Brief:
Semroc has gone "retro repro" again, bringing out a modern reproduction of one of the last Centuri designs before the Damon Corporation consolidated their product line under the Estes brand. The kit, although a Centuri model, featured Estes parts in its day. The Semroc reproduction features laser-cut fins, a balsa nose cone, and upgraded Kevlar®/elastic shock cord, plus includes a chute instead of the original streamer. It's a basic 4-fin design, but with the flexibility to fly on either 18 or 24mm motors, you can lob it up over a small field or load in a D and send it into orbit.

Construction:
The parts list includes the following, all of excellent quality:

• BNC55AC Balsa nose cone (Estes Cherokee D style)
• BT-55 body tube
• BT-50 motor tube
• Laser-cut balsa fins
• Laser-cut thin cardboard centering rings
• Metal motor hook
• 12" plastic chute
• Kevlar®/elastic shock cord
• Waterslide decal
• 18/24 adapter kit (motor tube, centering rings, metal hook, motor block)

Semroc has made one minor change to their instruction sheet format with this kit. The instructions remain printed on 8.5" x 11" paper, but instead of printing booklet style folded in half, you'll need to open up the whole thing flat. The left side of the sheets are perforated. The idea is that some builders will want to keep their instructions in a binder, and this makes it easy to do so and still read through the plans. It's probably a cool idea, but I have so many sets of instructions tucked away that it's probably a little too late to try and teach this old disorganized dog the trick of filing and neatness.

Overall, construction consists of about 30 steps over 3 full pages including illustrations and runs around 2 hours plus whatever time you invest in finishing. I built this side by side with the Magnum Sprint and found they are almost identical in build.

I started off with the motor mount, which consists of a simple 24mm tube with metal hook, motor block (20/50 centering ring) and a pair of thin centering rings. A loop of Kevlar® slips under the metal hook to anchor the shock cord. The completed assembly is later glued inside the body tube flush with the aft end. Note that the motor hook and tube are sized only for D's, so if you are nutty enough to want to try an E, you'll have to swap out tube/hook.

The fins are symmetrical trapezoids mounted 1/2" forward of the aft end. Tube marking is via a marking guide on the instruction sheet with no lug line indicator. Lug placement is not that critical, but for aesthetics I'd have preferred a lug line included on the pattern (and a wraparound guide is easier for me). I tacked the fins on with medium CA then applied wood glue fillets.

Tacking on the launch lug and putting the screw eye on the nose cone wraps up the main construction.

Because this is a fairly small/light model, a 24mm motor could be a little excessive. Therefore, a neat little adapter is included that supports 18mm motors. This adapter is a standard 18mm motor tube, block, and metal hook but with 3 centering rings. One of these rings has a cutout to allow the metal hook to open out of the way for removing the motor. If you place the centering rings carefully per the instructions, what you'll get slides perfectly into the BT-50, locking in place through the outer motor hook, and the 18mm motor is held in place by the inner hook.

Finishing:
Finishing is a breeze although the stock paint scheme does require a very tiny bit of masking. The main body got a couple coats of gray primer after the standard Elmer's Fill 'n' Finish for spirals and grains. I then followed up with Rustoleum yellow. After allowing a couple days to cure, I masked off all but one fin and the nose and then hit those with gloss black.

The waterslide decals are minimal but add a nice touch and are excellent quality and are easy to work with.

Construction Rating: 4 out of 5

Flight:
For the first flight, I was looking at winds holding steady at 12-15 mph and gusting to 20, so the thought of chasing this for the expected drift of a 24mm motor was out of the question. I was surrounded by lake, trees, and soccer games so needed to minimize the drift to about 150 yards.

Thankfully, this comes with a handy little 18mm adapter so I was able to quickly load up a B6-4 for the first flight. I flew off a 3' length of 3/16" rod, and this rocket held its own against the wind very nicely, with just a hint of weathercocking. I didn't get much altitude with the B6-4 (maybe a couple hundred feet), but it would at least remain in the park. The -4 delay in this instance was perfect.

Recovery:
The 12" plastic chute is certainly up to the task, and I was able to recover this with no problems.

