DAR... We Have A Problem...

[Firewalker]

Did you just use a reamer for the lead?

[crazyhorse1]

My friend has a lathe. We swap stuff for favors. 

[Firewalker]

Gotcha! I have a couple lathes but was wondering how the lead was cut?

My friend has a lathe. We swap stuff for favors. 

[nervoustrigger]

A reamer at 0.1mm over the nominal diameter works well.  So for example a 4.6mm reamer for .177, 5.6mm reamer for .22, 6.5mm reamer for .25.
 
Ream to a depth that accommodates the skirt when seated but allows the head to move into the rifling.  In most cases that means you’re reaming to a point just beyond the barrel port.
 
Then clean up the freshly-reamed area with a suitable abrasive regimen.  That could be wet/dry sandpaper on a dowel or a rubberized abrasive bit (e.g. Cratex point) or your method of choice.  Of particular importance is the step up into the rifling…the finish left by the tip of the reamer will be somewhat rough.  Blend this area to a smooth transition so pellets can gently swage into the rifling.  A sharp edge at any of the lands is apt to score the pellet and perhaps cause it to seat crooked and that’s no bueno.

[crazyhorse1]

Gotcha! I have a couple lathes but was wondering how the lead was cut?

My friend has a lathe. We swap stuff for favors. 

I left it with him after our match at his place...I'm sure he used a reamer but don't know details (after 6 years)...

[Firewalker]

FANTASTIC!! Thank you, though one last question, what pellet should I use to measure the insertion? I use CPHP most of all so where the probe ends
 and subsequent skirting hangs into the lead but is in contact with the lands is what you are saying?

A reamer at 0.1mm over the nominal diameter works well.  So for example a 4.6mm reamer for .177, 5.6mm reamer for .22, 6.5mm reamer for .25.
 
Ream to a depth that accommodates the skirt when seated but allows the head to move into the rifling.  In most cases that means you’re reaming to a point just beyond the barrel port.
 
Then clean up the freshly-reamed area with a suitable abrasive regimen.  That could be wet/dry sandpaper on a dowel or a rubberized abrasive bit (e.g. Cratex point) or your method of choice.  Of particular importance is the step up into the rifling…the finish left by the tip of the reamer will be somewhat rough.  Blend this area to a smooth transition so pellets can gently swage into the rifling.  A sharp edge at any of the lands is apt to score the pellet and perhaps cause it to seat crooked and that’s no bueno.

[nervoustrigger]

No problem.  What I was trying to convey is to ream the leade such that when a pellet is seated, its head is engaged in the rifling but the skirt is not.

For a gun with pin probe like the DAR, pellets will seat to a slightly different depth depending on the particulars of the skirt geometry.  Meaning, contrasted against a hollow probe which seats the pellet by the skirt perimeter.  The distinction is worth noting but for the most part, there is enough similarity that you can generally take a couple of pellets in and around the weight range you expect to use and seat them to gauge about how deep you want to run the reamer.

For your .22, the Crosmans and JSB 18.1gr (or 15.9gr) would be my recommendations.

[Firewalker]

Thank you, that is what I was trying to articulate (and doing so poorly) with you about the depth. I also did settle on those three pellets, others just dont pattern well from my DAR. With the .25 coming, I did order a 22g NOE mold today, I love the molds but..... 

No problem.  What I was trying to convey is to ream the leade such that when a pellet is seated, its head is engaged in the rifling but the skirt is not.

For a gun with pin probe like the DAR, pellets will seat to a slightly different depth depending on the particulars of the skirt geometry.  Meaning, contrasted against a hollow probe which seats the pellet by the skirt perimeter.  The distinction is worth noting but for the most part, there is enough similarity that you can generally take a couple of pellets in and around the weight range you expect to use and seat them to gauge about how deep you want to run the reamer.

For your .22, the Crosmans and JSB 18.1gr (or 15.9gr) would be my recommendations.

[Nvreloader]

Here is some info of the inside skirt depths of numerous 22 cal pellets I have measured,

Inside depth of skirt, from the bottom of skirt to pellets inside waist, the pin bolt probe pushes against.

