A Look Inside The Gamo Coyote..

Recently I was tasked with the dubious honour of re-sealing an example of this budget multi-shot PCP, and this seemed like a good opportunity for an appraisal for the entertainment / information of the AGF massive.

To kick off, a quick overview. The Gamo Coyote is an entry-level 10-shot bolt-action pre-charged rifle based on the BSA Buccaneer platform - the company's budget, export-only PCP offering.

Since Gamo own BSA, like all "Gamo" PCPs the gun is actually made (or at least assembled) by BSA in Birmingham, and (company ownership notwithstanding) it's only really a Gamo in name only.

Perhaps the best way to view the Buccaneer-based range of PCPs is as a revised variation of the more established Ultra / Scorpion / R10 range, with a emphasis on cost saving. While few parts are interchangeable between each format the designs share a lot in common, and as such observations will be made on the Coyote relative to the corresponding areas of the Ultra platform.

To be clear the Buccaneer serves as the basis for all Gamo PCPs (Coyote, Phox etc) as well as the Buccaneer itself and the dreaded and woefully overpriced Ultra XL.. these being set apart from what we'll now call for the sake of simplicity the "R10 platform" that includes this rifle as well as the Ultra SE and Scorpion SE.

This thread isn't intended to be a complete stripdown / repair guide, more a casual mosey through its construction with a few observations (and doubtless some ranting) thrown in. I'll briefly cover some aspects of handling and operation at the end of this post as well as a final conclusion.


What's Inside?

Our specimen today is a 2015 (serial suffix AB) .22 variant with the arguably less offensive wooden stock. This one is untouched aside from the fitment of the ubiquitous HW moderator:




On first inspection the rifle appears reasonably well put togther; with most parts on display being generally well finished blued steel, anodised aluminium and the odd injection moulded plasting part such as the trigger guard, blade and safety catch.

The stock is lacquered beech and well-finished; looking very much like a Minelli item (as per the woodwork on the rest of the BSA range) although there are no markings to support this, as far as I can see.




The rifle's pressure gauge is located in the inlet valve assy at the front of the cylinder; the fill port being shrouded by an injection molded plastic cover that pulls off completely for charging; lacking the greater refinement of the aluminium screw on cover of the higher-spec Ultra SE and Scorpion SE.




The action is separated from the stock via the removal of two stock bolts; in the forend and rear of the trigger guard.




Somewhat unusually (and unlike any other fixings on the gun) these bolts are torx-fitting as opposed to the more common hex / Allen head.




I was surprised to see what appears to be a large self-tapping woodscrew passing down through the inside of the pistol grip from the stock's inletting. There are no obvious signs of prior breakage that would require such a "repair", so I'm wondering if this is standard from the factory to strengthen the woodwork in the grip area.

An act of pragmatism or effort to compensate for sub-par materials or design? I'll let you make up your own mind.. I've never known any of these fail at the pistol grip though (assuming this one hasn't already!).




With the action out of the stock we can get more of an idea of the gun's construction. The breech block is the usual-for-BSA aluminum extrusion (albeit a different design to the higher-end BSA PCPs), while unlike the R10-platform rifles the the Coyote / other Buccaneer variants use a single-piece tube that both acts as the reservoir and serves to contain the exhaust valve and striker assemblies at the rear.




I beleive the trigger is the infamous Gamo "SAT" unit, evidently an iteration of the not-universally-loved unit found on their springers; re-packaged into a cast-alloy housing to suit this PCP application.


The muzzle assembly stripped; with the fill valve cover and barrel band removed. The plastic cover does the job with no issues but feels somewhat cheap and crude in use; being retained by a single O-ring.



It's interesting that BSA have chosen to fit a band on this gun, considering the R10 et al all have floating barrels; more on that later. The aluminium band does the job but courts little aesthetic favour as it stands outside the diameter of the cylinder so is quite obvious and IMO spoils the lines of the gun somewhat.

The band is retained by three (IMO particularly small) M3 grub screws and is separated from the barrel by an O-ring.


When viewed from the rear it can be seen that clearance has been given in the band at the grub screws to account for deformation at their point of contact with the inlet valve housing and presumably minimise any removal issues this might cause. Less pleasant is the lack of proper groove for the barrel's O-ring - it instead being located only inside a counterbore from the rear; with corresponding potential to move around which I'd imaging isn't great from the perspective of repeatable accuracy..




While removing the band it was clear that the barrel was under a reasonable amount of bending tension; evidenced by it's springing upward once the band was off. The barrel to cylinder gap is around 6mm at the breech block and 8mm at the front of the cylinder




Breech block removal was not straightforward. The block is retained by two long M3 bolts down into the exhaust valve housing in front of the mag aperture, and a single, hidden M5 CSK bolt upwards through the rear of the cylinder and into the breech block.

