Beeman 1085 - CO2 Puncture Problems

[AndyKunz]

I do have valve lock issues with one of my QBs when temps get above 85 degrees, I'm thinking more hammer spring to cure that.

The gun is usually in my air conditioned (73F) shop, at least until the first shot is fired.  It wasn't all that warm yesterday, only about 82.

I'll take a few shots before work tomorrow, as it'll be mid-60s.  Thanks for the suggestion.

Andy

[Ribbonstone]

Good news is that the 1085 will let you pull most the striker parts out without having to take the breech off.
(Pasrts 3/4/spring comes out...striker stays in).

DSCN2834 by Robert Dean, on Flickr

Can't see any difference in the plastic spacer  (#3) used that can go in either way.
There is an unused hole at #4 simply becasue it's a QB part and they already had a hole.
The spring could go in either way.
Thy used a standard QB78 striker,but added a threaded rear hole for the threaded cocking pin (#5). It's the only hole that's threaded,so never tried it in the non-threaded one.

Normal QB has part #4 using a pin....so you have to take the breech off to get to the striker spring if shimming the spring is on your mind.   This one,can just undo the rar action screw and pull out #3 and 4 leaving everything else in place.

Yeah...are mods to increase the gas flow tinto the valve. I'm not much for hot rodding Co2's anymore,but that's one step.

Becasue of the way the reciever covers so much of the tube, a transfer port leak is a lot harder to detect....always worht a tesst,but the escaping gas spreads out over such a wide area it's not as obvious with the 1085.

[fivestar45]

I had a similar problem. with my QB78. So I'll skip th the punch line. The valve stem...the steel  stem in the brass had pushed to the rear a bit. This effectively shortened the striker stroke to the point that it didn't have enough hit to do the job.

[Ribbonstone]

Different ends of the system....the valve stem poppet is just fine....the substitute 12gr.seal is a little stiff for the ProTop and needs to be a little more "finger-screw squishy".

[AndyKunz]

Can't see any difference in the plastic spacer  (#3) used that can go in either way.
...

OK, so I'm putting it together correctly.

Becasue of the way the reciever covers so much of the tube, a transfer port leak is a lot harder to detect....always worht a tesst,but the escaping gas spreads out over such a wide area it's not as obvious with the 1085.

I'm going to work on that angle first, since it's easy enough to do.  I picked up larger tubing at the hw store this morning to see if that fits the diameter better. 

One of the mods I saw was to recess the transfer port area on both sides to provide a positive well for the seal to center on and be retained within.  Now I need to find a friend with a Bridgeport

I had a similar problem. with my QB78. So I'll skip th the punch line. The valve stem...the steel  stem in the brass had pushed to the rear a bit. This effectively shortened the striker stroke to the point that it didn't have enough hit to do the job.

Mine has a steel rod end-to-end, and the end of the steel is flush with the end of the brass.

Andy

[AndyKunz]

I measured the depth at 1.6mm, so I made a new seal cut to 2.0mm.  I opened the seal up slightly with a drill bit to remove some material from the inside, then pulled it over a 7/32" bit and warmed it with a heat gun to help it like the new size better.

The photo shows how it fits.

While I was taking it apart this time, I noticed a slight hang-up with the cocking pin against the side of the slot.  Upon examination I noticed that there was a slight burr, so I polished it off.

The Umarex CO2 came yesterday, so I used two of them for my tests.  It was about 87 degrees outside, but the gun was about 72 from being inside my office all day.  I got off one or two good shots, but then the next 8 fell short.  Like, 2' drop in 20 yards.  I can shoot spitballs harder.

I didn't have time to continue testing, as I had to get out in the yard and get some raking and grading done where I had a piled up for two years.  A farmer came today and carried off 5 tons of fill for me.  Whew!

So this morning I take it outside, still with yesterday's CO2 in it.  It's about 69 in my office and outside. (It's a little more humid outside!)  I'm shooting at my 40 yard target - for a first shot I just aim at the middle of my burn barrel, and it hits about 1/2" off my point of aim.  OK, that's fine, I had that happen a few times in the past with the first shot.  So I take another.  Same thing.  10 pellets later, I'm still hitting my point of aim, and it's hitting it hard.

The improved port seal can't be hurting anything, and the polishing may have been a factor.  Maybe this temperature thing is a problem for this gun.  I'll find out this afternoon when it gets into the 90s. 

Thanks again for all the suggestions!  What a great bunch of guys you all are.

Andy

[fivestar45]

I measured the depth at 1.6mm, so I made a new seal cut to 2.0mm.  I opened the seal up slightly with a drill bit to remove some material from the inside, then pulled it over a 7/32" bit and warmed it with a heat gun to help it like the new size better.

