Recrown?

Here's a couple of photos of the crown on an old BRNO ZKK 601 in 243.

About to start chasing tighter groups. To date doing about 2.5moa. Just using some cup n core bullets with 2208, 85 and 100gn. Won't go into detail but lots of room for improvement. Next trial is 95gn Hdy plastic tips with 2209 and W760.

But thinking a new crown might be a useful first step

Attachment 289077

Attachment 289078

We need photos that show the rifling just inside the muzzle, ie: the first 3-4mm. A couple of shots taken at a 45 degree angle will give a clearer picture. I would say that first glance of the outside is not promising, quite a bit of fine pitting is visible.

I would think if the crown looks like that you might have a number of other age / wear / care issues to solve

A bore scope image of the bore might be consistent with the muzzle
In which case solve one problem find the next
Repeat...

Well it shouldn't hurt....it's another reason fellas shorten barrels,excuse for recrown....or is it the other way around??? Lol

If it still has the pop up peep its worth while getting the front sight put back on its sleeved but tapered as my 308 one was , also threaded for a can while in the lathe that way its still a good bush/truck gun .

Dug out the borescope. Probably demonstrates an excellent reason for hiding it away lol. Fill yer boots...

Attachment 289105

Attachment 289103

Attachment 289104

A recrown might bring it down to 2.25 MOA! If the rest of the bore looks OK then a careful 8mm counterbore, 10-15mm deep may improve things considerably. The problem with bore scopes is that you see more than you need to get a good picture of what is going on. It is a bit like knowing how sausages are made. If you are looking for real accuracy, then a rebarrel or a replacement rifle is in your future.

does not look like there is much rifling left near the crown?

a barrel.chop or counterbore might indeed help, but there probably are more issues...

Looks likes the poor quality steel CZ used for there barrels when under Russian control might be a goner, I had a 308 of similar vinage that would just hold 2 moa for 3 shots, I sold it for action value

I'd take Gundoc's suggestion of a counterbore, and then wrap a PH jag with cotton and a good smear of Autosol and give the bore a good huck out. You might be pleasantly surprised, and at the very least it won't be an expensive process.

Good luck with it whatever you choose to do.

Counterbore would also save the hassle of having to relocate the foresight.

Yep counterbore is the healthiest option

Well I scrubbed the bore out with a copper solvent. Not sure how much good it did but its certainly bright and shiny, well, at least until I shove a borescope down it.

I made up several loads with 95g Hdy VMAX, 4 rounds per with different powders, 2209, 2208, W760 and 2217. Went straight to max load on all them. Plus some 87gn HP BT and 85gn SP FB with 2208.

The there were no terrible groups for 100m shooting. Some would be spread past 200. One load stood out as far as one can tell with 4 shots. Barrel was cooled to warm between strings. Best load was max of 2208 with the 95gn VMAX. Used these because I had a few. Owner will go to 95g SST and will thread and suppress. So loosing the front sight and coincidentally the suspect front end of the bore and getting a recrown.

Here's the group

Point of aim was black patches to right. Scope to be zeroed.

Attachment 289175