TargetTalk

mrgt350 wrote:" the travel of the pellet is shorter but the velocity is also lower. Due to the shorter barrel"

Doesn't seem right in an air gun but I could be wrong. In a gun that uses .22 cartridge the longer barrel allows the powder to more completely burn thus giving it more velocity. In an air gun I am not sure the same principal applies.

Anyone else?

I measured the factory adjusted velocity of both full size and short AP and I can ensure you that it is correct (it is about 25m/s lower, actual velocity depending of the pellet weight). I also measured the velocity of AR that have an even longer barrel and it was higher than the one of the full size AP.

Now, as already said, part of that velocity difference comes from the barrel length, part comes from regulator adjustment to consume less air/shot and provide enough shots/cylinder with the short/smaller volume cylinder. The goal is to come to about 100 shots/cylinder to be able to do a 60 shot AP match including sighting shots and with some safety margins (the manometer on the cylinder isn't very accurate and also the filling of the cylinder is influenced by temperature, when filling the temperature increases and if you shoot at a lower temperature than the one at the filling place, you won't have a fully filled cylinder @ the shooting place).

It doesn't matter what the velocity is from a shorter barrel. There will be more change due to different pellets than from barrel length. I find about 45fps difference between the light and heavy pellets and you can set the gun anywhere you want it.

With my LP1 set up to shoot light (7gr) pellets at around 530fps, I get more than 200 shots per fill. I find it's no problem to shoot two matches with that.

I would like to know what's going on with that extended front sight.

It seems the question rather simple - do you have problems determining the placement of a shot that has been well released?

Every shooter can determine that for himself. If a standard length is fine to 'see' a ten when you shoot it, then the reason for shooting lower scores is not related to the sight picture and a longer sight length will not improve the score.

I think that this is true for myself.

Not arguing with you Funny Farmer, but I would suggest that your position on this makes it all the more interesting, wondering why these shooters are using elongated front sights. They are obviously top level air pistol shooters, hardly of the sort who would use such a modification without good reason.

Gerard wrote:Not arguing with you Funny Farmer, but I would suggest that your position on this makes it all the more interesting, wondering why these shooters are using elongated front sights. They are obviously top level air pistol shooters, hardly of the sort who would use such a modification without good reason.

I think the answer is that they are shooting the Steyr LP10e Compact, for weight and balance, and the extended front sight is to make the sight radius the same as it would be on a regular full length LP10e. Sight radius is something you get used to to give you the proper indicators as to when to put the gun down when you see unacceptable movement. If you shorten it, your hold will look more stable, and you may find yourself holding the gun up too long. Had dinner with a World class free pistol shooter, Saturday nite. He was telling us that he had stripped all the weight he could off his guns to get them as light as possible after blowing out his shoulder.

To each their own on a lot of these sorts of points. I'm finding my sight stability improved by the addition of a 135gram weight I added to my K10, bringing it up to about 1125grams total. The stock 990grams feels nice, especially to my still not quite healed shoulder, but the smallest sort of wobble in my hold is just too obvious at that light weight. The added mass below the cylinder on a rod threaded into the trigger guard steadies this movement down so as to be almost imperceptible, without being so heavy (like my old 46m) as to make my shoulder tire quickly.

I think the answer is that they are shooting the Steyr LP10e Compact

No way - go look at the ISSF website (http://www.issf-sports.org/photoplayer. ... =1294-7603), there is a excellent picture from the side. Standard length LP10E.

Looks long to me. Here's my new 'Korean' front sight for the K10. Shot a couple of targets with it this afternoon but only had time to sight in with the new foresight before wife and kid came home. I'll put in some time with it tomorrow and see what impressions I get beyond the initial sense that it's similar to stock... it'll take a while to really know. Meanwhile I'll have to figure out where I put the stock sight. Really have to develop an orderly procedure for small parts temporary storage in my workshop...



It's a ground-down 10mm steel rod, shaped roughly on a grinding wheel then a 1" sanding belt with platen, then some hand filing to get it just small enough to slip into the dovetail groove. A single set screw secures it about 1cm into the groove, same as stock. 28mm project past the muzzle shroud tip. It would be easily bent by carelessness, that's my first impression, so I'll have to be extra-cautious in handling the pistol. And it won't fit in the stock Pardini case, which I use for going to the club, but fits fine in the double case I have for travel, a Pelican 1490.

Looks cleverer than a bug. Would the unit fit nicely in a bottle for, say, 50 or 75 aspirin tabs? If it works on An FWB C20 or C22, I could be interested to try. Price will matter.