The photo shows how it fits.

While I was taking it apart this time, I noticed a slight hang-up with the cocking pin against the side of the slot.  Upon examination I noticed that there was a slight burr, so I polished it off.

The Umarex CO2 came yesterday, so I used two of them for my tests.  It was about 87 degrees outside, but the gun was about 72 from being inside my office all day.  I got off one or two good shots, but then the next 8 fell short.  Like, 2' drop in 20 yards.  I can shoot spitballs harder.

I didn't have time to continue testing, as I had to get out in the yard and get some raking and grading done where I had a piled up for two years.  A farmer came today and carried off 5 tons of fill for me.  Whew!

So this morning I take it outside, still with yesterday's CO2 in it.  It's about 69 in my office and outside. (It's a little more humid outside!)  I'm shooting at my 40 yard target - for a first shot I just aim at the middle of my burn barrel, and it hits about 1/2" off my point of aim.  OK, that's fine, I had that happen a few times in the past with the first shot.  So I take another.  Same thing.  10 pellets later, I'm still hitting my point of aim, and it's hitting it hard.

The improved port seal can't be hurting anything, and the polishing may have been a factor.  Maybe this temperature thing is a problem for this gun.  I'll find out this afternoon when it gets into the 90s. 

Thanks again for all the suggestions!  What a great bunch of guys you all are.

Andy

Have you checked the stem as I mentioned.. These guns have had this problem for yr's. Without full stroke it will never work correctly.

[AndyKunz]

Have you checked the stem as I mentioned.. These guns have had this problem for yr's. Without full stroke it will never work correctly.

Yes, I addressed that at the bottom of my previous reply:

Mine has a steel rod end-to-end, and the end of the steel is flush with the end of the brass.

I would add, there is no deformation of the brass to suggest that it was expanded as the steel rod pushed its way through.  And there was no burr on the outside end of the steel where the hammer hits it to suggest it had been shortened by repeated blows.  The diameter of the impact faces appears to be the same at each end of the rod.

Andy

[fivestar45]

Sorry Andy, I must have missed your earlier reply

[AndyKunz]

No problem!

If I ever have to open it up again, I'll measure how long the valve/actuator assembly is.  I didn't do that previously because I didn't see any wear/damage, but it wouldn't hurt to have that info available.

The gun is now outside warming up to the ambient.  I'll take a few shots later and see how it looks.

My son and I checked out the pock marks on my burn barrel, and there is a visible difference.  It was hitting much harder today.

Another change I made that I forgot to mention.  I removed all the felt this time, just in case that was a factor.

Andy

[AndyKunz]

So, yup, the temperature looks like maybe it's a thing for me.

When it warmed up (ambient 92, it soaked there in the shade for 2 hours) the velocity dropped dramatically.  I put the ProChrono DLX out at 40 yards and my phone to capture the data safely away.  I set up a sheet of plywood to protect the face of the chronograph (a lesson learned the hard way...) and I'm glad I did.  It was peppered with dents from the low shots.  Shots were dropping 2' and were very inconsistent shot-to-shot.  Out of two dozen pellets fired, only 2 made it through the gate - 306 fps and 201 fps with about 6 minutes between the two of them.  Photo 2 shows the impact one of these low-speed pellets had on the burn barrel.

By way of contrast, photo 1 shows what happened in the morning with temperature of the gun about 70 and the ambient slightly lower.  I hadn't set up the chronograph yet (those dents inspired me to for the afternoon session).

Andy

[Ribbonstone]

Radical idea...ignore it.



MAybe not worry about it?

Even a leaking o-ring has it's uses.

Put on a known to be leaky o-ring to the 1085 end cap.

Screwed it down tight...popping the 12gr. that was pointed up towards the end cap, pressurizing the tube when the end cap was screwed down.

Cocked/fired the rifle once.   Which popped the pointed down 12gr.next to the valve.


Let it sit in the corner for a day so the leaky o-ring would do it's thing and eventually empty the rifle after one cock-n-shot.

DSCN2902 by Robert Dean, on Flickr


HAy...a glance into the future.....welcome to "Old man hands".

LIKELy (and I'll test and show it if need be) would have just shot this rifle 60-70 times...all the while the bottom 12gr.would have been beaten with the piecing pin 60-70times and the pressure holding the valve closed decreasing pressure/closing force at the end....likely have come out empty with about the same sized hole.

But the bad end cap o-ring was useful....in letting the rifle slowly empty itself, showing what actually happens if you load the two 12gr  normally.

[AndyKunz]

That hole in your #1 is monstrous compared to the one I got the other day.  Mine was a crack so tiny a #79 drill bit didn't know where it was.

