I own two Savages with .243 AI barrels, both from Shilen. One a 8 twist, the other a 10. I learned long ago that I could swap brass between the two. Probably because they were purchased so close together and the reamer used was likely close in size when each barrel was made.
Even though Sierra has had the 110 grain bullet for a while, I just found out about it months ago. Gave it a try in the 8 twist, but didn't like the results. One quick call to James at NSS and I had a 7 twist Shilen in .243 AI coming.
Ooooh. Wouldn't it be nice if I had fire formed brass waiting for the barrel?
Purchased 100 pieces of SRP Peterson brass, turned the necks for my .270" barrels and soon to be had barrel, loaded them all up and shot some prairie dogs, jack rabbits, one coyote and a few targets between both barrels I currently had.
Deprimed, cleaned, annealed and placed all 100 pieces of ready to go Peterson brass back into the graciously supplied ammo box that came with the brass. I even put the foam pad back in there...just in case.
Then waited for the new barrel to arrive.
"Christmas came in July", quoted from another post title on here. Grinning from ear to ear to read his post, I knew that I was going to be granted a present as well.
My long awaited barrel showed up yesterday! Unfortunately, my work kept me from molesting it when it did arrive and even after getting home later in the evening, I was too tired to even pull the wrapping off. Finally, with some free time today, I tore open the package to see the new beauty.
TLDR, Skip to here.
I sat the barrel on my reloading bench, grabbed a piece of fired formed Peterson brass (from another barrel(s)) and tried to insert it into the chamber.
Not even close! Ok, let me FL size it, bumping shoulder .002"....nope. Maybe something goofy with that piece. Grab another, resize, nope. 
Grab the material and made a chamber cast. Found out my .200" mark was .002" smaller than what my sizing die was able to achieve. Google small base .243 AI dies....nothing. Remember reading recently about using another cheap die to make a small base die. I have a Lee 30-06 die that I haven't used for years and don't plan on using again. Cut, whack, lathe, I now have a small base (sort of) sizing die. My .200" mark is now .0015" smaller than the cast I made. Case falls right into the chamber, but looks a little long.
Grab my Go/No-Go gauges. Plop them in and record protrusion lengths. Can't remember exact numbers right now... ~.0025" between the two and then the newly sized case. ~.013" difference! Befuddled, I grabbed my two guns. Go gauge, perfect on both of them. No-Go, bolts close 1/4 of the way on both of them. Newly sized piece of brass falls in both of them and so do the bolt handles. Now I am really wondering WTF?
STILL TLDR, skip to here.
I pulled the 8 twist barrel and screwed the 7 twist on making sure the Go gauge fit without issue and that the No-Go stopped at the exact same spot of the bolt handle throw as it did on the 8 twist. Prepped a piece of .243 brass and loaded it up. Fired it off into some sand and did some measurements. .010" shorter from base to datum using the 400 Hornady gauge compared to the other pre-fire formed brass. Yet, the Go/No-Go gauges were identical on all three (or really worry about these two screwed onto the same action) barrels.
Summation:
Even though Sierra has had the 110 grain bullet for a while, I just found out about it months ago. Gave it a try in the 8 twist, but didn't like the results. One quick call to James at NSS and I had a 7 twist Shilen in .243 AI coming.
Ooooh. Wouldn't it be nice if I had fire formed brass waiting for the barrel?
Purchased 100 pieces of SRP Peterson brass, turned the necks for my .270" barrels and soon to be had barrel, loaded them all up and shot some prairie dogs, jack rabbits, one coyote and a few targets between both barrels I currently had.Deprimed, cleaned, annealed and placed all 100 pieces of ready to go Peterson brass back into the graciously supplied ammo box that came with the brass. I even put the foam pad back in there...just in case.
Then waited for the new barrel to arrive."Christmas came in July", quoted from another post title on here. Grinning from ear to ear to read his post, I knew that I was going to be granted a present as well.
My long awaited barrel showed up yesterday!
Unfortunately, my work kept me from molesting it when it did arrive and even after getting home later in the evening, I was too tired to even pull the wrapping off. Finally, with some free time today, I tore open the package to see the new beauty.TLDR, Skip to here.
I sat the barrel on my reloading bench, grabbed a piece of fired formed Peterson brass (from another barrel(s)) and tried to insert it into the chamber.
Not even close! Ok, let me FL size it, bumping shoulder .002"....nope. Maybe something goofy with that piece. Grab another, resize, nope. Grab the material and made a chamber cast. Found out my .200" mark was .002" smaller than what my sizing die was able to achieve. Google small base .243 AI dies....nothing. Remember reading recently about using another cheap die to make a small base die. I have a Lee 30-06 die that I haven't used for years and don't plan on using again. Cut, whack, lathe, I now have a small base (sort of) sizing die. My .200" mark is now .0015" smaller than the cast I made. Case falls right into the chamber, but looks a little long.
Grab my Go/No-Go gauges. Plop them in and record protrusion lengths. Can't remember exact numbers right now... ~.0025" between the two and then the newly sized case. ~.013" difference! Befuddled, I grabbed my two guns. Go gauge, perfect on both of them. No-Go, bolts close 1/4 of the way on both of them. Newly sized piece of brass falls in both of them and so do the bolt handles.
Now I am really wondering WTF?STILL TLDR, skip to here.
I pulled the 8 twist barrel and screwed the 7 twist on making sure the Go gauge fit without issue and that the No-Go stopped at the exact same spot of the bolt handle throw as it did on the 8 twist. Prepped a piece of .243 brass and loaded it up. Fired it off into some sand and did some measurements. .010" shorter from base to datum using the 400 Hornady gauge compared to the other pre-fire formed brass. Yet, the Go/No-Go gauges were identical on all three (or really worry about these two screwed onto the same action) barrels.
Summation:
- I wasted a bunch of time and money trying to make things easier on myself. Learned I will probably need a custom set of dies for this barrel or just maybe shaving down a shell holder will do the trick.
- Shoving the fire formed brass down .010" doesn't sound good.
- Go/No-Go gauges don't always tell the truth about a chamber.
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