I never stop learning or making mistakes.....

BillK · August 18, 2016, 01:16:18 AM

I have had a habit of leaning my thumb on the barrel of a gun while shooting off a rest. I especially do that when shooting off a bag, compressing the bag a bit with my thumb on the barrel, to get the crosshairs "just right". This has worked for me for years.
Then I got a 1720T and a new rest. (floated barrel & solid rest)
So I did the same things with a MTM K-Zone rest and a 1720T. My shots were very close but not like a LW barrel and a solid rest should be. Especially concerning was that they were not consistent.
Having bought the gun "used" I figured that the barrel was poor and that was why the gun was sold. So I bought a new barrel from Crosman, installed it and SOB it was doing the same thing. WTF
After many shots and many different pellets it finally dawned on me that when I used my thumb on the barrel the POE changed while the POA was the same.
Unsupported/ floated barrels DO NOT like to have a thumb adjusting the gun at all. The barrel will flex and the POE will change. This never happened with guns with barrel bands.
Only cost me $70 to learn this lesson. Hope this helps someone else.....

WyoMan · August 20, 2016, 03:37:11 AM

Nor do I... thanks for sharing

Bill, if you ever want to re-purpose that extra 1720 barrel (for a 17xx or 1377) send me a PM or email. Simple job... cut off the leade-in / port, and re-port and taper.

mudduck48 · August 20, 2016, 04:26:52 AM

Sounds like a good lesson learned.

agninja · August 20, 2016, 05:52:49 AM

You didn't waste the money, you just paid to learn information. That's how I look at it. If you hadn't paid then you would've never known for sure what the issue actually was.

Tater · August 20, 2016, 07:25:01 AM

Sorry it happened Bill, but thinks for sharing some good info.

BillK · August 22, 2016, 04:13:44 AM

Quote from: WyoMan on August 20, 2016, 03:37:11 AM
Nor do I... thanks for sharing
Bill, if you ever want to re-purpose that extra 1720 barrel (for a 17xx or 1377) send me a PM or email. Simple job... cut off the leade-in / port, and re-port and taper.

That's about the best thing that happened is that I have a 12" LW barrel. The lead will need a little taper but the Transfer Port lines up fine.
Now, what to put it on?

Redleg · August 22, 2016, 11:09:27 PM

A former supervisor once told me that "Lessons cost varying amounts". He was so right!

KevinP · August 22, 2016, 11:31:25 PM

Quote from: Redleg on August 22, 2016, 11:09:27 PM
A former supervisor once told me that "Lessons cost varying amounts". He was so right!

So true is that ...

WyoMan · August 23, 2016, 02:48:16 AM

Quote from: BillK on August 22, 2016, 04:13:44 AM
That's about the best thing that happened is that I have a 12" LW barrel. The lead will need a little taper but the Transfer Port lines up fine.
Now, what to put it on?

That's great news, Bill.... You may need to drill / ream the barrel port to .140", or a bit more for a Co2 build.
Let me know if you need one of these:

It's .250" o.d. and will fit the barrel port C-B

Can't help you with "what to put in on", but you could always get another gun... to make the decision easier