #20 on:** May 01, 2018, 04:51:25 AM »

Knife' told me about BNM sending him the wrong breech. In an effort to prevent that happening with my order, I specifically put in the notes field of the order page to be sure to send the BMDSH3002 (non-shroud version). They went ahead and sent the BMDSH3001 shrouded version, totally disregarding the order notes.

Still haven't heard from them. I pretty much figure that I will have to have someone machine a new properly size bolt to correct the issue. I hate it when people/businesses think we customers are naive and won't notice the problem.

What should have been a fairly straight forward mod has now turned into quite a large project. Breech defects to correct, another barrel to done due to bad machining, muzzle threads to cut and barrel bands to design and fabricate. I hope my machinist friend will get me straightened out. Generally, If I provide him drawings, he pretty much makes it.

pecor · « **Reply #21 on:** May 01, 2018, 05:01:41 AM »

ACZan, https://www.gatewaytoairguns.org/GTA/index.php?topic=130078.40
Bottom of page 3 Those 2 images for the barrel port, Is from Roy @ Mountain Air's Work?? WOW!!! That looks like Pure Laziness, By not wanting to set up his mill to spot face a slight counterbore!! I could have done that with a hand drill and a dremel with a stone

For what that man charges I would Not Accept that at all!! That's going to be a pain in the arse whenever you pull that apart!! then Try To Reseal. Next time I would use Tim@ Mac1 ;

Or are Very own, MotorHead

He use's Weihrauch barrel's that are every bit as Good as Lw, Choked or standard And you can order them yourself. http://silco.co.uk/categories/WEIHRAUCH-BARREL-BLANKS/ I;m sure you will get it sorted out, Hang in there! Jaa

ACZan · « **Reply #22 on:** May 01, 2018, 05:46:09 AM »

Pecor,

What photos are you referencing? I want to make sure I know which one you are talking about. If it is what I think you are referencing. Yes, I notice that, too and was disappointed to see that.

I thought maybe you were talking about this one below. I don't think I ever uploaded this one. I believe the surface end of the barrel should have been finished a bit better than this. At least take off the stamped letter.

I sent the same barrel port hole photo to him and mentioned the counter bore not being concentric with the hole. However, he did point out on this breech the TP tube doesn't come into contact with the barrel. The MS Word drawing represents that.

I did manage to measure both the bolt lengths on both the Breeches (BMDSHSH3001 and BMDSHSH3002) I received from BNM Custom. Both of them basically come out to 3.3000 on my micrometer. In simple terms, both the side bolt, shrouded and non-shrouded, breeches have the same issue.

Thanks for the suggestion on the Weihrauch barrels. I'll certainly look into them, since I haven't heard back from Lothar-Walther, yet.

Wait a minute. That is a "C" stamped into the end of that barrel. How can you tell which end of a Lothar-Walther is the choked end? See what I am getting at here?

pecor · « **Reply #23 on:** May 01, 2018, 06:22:20 AM »

I was looking a the 2 photo's of the barrel transfer port, were the air enters the barrel. The throat is where the pellet loads into. Your not going to hear Back from LW, LW sell's plain barrel blanks, They are not throated! That is Roy @ Mountain Air's, JOB to Throat the barrel and drill the transfer port, That is 100% on him, And it looks like S#@% in my opinion

If you used a credit card I would put a stop payment on it. And return it!. If you paid by money order it's yours, I hate to say. I would send it to a real smith and have that cut off, In Front of the transfer port, And have it re-throated and a real transfer port drilled. I would a least contact MotorHead for his opinion ** Home of MOTORHEADS AG Tuning Services **
** PM me for further contact & tuning info. And yes he does machine and install barrels https://www.gatewaytoairguns.org/GTA/index.php?action=profile;u=4853 Link Motorhead to this thread and have him look it over

That close up photo of the throat you just posted still shows burrs in the transfer port edges? No good.

ACZan · « **Reply #24 on:** May 01, 2018, 06:35:28 AM »

That is what I want, a barrel blank. If that stamped "C" on the end of the barrel is an indication of the choked end of the barrel, then I would have a case to send it back and get a refund. I did use a cashier's check, because he adds on the PayPal fee. I trusted him to do the job right.