This is getting old.  I'm going to try a little more, than call Mike next week if I can't resolve it.

I suspect that the Umarex cans in it now might have both pierced, based on how much better it's working (not that it's good, just that it's way better).

Andy

[AndyKunz]

I just degassed.  Both Umarex cans were opened.  After 50 shots the #1 hole was still smaller than a #79 bit.

I got one good shot - the first one.  It had been sitting on my bench indoors for 24 hours, untouched.  It hit spot on.

Everything after that was dropping.

The most irritating this about this whole episode is that Beeman/Marksman does not return phone calls nor e-mails.  So much for a 1 year warranty.

Andy

[AndyKunz]

If I ever have to open it up again, I'll measure how long the valve/actuator assembly is.  I didn't do that previously because I didn't see any wear/damage, but it wouldn't hurt to have that info available.

Well, I had a chance to open it up again.  Attached are photos of the piercing pin and valve/actuator showing their respective lengths.

I'm still trying to get reliable shot-to-shot performance that is better than 300 fps.

Andy

PS - I spoke with Mike and he doesn't service these airguns.  Since I can't get Beeman to return and e-mail or phone call, there is no warranty.  So I'm doing what I can, writing it off to lessons learned.  Next time I buy an airgun it'll probably be from Mike, so it does have somebody reliable behind it.  I'm very disappointed with Beeman, enough that I fixed my review on Pyramyd to reflect the dissatisfaction.  I hate doing that, but nobody else should be stuck like this.

[AndyKunz]

As suggested somewhere above, I made a dummy CO2 cartridge that allows a flow-through operation for the #1 position.  The bench grinder cut a nice hole on one end of an old Crosman, and the other end was simply drilled out.  The edges were deburred and polished.

The first dozen or so shots were made just to verify that it was working.  Then I let it sit for almost 2 days in the 71-degree shop before picking it up at lunch today and shooting through the chronograph.

What was kind of puzzling was the way the velocity dropped, then picked back up.  It dropped off quickly after that and obviously was the end of the CO2.  Temperature was pretty stable throughout - my shop was about 71, and outside right at 72.  I expected some drop in speed from the CO2 cooling off, but was surprised that it picked back up even as I fired about as quickly as possible (all this was with a single shot tray).

Andy

[Ribbonstone]

HAve to think about those first two-three shots...can't see a real logic behind that.


IF this were a PCP, graph would match up to one starting out at too high pressure...working up to a kind of plateau,then falling off. Opening striker force stuggling against the high closing pressure.... as the closing pressure decreased,it got in balance.

With a co2,pressure controled by temperture.  Warm co2 at the start (higer pressure),cooling down from being shot and lessening the closing pressure until it ran out of gas?

Harder to judge the internal tempture from the outside...takes time for conduction so we can measure it.

So long as you have the cut-out 12gr., swap the placement....that should check any valve stem limitations that might happen from a tiny-popped hole.

[AndyKunz]

That over-pressure explanation makes a lot of sense.

What would the solution be?  Reducing the spring pressure inside the valve?  Increasing the spring pressure on the hammer?  Adding weight to the hammer?

I'll try swapping them and see.  Early on my problem was not piercing the #1.  Having #1 with a drilled-out end takes away that problem.  And honestly, getting 60 shots is not a bad thing vs. the 120 when it was new, so I really don't mind having only one providing gas.

Andy

[Ribbonstone]

Usually take the simplest way to find out first and figure a cleaner/nicerway only after finding out if it works.....so shim the strker spring to increase tension.

With the 1085, just taking out the rearaction screw will let you remove the end cap and pluck out the spring.   Shouldn't take too much more tension (spacer thickenss) to see atleast the direction of change.

So something quick and simple for a test. Considering how that system works, could just use a washer/spacer between the rear end cap and the plastic spacer.

From your pictures and how far you can protude the piercing pin....not thinking the valve spring goes coil-bound or adds much to the closing force.

------

Basically...it's the same thing I'd do for a non-regulated PCP showing that graph.....increase the spring tension to the striker, increase the force opening the valve.

[AndyKunz]

That was an easy change, and it made a big difference.

I inserted a .060" thick washer at the rear.

This time the #1 was punctured on the first shot.  That was my long-term original problem, and it's SOLVED.  Thank you!

It also provided much improved velocity, though it still does creep upward for the first dozen or so shots, so maybe a wee bit more shim is needed.  It is cutting the efficiency down, though, as it went from about 60 shots to about 40.  That suggests either I'm getting liquid into the valve (possible, as there's no felt right now) or the open dwell time is too high.  Are those correct possibilities?

Andy