Flight Rating: 5 out of 5

Summary:
PROs: Classic design/tribute and great versatility. Can fly on large or small fields with A-D motors (potentially even 24mm F's).

CONs: None to speak of.

Overall Rating: 4 ½ out of 5

Brief:
Chan's build experience exactly fit my own so I'll try not to repeat. The Magnum concept is simple: large motor, small rocket, and it actually makes more sense today than it did when originally marketed. I got my kit from Apogee, and it was damage-free.

Construction:
It is extremely easy to build and all the components are of high quality. Smooth, perfectly formed nose cone, nearly invisible spirals, and flat fin material. Including the high-quality 18mm adapter is a deluxe move most manufacturers could take lessons from. Not sure you could ask for more.

Instructions are simple and well-illustrated. One little well appreciated surprise is how the Kevlar® attaches to the motor mount. It's simple, strong, elegant, and quick to build.

Finishing:
Finishes quickly and easily. Used Elmer's Wood Filler on the nose and fins, two coats of high solids automotive primer, then rattle can yellow and black to finish. Looks perfect.

Construction Rating: 5 out of 5

Flight:
Flew it 3 times in a small park on 1/2A3-2Ts. Semroc doesn't recommend the motor, but it's perfect for a small park or large back yard. Can't imagine putting a D12-7 in this thing. Had to use a 13mm adapter inside the 18mm adapter Semroc provides, inside the 24mm mount so it looks kind of funky.

Recovery:
Just about everything on this rocket is perfect for flight. It's light so it lifts off fast. The fins don't stick out below the body tube so they don't break. With 13, 18, and 24mm motors, you have an incredible range of possible altitudes. Half a point off for a shock cord that's a little short. The 3/16" lugs are a welcome feature.

Flight Rating: 4 ½ out of 5

Summary:
PROs: Simple, great looking, high performance, 18mm adapter provided, and Kevlar® upgrade.

CONs: Could use a longer shock cord, but I'm being picky.

Overall Rating: 4 ½ out of 5

Brief:
The Magnum Hornet is a Semroc Retro-Repro of a Centuri model. It is designed for 24mm motors but includes an 18mm adapter. Recovery is via 12" parachute.

I ordered my kit from Semroc directly and had it within two days.

Construction:
The kit includes a balsa nosecone, one BT-55 body tube, a 3/16" launch lug, water slide decals, an elastic shock cord, Kevlar® thread, a screw eye, four laser-cut balsa fins, and parts for both 24mm and 18mm motor mounts. The 18mm mount is a 24/18 adapter.

The instructions were easy to follow and check off as I went along. Everything went together well. The only discrepancy I found was with the placement of the launch lug. The instructions say to place it four inches from the bottom, but the illustration shows three inches.

I didn't make this mistake, and it's nothing against the design, but because of the fin shape, it would be easy for someone not paying attention (and not looking at the grain direction) to get the leading edge wrong.

I didn't like the fin guide in the instructions, which basically involved setting the tube over the circle and marking around the edge. I think a fin wrapper is easier to use for marking lines. For alignment I made my own guide using VCP and cardstock.

Finishing:
I normally do, but for this one I didn't fill the spirals. I did apply two coats of Aerogloss sealer and two coats of Elmer's Wood Filler to the nose cones and fins. I used two coats of Krylon white primer and two coats of Krylon white gloss paint. I painted the nose cone and one fin Krylon silver. After decals were dry I applied two coats of Krylon clear coat.

Construction Rating: 5 out of 5

Flight:
So far I've flown the Magnum Hornet three times. The first two flights were on B6-4s and third flight on an A8-3. I used the included 18-24mm adapter. All flights had perfectly straight boosts with deployment at apogee. This rocket goes surprisingly high on smaller motors. You would need a very large field to fly this on any 24mm motor.

Recovery:
Recovery is with a 12" plastic chute that is attached to two feet of 1/8" elastic. The elastic is tied to Kevlar® thread which is attached to the motor mount. The descent rate seemed optimal. The rocket suffered no damage from landing.

Flight Rating: 5 out of 5

Summary:
One of the pros of this kit is you can fly it on a wide range of motors, depending on the conditions and field size. The quality of the parts and waterslide decals are excellent. Service from Semroc is great too.

