R9 good for 20 shots, give or take

[nced]

I hate to say this, but I believe that after your 20 shoots, THAT IS YOUR POI!
The first 20 shoots just warm up the gun to where it normally wants to shoot.

-Y

That's fine if you only shoot paper. A hunting rifle has to predictably print the first shot on target. There's no warm up shots while hunting. I returned two Savage 17 hmr rifles that had unpredictable cold bore shots. The third one was no better I cut that rifle in half and threw it in a dumpster. No more Savage rifles for me.

I'm with Ron on this. Rabbits don't come into my field on a conveyor belt, and the interval between shots might be fifteen minutes to an hour or more, so every shot is a first shot.

In HFT, people zeroing their rifles shoot fairly quickly, so heat builds up in the piston seal and changes the pellet POI, which they correct by adjusting their scope. Then, everyone at a shoot has to attend the safety briefing, then make their way to their starting peg, by which time, the heat has flowed from the piston seal into the cylinder wall and end wall, and their first shot on the course goes high, in the order of an inch high at 30 yards. The interval between shots on an HFT course might be five minutes, so every shot is effectively a first shot.

I'm sure Yogi is right - if you keep shooting without allowing the seal time to cool, the 'new' POI will be maintained.

WARNING..........I've posted these experiences with my HW springers quite a few times so please feel free to ignore if desired!

Years ago I found that even shifts in atmospheric temperature during a shooting can shift the poi. In "US style hunter class field target" adjusting the scope during a match isn't allowed so all "aiming adjustments" are done using "holdover, holdunder, Kentuckey windage, etc". During an early spring FT match in Virginia the sight-in before the match was done during snow flurries but the temp rose to the mid 50s F during the match. About 3/4 through the 72 shot match both my brother and I started missing more target than usual. Aiming at leaves on the ground we found that our R9s had a 1" poi shift at only 20 yards so we used "holdoff aiming" to complete the match.

I theorized that the combination of piston seal durometer and lube viscosity thickening affecting the piston functioning was the reason for the poi shifting. I tested this theory decades ago by lathe cutting an aluminum piston cap that used a size 020 oring to do the sealing. The thought was that a 1/16" (1.8mm?) cross section oring getting compressed in the receiver would be less affected by these changes than a 10ish mm thick factory HW piston seal. My first attempt at an oring sealed piston cap was rather surprising because my velocity using the exact same spring and pellet increased 40fps, plus the poi shifting was greatly reduced. As a side note, at that time HW was using a seal with a "thin parachute edge" however over the years the HW factory seal has evolved to a "reduced seal skirt with thick rounded parachute sealing surface" (sealing similar to an oring shape). Testing the newer design HW piston seal I found similar performance to my oring sealed piston caps IF they fit the receiver properly. I also found that the fit of the later HW seals weren't very consistent and some fit loosely whereas other brand new seals fit properly. Another "issue" with the later HW seals which I never saw with the old thin edge parachute seal was piston seal face cracking............


The following caps I made were simply 6061 T6 aluminum with a size 020 oring but a few years I added a Delrin bearing on the outside of the cap...........


My first oring sealed piston cap after a thousand shot testing. LOL, only some discoloration on the face of the adapter from using "dinosaur oil based molly lubes".........


I've nixed the diesel prone "dinosaur oil based" molly lubes for non-dieseling Dupont Krytox GPL205 "space station lube" and I've been using the oring seal + Krytox for several years and did some testing years ago. After moving to North Carolina over a decade ago a test was done during the winter to see how atmospheric temperatures affected the velocity of a Krytox lubed R9 with oring sealed piston cap. I left the .177 R9 in my unheated sun room over night so the gun temp dropped to upper 20s F, then shot a dozen pellets over the chrony sensors noting the velocity. Then I took the gun indoors over night so it would warm up into the 70s F and again quickly shot some pellet over the sensors. A bit to my surprise the velocity of the upper 20s F shots were about 10 fps higher than the shots with the same gun at 70s F.

More recently I did some shooting upstairs over two days. The 1st day I shot some "bucket and sticks groups", then the following day I shot some more groups without warm-up shots or re-zeroing" and here is a scan of the target.........
>

[Oldgringo]

I thought that my scoped HW30S had gone bananas yesterday.  The shots were all over the place.  I took her back out this morning and she hit the 25 and 30 yard spinner spoons shot after shot.

Yesterday, it was me not the gun or scope.  Just sayin'....

[nced]

I thought that my scoped HW30S had gone bananas yesterday.  The shots were all over the place.  I took her back out this morning and she hit the 25 and 30 yard spinner spoons shot after shot.

Yesterday, it was me not the gun or scope.  Just sayin'....

LOL....I resemble that! I've had the same thing happen when I blamed a "bad shooting day" on my equipment, however during the following night an unknown "airgun gnome" fixed my gun because  "accuracy issues" certainly couldn't be due to this shooter!

[Tom1340]

Electricity finally came back on in Tulsa, and I get to catch up on this thread.  Lots of good input.

Bayman... My current breach seal in .173".  I shaved another down to .170 as an experiment.  Neither had barrel droop and both passed the tissue test.  I gave up on the .170 version after one shooting session as the groups loosened up quite a bit.  It wasn't satisfying and I did not spend enough time with it to see how it affected the poi shift.  Also, Thanks to you (& Ed) for posting your targets.  They are evidence that my POI shift is not the norm.

Jim,  I have set the gun aside for 5 minutes, or maybe even 10, and the poi did not revert to "initial shots" poi.  But it always reverts by the time I get back to the gun for a new session, about 24 hrs later.  I'm going to try some more structured pauses, and see if I can fix the time it takes for poi to return to cold barrel status.

Thanks all for your comments.  I love shooting this gun, and enjoy puzzles. 
 

