HW70

[pmh]

Having not owned one, all I can say is more than likely, but probably not always.

Kind regards,



Phil

[HW70]

I have recently purchased an HW70 from a dealer who had the pistol in storage for at least 10 years. When I test fired it the first time, the first shot group I got was 1-7/16" c-t-c with five shots at 10 meters which I thought is pretty good for a new spring pistol. However, I noticed after a few more shots, the shot groups spread wider shooting high, low, left, and right without adjusting the sights, and also noticed, instead of firing pellets straight through, it was just lobbing the pellets down range, sometimes having the pellet tumble sideways as it hits the target paper I was shooting at. In other words, it wasn't grouping anymore and lack expected pellet velocity. I even had one shot that wasn't able to launch the pellet out of the barrel. All the while, the pistol was dieseling as any new spring gun would.

My question is, is this normal for a new spring pistol like the HW70 or am I having other troubles with the gun?

[pmh]

Sounds normal for a new/stored gun.

You probably need a full tin of pellets through it before it settles down.

Kind regards,



Phil

[HW70]

Would you suggest that I stripdown the pistol and clean the piston cylinder or should I let it be and just fire off a tin of pellets to break it in like you mentioned? I'm worried because the groups I get are erratically spread across more than 6 inches at 10 meters with the pistol seeming to be just lobbing pebbles downrange.

Thanks Phil.

[kj68]

Hi phil that is quite a large spread at 10 yds, I would suggest for safety reasons strip her down and try again, hope you sort it mate,
atb kj68

[pmh]

It depends whether the group is like a shot gun pattern spread over 6", or a reasonable group with the odd fliers spoilling the spread.

If it's shot gunning then I'd strip it down, you could have a damaged piston washer.

Kind regards,



Phil

[HW70]

Groups improved to around 1-1/4 inched c-t-c after cleaning the barrel and lubricating the piston with a very tiny amount of moly paste. I'm guessing it was the soiled barrel that was slowing down the pellets through that caused the erratic groups.

[pmh]

Pistons should really run dry, apart from the inside where it contacts with the spring.

The spring can have a small amount of moly on it, but not too much.

Kind regards,



Phil

[HW70]

I stripped down my HW70 after recurrence of shotgunning. The strip down did not reveal anything irregular as the piston washer looks very new without any traces of wear or tear. During reassembly I applied a very small amount of moly paste to areas where there are metal to metal contact (i.e., spring to piston and piston to piston tube). Then, I fired the HW70 again and the shots grouped well again, but, after a number of shots, it was shotgunning again. So, I put two drops of chamber oil through the chamber port and fired again. The shots grouped nicely once again.

What’s your take on this issue? Is it the piston washer lacking lubrication or is it something else?

[TheWilding]

Just a thought, have you chronoed it?

I've just rebuilt an Original 6M that had been stored for god alone knows how long, and when I tested it I had similar results to what your describing, what I found was the breach seal had become squashed flat after being stored compressed with the breach closed, I added a shim behind the breach seal and gained nye on 100fps.

Its groups are still very random but that is most definitely me, as when I actually do my bit it is very accurate.

From what you describe it sounds like it'll group with a bit of extra power produced from dieseling, then as soon as this wares off its under powered and any anomaly in the system will be picked up by the pellet producing poor groups

Like I say.... Just a thought...

Sean

[HW70]

Hello!

You were right. It was the breech seal that caused the shotgunning. I had a breech seal fabricated out of a special plastic material that has characteristics similar to the standard breech seals.

Test firing the HW70 after the installation of the new breech seals resulted to 1-1/2 to 1-1/4 inch groups at approximately 9 meters. It occasionally punctures sardine cans, too, at 9 meters.

Many thanks to your advise.