Magfire Ultra .177 arrives tomorrow

[splitbeing]

Have you tried the NP in any other, even non-crosman rifles, Alton?

Hmmm.... curious what PCPs you are considering.

[ALWIII]

  No, I haven't tried any other NPs. I sort of stumbled in to airguns a few Christmases ago when my daughter moved to the mountains and took up hunting rabbits. I got her a Benjamin NP XL, and a couple months later I bought the Valiant for me so we'd have something for some father/daughter time. It snowballed from there. LOL I now have her Benjamin, the Valiant, my own Benjamin NP XL in .25, and the Vantage. I got a Shockwave in .22 for my girlfriend, and it's probably the nicest shooter of the bunch. Almost as much power as the modded Vantage, but it's quieter, shoots much smoother, and all the moving parts feel like they're on bearings. Except the trigger. I don't much like the Shockwave's trigger, but it doesn't get in the way of the accuracy. All I did was change the NP to an NPE and pay attention to every point of friction between parts. Sanding, mixing my own lube, trial fit, rinse and repeat until it has that slick feeling operation you get from machinery with many, well maintained, hours on it.

  For PCP I've been looking at the Air Venturi Avenger and Avenge-X. Great reviews, and what seems to be great pricing on some accurate and hard hitting rifles. The availability of wood stocks on either one is also a big plus for me.

[mikeyb]

Update (long one!):

Tearing down this rifle for no other reason than I'm curious.

Lots of GREASE for a gas spring rifle. Made in China so extra grease likely added to prevent corrosion during long sea voyage and warehouse storage?

I measured 33mm OD tube with 29mm piston seal. I always get a twinge of annoyance when Gamo stresses their 33mm tube. That's OD for their tube also :-/

Stroke length, as best as I can MEASURE, is 102mm (the typical 4"). Same as the old B19 engine.

Overall swept volume is ~35% LARGER for this rifle over the old B19.

The piston is buttoned! However the "buttons" appear to be steel AND are FLUSH with the rest of the piston body. WHAT? That's completely USELESS! Since the "pockets" are already drilled I may try to clean them out and insert some fitted UHMWPE buttons.



Maybe the button design INTENT was not properly conveyed to the China factory? Whatever the reason this is another good design idea that was a FACTORY FAIL.

Piston is welded and then machined. Pretty heavy also. I think better than the average crimped-head-pistons, but not by much.



AND... NO polymer-donut piston-BRAKE!

I've been curious how they implemented the brake IDEA since I first saw their videos.

To be fair, I'm certain that an anti-piston-bounce mechanism is mostly a SOLUTION LOOKING FOR A PROBLEM. I think this one was a good idea because it's the simplest one I've seen and may actually be able to brake the piston bounce without breaking itself!

However, all my simulations indicate even an "ideal" piston-bounce-brake would have a BARELY MEASURABLE impact on rifle performance. If the Crosman brake-donut design adds too much cost and/or CAUSES MORE PROBLEMS than it solves I'm not surprised it was omitted here.

OR... is this a design idea that was another FACTORY FAIL?

Gas Spring is part number B24-00-7 oriented with the BODY inside the piston resting on a small steel button. Looks like the button was added to get proper PRELOAD on the Gas Spring? Another FACTORY FAIL PATCH?

There is a traditional transfer port measuring
~3mm ID
~15 mm Length

... then there is the ADDED auto-feed transfer TUBE measuring
~3mm ID
~63mm Length

There is a typical breech seal AND an internal barrel o-ring to seal the transfer tube to the bore.

This mechanism SEATS the pellet ~2.5mm deep into the breech.

With this system there is no "cork to POP". In a normal springer the pressure builds HIGH until the pellet POPS the leade and gets a big KICK START down the bore. We all should know by now that seating a pellet deep into the breech eliminates this POP and reduces muzzle velocity.

Deep seating pellets MAY help with shot-2-shot consistency but it will lower muzzle energy. I don't normally seat pellets deeper than FLUSH with the breech face in ANY of my springers.

The total volume of the transfer tube+port is ~5x larger than normal which means the THEORETICAL PEAK PRESSURE is 5x LOWER in this rifle. Not good.

IMO this super-long (large volume) transfer tube is severely limiting the potential muzzle energy POSSIBLE considering the increased swept volume of this larger engine. Remember, the SPRING is the energy SOURCE. The swept volume of air is only the TRANSFER FLUID, but there needs to be ENOUGH air to transfer that spring energy to the pellet.

B19s can shoot up to ~18fpe under good working conditions.
That means THIS PLATFORM should be able to shoot up to 24fpe.
From the SIZE and WEIGHT of this rifle it really SHOULD be shooting in the 20-24 fpe range, NOT the weak sub-15 FPE measured here.

I don't regret my $53 clearance purchase. It was/is a learning experience and may be one of last Crosman rifles I acquire (waiting to see what happens under new ownership?). I'm going to have some more tinkering FUN with this rifle and may try to see if it performs differently with a coil spring installed :-)

Should anyone be interested in buying this rifle my advice is:

NO!  if you just want a repeating springer to shoot. Gamo is a better choice I think.
MAYBE?  if clearance priced LOW,  AND you are looking for a PROJECT RIFLE or just some Crosman "parts".


Just thinking about how sweet that cheap-simple-small-light-FUN Crosman Vital-Shot coil spring rifle performed after a simple cleaning/relube. Now THAT is what a cheap springer SHOULD BE!
Very educational dissecting this beast. The MagFire Ultra really IS a Frankenstein's Monster of springers ;-)
I do enjoy ALL of my OTHER Crosman rifles. In that respect Crosman has done an EXCELLENT JOB for a very long time. I've been a fan since the early 1970s. This is the first time I can recall that I would advise AGAINST buying a particular Crosman rifle :-(

Cheers :-)

edit: Piston seal was fine, no assembly damage from sharp edges. Gas spring MAY be weak (leaky?) but I'm pretty confident the multi-shot design is the fpe killer here.

[splitbeing]

Wow! I know so much more about this rifle now!  Thanks, Mikey!

Is there anything you can think of doing to address the tranfer bottleneck?

[mikeyb]

Hope you don't mind that I'm adding to this MagFire Ultra thread.

Quick/short update...
Piston "buttons" looked like blackened steel but were a black polymer. Since they were flush (or below flush) with the piston body the factory buttons did NOTHING. I easily drilled out the black polymer (moly loaded poly?) and will replace with some UHMWPE* which is almost as slippery as Teflon (PTFE). I didn't push too hard on the drill press because I did NOT want to drill the blind button hole clear through. Regardless, the piston steel IN THAT AREA felt like it had been HARDENED. I believe it is common practice to harden/temper the skirt area to minimize wear. The trigger latch force/area is quite large in spring-piston air guns.
More later :-)

*Why I prefer UHMWPE in this case.
https://info.slideways.com/blog/uhmw-vs-teflon-packaging-machinery-conveyor-applications

[splitbeing]

Keep the info comin, Mikey!  This thread is the best source of magfire ultra info on the web to my knowledge, primarily due to your investigative reports.  We've come this far, keep postin' here, magfire foreman!