Mk3 accuracy - seems to vary wildly

[andrewM]

Just a couple of thoughts that occured to me whilst reading some of the comments...

1) Obviously, an early Mk3 will have had many years more wear & tear, even if it looks mint.

2) On an airgun site, there was an article from a 'boys' magazine (Meccano?) of the 50's or early '60's. This mentioned the final stages of barrel manufacture at the Webley factory - which was done by eye inspection, looking down the bore, & physical straightening of the barrel. After this, the final inspection was again done by eye. Possibly this went out when button rifling was introduced, hence the later ones being a bit more consistent/accurate?

As I said. just some thoughts on the matter. My early '60.s Mk3 would be the last rifle I would sell, if I had to. Closely followed by my '70's A/Sporter.

That seems to me to be a most inappropriate way to oversee the production of a precision instrument. It would surely be impossible for the eye to detect minor variances and imperfections. This, therefore, suggests that earlier Mk3s were dependent upon luck as to their accuracy for there must have been inconsistency in production. Notwithstanding the magnificence of the finish and tolerances elsewhere, I think this confirms that the later models produced in the '70s had better barrels guaranteed to perform, by virtue of the new production method.
Unless I had personally tested an older Mk3 for accuracy, I would be inclined to buy the later models. That suggests they should fetch a premium if accuracy alone is the chief consideration.

[45flint]

In 1957 in Smith’s Encyclopdeia of Gas, Air & Spring Guns of the World, he tests Airguns of this era pretty thoroughly. He says the Webley Mark 3 is the best most accurate rifle in the world? Given my experience with my mid 1950’s Mark 3 I wouldn’t argue?

[slug-gun]

That seems to me to be a most inappropriate way to oversee the production of a precision instrument. It would surely be impossible for the eye to detect minor variances and imperfections. This, therefore, suggests that earlier Mk3s were dependent upon luck as to their accuracy for there must have been inconsistency in production. Notwithstanding the magnificence of the finish and tolerances elsewhere, I think this confirms that the later models produced in the '70s had better barrels guaranteed to perform, by virtue of the new production method.
Unless I had personally tested an older Mk3 for accuracy, I would be inclined to buy the later models. That suggests they should fetch a premium if accuracy alone is the chief consideration.

I believe the barrels of top class SHOTGUNS used to be checked by the naked eye, perhaps still are, an even shadow down the length of it denoting straightness? Any shotguns experts may like to enlarge/confirm?

As an aside Les Wesley in his 1957 book used to recommend pushing the pellet down to the bottom of the open tap, as opposed to merely dropping them in, in order to mitigate the negative effects of the pellets having to 'jump' from the tap into the barrel.
Even then he knew the tap loader was flawed.

[AC99]

I'm sure they would be achieving this with open or aperture sights, scopes on air rifles were uncommon back then, and the scope rail on a Mk.3 is dubious at best. Also consider the pellets, compared to modern offerings?

I think you're unfairly maligning tap loaders. While I agree that if the tap alignment is not perfect accuracy will suffer, if the alignment is perfect then I don't see why they should be less accurate. It's a simple matter to capture and inspect fired pellets, and an examination of the rifling imprint will show whether they are clipping or not.

Apart from hunting, I shoot tap loaders almost exclusively these days, and I get better results with them than any other guns. I also suspect that shooting a 1/4" group at forty yards with a springer takes a bit more than just a "good shot".

In Webley promotional literature of 1957 & 1960 the grouping claimed for the mk3 - 1.25" diameter for .177 and 1.75" for .22 at 40 yards and 3/8" at 10 yards (both calibres) - were achieved from a FIXED REST ie clamped in a special machine vice. This is what Webley said when, as a youngster I wrote to them at the time as I could not achieve anywhere near that sort of accuracy with my recently acquired, second hand mk3. Groups achieved by a good shot shooting off-hand using either open or aperture sights would be far inferior to this and those from an 'average shot' even worse.

