Posted by David Pautler on September 03, 2000 at 12:04:20:
I am currently shooting a 32 S&W long Hammerli 280 SN 101XXX and have experienced a problem where the first shot from a magazine is 3" to 6" higher than the following shots. Has anyone else experienced this problem? Does anyone know of a solution to this situation?
Posted by Paul on September 03, 2000 at 14:46:25:
A friend of mine had the same problem - only his gun put the first shot into the 7 ring low. After several weeks of testing ammo without usable result he went to the Haemmerli factory in Lenzburg (we are in Switzerland here) to complain. Result: they told him to buy a later version of the 280 (3. series, with the screw in front instead of the two bolts), where they solved the problem with some design changes. The old ones couldn't be modified. You can imagine his enthusiasm...
Would be interesting, though, whether somebody else on this planet found a solution to this, there must be some brighter heads around than they have in Lenzburg...
Posted by pilkguns on September 05, 2000 at 11:41:39:
Hammerli did have this problem with some of the early 280s, the barrel did not sit exactly true in the carbon-fiber slide. part of the reason for the change in attachment method. Seems they replaced a few way back, but now that they are totally discontinued I'd doubt getting anything.
As to a cure, I have never personally seen one that did this, but I wonder if some high strength epoxy applied judiciously to keep the barrel from moving. Would take some careful checking before any adhesive was applied.
Posted by David M on September 05, 2000 at 03:42:23:
I sold my early model 280 a number of years ago, but your problem sounds like a chambering problem of your ammo.
Check your ammo chambers fully on closing your slide.If you close the slide slow and carefully (and not let it slam as it would on the next rounds when cycling),it may not chamber fully and this causes ignition and velocity variations giving poor shots.
If your ammo is tight in the chamber firstly check your dies and try resizing after crimping.
Posted by Paul on September 05, 2000 at 11:49:20:
Ok, I did not want to go into the details, but here is what I heard from the Haemmerli guys and some of their test shooters:
The problem is at least twofold. First, you have a barrel which is held in position essentially by a spring, it's not absolutely fixed. If you have differences in slide speed, and you will have differences between the first and the following shots, obviously, the barrel does not always settle down into the same position. This was cured in the later version of the 280, where the upper part is screwed onto the frame instead of slotted in.
Second, nearly all .32s and a lot of other guns don't put the first shot into the same group as the others, because the dirt you collect in the barrel around the case does oxidize during the break between the series. Because of this, the resistance of the case when pushed into the barrel, and, much more important, WHEN PULLED OUT during the first cycle are different, so the movement of the gun is different - and in the early 280s, because of the spring loaded barrel, this is a much more serious problem than in other guns, because the system allows more a bigger variety of barrel movement. NOT ALL early 280s have this problem, it seems to be a tolerance thing like so much else. During the following cycles, the dirt has no time, or always the same time, to oxidize, so the resistance is the same everytime round.
Posted by Neville Cross on September 17, 2000 at 19:57:29:
This problem is not confined to the Hammerli 280,
a lot of semi-auto pistols do this. My theory is that the first round is always chambered gently and subsequent rounds are slammed in by the slide, this pulls the projectiles slightly and as a result they move forward in the case, thus resulting in decreased pressure and resulting drop in velocity. This results in the rest of the shots grouping lower than the first one. try tighter crimping to reduce the pulling effect.
Sponsored by Pilkington Competition Equipment