Access to the rear screw is prevented by the plastic rear cylinder plug, which in turn is held captive by a roll pin pushed into the blind hole behind the tapped hole in the rear of the trigger housing.

For fear of antagonising certain industry protectionists I won't go into how these parts were removed; suffice to say the rear cap has suffered and will need to be replaced, since I could see no obvious way of removing the pin.. answers on a postcard please if you have any better ideas!




The rear of the action with the cylinder cap removed; showing the cast alloy trigger housing inside the cylinder and plastic insert within it.




With access to the rear block screw now possible the block and cylinder were separated to reveal what lurked inside!

Again layout is broadly similar to the other BSA guns; with a separate brass transfer port bush and L-shaped channel for the bolt dog to run in, along with a pin that protrudes from the top of the striker to engage the bolt dog during cocking. There's also the familiar ball detente to lock the loading bolt in place once closed.




The Coyote differs however from the R10 platform in a number of ways; perhaps most obviously in its use of a plastic tray to accomodate the mag - a necessity thanks to the striker housing's thin-walled tubular construction. This plastic tray also contains a single magnet, instead of the more complex (and expensive) mechanical mag release with ball detente found in higher-end variants.


Finally we have two additional pins; one just behind the mag aperture to retain the bush that blanks off the loading bolt bore, and another near the rear of the block that passes through the cylinder to retain the trigger housing beneath.




Removing the plastic mag tray reveals the hollow construction beneath and exposes the striker. Note the patch of poor quality orangy / red bluing at the rear of the cylinder:




With the block removed the trigger assy and striker spring simply slide from the rear of the cylinder, allowing access to the grub screw in the striker weight that retains the sear / cocking pin. Once the pin has been removed the striker can be withdrawn in the same manner as the trigger assy.




Unfortunately some areas of the Coyote aren't finished particularly well - one example being the sharp edges left on the inside of the slot in the cylinder for the trigger assy.. to which my thumb will attest having got caught between said edge and the Allen key while removing the striker




After a break to super-glue down this flappy little trapdoor and prevent it bleeding all over the job, the disassembly continued..


The trigger assy, showing the inside face of the striker spring preload adjust. It's clear that this unit is built down to a cost from its cast alloy construction, plastic sideplate and use of nasty spring washers to retain some of the pins (although somewhat absurdly Steyr also use similar fixing on their triggers ).




To be fair it looks like it's been designed to last well enough, although I suspect should anything go wrong will most likely be unserviceable since (if these are anything like the springer equivalent) no spares are supplied; only complete units.



I had no need to strip the unit, and from its construction IMO this could go either way in terms of ease.


Again, the striker is a similar format to that of the higher-end models; consisting of an outer bearing, "hammer weight" and vertical pin that serves to engage the bolt during cocking and sear once cocked.

The hammer weight is similar, but different to the that found on the R10-platform models:




Likewise the synthetic bearing is a skeletonised injection moulding rather than the fuller, machined Acetal item found on the higher end guns:






Now to the front end of the gun; the barrel assy removed gives better access to remove the inlet valve assy (once the gun is empty of course!). This "simply" screws out, however this example was reluctant; I think due to a combination of excessive seal drag and crap (thick lube and a bit of corrosion?) on the threads.



Again this part differs from the inlet valve assy found outside the Buccaneer platform.




The gauge mount unscrews from the front of the assy, while the guts of the inlet valve are withdrawn from the rear once the crosspin has been removed.


The inlet valve itself is somewhat unusual in that it's a propriatory hard plastic, cruciform injection moulding as opposed to the usual O-ring based designs usually encountered. This should remove the issue of the shredded O-rings that the Ultra and Scorpion are famous for; thus giving longer service life. On the down-side it's potentially more prone to failure through the ingress of contamination as well as more difficult to source and costly to replace.

Despite the sintered phosphor-bronze filter upstream (a rare area of superiority over the more expensive BSA models) this example still had a few indentations in its sealing face; presumably from contamination present during assembly. Thankfully it still appears to seal OK though.




The inlet valve is held inside a brass sleeve that's a sliding fit inside the inlet valve housing. This one came out without too much fuss, however on similar systems on other BSA guns I've had to resort to brutality when I've found these to be seized in place due to corrosion..


