The front bbl block is in the way. Everything in the lower/upper slide is designed around that block. As you can see the upper shroud is designed to be held in place with a screw that goes into that block By the front sight/flat headed screw).
Those pistols would make a poor host for a can coupled with they are ammo specific. Americans got their hands on these and destroyed them in short order. The izh-35m was designed for match grade ammo that is in the 1000fps range.
When they 1st were imported into this country the russian ammo came with it. The cheap combo of the russian pistol/ammo took many shooter to the sate level and not only allowed them to compete but they were actually winning at the state level. pictured below is a picture of that combo.
Americans can't wrap their head around actual target ammo that was used in the 70/80.s. So they put sv ammo (cheap pistol cheap ammo right?) or US "target" ammo in them. The US "target" ammo was 1100fps/1150fps ammo used to function s&w 41's, 1911 conversion kits, high standards, etc.
The higher pressured ammo easily destroyed the soft steeled izh-35m's. To put it in perspective:
When you need a new main spring for a izh-35m you buy a high standard supermatic spring and cut it in 1/2 and put 1/2 that spring in the izh-35m.
When you want to rebuild the mags for the izh-35m you buy mad springs for the 10round high standard mags and again cut them in 1/2. & use them in the izh-mags.
The izh-35m are designed for 1000fps target ammo and the springs and steel are setup that way.
The cheap russian target pistols are best when they re used to do the shooting events they were designed for. They can and will provided decades of quality range time if used properly with the correct ammo and maintained properly. Adjustable sights, 4-way adjustable triggers, grips that fit like gloves & extremely accurate. A couple of the russian pistol I like to shoot.
top: izh-46m 10m pellet pistol
middle: izh-35m 25m sport pistol
bottom; toz-35m 50m free pistol
You'd be better off buying the new 22lr pistols that are comming out with the bbl's already threaded or buying a bbl for a ruger or a 1911 conversion kit. They can easily handle the us sv/target ammo that would destroy the izh-35m