[slug-gun]

The fixed rest bit is probably unlikely for the simple reason that if you rigidly clamp a spring/recoiling air rifle it will actually shoot far worse than if you let it recoil naturally in the hand and gently rested.

ie the clamp inhibits the harmonics of the rifle when it is fired.

That is why professional pellet manufacturers, when testing the accuracy of a spring gun, clamp it into a RECOILING test bench, which takes the 'sting' out of the recoil, allowing it to shoot to its full capacity.

It is extremely unlikely that Webley had such equipment back in the day. I would guess they simply rested the gun on a sandbag?
They may have told you as a boy, that they used a fixed rest as an attempt to make you feel better over the poor shooting of your MK.3?

[andrewM]

In 1957 in Smith’s Encyclopdeia of Gas, Air & Spring Guns of the World, he tests Airguns of this era pretty thoroughly. He says the Webley Mark 3 is the best most accurate rifle in the world? Given my experience with my mid 1950’s Mark 3 I wouldn’t argue?

A very interesting contribution to this thread. But Smith's observations were relative to what was achievable elsewhere at the time. Certainly, nothing then was capable of the type of accuracy we have today.

AC99, in this thread, goes on to say: "In Webley promotional literature of 1957 & 1960 the grouping claimed for the mk3 - 1.25" diameter for .177 and 1.75" for .22 at 40 yards and 3/8" at 10 yards (both calibres) - were achieved from a FIXED REST ie clamped in a special machine vice. This is what Webley said when, as a youngster I wrote to them at the time as I could not achieve anywhere near that sort of accuracy with my recently acquired, second hand mk3. Groups achieved by a good shot shooting off-hand using either open or aperture sights would be far inferior to this and those from an 'average shot' even worse."

I have personally tested four Mk3s at 25 yds. Two of them, from the '70s, group at approx. 3/4 inch. Of the two from the '60s, one grouped at around 3 inches and the other - tested the other day - at 2 inches approx. Laverdabru, here, has tested a further two Mk3s - one from the '60s and the other from the '70s and he confirms my general observations. The rifling in the later models, incidentally, is more pronounced within the barrels.

It could be that there was a deterioration in production techniques - or insufficient quality control - provided in the '60s as opposed to the '50s and earlier. That notwithstanding, the accuracy certainly seems to improve in the '70s against ALL earlier models and this can only be attributed to the change to button rifling, which we know occurred. The next question is whether there was a step-change between the '60s and the preceding productions models? Or could it be that purchasing a Mk3 was a lottery in terms of accuracy prior to button rifling, depending upon the hand-cut barrelling, during production, and quality control? It seems to me that hand-cut barrelling will not produce consistency and the inspection of the eye (as explained here and which I had read before) leaves too much scope for error.

Do we know whether rifles were tested before leaving the factory? When I bought an Airsporter, there was a test card, denoting the rifle had passed accuracy control at 25 yds. Did Webley engage in this type of certification? I have never heard of it.

Again, we need a rather greater sample of examples from other owners to confirm my findings - and those of laverdabru.

As things stand, as a result of this thread, I am now of the view that '70s Mk3s are the best of the production run for accuracy, by some margin, even although the rifles had succumbed to cost cutting in other areas. Not least, this improvement in accuracy is because the rifling in the barrels was machine cut, leaving no margin for error. Earlier rifles produce varying accuracy, depending upon the quality of the hand-made rifling. There might have been a deterioration in the '60s, leading to poorer accuracy than in the '40s/'50s or was this always the lottery of the purchase, depending on the efficiency of the production run in each instance?

My contention, if I am correct, is that 1970s Mk3s should fetch a premium at sale on account of improved accuracy.

Finally, the Airsporter and Mk3 must be some of the most widely owned and mass produced air rifles in the UK. Both were produced for some 30+ years and whilst other rifles have enjoyed that duration of production (eg HW 35), these have succumbed to competing models from their own factory (HW80 in this example). This is why the history, here, is rather more interesting than might be the case where production runs were somewhat smaller, over fewer decades, involving fewer owners.

