HELP, my NPSS is sick

[Perry]

The soda can trick works great for the Trail XL because of the threads at the end of the tube for screwing the end cap on. On an NPSS, there are no sharp threads to get the seal nicked up on. If you do a good job deburring the pin holes and cocking slot and trigger opening, I don't really see a need to use a sleeve to insert the piston and seal. It may be a lot of work for nothing.

[airiscool]

The soda can trick works great for the Trail XL because of the threads at the end of the tube for screwing the end cap on. On an NPSS, there are no sharp threads to get the seal nicked up on. If you do a good job deburring the pin holes and cocking slot and trigger opening, I don't really see a need to use a sleeve to insert the piston and seal. It may be a lot of work for nothing.

Yes, it's a must with the XL's end cap threads. And if it's long enough, it will also help protect the seal if any burred edges along the cocking slot were missed.

Even though I had de-burred all the edges of the cocking slot, I used a long piece of brass shim stock I have to help prevent any possibility of the de-burred edges 'rubbing' a groove in the seal lip, and to make it easier to get the seal past the inner end of the cocking slot on both my Whisper and Trail XL.

It wasn't absolutely necessary, but I had the shim stock, and didn't want to take any chances of harming the seal.

Paul

[Norm_m]

OK my parts have finally shipped and should arrive on Tuesday. Now I have a question on what lube to use where.
Do I use the silicone grease on all inside parts of the tube: chamber, and remainder of tube, inside & outside of piston, shaft of nitro piston? Then use the moly on the barrel pivot area.
I've read many post and articles in the GTA Library and it sounded like I should use the silicone grease in the chamber area and gas piston shaft, then moly grease on the inside and outside of the piston and remainder of the tube (from the cocking slot back). Also from what I understand is to just put a fine film of grease on everything.
Any info on this would be great as I would like this seal to last longer than the 1500 shots like the original.

[airiscool]

Great ! Hopefully the Christmas rush won't hold them up also !!!!!!

For a gas ram gun...

I used a very light coating of silicon grease on the tube and seal, based on info I read in a B-19 tune writeup that Charlie wrote. It's worked well so far.   

Then, Maccari's moly grease on the ends of the ram, sides of the piston, cocking slot and shoe.

Since then, I've noticed that Maccari on his website, and I believe Gene has also mentioned, also using Maccari's moly on the seal and tube.

Next time I open an AG up, I'll be switching from silicon grease to using the moly on the seal and tube also.

Tough to ignore the advice of folks who've done ALOT of AG tunes for a living.  

Paul.

[Norm_m]

Well the parts were shipped on 12/17 and they finally arrived today! From NY to NH seems to have taken a long time but with the Holiday season I guess it can be expected. So now that they are here I know exactly what I will be doing this evening. Hope all turns out well!

[Norm_m]

Well the Remington NPSS is all back together!  A new seal was installed, chamber honed, all possible areas that could damage the seal while installing where touched up and everything got a good lube job. I also hand made a set of brass breech spacer washers and they were installed during this rebuild. I am very, very happy with the results with my 1st attempt to open up my NPSS, not to mention the increase in the Chrony readings as you will see below. All comparison testing was done with Crossman Premier HP 14.3 gr

Original Readings       New readings right after tune     New readings after 500 shots
         701.5                             759.9                                     779.2
         721.9                             767.5                                     758.5   
         717.2                             766.4                                     762.4
         712.9                             763.9                                     756.6
         718.1                             760.3                                     769.9
         721.8                             751.8                                     766.9
         721.2                             761.0                                     771.9
         717.8                             761.6                                     766.6
         718.3                             746.4                                     759.2
         708.5                             762.2                                     773.2
Ave. Vel. 721.8                        760.1                                    766.35
Ext. Dev. 20.3                           21.1                                        22.6
Ave. Dev. 4.97                          4.44                                        5.74
Ft-lb      16.28                         18.35                                      18.65


I Chronied several other pellets including the following: H&N HP 12.65 gr., RWS wadcutter 11.96 gr., Crossman Premier Domed 14.3 gr. And the Crossman Domed Select 14.3 and all results showed the same type of increases from before the tune job. Now all I need to do is see which pellets will give me the best grouping.
Thanks to those of you that gave me the useful information that made my 1st attempt at this a success.

[Perry]

Norm, those numbers look much better and they will probably get better over time.

I find my NPSS like H&N FTT pellets, good velocity and accuracy. You should give them a try too.

[Norm_m]

They're on order!

[Norm_m]

Now I find out they are out of stock and cannot find any H&N FTT .22's anywhere. Anyone know who may have them in stock?

[Chortdraw]

I used the old seal and put it on the end of a dowel and put some silicon on it and worked it in and out of the chamber before I assembled the new parts. Every thing went together very smooth and I got very little smoking from the very start of the break in period. It is an easy gun to work on.