Shortest
Benjamin Super Point =============----.052"
JSB Match Exact Jumbo Monster Diabolo==----.058"
JSB Match Ultra Shock Heavy Diabolo====---.064"
JSB Match Exact Jumbo Heavy Diabolo ===---.065"
Skenco Ultrashock Hollow Point========---.072"
Benjamin Hollow Point =============---.076"
Crosman Premier HP ==============---.084"
Benjamin Pointed Expanding =========---.094"
Benjamin Domed Magnum ==========----.096"
Crosman Premier Piranha ===========---.098
JSB Match Diabolo Straton Jumbo ======---.100"
Kodiak Tapered Dome=============----.108"
H&N Baracuda Match =============----.108"=5.51 Head Dia
JSB Match Exact Jumbo Diabolo =======---.112"
H&N Baracuda Match==============---.112"=5.53 Head Dia
Gamo Red Fire =================----.114"
NOE .217 Hunter================----.130"
NOE .217 Mag Hunter =============---.133"
Skenco Newboy Hollow Point =========---.136"
H&N Field target Trophy ============---.142"=5.54 Head Dia
Skenco Newboy Junior=============----.144"
H&N Field Target Trophy============----.154"=5.55 Head Dia
Ruger Superpoint================----.170"
Daisy HP (Spanish made)===========----.175"
Gamo Platinum==================---.200"
Longest

Shortest Skirt/base depths = .052"
Longest Skirt/base depths = .200"
Difference of .148" in skirt depths.

I will update this data base, when I find more pellets that are not included.

HTH's
Don

[Rat Sniper (AKA: PaulT58)]

Don, You sure seem to spend a lot of time looking up those skirts!   

[nervoustrigger]

It’s okay, he has a signed consent affidavit from each of them.

[Nvreloader]

Thanks Paul/Jason
ROTHFLMAO..................at my age you take it ANY way you can find it..........    
I can look, but CAN'T touch....................

Back to regular programing...............

Thanks,
Don

Don, You sure seem to spend a lot of time looking up those skirts!   

[Firewalker]

Someone posted a link to some Czech or Russian barrels yesterday, I think I might drop 70 Euro on one of those fancy if that works in my DAR. They have a 1 in 14 twist that looks like a great candidate for me!

[Firewalker]

I have the chrony results from todays session. There is some very interesting data below starting at shot #30 with a rise to 841 fps. Then again at shot #33 as it rises to 870 fps then falls off the regulator at shot #54.

Certainly not what I was hoping for...

Created: 02-27-2021 12:37:00 PM
Description: .22 DAR
Temp: 36 °F
BP: 1014.00 inHG
Shots
#     FPS        FT-LBS     PF
57    808        0.00       0.00     
56    812        0.00       0.00     
55    822        0.00       0.00     
54    824        0.00       0.00     
53    831        0.00       0.00     
52    834        0.00       0.00     
51    844        0.00       0.00     
50    842        0.00       0.00     
49    832        0.00       0.00     
48    836        0.00       0.00     
47    852        0.00       0.00     
46    858        0.00       0.00     
45    853        0.00       0.00     
44    ERROR 2
43    870        0.00       0.00     
42    868        0.00       0.00     
41    856        0.00       0.00     
40    864        0.00       0.00     
39    867        0.00       0.00     
38    863        0.00       0.00     
37    854        0.00       0.00     
36    850        0.00       0.00     
35    847        0.00       0.00     
34    840        0.00       0.00     
33    832        0.00       0.00     
32    820        0.00       0.00     
31    827        0.00       0.00     
30    841        0.00       0.00     
29    833        0.00       0.00     
28    837        0.00       0.00     
27    834        0.00       0.00     
26    836        0.00       0.00     
25    837        0.00       0.00     
24    834        0.00       0.00     
23    838        0.00       0.00     
22    827        0.00       0.00     
21    828        0.00       0.00     
20    829        0.00       0.00     
19    829        0.00       0.00     
18    833        0.00       0.00     
17    835        0.00       0.00     
16    831        0.00       0.00     
15    832        0.00       0.00     
14    833        0.00       0.00     
13    828        0.00       0.00     
12    835        0.00       0.00     
11    826        0.00       0.00     
10    827        0.00       0.00     
9     835        0.00       0.00     
8     834        0.00       0.00     
7     833        0.00       0.00     
6     835        0.00       0.00     
5     836        0.00       0.00     
4     833        0.00       0.00     
3     832        0.00       0.00     
2     836        0.00       0.00     
1     830        0.00       0.00     
Average: 837.38
StdDev: 13.15
Min: 808
Max: 870
Spread: 62