Overall Rating: 5 out of 5

Brief:
I'll try and repeat what's in the other reviews, the Semroc Magnum Hornet is Retro-Repro of the Centuri Magnum Hornet with a 18mm motor adapter and 12" cute replaces the Streamer and Kevlar® thread/elastic shock cord replaces the rubber band from the old Magnum Hornet.

Construction:
The instructions are well written and easy to follow with quality parts, what I like that Semroc includes the 18mm motor adapter in this kit which is of high quality.

Starting with the fins was sanding lightly each side of laser cut fins and cutting them out and rounding the leading and trailing edges. The 24mm engine mount is easy to assemble what I did was take a empty 24mm engine casing and wrap 320 grit sand paper to smooth the inside of the RAH-5055 the rings slide easily on the motor mount tube. Another thing I like about this build is the Kevlar® thread attaches to engine hook, Also surprise was wrapping the masking tape around the engine tube and adding a light coat of glue that was some thing new to me. Pretty straight forward with the rest of the assemble attach the mount,fins,launch lug,gluing the fillets and screw eye to the nose cone. Last step 18mm engine adapter I use a empty 18mm engine casing with 320 grit sand paper to smooth out the 2 AR-2050.

Finishing:
I applied 2 coats of sanding sealer to the fins and nose cone, used 320 grit sandpaper to sand smooth, added a third coat of sanding sealer, and sanded smooth. I spray painted a light coat of white primer, let it dry, then sanded it smooth again. Using Valspar gloss black, I painted the nose cone and one fin. Taping off the already painted fin, I used Valspar bumble bee yellow to finish the rocket. I let the rocket dry for two days and applied the decals.

Construction Rating: 5 out of 5

Flight:
First flight I used a Estes A8-3. It was a nice flight and landed close to the pad. Second flight was on a Estes B6-4. Another nice flight a little walk to recover this rocket. Third flight was on Estes B6-4 for another nice flight.

Recovery:
The 12" chute works great on this rocket and makes it a nice small field flier.

Flight Rating: 5 out of 5

Summary:
PROs: 18mm adapter included in the kit, Kevlar® thread, and 12" chute.

CONs: None.

Overall Rating: 5 out of 5

Brief:
A lightweight, fast flier possibly capable of supersonic speed.

Construction:
This baby was a fun build. I loved every minute of it. The kit contains high quality parts. A straightforward build, but I tweaked it. This kit was built entirely with epoxy with microballoons for added strength and sandability, so she can fly on AeroTech E-30s. I replaced the balsa fins with 1/8" aircraft poplar plywood. The stock shock cord was replaced 1/8" braided Kevlar® strand. The stock chute replaced with a 15" thin mil nylon chute. I used an Estes D engine hook. I also purchased a plastic nose cone when I use AeroTech Motors. No cons here.

Finishing:
This baby was fun and easy to paint also. After the epoxy fin fillets, I primed the rocket, sanded, and repeated again. After sanding I applied 3 coats to the body of the rocket in Rustoleum Apple Red. After 2 days dry time I masked off 1 fin and applied 3 coats to 1 fin and nosecone in Rustoleum Gloss Black. After 2 more days dry time I applied the decals.I rarely follow manufacturers color schemes.

Construction Rating: 5 out of 5

Flight:
The first 3 flights were absolutely amazing. Flawless and fast. Some spectators got whiplash! First flight was on a C11-5. Wow. Estimated altitude of 1000'. Second flight was on a D12-5 to 1300'. It resembled a hummingbird with his tail on fire. Third flight on an AeroTech E15-4 with a streamer and plastic nosecone. Shock and awe was the best way to describe it. Amazingly loud and fast to an estimated 2800'. All you saw was exhaust. I thought she would spin out of control, but she logged the flight of the day.

Recovery:
No cons when you have an assortment of chutes and streamers for various conditions. Custom mounted 1/8" Kevlar® shock cord and 12" nylon chute. Lots of barf wadding for Estes motors, dual Nomex® cloth 1-1/4' for composites. The first 2 flights were perfect, and on the third I broke a fin. No biggie.