With the inlet valve removed the exhaust valve assy can now come out. Again unlike the Ultra-based guns this sits inside the mono-tube, retained by two radial bolts and stock bolt boss; all held in shear to keep the valve assy in place. Once the bolts are removed the valve assy can be pushed towards the front of the gun with a dowel; avoiding the myriad sharp edges on the back end of the cylinder!

It's a bit crude and old-hat, but works and I guess keeps costs down.






Unlike the valve assy on the higher-end guns (which has a screw-on valve retainer) everything in the Coyote exhaust valve assy is kept in place by a fat aluminium disc and internal circlip. The exhaust valve return spring and synthetic spacer / seat are shared with the more expensive offerings.

The exhaust valve itself is broadly similar to that found on the R10 etc, however again not the same and actually more complex with a fatter, stepped steel stem and acetal head with no less than four sections of different diameter.




Just like the unregged versions of the R10-platform guns the Coyote's exhaust valve head runs inside a close-ish fitting restrictor that serves to limit flow through the open valve. The good news is that BSA appear to have sidestepped the valve deformation issue that causes ever-falling muzzle energies on their other guns by using a stepped profile near the valve seat; meaning that any deformation doesn't add to the diameter of the valve portion that runs inside the restrictor.

The (potentially) bad news is that unlike the other guns the restrictor in the Coyote isn't removable; meaning if wishing to fit a reg you need to either machine out the restrictor in the valve body or possibly slim down the exhaust valve head to allow the higher volume flow rates required by the lower operating pressure of the reg. That said IMO attempting to reg these rifles is of questionable value; the higher-end models making much better candidates for various reasons I can't be arsed to go into...

Unfortunately as with the inlet valve, I did find some indentations in the seat contact area of the valve head, most likely due to contamination present when the gun was assembled.


Disassembly of the breech block was limited to removing the loading bolt to replace the breech seal and clean / relube the bolt itself. Unlike the loading bolt of the R10 etc (which runs inside a full-length Acetal bearing inside the block), the Coyote's bolt has a pair of hard plastic bearings that run directly inside the breech block.




In theory this isn't the end of the world, although does mean that worst case the block itself could wear instead of smaller / cheaper components. Unfortunately in this example the bearings were fairly tight in the block, as well as being pretty tatty on their bearing surfaces and lubricated with a fairly thick, sticky grease.. making operation feel somewhat stiff and notchy.

The bolt was cleaned and refitted with moly grease which made a marginal improvement to feel. Dressing down the OD of the bearings for a better fit would be a good budget route to improving the pull; while brass replacements would be even better but somewhat excessive on a gun of this standing.



Additional Observations

Design and Construction

During reassembly the large difference in barrel / cylinder alignment became extremely obvious again; getting signficantly worse when the front two breech block bolts are tightened.

Long story short the issue appears due to excessive effective length in the transfer port bush (and seals) preventing the block and cylinder from properly mating in this area. When the front two block bolts are tightened the front end of the breech block and barrel pivot about the transfer port bush, tipping the barrel upwards; aided by visible flex in the breech block at the silly-thin section above the mag aperture

On the one hand this situation is far from ideal and the floppy design of the breech block certainly doesn't help. On the other it could conceivibly largely be remedied by shortening the port bush for a better fit in the parts around it.


I did sling the borescope down the tube and it seems surprisingly good compared to a lot of other BSA stuff I've seen. Interestingly, in stark contrast to my crappy old R10 of about the same vintage the bore finish generally looks very good for the most part; with none of the jagged, rough surface to the lands as seen in numerous other barrels from the same era.

This could be due to "natural" production variation, although based on previous discussion with others I reckon the quality of the .22 barrels is generally better than the corresponding .177 efforts, a feasible theory considering that the larger calibre tubes should require less force / fewer cycles to achieve a decent finish.

While the bore finish is certainly better than expected we can't let the rifle off too lightly as the finish at the leade and more importantly muzzle crown are pretty bloody ropey; although at least that's a lot easier to fix than a shonky bore finish.

At some point I might sling up some stills from the borescoping if anyone's arsed.


In Use

The rifle was only fired during setup / over the chrono, and only shouldered to assess handling but I think I got the measure of it fairly well.

The gun is fairly weighty and feels dense / solid with a fairly neutral balance. The ambidextrous stock is pretty chunky and while not terrible; limited somewhat ergonomically. The grip is fairly fat, reach to the trigger significant and the comb very low; being more suited to use with iron sights IMO and far too low to be optimum with a scope. It's useable but compromised and far from ideal.

The cocking stroke is fairly stiff and resisitive if fairly smooth, and stacks up a fair bit towards the end. The bolt locks and unlocks fairly positively thanks to its sprung detent, although this is accompanied bit a bit of resonance from the action.