[45flint]

[QUOTE=andrewM;7766533]A very interesting contribution to this thread. But Smith's observations were relative to what was achievable elsewhere at the time. Certainly, nothing then was capable of the type of accuracy we have today.

I think it is way too easy to dismiss these early rifles with a current rifle bias when they are set up for optics etc. I often think the comparison is new vs. warn by years of use.

[andrewM]

[QUOTE=45flint;7766554]

A very interesting contribution to this thread. But Smith's observations were relative to what was achievable elsewhere at the time. Certainly, nothing then was capable of the type of accuracy we have today.

I think it is way too easy to dismiss these early rifles with a current rifle bias when they are set up for optics etc. I often think the comparison is new vs. warn by years of use.

Yes, I think wear might be a factor although I wonder to what extent a barrel (and loading tap) wears after tens (?) of thousands of rounds. In the examples above, we are only discussing a difference of approx eight years, so I don't think wear is a factor here. Indeed, I have had better groupings with my BSA Standards than the two tested Mk3s from the '60s. One is nearly 100 years old.

[45flint]

[QUOTE=andrewM;7766566]

Yes, I think wear might be a factor although I wonder to what extent a barrel (and loading tap) wears after tens (?) of thousands of rounds. In the examples above, we are only discussing a difference of approx eight years, so I don't think wear is a factor here. Indeed, I have had better groupings with my BSA Standards than the two tested Mk3s from the '60s. One is nearly 100 years old.

I’m talking rifles from the 1950’s. You seem to imply the button rifling and or later changes made for better rifles than these very early classics? Of course it could but more often it was a cheaper way to manufacture? Are you shooting your rifles with optics for these observations?

[rancidtom]

[QUOTE=andrewM;7766566]

Yes, I think wear might be a factor although I wonder to what extent a barrel (and loading tap) wears after tens (?) of thousands of rounds. In the examples above, we are only discussing a difference of approx eight years, so I don't think wear is a factor here. Indeed, I have had better groupings with my BSA Standards than the two tested Mk3s from the '60s. One is nearly 100 years old.

Not knowing the history of your gun I would hesitate to say that the barrel isn't worn or damaged in some way due to misuse or neglect by a previous owner. It doesn't take much damage to the crown to completely destroy the ability of even the very best barrel to produce a tight group regardless of the internal condition of the rifling and choke.
It only takes somebody putting the gun away damp or storing it in a damp environment even if they wipe down the outside with an oily rag for the insides of the barrel to corrode. Add to this potential wear in the loading tap or even an owner who may have repaired the gun with mismatched parts (tap) at some time in its history then you really cannot predict whether any barrel be it from a known good batch or not could produce a tight group.
Who is to say that the gun hasn't had nails, pins or other unsuitable ammunition through it while being used by a youngster at some point? What if somebody dropped the tin of pellets in the mud or dust and continued using them? All that grit and debris could have worn the barrel in places that are difficult to see. I once dismantled an Airsporter than had a 1.5" panel pin stuck in the piston head. It had obviously been dropped in from the muzzle while the gun was cocked. I bet the kid didn't tell his dad what he'd done!
I have repaired guns that produced slack groups or random fliers that have had damaged barrels due to owners getting pellets stuck then trying to remove them with unsuitable tools such as steel cleaning rods and hammers. On inspection of the rifling the internal view gave it away but sometimes you need a bore scope to diagnose it correctly.

As regards visual inspection of barrels after or during manufacture it is perfectly acceptable. Light travels in straight lines and an experienced quality control inspector at the factory will know what to look for regards internal straightness and finish. It's not just high end shotgun manufacturers who use this method, rifle manufacturers do too. It's easy to spot a bent barrel when you know what to look for.

[AC99]

The fixed rest bit is probably unlikely for the simple reason that if you rigidly clamp a spring/recoiling air rifle it will actually shoot far worse than if you let it recoil naturally in the hand and gently rested.

ie the clamp inhibits the harmonics of the rifle when it is fired.