Pete

The extended foresight seen from a different angle confirms that it is fitted to a regular/long LP10E model.

peterz wrote:Looks cleverer than a bug. Would the unit fit nicely in a bottle for, say, 50 or 75 aspirin tabs? If it works on An FWB C20 or C22, I could be interested to try. Price will matter.

Pete

Oops, sorry if I worded that poorly. I'd no intention of hinting that I'm up for making these for sale. FAR too much work on my plate for that, and I'm not set up for production work anyway. Can't stand production machining, having given it a good try back in '88 and gone a bit nuts after making hundreds upon hundreds of one thing... then hundreds more of another. All to excellent standards for a really fun company, but that's just not my bag. I've made a bunch of metal bits for doublebass C-extensions over the years (you can see those on my site if curious - luthier.ca) but even that I've given up, as a machinist in Germany does a better job for less money than I can do it, so I just get bassists to buy those then I make the ebony bits to mount them on.

Making one of these should be pretty easy stuff for any decent machinist, and most towns have a few machinists around. You'd just need to bring your sight into the shop for some measurements and a sketch and it'd not likely be more than a 1 hour charge plus nothing at all for the scrap of steel. Heating to past blue and quenching makes it dark enough, though you could paint it if you liked with a matte black BBQ spray or something. And yeah, it'd fit in a small pill bottle, total length only about 43mm for my pistol, which might vary a little for different models.

(Oh yeah, and I found the Pardini original front sight in my workbench. Made a pair of new holes in it last month for a new jig and I keep losing small parts in them, not used to them being there yet.

If it works on An FWB C20 or C22, I could be interested to try.

I think the C2* have a 12mm barrel like most APs. So if you want a longer sight radius, just get a different compensator / front sight unit, like a early Morini (no comp holes or deflector in there, so no problem to move it around). It won't work with a standard old style FWB front sight holder anyway, the fs is just a blade of steel there.

The UK Steyr man who was there looking after guns has confirmed to me that the Koreans were using standard full length LP10 e's (not compacts or any special variation) with their own site base extensions.
Also note the "special" shooting jackets, and no, before that turns into a discussion on special supportive shooting aids I'm just joking, they are ordinary anoraks and an attempt to combat the very cold range!!!
Good Shooting
Robin

Tycho wrote:The rules are clear. The pistol's got to fit in the box, no matter how. If that is squarely, diagonally or upside down, doesn't matter. Most current SP wouldn't fit into the 300 / 150 / 50 box without using every corner available. The AP box is much bigger, because there was a time before compressed air when many AP had big cocking levers and such things. You could probably squeeze some more cm out of your sighting radius by moving the rear sight, but I (IMO, YMMV etc.) don't believe that's a useful thing - what you're looking for in a competition is a stable sight picture, and that's exactly what you're not getting by making the thing longer.

Quite right, it has to fit, any way! the problem one we have come across is a standard left handed LP10 which required a bit of modding to get it in the box due to the depth of the box and the width of the grip and loading lever.
Robin

A first follow-up on my posting 5 days ago regarding my newly-made extended front sight:

- I found there was no easy way to fit the pistol into the Pardini case with the foresight extended to 28mm beyond the front of the aluminum shroud, so I pulled it back to 25mm; no great difference and it fits in safely now.

- I finally received glass lenses for my new Olympic Champion shooting frame the other day, one cut for focus at 10metres as I've been aiming that way for several months, and the other focused on the front sight in case I decide to go back to that. So this is an added variable, this past week as I've tried both back and forth a bit in trying to decide which way to shoot for the next competiton. In the end, this morning I decided to stick with 10metre focus. While I haven't tried the shorter focus lens with normal or sub-normal sight radius, it quickly became obvious that focus on the front sight was far, far too wobbly for my tastes (the reason I stopped doing it in the first place) and was causing much more 'chicken-finger' than usual. This afternoon I shot a bunch of un-counted pellets (turned out to be 29, as I stopped before making myself too tired to shoot at my weekly club outing tonight) with the 10metre lens.

- Below are two targets put together for comparison in a simple animation. One was 38 shots fired in fairly rapid succession on one target, on a day when I felt really good, everything clicking along, good sense of stability. The second was this afternoon, the 29 shots, and I've been feeling rather more shaky than usual today, finding it impossible to settle in properly and watching my hand wobble quite a lot while trying to hold. I had to try and keep my holds below 3 seconds or the shaking would take shots out to the 6 or lower, as evidenced by the several hits in the 7 and 8 rings.



