You just may not be able to get all that great of accuracy from your Topper. I had one back around '75 to '77 and never got much out of it. I tried 40 to 50gr bullets, had the trigger lighted to ~2lb; it didn't stay that way long though; and shot up about 4lbs of H110, 2400, 4227, and some 296 and a little BlueDot trying to get it to "shoot", unfortunately, Win680 dissappeared before I could get any to try.
About 2" at 100yds w/40gr Sierra's SMP was about the best I could do, but a T/C Contender I had w/7.5"bbl and 3x "Lobo" scope would match it, or usually better it.
I've had a Ruger m77/22 "carbine", a "botched .22 K-hornet in a Ruger #3, and now have the only Hornet "Keeper", a Ruger M77/22 Hornet KBZ, the stainless/laminated w/med.-heavy 24"bbl.
It is fond of the following loads:
Sierra 40gr HP "VarmintMaster" .224", seated to 1.78" oal.
12.5gr of Hod. Lil-GUN
Winchester "Prepped" cases(neck turned, flash holes deburred and primer pockets reamed-much work! or Sellier&Bellot cases which have an extreamly small flashole (~.060") that required grinding down my decapping pins to load. With the S&B cases, this load will reliably shoot 7/8-1" 5-shot groups, winds permitting.
Winchester Small Pistol primers!
This load gives 3,050fps and has taken a lot of game/varmints including the only coyote I've killed, several fox, and a number of deer!
Hornady 50gr SX .224"
10.8gr AA#1680
Win SP primer
Seated to 1.835"OAL
This load only chrono's 2,480fps, but is an absolute reliable tack driver from mine and several other Hornets I've tried it in. Note that the OAL is very long- dosen't fit any magazines- must be single loaded. I shot a witnessed 5 shot group that measured .4" one calm evening, but have been unable to repeat it, ever! Usually 3/4" to 7/8" is nominal.
Hornady 35gr V-max
11.2gr of H-110
1.720" oal (likes this bullet seated deep! ditto with Rem 45gr HP over 10.8gr of H-Lilgun)
V-max is "screaming" at 3,150fps.
Note my loads for this rifle are bit lower than most published maximums. It has a very tight chamber for a Hornet.
One deer took one to "heart" one evening delivered by my then 13yr old neighbors son. Only ~9" penetration and only plastic tip recovered from "mush" of what was left of deers heart. I DON'T recommend using this load on larger game, but the "kid" insisted on using this rifle/bullet to kill his first deer. I had let him shoot it at the range and he "deerly" loved it. He now prefers/uses the .243 Rem700 I bought him.
This rifle took a LOT of tweaking to get to shoot like this. (Free floating barrel, glass bedding, trigger pull reduction, barrel fire lapping, ect, ect, and LOTS of load testing, and trying three makes of reloading dies.) It still needs a bolt sleave tightening as I've gone through 3 home-made wire shims to keep it tight enough to extract fired brass as it has enough play between the bolt body and bolt head to prevent the cases from being cammed out of the breech requiring a wooden block to rap the bolt backward to achieve extraction.
A common problem with m77/22 Hornets, I'm told. This one's just worse than most, but I'm afraid of what Ruger might do to it if I send it back. I'll just fit another piece of wire from time to time I suppose!