A micro barrel flaw to the crown directing pellets awry ?
Try the ear bud test , drawing a bud out the barrel slowly to see if anything snags the cotton and drags it .
I don't know if I'm experiencing a "senior moment", but I can't make sense of something & am hoping one of you gentlemen can de-confuse me please.
Yesterday I decided to take my recently acquired alte Frau, a 1931 Haenel IV fitted with a BSA
19a thin ring & blade front sight to the club & try her out over longer distances than my little garden range will allow. At my home 8 yards maximum I needed a bit of hold under, as expected, so I thought I'd make a crib sheet out to 30 yards & then go and have some fun on the HFT course, trying to hit the plates. This is where my confusion began when I discovered the hold under increased with the distance to the target, rather than decreasing as I'd expected - thus
10 yards 2" hold under
20 yards 4" hold under
30 yards 8" hold under
The rear sight is wound right down as far as possible, raising it increased the hold under needed to hit the target card, as expected. The rotating front sights, blade & ring, both give the same impact point, when set in the correct upright position.
Am I losing me marbles or does this lovely old girl defy the laws of gravity?
Yours in confusion,
Glyn
A micro barrel flaw to the crown directing pellets awry ?
Try the ear bud test , drawing a bud out the barrel slowly to see if anything snags the cotton and drags it .
I'm not all that familiar with the Haenel but a quick search showed it's a break barrel so have a look see if the barrel and cylinder are aligned properly when the gun is closed. Sounds to me like the barrel is tilted up a bit or perhaps even bent.
Last edited by vbull; 17-08-2017 at 01:14 PM.
Remember, it is the strongest character that God gives the most challenges.
Thanks for your replies, chaps.
Jimny, I've given it the cotton wool bud test as you suggested & couldn't detect any snags or burrs in the crown.
vbull, actually the Haenel Modell IV is a tap loading underlever, apparently based on the LJ type BSAs, so the barrel is pretty well attached to the rest of the gun. I've put a long straight edge along it & it's perfectly true. In fact, it would take a bit of effort to bend it as it's a good 0.6" diameter along its slightly tapering length, with a 0.177 bore.
Thanks again though, both.
Glyn
Wierd
Good website here for Haenel owners
http://www.waffencenter-gotha.de
Yes ... a puzzle. Thoughts: is the rear sight original? Could barrel have an upward lilt where it fits into the cylinder? The visible barrel might be perfectly straight but the join to the cylinder could be a tad out? Could the barrel bore not be central?
Certainly a puzzle as you would expect the issue to self correct with distance, assuming the 8yd point of impact is akin to the primary zero, as it were.
Cheers, Phil
The sight line and bore line converge, and cross at less than 8 yds.
Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?
If you spread your legs , bend over and take aim shooting backwards thru yur legs , what effect would gravity have on pellet trajectory upside down , as it leaves the muzzle to a 10m-15m zero then on to 25m , then 40m in general ? And specifically this particular weird Haenel ? Answers on a postcard .
Last edited by Jimny4x4; 18-08-2017 at 04:17 PM.
The rear sight is clearly higher than the front in relation to the bore line, so on aim the barrel line is pointing up. You are just considering decreasing velocity and pellet drop, but its clearly being pointed up which compensates for that. For its first part of its trajectory its climbing as its pointed up, it will probably only stop climbing and start dropping after 40 yds or more. At 8 yds you still need to aim down to hit your target, and as the barrel is pointed up in relation to the sight line its still shooting high at 30 yds. If you go out to 50 mts you may probably find that pellet drop is then coming into play and the aim point will likely be the same as 30yds or less if the drop is really coming into play.
If you shoot closer than 8yds you'll find the cross over point. OR to do it technically, measure the front sight above bore centre, and measure the rear sight above bore centre that will give you the picture of bore line and sight line, I think from what you have described the bore line and sight line will cross at about at certainly less than 8 yds with bore line pointing up and the sight line down, if in doubt then draw it out, it should be obvious then.
As an example I have just re zeroed two 6 mmBR 300 mt rifles, I have done it as they have both had the sight length increased with having barrel tubes fitted. Both are identical, same barrel, and same length, same sights, and same ammo. Before fitting the tubes both were perfectly zeroed at 300 mts. BUT, one (mine) has 15mm of sight raising blocks fitted front and rear, my wife's has none just the sights. When I fitted Identical tubes to both we re zeroed on zero cards at 25 mts, but hers needed only a click or two, mine with the sight raising blocks needed masses of adjustment and was shooting two inches low! That was because my bore line and sight line were converging and by fitting a tube I altered the sight line and the relation to the front and back sight. This is the same effect as you are getting with your air rifle.
And the further apart the bore line and sight line are the more the effect is!
Sorry, that has probably really done in your head now!!
Last edited by RobinC; 18-08-2017 at 02:22 PM.
Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?