SpudFiles

So I bought myself a bit of an antique, an Apache Fireball pump-up rifle from the late 1940s:



0.24" caliber made for #4 lead shot but also featuring a 0.175" smoothbore insert to fire steel BBs. Fairly good condition but it loses a bit of air while pumping. The plan is to get it shooting hard again, because of its vintage I won't be modifying any of the original parts but I do intend on machining a new chamber/valve unit with a different design.

First step is to take it down, I have to say what a joy it is to handle something from the age of "iron and wood", it's a cliché but they really don't make 'em like they used to, modern air rifles with their emphasis on synthetic materials don't exude the same feeling of solidity. Here's some detail shots of the different components, most of which appear to be original:



Bolt, hammer and trigger assembly. The hammer is not linked to the bolt and needs to be cocked separately. There is also no seal on the bolt so I will probably make a new one with an o-ring.



Closer view of the trigger assembly which is a simple lever with a return spring. You can also see the threaded section on the right where the stock bolt attaches to the action.



Valve and chamber unit which is of a conventional design, with the check valve opposite the firing valve held shut by the same spring. The chamber and valve head are held together by a plug threaded inside the pump tube, while a set screw keeps the exit port aligned with the barrel.



Valve head and chamber assembled with retaining plug on the right.



Synthetic pump head in good condition.



Pump lever pivot detail.



Pump lever handle.



Channel stamped in the pump tube at the end of the piston head travel to enable the pump cylinder to refill rapidly.



Muzzle endcap with pump lever retaining pin along with rear iron sight.



Muzzle detail with partially unscrewed 0.175" BB insert.



Breech end of the insert.



View down the rifled 0.24" barrel.



Breech end of the action showing the loading port.



There is evidence of something having been engraved on the action that was subsequently filed off, the research I've done so far indicates that they were not marked at the factory so it's a little odd.



Stock detail with stock bolt, the wood has seen better days but I will not be refinishing it. One of the butt plate screws is not original.



Evidence of a repair to the stock where it attaches to the action.

Next step is to measure the insides and think of a more efficient valve setup, likely along the lines of a balanced spool. Watch this space.

Didn't take you long to get that one apart. Looks and sounds like a fun project. :headbang:

Gippeto wrote:Didn't take you long to get that one apart.

To make things better you must first make them more sparse

You know, beyond the obvious parameter of construction method and materials, it's pretty amazing to see how little things have changed in the past 70+ years of airgun design (at least for the conventional multi-pump pneumatic).

It would be interesting to see this dinosaur with something more efficient like a spool valve... possibly with a CO₂ or PCP upgrade if portability isn't an issue?

Fantastic post as always.

Pretty much, there is literally zero difference in the operating principle between this and a Crosman 1377 you could buy today, right down to the single spring holding both check valve and firing valve.

It would be interesting to see this dinosaur with something more efficient like a spool valve... possibly with a CO₂ or PCP upgrade if portability isn't an issue?

While I was briefly tempted to use it as the basis for a PCP autoloader (the fact that it's meant for lead shot would have made a tube magazine easy...) it's just too old for that - not exactly a rarity or expensive collector's item but I still want it to look stock from the outside, so spool valve and general leak prevention (ie o-ringed exit port, stem support, bolt) it will be.

That stock would be pretty to look at if the old lacquer was removed, woods sanded to 2500 grit and then oiled/waxed....

You're probably right, I believe it's walnut so I suppose it will be worth the effort. Still, worky bits first

It IS worth the effort! Few years back I restored an old Sako hunting rifle stock which was walnut and looked a lot like that stock. It was very satisfying to reveal the beautiful fresh wood grain under the old and cloudy lacquer!

So I finally made some progress on this thing, click the images for higher resolution.



This is what the new valve looks like compared to the standard valve, as you can see it's a balanced spool with significantly more flow. Resting the hammer against the valve stem will open it even after 7 pumps, while the old valve would remain closed even after one pump.



Here are the chamber components excluding the return springs, also showing the new Delrin pump head. Since there's a refill channel stamped in the pump tube at the end of the pump head's travel I didn't make it a floating o-ring. If it looks a bit scorched it's because yours truly went a bit overboard with the silicone oil and it dieseled wouldn't be a JSR project without an unintended explosion.



Check valve assembly and pump head.



Chamber components assembled with valve closed.



Chamber components assembled with valve open.



Another view of the chamber parts.



Rear end of the valve showing the bleed hole that is rather critical to the spool valve operation. It ensures that the valve encounters minimal resistance from compressing air while opening, while also preventing a pressure imbalance when the valve is open.