My sense is that today's target is better, with more 10's and slightly better outside 9's. The strays were all badly messed up holds, the ones where I yanked the trigger or just held too long and started shaking a bunch, both because of it being a 'bad day' for whatever reason. Think I need to go for a run.

My first-round conclusion is that allowing for variables outside the longer sight, I like it better. I definitely DO NOT recommend it for shooters who focus on the front sight, as the apparently increased movement when that's in focus is rather unnerving. As I understand it, that would include most shooters, as focusing on the foresight is by far more common. So my next question for the Koreans would be 'are you focusing on the front sight, or on the target?' This could be an individual thing tied to my relative inexperience. Perhaps with the more accomplished hold of a longer-term shooter the increased amplitude of the longer sight radius would be subtle enough not to matter. For what it's worth, with the way I focus and use centre aim, this longer sight radius is a positive move, lending a greater sense of precision to what I'm seeing. To a degree I can feel during a session of practice it seems that I am more likely to abort a shot than previously when the sights aren't lining up the way I'd like, as the sight picture is more exacting, making easier to see when I am on the 10 with certainty.

Of course I'll report back here in a week or two and/or sometime later with further comments as the new sight gets more trigger time.

Gerard,

I will have to commend you on your remarkable talent in the design and construction of D-Bass Instruments. You have a wonderful and interesting web-site illustrating your knowledge and abilities. You are a true master.

Best wishes.

Gerard, don't take my remark bad, but your level of shooting is not comparable/far below the one of the two Korean shooters and as consequence the benefit you and them may have from the extended front sight is probably not comparable too.

I'm well aware of that jipe, and no offense possible. It just seemed an interesting thing to try and I will continue with it for the season and see if it seems to help me improve. Still getting used to it at this time.

Deigeh; Thanks, that work is my core passion, something I've devoted half my life to so far.

[EDIT: I don't normally edit forum posts, but made this one from my phone and spell-correct (Android) managed to substitute 'hope' for 'jipe' so it seems justified to fix it now that I notice.]

I can understand that they prefer a longer line of sight (provided you can hold it steady). But why didn't they just pull back the rear sight? On a Steyr it is very simple to do and the gun will surely fit the box? Has someone an explanation?

My suspicion is that moving the front sight further from the shooter's eye is more useful than moving the rear sight closer to the eye. The longer front sight has a similar effect to lengthening the arm, making for a longer total sighting radius between eye and front sight. Moving the rear sight backwards would only increase the pistol's sight radius, which may or may not be useful, but seems not so advantageous as increasing the total distance from the eye.

By doing it this way, it could be stated as being similar to 'cutting down the angle' in football (soccer) or in hockey, where goalkeepers seek to cover a broader angle against attackers by approaching them. Only in reverse. Taken to an extreme example, by holding the gun much closer to the eye, it becomes less and less possible to accurately align the sights with the target, more and more an exercise in luck. At the other extreme, imaging putting the pistol on a metre-long stick (also imagining that you could hold such a stick for any duration!) - think how this further sighting radius would make it almost automatic to hit the 10 every time. On rifles it is generally considered desirable to have a fairly long sight radius for this reason. If the 'box' rules were not in effect, it could be that we'd see some long, thin pistol foresights going up to a foot or even further towards the target.

Of course the limitations of the eye are in play, and the distance between sights increasing make for a likewise increased difficulty in keeping them reasonably clear to see. Too great a distance between, and without a very small iris to improve apparent depth of field the rearsight could be just a blurred mess, impossible to aim with. I experience some of this problem in my choice to focus on the target; I find this easier to do with the iris on my shooting glasses stopped down quite small, though not so small as to cause edge distortion.

Overall, I see the extended front sight as being of especial advantage for shorter-armed shooters. For such physiques there is the inherently superior stability of the shorter arm with comparable muscular development, contrasting with the relative instability of a much longer arm. My wingspan is 6' 4" (I'm 6' tall) from middle finger to middle finger, and one of the resulting challenges for me with pistol shooting is reducing arm wobble. My youngest brother has about a 5' 11" wingpan, matching his height, and his hold is visibly more steady though he's only shot a little with no related training. I've seen some Asian pistol shooters of rather shorter height (5' 6" or less) whose holds look almost statue-like. In such a case, the extended foresight would offer a distinct advantage, where for me it's something of a challenge to use if I focus on the foresight. I might actually benefit from using a shortened foresight were I to choose instead to focus on that, than the target as I happen to prefer.