[Yogi]

Well you sure got one!

-Y

[Tom1340]

Well, after another 1000 shots and experimentation, I have reached a conclusion in this matter.   Airnut's response called it first and called it right  (shooter fatigue).  And several others followed with similar assessments.  So now I would like to change the thread subject to "this shooter good for 20 shots, give or take".   

[nced]

Well, after another 1000 shots and experimentation, I have reached a conclusion in this matter.   Airnut's response called it first and called it right  (shooter fatigue).  And several others followed with similar assessments.  So now I would like to change the thread subject to "this shooter good for 20 shots, give or take".   

LOL....this is why I normally use "5 shot groups".

If I use more than 5 shots in a group I'm mostly testing my "steadiness" rather than accuracy of my rig. Also, using a "bucket and sticks shooting form" for testing rather than "benching" is the norm for me and I don't use a shooting bench for squirrel hunting or field target matches.

[Bridger3]

This was a great thread, maybe some of us learned a thing or two 😂 made me think about my own shooting experiences and how it made sense to me that, those days that I have problems hitting my goal, maybe it’s just because I’m tired and it’s not the gun! !

[Eclem]

I clean my .177 R9 and HW95 barrels when the accuracy "goes south" and after the bore cleaning my poi does move some till the bore gets "re-seasoned" after a couple dozen shots, then the poi remains consistent for another tin or two of pellets (perhaps 1000 shots) and the process of cleaning/seasoning the bore is repeated. If you're always shooting after a fresh bore clean perhaps you need to continue shooting after the bore is 'seasoned" and see if the poi is stabilized.
[/quote]

Ditto here in NE CT USA. My 5 .177 Weihrauchs tell me when they need a barrel cleaning - usually after 400 or so shots (H&N FTTs) POI will shift erratically with each shot when lead and lube buildup occurs. I run a nylon brush dipped in Balistol once from breech to muzzle. Let it sit for 10 minutes. Then give it 5 or so passes and follow up with a rag patch or 2. I finish up by pulling an airgun bore snake (no bristles) through. Works for my guns. It does take approx. 10 shots after cleaning to get back to 1/2 inch / 25 yards centered POI. But like everyone else I do sometimes experience a slight POI shift with temp changes - usually a 2 or 3 click correction needed. All my scopes are Hawke Airmax or similar quality - nothing big bucks.

[Yogi]

400 pellets is awfully often!  Maybe you should wash /lube your pellets.  My bore easily last 5X that with JSB's.

-Y

[Struckat]

I clean my .177 R9 and HW95 barrels when the accuracy "goes south" and after the bore cleaning my poi does move some till the bore gets "re-seasoned" after a couple dozen shots, then the poi remains consistent for another tin or two of pellets (perhaps 1000 shots) and the process of cleaning/seasoning the bore is repeated. If you're always shooting after a fresh bore clean perhaps you need to continue shooting after the bore is 'seasoned" and see if the poi is stabilized.

Ditto here in NE CT USA. My 5 .177 Weihrauchs tell me when they need a barrel cleaning - usually after 400 or so shots (H&N FTTs) POI will shift erratically with each shot when lead and lube buildup occurs. I run a nylon brush dipped in Balistol once from breech to muzzle. Let it sit for 10 minutes. Then give it 5 or so passes and follow up with a rag patch or 2. I finish up by pulling an airgun bore snake (no bristles) through. Works for my guns. It does take approx. 10 shots after cleaning to get back to 1/2 inch / 25 yards centered POI. But like everyone else I do sometimes experience a slight POI shift with temp changes - usually a 2 or 3 click correction needed. All my scopes are Hawke Airmax or similar quality - nothing big bucks.
[/quote]

My HW30 had to be cleaned about 1,500 shots. Sometime after 3,000 and the second cleaning, I ran some JB Bore paste thru it. I am now over 4,000 or so since then and have not had to clean it.

[Hoosier Daddy]

400 pellets is awfully often!  Maybe you should wash /lube your pellets.  My bore easily last 5X that with JSB's.

-Y

^truth^
Using quality pellets I seldom clean my barrels.
 By the time you "lead "them back up, you are close to where you were before.

[nced]

400 pellets is awfully often!  Maybe you should wash /lube your pellets.  My bore easily last 5X that with JSB's.

-Y

^truth^
Using quality pellets I seldom clean my barrels.
 By the time you "lead "them back up, you are close to where you were before.

Hummmm.....for a couple decades I've been using the "most accurate pellet" for my HW springers (the now unobtanium 7.9 grain die lot marked and dated boxed Crosman Premiers) and sought ways to make them "less fouling".
Boxed CPLs.......
Anywhoo, as mentioned previously, I had "quick barrel fouling" issues with the hard lead CPLs till I started lubing the pellets with aerosol Slick50 One Lube and then the barrel cleaning chore was reduced to about once for each 1250 count box. The "boxed CPLs" have been discontinued so I'm currently testing out my H&N & AA offerings.....



H&N FTT 4.52mm however the Air Arms Dome 4.52mm is pretty good................


LOL....whatever procedure works best for the individual shooter and gun is certainly the best approach!

[shep]

  This subject sure hits home for me,so much good advice,one thing I notice is some HW springers are more prone to these problems than others.I also think when I first start shooting I always get great groups,so I say to myself," keep it up" , then things go bad from there,I get perturbed at the gun, and now I think it is ME!...I am trying too hard and not relaxing, tensing up without really thinking about it. I noticed when I adjust my trigger pull my groups change a little, which proves to me it is ME,...This HW50 is so sensitive it is like a crybaby, telling me to hold it just right, to pull the trigger just right, everything has to be just right," yes honey" whatever you like....what a pain, guess it makes me become a better gentleman,LOL.