APS CAM870 Impressions

[aznriptide859]

Great news NonEx, though what does 250gr paper transfer to LB weight per ream?

 

Ordered some RS parts last night:

 

Pump assembly

L + R shell latches

Mag follower

Firing pin

Firing pin return spring (probably won't work, but worth a $4 try)

 

Will let everyone know if the work (especially the firing pin). I'm a little bit worried about the pump assembly and follower though; I had a 12GA shell lying around, and found that it won't enter the mag tube (the brass rim is just too wide) and it won't enter the chamber (shell diameter is just large enough to not fit). Hopefully I can get them to work though.

 

Also just contacted Mesa Tactical - they were very nice, and agreed to RMA my newer skeleton rail for the older bar-shaped rail. \o/

Edited September 19, 2014 by aznriptide859

[NonEx]

The APS CAM 870 shells are closer to 14ga than anything else.

 

So the mag follower is most likely a bust as well.

 

But let us know about the rest.

 

According to Google 250gr is 0.55lbs .

 

Haha, no idea what that pattern is. I thought it looked wierd as well.

Edited September 19, 2014 by NonEx

[mvirtue]

@NonEx -- Thanks for the testing of the paper!

[aznriptide859]

The follower I got was "12-16GA", so who knows maybe it'll fit ?_?

 

Dang 0.5lb per sheet? That's almost like cardstock.

Edited September 19, 2014 by aznriptide859

[NonEx]

Ah OK, maybe the follower is multi-gauge fit somehow, possible.

 

No problemo.

 

However this was just basically a fitment and rigidity test. I can't speak for how it works when operating and firing. But like I said the numbers I gave should at least get you in the ball park for what you can use as a substitute.

Edited September 19, 2014 by NonEx

[mvirtue]

Dang 0.5lb per sheet? That's almost like cardstock.

It would be like Strathmore paper.  Good art and photo paper is in the 200-300gr range.

[NonEx]

Yeah but those types of papers (art at least) fall under the category of cardstock and even though the weight may be the same the rigidity and fiber structure is nornaly much stiffer.

 

I used regular plain white printer paper for my tests, so that's the guideline for this. Plus that is certainly cheaper than high end photo paper or cardstock.

 

 

You know looking back and thinking more about it. The fact that the OEM caps are glossed/waxed paper, thick material and oversized makes me think it might be an integral part in building up the pressure in the shells and making it fire properly. So perhaps 300gr paper isn't that bad after all, maybe even better? Hurr durr...

So taking care and pushing the cap paper just under the retaining ledge without wrinkles and crimpling may be a key to consistent and powerful shots.

The wadding appears to do the bulk of the job of propelling the BBs etc, but I dunno.

 

Thoughts? Is the paper just to hold in the BBs, or to help build pressure as well?

 

 

Anyways. I stand by my previous recommendation of 250-280gr paper should be good.

 

This may also very well explain why my first experience was a complete disaster. My friend Simon put the caps on and it looked like he pretty much took a dump in each shell lol

Edited September 19, 2014 by NonEx

[mvirtue]

In the US we are more likely to find heavy weight card stock than heavy weight printer paper ( at least in our big box retailers )

[aznriptide859]

Yea, I don't ever recall finding paper in large quantities at Office Depot more than 50lbs.

[Brigg]

Just go to the art section at any bigger store and get some bristol board. It should work fine I would think.

 

Also the chances of a real firing pin working are incredibly slim, since the APS cartridges don't work like a real shell. Real firing pins are made to detonate a primer and so are fairly pointy. Even if it somehow did fit the bolt, it would likely just destroy the shells when it hits the valve release and peens it out.

Edited September 19, 2014 by Brigg

[NonEx]

Right. I suppose I am spoiled working at a printing company

 

But you should be able to find like a 250 pack of 250gr paper online for a decent price. Should last you for a good while.

Edited September 19, 2014 by NonEx

[mvirtue]

Right. I suppose I am spoiled working at a printing company

 

But you should be able to find like a 250 pack of 250gr paper online for a decent price. Should last you for a good while.

And then to find cheap wadding.

[aznriptide859]

Just go to the art section at any bigger store and get some bristol board. It should work fine I would think.

 

Also the chances of a real firing pin working are incredibly slim, since the APS cartridges don't work like a real shell. Real firing pins are made to detonate a primer and so are fairly pointy. Even if it somehow did fit the bolt, it would likely just destroy the shells when it hits the valve release and peens it out.

 

I'll try to compare the lengths/shape once I get it in, and if it doesn't work, at least file the front to where it wouldn't damage the release valve when it hits.

 

We'll see.

[NonEx]

Well to be fair the waddings from my first experience look to be very re-usable. So let's say you drop 1/4 maybe and can re-use 2-3 times. That's pretty good value. Granted you are in a situation where you can pick them up of course.

