PSL Ammunition Choices.
This is from InterOrdnance, an importer of these rifles.
I.O. Inc. has determined that the use of old military surplus ammunition in the SSG-97 and SSG-2000 rifles may cause malfunctions and damage due to erratic or excessive pressures caused by long-term and/or improper storage. Therefore, the use of any ammunition without a commercial headstamp or the use of any reloaded or otherwise unsuitable ammunition will void the warranty. Repairs on such rifles will be at the owner’s expense. If I.O. cannot repair the rifle, it will be returned to the owner. For best results, I.O. recommends the exclusive use of commercially loaded 7.62x54R cartridges with 146-150 grain bullets. Heavier bullets are unsuitable and may cause extraction, ejection and feeding problems in the SSG due to excessive gas port pressure.
The following was provided by an AK expert gunsmith:
"I recommend to all users of such a rifle to stop using commercial Sellier& Bellot 7.62x54r and any other heavy ball such as the Bulgarian, Russian or German 54r. The rifle is not designed to EFFECTIVELY handle such rounds and almost everyone having problems that I have seen and fixed in the shop were due to shooting this stuff. They just beat the living hell out of those bolts even with the pin relief cut-out in the rear trunion. The gun is designed to use a STANDARD military 54r with a 147-158 grn bullet. This is a safe range of the 54r standard round to go by when using this rifle. I own a PSL and have never had one problem with it. It is a joy to shoot, quite accurate and the long stroke gas system is surprisingly smooth. I have fixed a wide array of problems for many people, but I must admit that more often than not they were brought on by the operator. Trust me, I have seen some screwy things fall out of the inside of the bolt assembly which I could write pages on, some really hysterical.
Don't get me wrong, I don't want to deter anyone from enjoying their PSL. Just follow this advice, and you should be fine:
1. Use military 7.62x54r ball
2. Keep the inside of the bolt well lubricated (Breakfree® is good)
3. Keep your internal trigger components lubricated and free of residue."
Posted by Jim Fuller of Rifle Dynamics 04-14-2010
The possible damage that can happen with Heavy Ball in the PSL is from the bolt carrier hitting the rear trunion with too much force. The results over time can be deformation of the rear trunion and rear of the bolt carrier. Some trunions can actually shift rearward from the battering.
There are multiple factors involved that can cause the issue,
1. Heavy Ball ammo =180 grain and heavier bullet...
The type of powder used is a factor as much as the bullet weight. Higher pressures in different powders will enhance the battering.
2. Heat treating of the rear trunion/reciever....
If the heat treating on the trunion or the reciever is too soft lightball ammo can cause the same damage.
Factory guns will have proper rivets (right amount of lead vs, steel content) Some of the PSL's built in this country have possible substandard rivets. The PSL requires longer length rivets in the rear trunion than the standard rivets that are available in the US. Most of the US built PSL rear trunions have questionable rivets or they use the standard length rivet which will work but are subject to failure do to the inability of the shorter rivet to properly fill the voids in the trunion/reciever.
4. Strength of the recoil spring (or lack there of)...
If your recoil spring is too weak the bolt carrier will travel too fast to the rear causing the battering with even light ball ammo.
5. Amount of rounds...
A couple hundred rounds is not going to cause the problem. In most cases it will take a few thousand rounds before any failures will occur.
What to look for...
The first sign that you are getting battering will be the imprint of the rear of the bolt carrier on the front of the rear trunion. You will see this within a few hundres rounds. If you notice deforming on the tail of the bolt carrier that is a sign that you have issues somewhere in the system and it will get worse.
The good thing is in most cases the damage can be fixed or avoided as long as you look for the warning signs and don't let it go too far.