[nervoustrigger]

The velocity rise near the end of the string is an indication you have the hammer spring tension set too light for the regulator's setpoint.  If you want it to have a gentle rolloff, dial the HST to about 97% of the maximum velocity.  Doing so will reduce the shot count but will improve consistency.

[RDB]

Like Jason suggested....dial it up or turn the reg down some. It came off the reg about shot 33.

[Firewalker]

Thanks guys! That's the info I was looking for. I would like to add that the poppet spring has also bee tightened up some to fight off leaking (didn't work, still loosing 500 psi a day) so I'll return that to it original setting and then turn the hammer spring back in 1/2 turn to factory specs and hit the chrony again.

Looks like I will pull the reg at that time and replace the rings (Joe could not give me a part number but I will parse that information from the ring/s I pull) and will wait for that new barrel from Joe and decide which shoots better but after yesterdays session (about 50 shots), I may keep the old barrel. I will show you all the results from 65 yards in my next post.

[Firewalker]

My plans for yesterday afternoon were dashed when I picked up the DAR to try a few pellets and noticed the gauge read zero, it had leaked down to empty overnight.

I shifted gears and decided to tear the entire gun down and figure out what was going on. I replaced all the O-rings that were in the kit except for the smallest of them, I have no idea where that teeny tiny one goes!

There were a few issues, flat O-rings on the regulator, flat O-rings on the plugs at both ends of the air reservoir, gauge and poppet side both.

The poppet looked good to the eye until I put a loupe on and noticed that it had some wrinkles on one side of the face, I chucked it up in my lathe and refaced it with a 1 degree chamfer. Putting it back in, I had a severe leak through the poppet still.

I am ended up simply chucking the poppet stem in a small drill and faced the popet by pulling it back into the poppet seat while turning the drill slowly, a poor man's version of burnishing.

That seems to work well, it's holding 3,000 PSI overnight with no movement on the gauge. The good news is that I can now disassemble and reassemble the DAR with a blindfold! I think I pulled it apart no less than a dozen times last night.

In a related issue, I couldn't get more than a thousand pounds in the gun off the hand pump once I had the DAR fixed, turns out the hand pump was all gunked up with a junk and had to rebuild the hand pump last night as well. No O-rings were used, just a good cleaning to get seals on both ends working once more. Hopefully I will get some shots down range tonight.

The .25 is scheduled to arrive monday, we will see if its holding air. It will be fun to see what the cast pellets do, I have low expectations so as long as they will hit 1/2" groups at 20y, they will be good for close paper punching.

[B.Guns.]

Glad you got your leak worked out.
I have to do that with mine now. It's leaking 1000psi a night.
Still shoots great but its leaking pretty bad now.

[crazyhorse1]

My plans for yesterday afternoon were dashed when I picked up the DAR to try a few pellets and noticed the gauge read zero, it had leaked down to empty overnight.

 I replaced all the O-rings that were in the kit except for the smallest of them, I have no idea where that teeny tiny one goes!

There were a few issues, flat O-rings on the regulator, flat O-rings on the plugs at both ends of the air reservoir
That seems to work well, it's holding 3,000 PSI overnight with no movement on the gauge.

The .25 is scheduled to arrive monday, we will see if its holding air. It will be fun to see what the cast pellets do, I have low expectations so as long as they will hit 1/2" groups at 20y, they will be good for close paper punching.

Good luck with the "kit" o-rings....

Is the .25 cal a new rifle ?

Rich