Flight Rating: 5 out of 5

Summary:
As I have already stated there really are no cons. Out of all the small rockets I own, this is my favorite. I plan on building an exact replica of this rocket with LOC/Precision body tubes and through the wall fins.

Overall Rating: 5 out of 5

Brief:
Centuri Engineering Company was started in the early 60s and was one of the early pioneers in the model rocket industry. Centuri was sold to Damon Corporation in the late 60s and maintained their product line separately from Estes until 1983. The Magnum Hornet was produced by Centuri from 1980-1983 and is unique in that it was one of a handful of Centuri kits comprised entirely of Estes parts.

The Magnum Hornet is a basic 4 fin and nose cone (4FNC) sport flier with a 24mm motor mount. Released in March 2009, the Semroc reproduction of this classic kit includes a few modern upgrades, such as laser cut balsa fins, a balsa nose cone, Kevlar® shock cord, and a 12" parachute. One of the nicest features of this kit is that an 18mm motor adapter is included which makes the Magnum Hornet a very versatile flier.

Construction:
As with every Semroc kit I've encountered, the quality of the parts is first rate. The kit come packaged in the standard "hang-tag" plastic bag, and the full color header card is actually the first page of the instructions, which includes not only the cover artwork but a parts list with an exploded view of the rocket and a nicely detailed history of Centuri Engineering and the Magnum Hornet. The following parts are included:

• BT-55 Body Tube – 14"
• Balsa Nose Cone BNC-55AC
• 24mm x 2.75" Motor Tube
• 2 Centering Rings CR50/55
• Thrust Ring CR20/50
• Standard Engine Hook
• 3/32" Laser Cut Fin Sheet
• Kevlar® Shock Cord 18"
• Elastic Shock Cord 24"
• Launch Lug – 3/16"
• Small Screw Eye
• 12" Parachute Pak – Unassembled
• 18mm x 2.75" Motor Tube
• 3x Centering Rings CR20/50 (one ring split)
• Thrust Ring
• Standard Engine Hook

As stated right on the front of the kit, the Magnum Hornet is "Easy to build". The 2 pages of instructions are simple, effective, and very well illustrated. The construction steps are familiar to anyone who has built a low power rocket before with a couple of steps unique to Semroc and/or this kit. The motor mount is assembled first. The centering rings are laser cut and must be detached from the supporting material. At first I thought they were made of a lite-ply material, but closer inspection showed them to be made of a very sturdy paper matte board. The only unusual step in constructing the motor mount is that the Kevlar® shock cord is tied around the upper end of the motor hook and then secured with the aft centering ring and a fair bit of glue. At 18" the Kevlar® included with the kit is only a few inches longer that the body tube and is shorter than I would have liked. It will probably do the job, but I replaced it with a piece about twice as long.

The fins are laser cut but still need to be removed from their balsa sheet. After getting them loose the fins require minimal cleanup, and I decided to round the leading and trailing edges. The instructions do not make use of a wraparound marking guide but rather the stand up type, where you set the end of the body tube over a circle template in the instructions and mark the fin positions. I use a length of small aluminum angle stock to extend the fin placement lines on the body tube. The template in the instructions does not have a mark for positioning the launch lug, so I just eyeballed a line between two of the fin lines.

By now the motor mount had dried sufficiently to install in the body tube. The installation is a little unique in that the motor mount does not slide all the way into the body tube but rather only until the aft centering ring is flush with the end of the body tube. This leaves about 1/4" of the motor tube extended aft of the body tube and actually creates a nice look.

The fins are attached next. My standard routine is to tack them on with a double glue joint and then add a second fillet of wood glue. The launch lug is attached in a similar fashion. The instructions mention that this rocket can be built with either a 1/8" or 3/16" launch lug, but only a 3/16" lug is included. For a rocket of this size and weight, I think a 3/16" lug is overkill so I dug out a 1/8" lug. In my opinion it gives the rocket a slimmer look and of course knocks down the drag coefficient just that fraction of a percent...

At this point the rocket is ready for finishing and there are a couple of steps that happen later, such as installing the screw eye in the nose cone. This is accomplished by screwing the eye part way in, removing it, adding a generous drop of medium thick CA glue, and then screwing the eye all the way down. Finally the elastic shock cord is tied to the Kevlar® cord and to the nose cone with a drop of CA glue on all the knots.

