BNM Multi-Shot breech and shroud on Benjamin Maximus

[avator]

Phil.... If I'm being honest, my Varmint in .177 shines at 2700 psi. Filling to the full 3k unregged is virtually fruitless. Not worth the added pressure on the weakest parts of the gun... the O-rings. I can't speak to the characteristics of the .22, I don't have one.
I have a deal with Betty Lou.. Any future guns I buy would be funded by selling guns we already have. Bless her heart. I don't own a single gun that would bring me enough to fund the Urban except ones that I don't wish to sell. We now own the Varmint, the .22 SynRod w/tss and mds and a pair of hpa converted "lego" carbines. This makes the Urban more of a want than a need. I've listed a couple guns in the classifieds with the goal in mind to fund the Urban... The problem has been that before I reach the needed funds one of you enablers point out a "must have" deal and I get weak..... lol

[Lmgunner13]

Bill,
You have one of the Mrodair compressors don't you? Is it doing the job? I am thinking before I get another rifle I should  get a compressor.

Phil

[avator]

Yes, I have the MKII with the auto shut off. I use it to top off my 2 3300 scuba tanks. 1 at 100cf and one at 80cf. I've probably topped of each 10 times no with no issues. I was not around for the first go round with the MRod Air compressor fiasco but I've read about it. This new model reportedly addressed those issues. I obtained mine from MrodAir through a trade deal and like I said... so far, so good.
It fills the 100 cf from aprox. 2500 to 3400 in just under 20 minutes and, once I figured my water cooling out, the max temp is 54c with no stopping to cool during the fill. I do live bleed a couple times during a fill. I choose not to fill gun directly... it fills too fast for me to be confident in the auto shut off. Stuff happens you know. It will top off a 3k gun in less than 15 seconds. Not much room for error.

[ACZan]

So, 11mm Weaver is one of the choices.  I might be able to use my current scope and rings.  But, it is a low profile and need to check for clearance with the magazine.

Can you put just the barrel on the BNM breech without the shroud?  Or, is it only manufactured for the shroud?  Would be nice to put a custom thicker barrel. Instead of the soda straw ones.

[KnifeMaker]

It is available for either with, or without shroud. I ordered a breech made for the shroud. ( The breech that arrived, was for no shroud. GRRRR!!!

Knife

[ACZan]

KnifeMaker,

That is good news that I can get one without the shroud.  I intend to use my TKO silencer.  Obviously the barrel band will need to be change out with the increase distance between the air tube and barrel.  Unless, there is no change on that dimension.  I am having trouble with getting a good replacement barrel from Crosman.  Asked a manager to go through his inventory to find one for me, special request.  Anyone have any suggestions to a good barrel to use with this BNM breech?

ACZan

[KnifeMaker]

BNM has a barrel band for the barrel only. I have one on this one.

Knife

[ACZan]

Is that a two set screw or a six set screw band?

[TF89]

I think it is a single screw in the bottom.  Wait that is the band with the shroud, not sure about the one for just the barrel.  I ended up doing 5 set screws for the part of the band that goes around the air tube and left the shroud portion without any.

Perhaps I should have not answered as I believe you are looking for the one with just the barrel.

Dave

[KnifeMaker]

Single screw on bottom for tube. BBL. is an "O" Ring. 

Knife

[ACZan]

Well, you guys have me convinced to seriously consider a BNM custom upgrade on my rifle.

I considered replacing the Discovery with a European version, but I just couldn't find a foreign one with the fundamental characteristics with which the Discovery was designed and I like.

I did speak to Sergio at BNM a little bit about the repeater breech. I was concerned about the drop in the fps going to the BNM breech.  I really need to try and keep it at the factory 900 fps level or close.  Does anyone know if and by what the velocity drops with the new breech?  I did get a bit of a drop into the upper 700s with the replacement of the barrel.  Don't know why that happened.  If there is a drop BNM breech, what can be done to compensate for that?

I would really love to replace the plastic trigger housing with a metal one.  Would be willing to drop some cash to make that happen.  I just don't like having plastic in critical places.  My Pontiac 2000 Grand Prix SE with the 3800 Series II engine had way too many plastic parts that were failing on a regular basis.

[KnifeMaker]

My valve-tp-barrel seal was leaking in the factory set-up.  I drilled the BNM thru port a bit bigger, and matched it to the barrel/ valve port that I had ported. FPS went up, due to less blow-by.

I replaced the plastic trigger group with the MRod Gen I Trigger Group. Man, what an Improvement!!!

Knife

[ACZan]

KnifeMaker,

What did fps go from and up to after the modification?

[avator]

Crosman would do well to add a repeater breech for the "lego" guns in the CCS.

[toddbrat]

I would love an off the shelf repeater at 2k. Going to go out on a limb and say I've *finally* gotten my BNM where I want it, well almost, waiting on some Krytox to get here. Looks like I can track down my shotgun patterns to a bad scope; I thought it was  holding zero and maybe the shroud/barrel was moving or was getting some clipping. Bought a laser boresight and while using that at 25 yards to align the scope, what should have been a small adjustment of less than 1/2" moved almost 6"! To test the theory, I stopped moving the turrets and gently thumped the housing near the turrets. The dot swung from 2" left of the line to almost 5" right of it. Guess that's what I get for buying cheap scopes. Put an old scope on and it is holding true. And I missed the Amazon return window by 3 days...

Anyway, loving my "new" rifle. Next up is a FFH and power adjuster to try to flatten the curve out, it is steep enough I get more POI shift than I'd like at 50 yards.

[KnifeMaker]

Without changing spring setting, it went from shooting 14.3's at 880 to high 890's, so backed the spring pressure  down a bit.

The Crosman domes are odd beast in my AG. Cheap, and shoot well, but not over 880's.

Knife

[KnifeMaker]

I know they cost a bit, but a good scope is well worth the money spent. 

Mine are Zeiss and the  Athlon 6.24 FFP. Both are completely accurate in their tracking.

[toddbrat]

Those are some nice scopes. I'm too cheap to spend the money on them, especially when all I do is poke holes in paper. With that said, I do have my eye on a nice PB that'll let me poke those holes at 1000 yards plus and if I get it that will definitely be dressed for success...lol.

My Maximus is .177 and really shoots the Snipers, both medium and heavy as well as Monsters really well.

[Vee3]

Crosman would do well to add a repeater breech for the "lego" guns in the CCS.

No kidding. Might even save their bacon from the Chinese repeater invasion.

[Blue]

Crosman would do well to add a repeater breech for the "lego" guns in the CCS.

+1

And the option of a two stage trigger (Prod trigger and hammer assembly).

But so as to digress no further and bring it back to the BNM breech, here's my disco with their breech and shroud.

Blue