D54 pellet testing

[mcoulter]

One of the things I learned early on regarding my d54 is that it has some non-standard rubber washers used in the mounting mechanism.  Being the procrastinator that I am, have not ordered replacements yet.  I've just been having a ton of fun just shooting it and "getting to know" the gun.  I figured now that I have about a tin-and-a-half of pellets through it that I  should get a good baseline before ordering the right washers.

What's in there now (thanks Hector for the added graphics)!


And we had some great weather this weekend so I swapped the peeps for a scope in a zr mount and decided to test a variety of pellets.  All targets are 10-shots at 50 yards. 

Here are the JSB 14.3, 15.9, and 18.1 groups:


And Polymag and Superdomes:


Lastly, H&N FTT (5.54):


While the H&H group does not look that much different than any of the rest, that was the last group I shot due to the wind.  I'll definitely revisit these again as we get some calmer days.  Also, it's safe to say that  I'm done with the polymags and superdomes in this gun.  I have a few tins of Crosman .22s which I'll eventually test, but I'm not in too much of a hurry :-)

So my thoughts are to do some further shooting playing with various holds and points were I'll rest the gun and get a good baseline.  Then it'll be interesting to see how swapping to the OEM washers affect its accuracy.

Here are the chony numbers for each pellet:

JSB 14.3 = 770 fps / 18.8 fpe
JSB 15.9 = 717 fps / 18.2 fpe
JSB 18.1 = 678 fps / 18.5 fpe

PolyMag = 716 fps / 18.1 fpe
Superdome = 761 fps / 18.7

H&N FTT = 733 fps / 17.5 fpe

[Robert 5mm]

Matt,
As a reference, here are my chrono numbers from the D48 I got from you.

2/14/2020 Elev 450' Temp 57d   
Diana Model 48 .22 with Vortek Replacement Spring
   
                                                FPS        Wt         FPE
JSB Diabolo Express                    797     14.35      20.22
JSB Diabolo Exact                       788     15.89      21.94
JSB Diabolo Heavy                      744     18.13      22.26

[mcoulter]

Thanks Robert.  That 48 was always a strong shooter  :-)   

I went back and looked up some of the earlier velocities (pre Vortek spring).  Here are some numbers not long after I received it 9/26/2016

JSB Diabolo Express = 808 fps
JSB Diabolo Heavy = 758 fps
H&N FTT = 849 fps

And just for giggles I went back a bit further in my saved photo albums and was reminded that they are all humbled by a Hatsan 135 I owned before that...  that bad boy was truly a 30+ fpe springer (jsb 18.1 = 888 fps).  I also think it was the cause of few loose teeth from shooting it!  Unfortunately That gun met an early demise one Christmas morning when the barrel slipped out of my had while cocking it.  I'm truly lucky I wasn't injured when that happened!

[Louis Loria II]

Have you checked the barrel shroud to make sure it is secure, that will cause accuracy issues. If it slides back and forth the least bit, fix it. Otherwise, I have a 54 that is sub MOA accurate, easily shooting 1/2" groups at 50yds from a bipod. I did learn the hard way about the shroud. I hope you sort it out.

[mcoulter]

Have you checked the barrel shroud to make sure it is secure, that will cause accuracy issues. If it slides back and forth the least bit, fix it. Otherwise, I have a 54 that is sub MOA accurate, easily shooting 1/2" groups at 50yds from a bipod. I did learn the hard way about the shroud. I hope you sort it out.

Hi Louis, Yes, there is a *small* amount of fore / aft movement on the shroud.  Were you able to eliminate this on your rifle?  If so, what did you have to do? 

I'm having a flashback to a similar post I made about my 48 (https://www.gatewaytoairguns.org/GTA/index.php?topic=115865.0).  I never did manage to remove the front sight housing on it.  In that case, the shroud on the 48 ONLY rotated unlike the 54 where it does slide front/back a small amount.

[dtdtdtdt]

Matt, if you have a Tru-Value or ACE hardware near you, some have a wall of little bins of interesting things.  They may have rubber washers that might work for a start in your 54. My local one actually has a set of bins specifically marked gun screws.  They have come in handy for me a few times. 

Although, I have accumulated kits of most English and metric thread gun screws of most useful sizes.   I keep my friends in screws when they lose them.  buying the whole kits turned out to be not too terrible as much as I use them.  Instead of paying for one - two screws at $3 each and then $5 shipping, I spent the $40 or so with free shipping for all of them (net cost/screw less than $0.25 ! 