I originally didn't want to refinish the stock but I gave it a go thanks to jakethebeast's advice, here it is along with the pump handle sanded down.



The buttpad was originally held on by wood screws, one of which was not original. I decided to replace these with machine screws so I put in a pair of 10-24 threaded inserts.



Here's the finished result, I wasn't too obsessed with bringing it to a satin finish or removing the dents but it's still a very decent result. The finish is 6 coats of tung oil applied over a couple of days, sanding with 600 grit sandpaper in between.



Buttpad held on by two brass 10-24 screws.



Another view of the stock.



Stock now properly aligned with the receiver, it was a little off-center when I received it.



Original steel bolt with the new aluminum bolt featuring an o-ring and steel insert, which seals off the chamber completely and allows for better flow.



Bolt installed and full open.



Bolt closed.



Pump partly open.



Pump head at its fully open position.



Hammer knob in its fully cocked position.



Hammer knob in its closed position.



Rear view of the action.



Muzzle closeup.



Overall view.



The big question of course, how does it shoot? Unfortunately I haven't been able to source the ammunition (#4 Lead Shot) for it in reasonable quantities, they only seem to be available in 25 lb bags. In the interim however since the bore is approximately 6.1mm, airsoft BBs are a loose fit but at 6 pumps it will put a 0.32 gram BB clean through the lid of a soup tin.

I love those old guns!

Firstly....very nice job bringing the old girl back to life. Secondly...nice improvements. 8)

As far as ammo...wondering if you've checked Ballistics products? Have a jug of their .300" round ball, and some of it is...some of it isn't.

That aside, it's an 8lb jug, and also the only game in town. Should be able to find it if you go to a gun show...where I found it anyways.

http://www.ballisticproducts.com/Super- ... nfo/SBK03/


Edit: Should have added something about the delrin pump head...Some folks have found they get a little scorched...not necessarily the oil. Switching to brass maintains a low coefficient of friction and eliminates the issue.

Gippeto wrote:Firstly....very nice job bringing the old girl back to life. Secondly...nice improvements. 8)

Thanks, I'm not done yet!

Notice that in the original design the chamber has a brass liner, while I went ahead and used the housing as the chamber. Well, turns out that liner was there for a reason as the housing is not completely airtight, not sure how it's built exactly but it's losing air where the pump tube meets the receiver. I've taken it apart again, will have to make my own liner to solve the issue. A bit less chamber volume but it shouldn't hurt.

As far as ammo...wondering if you've checked Ballistics products? Have a jug of their .300" round ball, and some of it is...some of it isn't.

I found that while searching but eventually found a local outlet that was selling 25lbs of Hummason #4 shot for less than twice the price of the 8lb jug. Ordered it online, apparently there's a two week wait as it was out of stock.

[rant]As a member of a team that makes a supreme effort to never advertise anything that isn't available in stock, I find this appalling. Apparently very common practice too, because people still call to make sure we have items in stock even though it's clearly marked "ready to ship" online.[/rant]

Hope it's mostly the right size because otherwise that's a lot of useless lead!

Should have added something about the delrin pump head...Some folks have found they get a little scorched...not necessarily the oil. Switching to brass maintains a low coefficient of friction and eliminates the issue.

That aside it was annoying me to have an anachronistic synthetic part in a rifle made before my dad was born so I was planning on making a new head anyway

It definitely did diesel in my case, there was an audible "PFFFTTTT" with smoke and the interior when I took it apart was black with soot.

What a joy it is though to be able to work on airguns (within the confines of the law) without needing a license for it though!

Hey this got me wondering... when do we not work on these older guns because of (potential) collector value? Sometimes I start planning to improve airguns and then... depending on the situation... decide to fabricate an entirely new one based on the venerable piece... leaving the original untouched.

I feel like the answer has something to do with marital status.

Hey this got me wondering... when do we not work on these older guns because of (potential) collector value? Sometimes I start planning to improve airguns and then... depending on the situation... decide to fabricate an entirely new one based on the venerable piece... leaving the original untouched.

In this case it's definitely an old piece but not one that really fetches much, you'll see them go for less than 300 dollars online, so I don't feel I've ruined an antique here. On the other hand aside from the wood I've replaced rather than modified original parts, while preserving the latter separately. It's a kind of middle road then, breathing new life into a classic rifle without fitting it with Picatinny rails and an AR-15 stock and grip

I feel like the answer has something to do with marital status.

That's a curious point, care to elaborate?