That is why professional pellet manufacturers, when testing the accuracy of a spring gun, clamp it into a RECOILING test bench, which takes the 'sting' out of the recoil, allowing it to shoot to its full capacity.

It is extremely unlikely that Webley had such equipment back in the day. I would guess they simply rested the gun on a sandbag?
They may have told you as a boy, that they used a fixed rest as an attempt to make you feel better over the poor shooting of your MK.3?

I do not recall the exact wording of Webley's response (almost 60 years ago) but I think the implication was that the claimed group size was not achieved by off hand shooting. I would not have been aware at the time of the detrimental effect of rigid clamping on the harmonics of the rifle assembly although in later years I became aware of this - so you are quite right and I also think you are correct in assuming Webley would not have had a recoiling test bench then. However, their letter did give me some reassurance that my shooting was not that bad after all and I was quite chuffed to actually get a reply but I think Webley public relations then were quite good.

[bill57]

There seems to be a determined effort to blame the barrel quality here. But remember these are tap loaders, and only once you are 100% convinced that the tap is perfectly aligned, should you be questioning the barrel, whether bore or crown.
You're practically saying that good accuracy wasn't achievable until button rifling was invented, which is simply not true. Straightening barrels by hand was common practice as well, and to a high degree of accuracy.

I also have a Mk.3, which is not very accurate, because of tap alignment. I guess one day I'll have to fix it to see if it makes a difference.

[andrewM]

Great responses - thanks. In order:

1 Flint: I used open sights. I have a light scope from the era but it is impossible to avoid scope creep due to recoil.

I believe Webley's hand-crafted rifling took some time to produce (90 minutes?). Seeking to cut costs again, they eventually saved labour by progressing to button-rifling, albeit at a capital cost in terms of machinery. Button rifling improves accuracy (compared with hand-cut rifling), as a check online will confirm (I posted a link in a post or replying to a post some weeks ago).

One has to be careful to replicate one's hold to produce good groups with these rifles, due to recoil nuances.

2 Rancidtom: Yes, you make valid points. I checked the crowns visually and, to the best of my ability, the inside of the barrels but only via torch light - which is probably insufficient.

The loading taps all seemed firm and aligned but - of course - one could not tell they were original. I also performed the lever test - opening the tap and de-cocking, to ensure the air held.

3 Bill57: Yes, one has to bear these points in mind. I really do not know if the taps are/were 100% aligned. I am saying that accuracy improved as a result of button rifling and, being machine produced, there must also have been greater consistency. By the way, are you certain it is your tap that is responsible for poorish accuracy?

[bill57]

By the way, are you certain it is your tap that is responsible for poorish accuracy?

No, but I know it is misaligned as captured pellets show clipping. With this in mind, there is no point in looking for other causes of inaccuracy until the tap can be aligned properly. If I fix it, and accuracy remains poor in spite of this, then logically the cause must lie elsewhere.

[Geezer]

I am not sure, all things being equal, that button rifling is better than cut. A lot of the CF precision shooters seem to believe that cut (or broached) is superior to button. I’d be interested in your source for that.

On WHB Smith, I’d note in passing that Lesley Wesley described the MkIII as “extremely powerful and accurate”. Of course, we now know that even by 1950s standards, it wasn’t the former. So maybe not the latter, too?

Of course, 1950s/1960s expectations of accuracy were less than ours. But did no-one then notice that the MkIII was perhaps worse than the Airsporter, Diana 50, etc?

I am sure that ammo quality was a factor. Two examples. The Crosman 160 was regarded as a pretty average rifle until in the 1990s people used modern pellets in them (typically Premiers) and discovered that they had very good barrels and shot very tight groups. Similarly the old Sheridan C9 Streaks had at best “ho-hum” accuracy with the classic Sheridan “slug”. They do much better with modern pellets.

And I still think the tap is critical. Good taploaders are quite capable of shooting into significantly under 1/2” at 25 metres.