The trigger is typical Gamo; offering a (possibly pseudo) two-stage pull that's not heavy (maybe 2-3lb) or rough, but with a silly-long second stage travel and completely unpredictable release point

I'm aware that there are upgrades for this unit and believe it can be made a lot more crisp - in which case IMO it could be perfectly acceptable. That said I'm not sure if this is a true-two stage setup (I suspect not) so you may have to be careful how little sear engagement you run to ensure safe and reliable operation.

Safety location is convenient and it's fairly positive in operation, although the tab gets very close to the blade when "safe" - making contact with the finger minimal when releasing the safety and causing some discomfort.

The firing cycle is acceptable if not particularly refined. There's a sense of a fair bit going on inside when the trigger is pulled; greeting you with a fairly damped, solid "thud" and an amount of resonance / spring noise.. this is obviously with a mod fitted and hence the mechanical noise not overshadowed by the muzzle report.


Conclusions

The rifle is clearly built down to a price but this has largely be achieved sensibly. Material quality seems reasonable throughout and the cheaper materials and processes used (such as the cast alloy trigger housing and plastic blade, safety and guard) appear appropriately accommodated for in the design and sufficiently robust - I guess time will tell although I've heard of no failures in these areas so fair.

Aesthetically fit and finish are largely acceptable; cylinder and barrel could have a higher gloss finish but what's offered is fine while the bluing itself is generally uniform, with the exception of the grotty patch at the back of the cylinder (not sure if they're all like this / this particular area is consistantly affected). Most parts appear competently machined and finished - although I do find the number of sharp edges totally unacceptable; especially considering the chunk of my thumb that's now missing as a result.

Somewhat unsurprisingly for a rifle of this spec and price, QC seems a bit shifty. Everything physically goes together but the tolerances don't seem great; as attested to by the issue with the transfer port bush / barrel deflection. In addition the gun was a bit grotty inside with evidence of contamination on both valves, suggesting it wasn't particularly clean when assembled.



IMO this gun is the archetypal entry level / "value" model - pretty mediocre throughout but mercifully consistantly so from construction and use perspectives. Everything is just about OK / does the job to an extent and most issues aren't insurmountable and fixable with time, effort and money.. however it's questionable how worthwhile expending said commodities on this gun would be given the expected outcome and potential alternatives.

I'm concerned by the many stories of sudden / significant zero shift experienced by some with this rifle; and think the issues identified in this thread with the barrel deflection and potential movement of the barrel band O-ring are (for anyone bothered) well worth further investigation in this regard.

While it seems this could potentially yield significant improvement, the design has its limitations and the gun is unlikely to ever be a proper tack driver.

I must admit having seen many / all of this gun's flaws exposed my inner engineer is enthused by the idea of sorting one out - size and polish the bolt bearings, lube and mod the trigger for a better pull, remove all the sharp edges, trim the transfer port bush to an appropriate fit, re-crown and throat the barrel... but after all that I'd still be left with something inferior to more accomplished off-the-shelf items.

Of course it's a somewhat cruel irony that (generally) those in the market for such a gun (usually newcomers) are the least-well-positioned to carry out any of the work necessary to make the gun work better or indeed work to an acceptable standard in the case of the zero-shift issue.


Comparison with Alternatives

The Coyote fits into the BSA lineup fairly well IMO. It's about 2/3rds the cost of a Scorpion - which is far from perfect but clearly better; justifying the cost difference to a large degree; so from this perspective they both seem to offer similar levels of value.

That said the Buccaneer-based guns do offer superiority to the higher-end models in a few small areas - namely the use of a filter at the inlet valve and the revised, (hopefully) energy-loss-resistant exhaust valve. These aside, while far from perfect the R10-platform rifles are, as would be expected better in pretty much every way.


Compared in isolation to similarly-priced entry-level guns the Coyote stacks up reasonably; less ergonomically and aesthetically accomplished than the RM8 and potentially with inferior barrel quality (especially in .177), but more rounded as a whole and crucially not blighted by the deal-breakingly disposible attitude to materials and construction used in the RM8. I'd fully expect the Coyote to be soldering on years after the RM8 has been junked for being uneconomical to repair.

The Coyote is very similar in many ways to rifles like the Hatsan AT-44 (heavy and fairly crude but pretty solid) each with its own set of unique faults; unsurprisingly as nowt's perfect - especially at this price point!


Final Thoughts

Ultimately I remain of the opinion that anyone looking at one of these would be better advised to go go for something lower-spec and better made (such as the usual Air Arms S400) - either by saving for a bit longer or going used. This would give a gun that's much more refined and capable out of the box, and as such will last a lot longer before the shooter feels the need to upgrade to something better

 

Thank you Clover, very interesting for, I'm sure, many of us.

