HELP! breech face erosion or normal wear?

[monicataliani]

I shoot a 9major open gun. I used to use 124hps with 7.1 grains of autocomp. I did not prefer that as grip strength is an issue for me as a small girl and the muzzle wanted to flip up and my dot would not settle down. I tried 115hps with 8.6 grains of HS6 and it was better but my dot still didn't track super well and it still was flipping a bit and it was barely making major. I got load data for 115hps with 9.2-9.3 grains of HS6. Wow did that make a huge difference! No more muzzle flip! It is a pretty hot round coming in at 175-179 pf. (All loads using Federal small rifle primers.) Someone told me that I could get breech face erosion using loads that were so hot. So I started really looking at my breech face. I had never inspected it before (newer shooter here) and I have noticed that there is a discolored circle where the primer would be and a couple little chips. Now I don't know if the circle was there before this load change or not. Can someone tell me...

1. if this is normal wear/how much wear is normal

2. what to look for when it comes to breech face erosion

3. what to watch for with pressures and loads for 9major open guns

4. any pics would be very helpful

(I will take a pic and post it so you can see what I mean.)

[Sarge]

Monica My loads are 7.3 WAC with a 121 and with my new barrel my PF went up to 177 from 174. I also use Fed SR's. I have the permanent primer colored circle but no chips cracks etc. I don't think breech face erosion is typically caused by hot loads as much as it is created by primers not deforming and sealing the case. I guess if you punched holes in a soft primers it could happen as well? A few months back I saw a thread about this and it seems there may be some QC issues with some slides lately.

[PaulW]

Oh boy another dreadful breech face erosion issue. What is casing it? Pressure or gas if you will is escaping around the primer and pitting the breech face. What is the strangest part is on my gun earlier in the year I was shooting a minor load with small magnum primers. So the question is what has changed? Your load has and I would suggest asking around and looking a breech faces of other open guns at the next local match. I shot N350 for years at both the old 175 and the newer 165 pf and never saw an issue. I have friends who looking at their gun the BF looks fine. This is a tough on to figure out. Take pictures for us and keep as a record so you can keep track of it in the future.