Combro CB 625 Mk 4

Got a chance to test out me other birthday prezzie this evening after finishing some gardening. Having seen the price of new F1 Chronys (142.80€ plus shipping), I decided to go for one of these, which at £49.50 plus free shipping to France was a bargain IMHO.



I refused to pay £3.95 for the plastic stick called the Alignment Tool, preferring my own low-tech (and free) approach. Masking tape is easier to use and more secure than the recommended rubber bands, too...



Ran 12 pellets through it from the BSA Lightning XL Tactical. They were 13.43-grain JSB Exact Jumbo RS (aka Falcon Accuracy Plus), and averaged 541 fps for a muzzle energy of 8.73 fpe. A tad lower than the ideal, but it's my cheap, second-hand barn rifle, used for rats, close-range magpies (25 yards max) and plinking to 33 yards, at which range it will shoot one-inch groups, so it'll do.

The Combro seems a well-made bit of kit, although the first shot registered 1068 fps for 33.9 fpe, which I guess was the device clearing its throat on first use.

May I suggest my method of attachment for the Combro,if you obtain self adhesive Velcro fit one piece long enough to go round the bracket and barrel etc and two pieces of the opposite(hook etc) on each side of the combro bracket you can then attach the velcro to one side and pull tight and attach to the other side.
Takes seconds to swap gun to gun.

sarfarm said:

May I suggest my method of attachment for the Combro,if you obtain self adhesive Velcro fit one piece long enough to go round the bracket and barrel etc and two pieces of the opposite(hook etc) on each side of the combro bracket you can then attach the velcro to one side and pull tight and attach to the other side.
Takes seconds to swap gun to gun.

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That idea is as smooth as a very smooth thing. Where on the Combro bracket do you attach it? On the flange thingies at each end of the barrel bracket?

I happen to have some self-adhesive velcro in my sewing basket, I mean the wife's sewing basket, so will have a fiddle. Nice one.

Coypu Hunter said:

That idea is as smooth as a very smooth thing. Where on the Combro bracket do you attach it? On the flange thingies at each end of the barrel bracket?

I happen to have some self-adhesive velcro in my sewing basket, I mean the wife's sewing basket, so will have a fiddle. Nice one.

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Will have a look and see how I did it,try also to post a pic.

Like the idea of the velcro thing. I've ever used mine on my 77 when I was fiddling with it. Had to remove the front sight and mount the combro upside down, fixed with some string. Velcro is far more suitable.

Right had a look to see how I did it and its as follows.
On the underside of the barrel mount I fitted two pieces of self adhesive Velcro one on each side of the V,then the opposite velcro attaches to one side,you pull the velcro tight over the barrel and press onto the attached piece,I used Hook side on the bracket and the fluffy one as the strap.
The self adhesive type came from a car acc shop as about a 3"x2" piece,the 2" wide fluffy I had ,its industrial grade.

Right, gotcha, much as I had imagined. The velcro I have is more of a strip, maybe 2cm wide or something. I can certainly attach it to the underside of the barrel mount, but might have to use a couple of strips to go over the barrel/silencer. I'll have a look at it and post some pics if I get it to work with the velcro I have.

On my combro I attach it so that the unit is about a 1/2" from the barrel,it doesn't give me quite so many erroneus readings.

I only had the one error, after which it seemed to settle down...

Did the velcro thing. I had some 2cm-wide strips of the self-adhesive stuff, bought a while ago from the haberdashery section of the supermarket, for a purpose lost in the mists of time... Still sticky, so worth a punt.



The "hook" side is less flexible for wrapping around the barrel, so I cut lengths of this to fit on the outer sides of the barrel clamp.



I then cut the rest of the offcut (23c long) into two equal-length straps to go around the barrel/silencer.



I left the backing paper on these straps, to avoid them sticking to everything. I could replace the backing paper with some cloth later, if the paper falls apart. As it stands, the straps hold the Combro solidly in place on the Lightning's silencer, with room to spare for larger silencers.



The whole lot still fits neatly into the box ready for use.



Nice idea, @sarfarm.

Gonna have to get me one of these. Are they as good as the generally one sided views in the shooting press ?

Heisenberg said:

Gonna have to get me one of these. Are they as good as the generally one sided views in the shooting press ?

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Yes they are very good and are accurate enough for our needs

It's obviously different from "standard" chronys, which require a tripod or stand, plus light diffusers.

I had an F1 Chrony for a few years, and it was easy enough to set up, although a bit of a faff. It also gave lots of read errors if not set up exactly level with respect to the pellet trajectory, or if I shot slightly high or low under the diffusers. They're also three times the price of a Combro. The only advantage they have is that you can use them downrange to accurately calculate a pellet's BC, which is what I was trying to do when a flyer punched through the display on mine.

The Combro in comparison appears small and flimsy, but in use is solid enough, and doesn't feel fragile. The barrel clamp slides into a slot on the rear of the unit, and is very stiff, but a drop of oil in the slot has eased it up considerably.

Obviously, you need to make sure that the alignment is correct, otherwise you'll blow it to kingdom come. A pencil does the job for .22, and one of those split bamboo pot-plant support canes fits a .177 bore perfectly -- or you can buy the alignment tool.

So far, I've had two read errors, but for the other 20 or so shots I've put through it, it's worked perfectly. It's light, compact, easy to fit and align, and seems to work pretty well. I'll be trying it on my other rifles to make sure that it's reading accurately -- I ran most of them over the F1 before its demise. At this stage however, I'd say that it seems to be a good buy, because it does the job, and doesn't cost a fortune.

Where did you order it from CH ? Price sounds good.

Just to say I have used my combro for 8 years now. I have shot it to bits twice and repaired it with parts supplied at very reasonable cost by combro. It compares very well with the readings from my Skan chrono which was 3 times the price. It works well because the sensors are hidden inside the housing so tend not to be affected by external light source. I also have a link cable which allows me to download each shot to the laptop and then graph the results. Great piece of kit at a very reasonable price.

Heisenberg said:

Where did you order it from CH ? Price sounds good.

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They seem to be available from most online dealers at about £45

Heisenberg said:

Where did you order it from CH ? Price sounds good.

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Direct from Combro, £49.50 including shipping. http://www.chronoscopes.com/

Good price and a roll of gaffer tape thrown in, excellent..........MiK

Looks like Combro are going to do some goos business,should add that they offer excellent after sales service.

First Combro I had lasted about 10 minutes before a pellet hit the side of it when the elastic band slipped , I then bought a F1 but I find both are quite fussy regarding light and alignment plus the Combro states not suitable for most pistols or CO2 guns .

I wasn't aware of the pistols or CO2 gun restriction. Mine works well on my Webley Alecto pistol now that I have organised a suitable method of attachment. I'll have to do some experiments with my Umarex CP99 Co2 pistol and see what the results are.