I brought home this L579 243 Heavy barrel FI last Sunday. I was getting ready to load some "first rounds" with hopes of finding some fine accuracy.
As a first step, I pulled my Hornady Comparator and set it up with a .243 win casing and a Fowler 80 gr match bullet. I find that it hits the lands almost 1/8 inch beyond the end of the case mouth. I then selected a Speer 105 gr spritzer. This hit the lands exactly at the end of the case mouth. To the outside of the case mouth.
What the heck, this is a 1:10 twist barrel, I can't go any bigger bullet. Is this just extreme throat erosion or is this chamber very long throated or long free bored? Is there something everyone else knows about the chambers in late 60's Sako's?
I really don't have any history on this gun. I have never fired a round. I have confirmed the twist (more or less) with a cleaning rod. I don't see any "smith" stamps for an AI or anything plus an AI chamber should still accept a standard 243 to the shoulder.
I am stumped. Can anybody shed any light on this. I have been reloading for 40 years and have never seen the like. Maybe I need to tap the comparator into the chamber to fully seat the dummy casing?
Help if you can.
thanks rch
As a first step, I pulled my Hornady Comparator and set it up with a .243 win casing and a Fowler 80 gr match bullet. I find that it hits the lands almost 1/8 inch beyond the end of the case mouth. I then selected a Speer 105 gr spritzer. This hit the lands exactly at the end of the case mouth. To the outside of the case mouth.
What the heck, this is a 1:10 twist barrel, I can't go any bigger bullet. Is this just extreme throat erosion or is this chamber very long throated or long free bored? Is there something everyone else knows about the chambers in late 60's Sako's?
I really don't have any history on this gun. I have never fired a round. I have confirmed the twist (more or less) with a cleaning rod. I don't see any "smith" stamps for an AI or anything plus an AI chamber should still accept a standard 243 to the shoulder.
I am stumped. Can anybody shed any light on this. I have been reloading for 40 years and have never seen the like. Maybe I need to tap the comparator into the chamber to fully seat the dummy casing?
Help if you can.
thanks rch