New barrel problem(Newbie)
Hi guys,i’m new to the forum but have been reading and learning for a few month now.So i would like to say a big thankyou to all of you for keeping me amused,educated and inspired.
To the matter at hand.I own a Gunpower Stealth with a 12″ LW .22 barrel 😀 and have been consistantly shooting H&N FTT 15.55 gr pellets @ 650fps over the chrony on a 2800psi fill.I ordered a brand new LW 18″ .22 yesterday,which arrived this morning(impressive).A quick clean of the new barrel rifling to get rid of excess production swarf and into the Stealth it went.
Expecting the fps to go up by 90fps i was shocked to find it had gone down to an average 580fps 😥
I have made no new adjustments to the top hat sine the swap,so i’m stumped as to the cause.
Maybe i’m missing something or the barrel needs a bedding in periond before velocity improvements are noticed.
Any ideas anybody?
My five wives.
All Replies
weird, because I gained 200 fps from a 12″ barrel to a 24″, with no TH adjustments.
Ill wait till tomorrow before i start tinkering with the tophat over the chrony cos as usual its raining.
It’s an extra 12″ of friction. I’ve just gone from an 18″ barrel to a 24″ and I lost about 100fps until I did some tweaking.
Thaks Wok,i hadn’t thought of increasing air output.For some reason i just expected the velocity to increase with adding a longer barrel,without touching the tophat.
Ill wait till tomorrow before i start tinkering with the tophat over the chrony cos as usual its raining.
Welcome,
Sounds like you had your valve matched to the length of that 12″ pretty well. You are going to need to adjust the valve to put out more air so it can get you up to velocity.
Read up on how to adjust the top hat in the quick reference section
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Yea,
I’m sorry but i never heard of that either. If the rifle was running well with the 12″, he should gain and easy 110-130 fps with the 18″.
Make sure your tophat is tight and the breech slide is not dragging on the barrel breech.
Lube your breech orings, the breech slide needs to glide on the barrel with no resistence..
And also make sure you are not clipping that shroud.
Good Luck
Tony