Fluctuating Adjustments

[RetatCDude]

Been playing with the 1720T. I have been shooting 10.34 AA pellets at 842fps.
About 25 shots 3000-2000psi.
I had my you know what handed to me at a pistol match in San Luis Obispo in May.
Discovered HT and HS are not staying where they should.
Recently I found that the Crosman 7.9 CPH does very well in the 1720T and I have come up with a tune that is right at 12fpe, perfect for Pistol Class Field Target.
I enlarged the TP to .109.
Yesterday I shot what I considered the perfect string.
30 shots from 2600-1800psi. 801-840-802.
I had removed my custom stock because I couldn't make the adjustments with it on and was using the standard plastic grips and forearm for that string.
Today I put the Steve Corcoran back on shot another string:
30 shots from 2600-1800psi.
755-812-776....for an average of 789fps.....A loss of 51fps.
I am sure the HS or HT or both have moved a bit.
I am going to drill a hole in the back of the Steve Corcorans similar to the hole some of us make on our Ruger 10/22 rifles so we may clean the barrels from the breech. With that hole I can easily check the HS and HT adjustments before each match.
But I am also thinking of using some Purple Loc-Tite on both the HS and HT screws to help hold their positions.

What do you think?

BTW the targets today even with the lower speed were the same as yesterday but it is only at 20 yards so much difference should not be expected....

[CraigH]

Perhaps Vibra-TITE VC-3 - have had it recommend by others.

https://www.amazon.com/Vibra-TITE-213-Threadmate-Threadlocker-Degree/dp/B0088YEGXM/ref=pd_rhf_ee_s_rp_c_0_3/134-1092511-0803430?_encoding=UTF8&pd_rd_i=B0088YEGXM&pd_rd_r=88426062-edd1-4867-a8a5-9edcd442cf75&pd_rd_w=qQBO9&pd_rd_wg=0Rjuz&pf_rd_p=d59c4be5-f193-4660-b12b-ea6611e15f85&pf_rd_r=V2X0VJ006H90SST0J2CF&psc=1&refRID=V2X0VJ006H90SST0J2CF

I'm using this on a Maximus with PRod / Challenger hammer in it.

[RetatCDude]

I don't want it to be permanent.
The red stuff locks it up for good with a bunch of heat to lossen.
The purple Loc-Tite allows for adjustment.
Thanks for advice, though..

[CraigH]

The purpose of VC-3 is to hold, but allow adjustment.

[RetatCDude]

Oh, OK

[CraigH]

Hard to say which is a better solution.    Locktite 222 or Vibra-TITE VC-3.    Not having used the former and limited experience with the latter, I think the Locktite may be better for smaller screws, and Vibra-TITE for medium sized screws.

Looks like a major science project study is needed!   

[RetatCDude]

Ordered VC3.

I will send you a pm...