[dtdtdtdt]

By the way, what were the group sizes?   I'm guessing about 2" from the hole sizes.  My .177 and .20 will typically shoot about 1" at 50yds when the wind cooperates - not often at my outdoor club.  The 20 does better because of the higher weight and better bc of the pellets. 

[Louis Loria II]

Have you checked the barrel shroud to make sure it is secure, that will cause accuracy issues. If it slides back and forth the least bit, fix it. Otherwise, I have a 54 that is sub MOA accurate, easily shooting 1/2" groups at 50yds from a bipod. I did learn the hard way about the shroud. I hope you sort it out.

Hi Louis, Yes, there is a *small* amount of fore / aft movement on the shroud.  Were you able to eliminate this on your rifle?  If so, what did you have to do? 

I'm having a flashback to a similar post I made about my 48 (https://www.gatewaytoairguns.org/GTA/index.php?topic=115865.0).  I never did manage to remove the front sight housing on it.  In that case, the shroud on the 48 ONLY rotated unlike the 54 where it does slide front/back a small amount.

To tighten the shroud, first loosen the screw fixing the front sight in place. Tap the muzzle with a mallet or plastic face hammer, not too hard and retighten the set screw. The front sight is what keeps the shroud in place against the breech block. The front sight is "keyed", so you don't have to worry about it twisting out of place. This is what fixed my problem and my groups were crazy, like yours.

[mcoulter]

Hi Dave, Yes, you are correct.  The JSB and H&N groups were all right around 2-inches.  The others were more like 3 inches.  Yes, I am hopeful that I'll be able to squeeze these down to what you're able to do!

Louis, thanks again for the info.  I was able to tap the front sight housing back almost 1/4 inch and tighten it down again.  Eezy-peezy!  Now for the hard part...  waiting for the next opportunity to shoot some more and see if it makes a difference :-)

[Robert 5mm]

Matt,
If you get rid of the front site Hector has a "Adjustable, High Performance Muzzle weight".
He sent me one for the D48 - but I sent it back to him.

[mcoulter]

Hi Robert, thanks for the suggestion.  However, I do want to keep the ability to have the front sight.  I did get a small window to shoot since cinching down the shroud.  Groups at 50 might have shrunk 1/2 inch (maybe...)  So I did not get the night-and-day improvement that I was hoping for. 

The group in the center was the first.  I was actually aiming at the left dot.  So the point of impact changed pretty significantly after tapping the front sight housing back.  That group started out really promising and then opened up a bit.  I made some scope adjustments and ended up with the group on the left. My last group on the right opened back up to about 2 inches.  I will say that there were the makings of a decent group here, but I'm not where I think I could be yet. 




The good news is that all of this did prod me to finally order the proper rubber washers that Hector pointed out in the very beginning of my posting about this rifle. 

I called Umarex and they were SUPER friendly and helpful.  Oh, the parts shipped to me ended up costing about HALF of what Pyramyd would have charged me.  So when they come in I'll also take the time to clean up the grease from the sled when installing them.

[Louis Loria II]

Matt,
If you get rid of the front site Hector has a "Adjustable, High Performance Muzzle weight".
He sent me one for the D48 - but I sent it back to him.

I'm glad you found the shroud loose, sorry it happened, but it may well fix the problem.

If interested, Umarex will sell you the muzzle brake for the 56TH. It is a direct fit for the 54.

[truck driver]

You have two other options besides the rubber washers. I got a set of self centering washers from Hector but haven't tried them yet since I had replaced the OEM washers with steel fender washers which makes the bedding more solid and you can use a higher torque value on the action screws.

[mcoulter]

Hi Louis, thanks for that information regarding the 56 muzzle brake.  I can't help but notice the placement of the front rest on the photo above.  It's really far forward.  This front rest placement is one of those variables for which I have not found my by 54's "happy place".  I have had intermittent good results with BOTH fore and aft bag placement.  Unfortunately, I have not been able to find the right combination for consistent good groups. 

It'll be interesting to see how the OEM washers change the gun's behavior.  And Rodger, thanks for the fender washer suggestion.  I suppose that'll come after testing with OEM ones.  I'm also planning to swap my swfa ss 16x onto the gun and see how that does with a UTG drooper mount and some other rings.   

And I also want to say that I truly appreciate everyone's input on this!  I have to admit to enjoying working through issues like this     I had a similar experience with a Kalibrgun Cricket I traded for over the winter.  It was quite the learning experience.  I'm happy to say that had a very good conclusion and I know have a gun I truly understand and it's shooting the way I want.  I documented much of that and the site's owner was kind enough to publish a little write up about it here https://hardairmagazine.com/ham-columns/a-previously-used-misbehaving-airgun-is-a-great-teacher/.