I'll call L-W tomorrow to see if I can get a blank. Was told it would take Customs FORM BIS-711 to complete the purchase. It is worth a try. Wiehrauch didn't have the barrel dimensions I need. Can't shorten the barrel need it to be as much of the 23.8 inches it has.

pecor · « **Reply #25 on:** May 01, 2018, 06:44:51 AM »

So what your saying is you don't want a Choke? Confused? That C does not mean {that end has the choke}, Push a pellet thru and you will feel it tighten a bit at the muzzle

ACZan · « **Reply #26 on:** May 01, 2018, 12:49:17 PM »

Yes, I did want it choked. Wow, just heard back from Lothar Walther. They confirmed the stamped end is the breech end. The stamped "C" is a 50/50 shot as to what it means. Did realize that it is quite possible that the "C" stamp doesn't indicate the choked end. However, they would have to mark it in some way.

It was just wishful thinking. Oh well, I can just hold on to the bad one and use it to test a reamer. Then, the remaining can server another life in another gun. Sure someone might want to buy a shorter barrel for some custom project.

Also, I was really shocked that the guy had the invoice sent to me in an email this morning and is ready to ship upon payment. I thought they needed a Customs Form BIS-711 for a purchase.

Still haven't heard anything back from BNM Custom.

pecor · « **Reply #27 on:** May 01, 2018, 03:35:28 PM »

Good Luck on your Endeavor

ACZan · « **Reply #28 on:** May 01, 2018, 05:18:11 PM »

Thanks Pecor,

I'll need every bit of it, based on many of your accounts of experience.

It will eventually get done the right way. Just have to be persistent, resourceful and out-of-the-box creative.

BTW got confirmation that Lothar-Walther in GA doesn't require the Custom Form BIS-711 for a purchase, I assume if the purchase is in the USA. Must have been a recent change in the past year or two. That's a relief. Hate doing those forms, makes me feel like I am dealing with the IRS.

proz83 · « **Reply #29 on:** May 02, 2018, 03:40:20 AM »

just a question! is there any o'ring in the middle block? as in the picture attached here! encircled in red ! because on the breech that I received, there is no o'ring! It's normal?

miksatx · « **Reply #30 on:** May 02, 2018, 07:59:27 AM »

Regarding the picture with the pellet in the barrel that is has the c stamp. Yes someone at BNM turned the wrong end. I own 4 BNM breechs, 2014 I sent a LW barrel and one of the breech. When I got it back I was in the same boat c stamped on the breech end. I called LW and confirmed it was indeed wrong end.
Sent it back they ordered and cut a new barrel blank. So they should know better. All bolt probes left the pellet in the center of the TP I've told Sergio about it. I went ahead and made new probes for all.
Another thing to be aware of is the bolt handle is made of soft steel of some kind. I've broken three bolt handles and shot one hole in my deck roof. I just buy another bolt handle for all my breechs. For what it's worth even with the few problems I've had I'd still buy from them.

rsterne · « **Reply #31 on:** May 02, 2018, 12:34:51 PM »

LW barrels are stamped on the BREECH end.... Some are stamped with a C, some aren't (just have the caliber).... but I have never seen ANY barrels from LW stamped at the muzzle....

If the bolt probes leave the pellet in the middle of the transfer port, there is an easy solution.... TELL US !!!.... If nobody says anything here on the GTA, and therefore nobody knows until they spend their hard earned cash.... BNM have no incentive to change.... If all that is needed is a longer probe, how hard can that be?.... If there is a problem, and it becomes widely known (affecting sales).... you can BET it will get fixed....

I follow this forum pretty closely, and there has been VERY little reported about this.... I have seen quite a few complaints about low velocity, and it has been blamed on the longer transfer port.... Knowing that is probably not the cause, I paid no attention to that.... but when I saw a photo of a pellet obscuring 3/4 of the transfer port it sure got my attention.... which is why I started this thread.... to find out if this is a common problem or not.... If it is, then as a community we need to shine a light on it, IMO....

A couple of years ago there were some BNM breeches that blew the O-ring out of the back of the block because there was not enough metal behind it.... That came to light here on the GTA, and the company fixed the problem immediately, and I have seen no repeat issues reported.... That shows the collective power we have.... if we choose to share info and identify and analyze problems.... and make them public, often along with a proposed solution.... Everyone benefits....