 

A great read as always. Thank you for taking the time for such a detailed analysis.
It seems to suit it's price bracket rather well. I completely understand that there's an entry level pcp market but like you said, a second hand s4** is in the same ballpark.
I hope down the line that someone brings a kral NP-02 to you for service. Owners seem to really rate them and at £299 new, could be a budget PCP king.

 

Great read as usual clover. I have the gx40 version as my "knock about" gun and love it. At £295 new an absolute bargain.

 

BRILLIANT analysis and breakdown of a fairly popular rifle..

Well done Sir...

 

A great read as always and very informative with first class pictures , thank you for taking the time to do this much appreciated

 

A brilliant in depth read if I owned one the info will be a huge benefit, nice one

 

Thanks for sharing your experiences with this rifle. A well written piece, very informative.

 

Excellent informative read thank you Cloverleaf keep em coming

 

A very interesting read, I've been toying with the idea of a gamo gx40 supposedly made in brummy land. It looks like a shorter version of the coyote? The barrel rising upwards from the breach is a deal breaker for me. You will struggle with decent accuracy with the band resisting against the barrel.
I need a cheap multi shot for ratting and the gx40 looks like it would fit the bill, decent mags and barrels, unlike all the Turkish guns I've owned.

 

This is exactly the sort of thing that we need to see. I suggest a separate gun review/stripdown guide section. Additional entries/posts allowed only after being inspected by Cloverleaf for quality and relevance.

 

WoW good film and book that .

 

As usual a deep insight to the inner workings , articulate , professional and unbiased . Superb !

 

Really informative Mike and no doubt a big help for anyone looking to purchase a coyote.

 

Superb and informative write up.

 

Very good write up and information. I hope I don't need to use this for mine! The barrel band is not like mine, looks similar but mine is plastic with only one pinch screw in the narrow of the 8. Also, my barrel sprung up when the band was removed (Internet owners report similar) but nothing like as much as yours. All good so far

 

Cracking write up as usual @cloverleaf. You seem to have found your mojo. Good to see this sort of in depth work.

Always wondered exactly what went on in these budget Gamo offerings, but wouldn't have spent my money to find out

A bit of a shocker with the barrel. I've noticed this on a couple of Ultras / scorpions over the years, where out of the stock, the barrel does deflect upwards a touch. Interestingly on the wooden stocked ones, this deflection changes with stock bolt tension when refitted into the stock. When I reassemble mine, if this deflection is present, I adjust stock bolt tension to get barrel and cylinder parallel. May be worth trying on this one if you still have it.

Ahh the Gamo trigger unit. A unit thats been around an awful long time. Also used in the early Rapids and some of the Theoben designed rammers. Your description of the second stage break is pretty typical. There is a retro fit blade available to remedy some of this but not sure it really sorts it out.

Most interesting here for me is the probe, which looks to be blued steel. Am I right with that?
Shame BSA don't use a blued probe in their higher end rifles. The addition of nickel plating adds to the aesthetics, but means they are doomed to shed that plating, often from new.

Top job Mike.

Edit : Not sure I'd have drawn a comparison with Steyr, even in terms of a clip

 

That seems a pretty fair assessment overall, it's built down to a price to compete in the lower end of the market and as such it has achieved good sales with seemingly very few failures. The barrel band and barrel mounting is a problem in many guns including my S200 where removal allowed the barrel to drop onto the tube, I see that as worse than a barrel deflecting upward.
Every manufacturer has to build to a price to make a profit but another £1000 spent buying an upmarket rifle does not mean the purchaser will get something 5 times better than the Coyote/Phox platform. Any PCP relies on O rings supplied by someone else so the rifles at each end of the price spectrum may actually have the same rings fitted and eventually fail at the same time.
This series of rifles may be a little crude in some areas but essentially they work and seem to be reliable which after all is what most of us want.
I got my Phox purely for pest control, to give a better shot count than the S200 (twice as much!) and consistent power without having to muck about trying to fit a reg. Mine has now passed 2 years of use without a problem apart from adjusting power right at the start, I would imagine that many of the earliest units are still going strong with no problems whatsoever, something we all want and Gamo/BSA have achieved that at a very low cost.
Sorry you cut your thumb Mike, would it have been less painful if you'd cut it on something like an HW?

 

I still carry a scar, thats still very visible, from working on a HW80 in the early 90's.
Obviously a far higher quality injury

 

But no less painful?