I'm very hopeful this will have a similar outcome!   

[dtdtdtdt]

A follow up on the recoil of the 'recoiless'. D54.  You mentioned some recoil issue. I finally got my Hector Special d54 out and did some chipmunk extermination oner the weekend.  I could feel absolutely no recoil at my shoulder. I haven't shot my .177 D54 that is more or else OEM for a couple weeks.  I will try a couple shots right now in the basement shop to see.  Just shot it twice offhand paying careful attention to the rifle - not the target.  I could feel no recoil in the stock while shooting but could feel the action and barrel bump the end of the slide after the pellet was already gone.  It would have no impact on the accuracy though. I still recommend getting the gunk out of that rifle before you get serious about shooting it.  Also, get the action/stock tuned together - along with correct washers and correctly any binding. 

Here are my experiences getting it "right."

1. Regarding the rubber washers and other kinds too!!  Early on, I found the rubber washers improperly installed on my .177 D54.  Put them right and things got better. 

2. Metal fender washers with and without the rubber washers to raise the action a bit to minimize any binding.  Didn't see any improvement. 

3. Adjustable washers that Hector sent me.  These are thicker washers with curved faces to make them align uniformly when tightened in.  Again, no improvement but they were so thick that the trigger set high enough that I had to use the tip of the trigger rather than the curve. 

4. Back to OEM washer stack and lightening up on the tension to hold the sledge in place.  As earlier stated,  30inlb of torque compressed the rubber to the point of uselessness.  Backed off to 25inlb.  Accuracy improved a bit.  Reduced to 20inlb will some modest improvement.  Tried the same torque front and back and then set the front to 25 instead of 20.  No improvement.  Set back to 20 and front to 25 with no improvement.  Then went down to 15 in the same sequence.  No significant change except the action seemed wobbly in the stock.     Settled on 20inlb front and back.  I think this is about optimum for my rifle.  The changes I saw were mostly change in POI rather than group size. 

5.  The detent ball to control the movement of the action front-back.  I found mine too tight so loosened it a bit.  AND using a countersink I carefully chamfered the hole into which the ball sits to remove the sharp edge.  Did it do anything?  I can't tell but it made me happy!  I keep the detent ball spring fairly loose and well lubricated as well as the rods so the action releases quickly and moves easily on shooting.

Most of my shooting is either in the back yard where I have 50-100' high trees on three sides and the house on the other side the area is small enough that wind is rarely noticeable..  The maximum range I have is about 35 yards.  This is where I get the best groups for both of my 54s.  On a good day as small as .4" when my eyes are misbehaving .9" average.  At my indoor range that is max of 50' the groups are in the 0.25" range with all time best groups being in the 0.1" c-t-c.  These are not common.  The outdoor range gives up to 300m (50yd, 100yd, 200yd,  300m) from bench rest. It is notorious for its difficult wind currents. Prevailing wind is SW to NE with the range being perfectly N-S.  The left side has a row of trees about 40-50' all along.  The wind sweeps over the top of the trees and rolls down into  range area like a rolling barrel.  The bench-rest shooters put out as many as 5 flags in 20 y d increments.  I have seen each of them pointing in different directions at the same wind gust. 

The point of all this is that air rifles are REEAALLY SENSITIVE TO WIND!

My best 50yd groups are around 1".  I tried a couple at 100yds and got 3-6" groups.  One day while watching the grass move at the 50yd target, I had to hold left about 4" to keep the shots in the group.  Out of 20 shots into the same "group" 8-10 were inside an inch while the rest opened the group to about 3" using Kentucky windage.  Had I not done that I think the group would have been an oval about 6"wide and 2" tall trending left to right at 50yds.  I surmise that the 8-10 were fired when I caught the wind behaving.  My purpose in that experiment was to see the impact of wind in a systematic way and whether I could have a positive effect by wind doping.   The bench-rest shooters with powder guns were estimating the cross wind at 10 or so mph.  Their groups were opening up to .5" at 100yds!!!!!!  The Nelson Berger Memorial Range is home to many very competitive bench rest shooters!!

By the way, with the rifle zeroed at 50yds, I had to hold over about 2feet at 100yds to hit the bull!!!

The real fun of shooting these air rifles is not the shooting but the tinkering!!!

Cheers