Bob

Machinist · « **Reply #32 on:** May 02, 2018, 01:46:16 PM »

I was going to buy a BNM breech. I figured all I would have to do is open the box and bolt it on. I don't want to spend hours and hours making a breech.

But I'm not buying something that doesn't work.

Steve

Hobbyman2007 · « **Reply #33 on:** May 02, 2018, 03:04:13 PM »

I have two BNM breeches installed in guns I own and love . Now with that being said both , one in .25 and the other in .22 had the pellets (JSB 25.4 and 18.1 respectively)blocking the transfer port to some extent . My fix was to cut off the existing probe and install a longer probe made of 1/8 “ drill steel . I won’t be ordering from them again . After numerous attempts to order new bolts at my expense for some sort of design flaw I decided to repair it myself . There really isn’t too much room for elongating the probe when enlarging the transfer port , especially in the .25 . Iv also done a bit of material removal to get the bolt further forward in the breech , this allows the pellet to seat further in the barrel . I can post pictures when I get back from Africa.

miksatx · « **Reply #34 on:** May 02, 2018, 03:41:31 PM »

I cut a piece of 1095 1/2" longer then the original pellet probe turned it to the diameter cut near same front part of the probe. Stuck in in the breech pushed it in till it pushed the pellet further forward marked a screw hole. Drilled tap to 8-32 I did change Allen screw to a smaller size Allen key.
Pics are my .25 breech first pic should be original bolt probe and how far in the TP port it leaves the pellet. Second pic is the adjusted screw hole. Pellet is jsb 25.39.

miksatx · « **Reply #35 on:** May 02, 2018, 03:59:09 PM »

Sorry for the double post.

pecor · « **Reply #36 on:** May 02, 2018, 06:19:11 PM »

Quote from: miksatx on May 02, 2018, 07:59:27 AM

Regarding the picture with the pellet in the barrel that is has the c stamp. Yes someone at BNM turned the wrong end. I own 4 BNM breechs, 2014 I sent a LW barrel and one of the breech. When I got it back I was in the same boat c stamped on the breech end. I called LW and confirmed it was indeed wrong end.
Sent it back they ordered and cut a new barrel blank. So they should know better. All bolt probes left the pellet in the center of the TP I've told Sergio about it. I went ahead and made new probes for all.
Another thing to be aware of is the bolt handle is made of soft steel of some kind. I've broken three bolt handles and shot one hole in my deck roof. I just buy another bolt handle for all my breechs. For what it's worth even with the few problems I've had I'd still buy from them.

Sorry Boss but you have it wrong, All Lw barrels are stamped at the Breech Not the Muzzle, So your barrel is in fact Not choked at the muzzle as it should be!! Push a pellet through where is your choke, I Bet it's not at the Muzzle like it should be. Unless you sent them a crosman LW barrel witch are Not marked.

pecor · « **Reply #37 on:** May 02, 2018, 06:48:49 PM »

If you have to contact them you might try here it's the Same place, Same Address!! Everything! When he has an empty CNC mill - lathe machine he make airgun breech's and Parts!!! This is Why He could give a &^^& about his Parts, Just pocket change for him! Look At The Address's = https://www.bnmcustom.com/contact-us/ == http://www.mnbaerospace.com/ ==
https://www.yellowpages.com/holbrook-ny/mip/mnb-products-service-inc-501832296 If I was going to Contack Him I would use the phone number listed @ this web site http://www.mnbaerospace.com/

ACZan · « **Reply #38 on:** May 02, 2018, 06:49:25 PM »

Proz83,

Yes, there is supposed to be an o-ring there as show in my photo uploaded in another topic. But, will put it in here if there is no problem having it in a couple of places. There are some folks who didn't know there was an o-ring in there. You have to look closely as it is hard to see it at times.

Canadianguy55 · « **Reply #39 on:** May 02, 2018, 07:08:09 PM »

Hi....noticed this thread and i noticed this problem a while ago. I asked him and he made me a extended bolt and an enlarged TP. i had no idea he did aerospace stuff! i think this is the right pic...

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BNM Bolt Probe Problems?

Author Topic: BNM Bolt Probe Problems? (Read 22431 times))