Please call out the steps involved in tuning a springer/gas ram

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Bigragu

Bigragu

Member
Jul 8, 2018
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CA, United States
Wow, I finally decided to “hang out”on this sub forum, and didn’t realize that the break barrels still had a great following. I always thought once into PCP’s, all break barrels collected dust or got sold off. You all on here have inspired me to set aside the PCP’s and start shooting my break barrels again!

So, here’s what I got-

1.) Beeman R10 deluxe in 177 caliber, circa 1991, bought right at Beeman’s place in Santa Rosa

2.) Beeman RX1 in 20 caliber gas ram, circa 1992, also bought at Beeman’s store

3.) Beeman FWB 124 sport deluxe in 177 caliber, has the San Rafael Beeman on it. Mint condition bought from neighbor

4.) Benjamin Titan NP in 22 caliber gas ram

Can anyone tell me what can be done to these, besides seal replacement, to better the accuracy and jolt that comes from shooting springers? I hear of talk about tuning these things, and aside from the re seal I’ve done to the FWB, the R10, and the Charlie da Tuna trigger on the Titan, what else can be done?

The RX1 went thru the Beeman upgrade back in the day, had the special gas put in, and although I own both the pressure gage and pump for it, I’ve never messed with adding or removing air from the power plant.

Thanks, fellow break barrel folks!
 
Disassemble it and clean all the factory goop out of it.

Inspect all the parts and look for wear patterns, and minor imperfections. Fix them all as best you can by grinding/filing/honing/polishing/or whatever it takes.

Make sure the transfer port is perfectly round and smooth. 

Replace all seals and bushings as needed and relube sparingly (but sufficiently) with the proper stuff (moly and silicone).

Give the bore a really good scrubbing, and then put her all back together.

Give attention to detail, regardless of how seemingly minor.

Take it out and shoot about 20-30 pellets through it, THEN re-sight it in and see if you helped it any. I bet you did.

😊


 
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What fishinwrench said. I own two np’s and have done everything possible imo to them to make the shot cycle smoother and the gun more accurate. Useing a dremel I have filled down and polished the trigger sears on both. I also tried different piston seals to see if I could limit the piston slam to increase accuracy.

The main thing I’ve been experimenting with is different powered gas rams. I removed the factory ram from my 22 and installed a Gamo ram. The result was an easier to cock rifle, pleasant shot cycle and improved accuracy. It now shoots H&N 14.65 grain pellets at a respectable 710 fps. I tried a 50 kilo ram in my 177 but it didn’t have enough oomph to push the pellet out of the barrel. I have to travel a fare distance to have the ram increased in power so I haven’t done anything yet.

If you have an adjustable ram and it’s the same size as you np ram try adjusting the pressure to see what happens.

Good luck

Gary
 
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The RX1,a gas ram in 1992? Please tell us about it.How does it shoot now as compared to in 1992? Do you have any chrony stats?
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Yes, it was like the first of its kind. Actually, I believe Theoben made them for Beeman. I know on the barrel block on my RX it says Theoben on it. If I am wrong about the fact that Theoben produced these for beeman, please correct me, anyone. 

This RX has a built in shcrader valve at the end of breech, basically at the plug one would remove to get to a mainspring on a spring gun. The valve was housed in there, and there is a bolt plug to keep the dirt out. Armed with a pressure gage and hand pump(specifically made for this gun), one could add more pressure to the ram for added velocity, or decrease the pressure for easier barrel cocking. Adding more air was actually detrimental to accuracy, so in this case, more was not better. It would also increase cocking effort. It already takes 45 lbs of cocking force, just on the stock setting!



ill have to find my notes, but going off of memory, it’s shooting the 20 caliber crow magnum pellets in the mid 800’s. 



Theres one for sale in the classifieds here and also on GTA, by the same member. His is like in mint, mint condition. Beautiful gun. 20 caliber, just like mine.
 
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So, thanks for the replies. Polish, hone if necessary, remove old lubes and replace with new, is that it? I thought maybe there was some extra magic required. I’ll start with what was suggested. Thank you!
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If you go with one of the kits like Vortek or Macari, they bring everything needed including some grease and washers to fine tune the power level. 
 
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What fishinwrench said about the transfer port was what I found on My Crosman NP22. When I disassembled the rifle and looked down the piston cylinder to see the light coming through the transfer port, it wasn't round, like something in the way of it. I inserted a 1/8th" drill bit in the breech end of the cylinder and sure enough it stopped after going in a 1/4". So I drilled through the obstruction (it was nothing major). I put in a new piston seal, lubed everything lightly, and a new breech seal, got some good pellets(H&N FTT's 14.66gr) and wow what a difference this thing now hits what ever I'm aiming at! Really much more confident with this rifle now, before it was literally hit and miss! Hope this helps!
 
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Oh, wow, ok. There’s the magic. I understand better now. Now, if one had to choose, go with the vortex or the Maccari? 



On those vortex kits kits I see this plastic tube 1/4 way up the spring on one end. Is that tube suppose to go back inside the gun, also? I’ve seen the instructions on those vortex kits, as I got one for my R10. The instructions are craply written, along with whoever tried to draw a section view of how it goes doesn’t know how to draw mechanical drawings to understand. I tried calling PA for better definition, and I got the run around. I basically broke the kit, that plastic tube shattered. The mainspring is way way shorter than what came out of the R10. I tried emailing PA to make sure it truly was for an R10, and got no reply back. That’s pretty much the last time I bought from them moving forward.
 
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As far as increasing the transfer port, which I’m highly assuming is the hole you see when the barrel is broke open, is there a rule of thumb as to what size not to go over when porting it? Just thinking of my Marauder. I know they are different beasts, but as an example, going too big on a TP can also not be a good thing, and something you can’t revert.
 
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The RX1,a gas ram in 1992? Please tell us about it.How does it shoot now as compared to in 1992? Do you have any chrony stats?
Click to expand...

I bought one around that same time in Santa Rosa. Mine also was in 5mm. With Beeman Silver Jet pellets (most accurate pellet) weighing in at 11gr my RX1 averaged 910 fps. Or 20 ft/lbs of energy. That gun is still my most favorite airgun. Even including my current Sig ASP20. Wish I never sold it.
 
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Not sure why they choose that size for the TP but I'm sure there's a good reason. Possibly to keep the piston from slamming so hard.

One thing to consider when attempting to increase velocity, is that unless the barrel is choked you can definitely blow the pellet through the barrel TOO FAST and cause the pellet to skid over the rifling grooves. Doing so will leave lots of lead in the barrel, and turn your accuracy to poop.

In my experience the biggest boost you can hope to achive by modifying a NP gun is about 30-35fps, and if you study that difference with a ballistic program I think you'll agree that you're not really "helping your cause" very much at all. Especially since an increase in power on those guns usually comes with a decrease in accuracy.
 
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