Even though the rocket is essentially complete, there is another assembly job to tackle. Parts for an 18mm motor adapter are included with the Magnum Hornet, and the assembly steps are part of the instructions. The adapter is a little different from a standard engine mount in that there are three centering rings, one of which has a gap cut in it to accommodate the motor hook. Two of the centering rings are glued flush with each end of the motor tube with the third in the middle. In essence this creates an 18mm motor mount which loads up like a 24mm x 2.75" engine.

Finishing:
Finishing the Magnum Hornet is fairly simple. My standard routine involves laying down nice smooth fillets along the fin and launch lug joints using Elmer's Wood Filler and then sealing the balsa fins and nose cone with one or two coats of wood filler thinned down with water. When I'm happy with the surface, I start with two coats of primer followed by two coats of gloss enamel paint, working down to 400 grit sandpaper in between coats. The Magnum Hornet gets a yellow base coat on the rocket, then one fin and the nose cone get gloss black. The decals included with the kit are first rate and do not require any special treatment. I had no trouble applying them. They laid down well and looked great after they had set. I did apply a coat of Future Floor Polish to the finished rocket to give it a little extra shine, and I am very happy with the way this particular rocket turned out.

Construction Rating: 4 ½ out of 5

Flight:
Obviously with a 24mm motor mount and a finished weight of 2 ounces or less, this is a screamer of a rocket. Including a motor adapter with this kit is a stroke of genius since it allows you to fly the Magnum Hornet in just about any type of weather on any size field. I have flown my Magnum Hornet on a B motor in a small schoolyard, a C motor on windy days, and a D motor on the sod farm. It flies fast and straight every time, and keeps coming back for more. It could easily handle composite E motors if you had the room and the courage.

Recovery:
The Magnum Hornet comes with an unassembled 12" Chute Pak. I'm afraid I must take away cool points here because when I dumped out my parts the chute was red and yellow, which just doesn't sit right with my idea of a yellow and black rocket, I mean style counts after all (say what you want but you can stuff a big motor in an ugly rocket and it still comes back ugly...) What puzzled me the most was that I know Semroc produces a nice black & yellow chute pack... It just didn't make sense. Luckily I needed to order some stuff from Semroc anyhow (probably their plan all along) and with my black and yellow Semroc chute in hand, all was right with the world. The 12" chute is about right for this bird, although I have swapped it out for a 9" chute on windy days. I also added a small Nomex® heat shield to protect the chute in place of wadding. In all cases so far, I've had no issues with deployment or recovery and the Magnum Hornet has come through without a scratch.

Flight Rating: 4 ½ out of 5

Summary:
PROs: Classic 4FNC rocket with a great look, simple construction, and an awesome range of flying potential with the included motor adapter. This is a well thought out design, and Semroc has fielded another winner with this addition to their "Retro-Repro" fleet.

CONs: Kevlar® shock cord is too short for my taste, and what's up with the red and yellow chute?!

Overall Rating: 4 ½ out of 5

This was my first Semroc kit, so it was all new. It's a reproduction of an old Centuri kit with a few updates.

There is an exploded-view diagram so you can see how the pieces go together. It also serves as a parts list showing how many of each part should be there.

The parts were well laid out. The fins came on a laser-cut balsa sheet. This rocket also has a balsa nose cone for all your purists.

One of the interesting features about this kit is that it can fly A through D motors. It's a 24mm kit, but includes a motor adapter for A-C motors.

There weren't any problems with assembly. I had one concern about the motor adapter, since the last 'centering ring' hangs out of the back of the kit. But that's what engages the engine hook on the model when you use smaller motors. It actually worked quite well.

I took the kit to a local school field to launch. Since it's a small field and it was windy, I flew it with an A8-3 for the first flight. It got up to about 110', give or take. However, the chute didn't eject, and the rocket came down flat enough that I assumed there would be no damage. I didn't get that lucky - one of the fins snapped. I never use A motors, so I don't know if the nose cone was too tight, or if that motor doesn't have a big enough ejection charge. Probably a little of both.

All in all, the Semroc Magnum Hornet is an easy kit to build and fly.