[mvirtue]

Well to be fair the waddings from my first experience look to be very re-usable. So let's say you drop 1/4 maybe and can re-use 2-3 times. That's pretty good value. Granted you are in a situation where you can pick them up of course.

I've been gleaning them when I shoot out side at home. So as an every day plinker, it's cost effective that way.

[DEVILHUNTER]

Thanks NonEx, they are pretty similar, just a bit longer. In red the AS ones:

 

Here you go;

 

Rim diam: 21.0mm 21.8 mm

Base diam: 19.62 19.5 mm althougt fit even 20 mm

Base total height (~tot. leng. - shell body leng.): 11.6mm 10 mm

Rim lip thickness: 1.6mm 2 mm

Total lenght: 56.5mm 58.5 mm

Shell body lenght: 45.0mm 48.5 mm

Shell body outer diam: 19.45mm 19.6 mm

Shell body inner diam: 17.09mm 14 mm slugshot, and I think 17 mm buckshot

 

Anything else you need ?

 

Hopefully it makes sense what I am refering to with the above.
 

[NonEx]

I asked APS directly about dry firing the CAM870 and this is their response;

 

 

Hello
Dry fire is never a good things. Not only on our CAM870 but also in other rifle or pistol made by other manufacturer, dry fire is always NOT recommended. We never encourage people to dry fire our CAM870

Derek Leung
General Information
APS Ltd

 

You can do with that information as you wish

I will try to not dry fire my APS anyways, since it's so close to RS design and centerfire RS weapons are most often strongly recommended to NOT dry fire.

Might look into converting a few of my shells into some for of snap-caps. Should be do-able with some springs or something.

[aznriptide859]

Oops.

 

Well, on a related note, I found out that continuous dry firing has warped the back of the bolt carrier to the point where the firing pin no longer springs out. Pot metal FTL.

[Brigg]

sounds like that would be relatively easy to fix with a small round file. Im not sure exactly how it looks now but if you disassemble the bolt and remove the material from the path of the firing pin, it should fix it.

[mvirtue]

Oops.

 

Well, on a related note, I found out that continuous dry firing has warped the back of the bolt carrier to the point where the firing pin no longer springs out. Pot metal FTL.

 

 

sounds like that would be relatively easy to fix with a small round file. Im not sure exactly how it looks now but if you disassemble the bolt and remove the material from the path of the firing pin, it should fix it.

And the good thing about pot metal you can reshape it unless it cracks.

[NonEx]

OK, I guess we all learned something new here

[aznriptide859]

Yup, I spent last night disassembling the bolt so I could install the RS parts when they come in later today. The deformed pot metal was already filed off.

 

Lesson learned >_<

[NonEx]

You didn't happen to take any pics of what it looked like ?

 

Just curious. The way you describe it I am visualizing hamburger meat at the back of the bolt

[aznriptide859]

Nope, but I think this is how it happened:

 

1. When there's a shell in the chamber, the firing pin has a portion that's against the gas valve. This will keep the pin pushed back towards the rear of the bolt carrier - releasing the hammer pushes the firing pin forward into the gas valve, so most of the resistance the hammer is hitting against is due to the shell's valve.

2. If there's no shell present, the pin is still pushed back (due to the firing pin retention spring), but when the hammer hits now, it's more likely to contact the rear of the bolt carrier.

3. After repeated hits, the hammer (which has a pretty damn strong spring) starts to push the metal around the rear of the bolt carrier and deforms it into the hole where the firing pin should be sticking out of. This results in the firing pin being "stuck" forward (in my case it wasn't noticeable until I took the bolt out, since the front of my firing pin was broken anyways).

 

So, from experience, I'd suggest to:

 

1. Try not to dry fire the gun.

2. If you do want to dry fire, do it with a shell in place (though not sure how much this would decrease the bolt deformation effect)

 

If the rear hole does deform, just use a round/semi-circular file and enlargen the opening. Of course there will eventually be a limit to how far you can do this until you'd have to replace the bolt assembly.

[aznriptide859]

Whelp, disappointing news everyone.

 

But you were already expecting that.

 

RS firing pin won't work - it's almost 3x as narrow. Boo.

RS shell follower won't work - too big (NonEx called that *suitcase*).

RS plates could work with mods - the "height" of the plates is a bit too tall to fit in the grooves in the receiver. Could work with some dremeling (the steel is much less malleable than APS's is), but not sure if I want to go through the work.

RS pump could also work - tube fits, pump guides fit into the receiver. But the grooves/cutouts for holding the bolt don't match - mods could be done to the bottom plate of the bolt carrier to get it to "fit" w/ the RS pump assembly.

 

Kinda bummed out, not sure if it's worth calling and returning the items I don't want to try to get to work (10% restocking fee T_T). Looks like I'm going to have to order a spare bolt assembly from APS.

 

On a side note, has anyone gotten a RS side shell holder to work?