Fast14riot
Gold $$ Contributor
A couple years ago, I finally snagged a 700 I had been eyeballing on the consignment rack of my LGS. It sat there for years. 6, to be exact. Was a decent 700 short action repeater, drilled for side mount rear sight, McMillan prone stock, 5-way butt plate, Jewell trigger, sako extractor, and a stainless barrel. Only two reasons it sat there for so long was one, it was ugly as hell! Previous owner dished out the comb (think Speedy's SOD, but redneck), inlet with a die grinder and rattle can painted the red-ish stock metallic purple, but only on the butt, and it had an asking price of $850. And two, only information on the barrel was very nicely engraved "6x250".
When I saw the price was finally lowered to $495, I brought it home. Expecting to toss the barrel, I cleaned it and bore scoped it. It looked like it had barely been broken in! So now I had to try and shoot it. Took a couple pieces of fired Rem and Win 22-250, necked it up and tried them. Fit snug, but could force the bolt closed. Ok, close enough. Checked freebore with some Hornady 105 and 108s, it had enough length, and was a 1:8 twist. Had a full keg of XMR4350 sitting on the back of the shelf that would work perfect for this.
Found a RCBS 6mm-250 FL die on ebay, pieced together a seating die from a Hornady custom with a new sleeve and stem, and got to loading.
After trashing a couple cases with an educated guess on charge weight and a 108° day, I finally found its load range. Picked up some Lapua 22-250 brass and got to loading a ladder.
This is where the caution should have been inserted, however for whatever reason it just passed me by this day.
I never measured loaded neck diameter and fired neck diameter of the previous Rem or Win brass and just went ahead with the Lapua. Well, tonight while loading some fire form ammo for another gun, that box of 6x250 brass was sitting there and I finally decided to inspect it closer. Fired inside neck diameter was ~0.2415"! A bullet would not fit in a fired neck! I have EPS 106 bullets for this gun and they measure 0.2436" at the pressure ring. (Please excuse the calipers for measurement, thats just what would show the diameter in the pic the best)
So now I've neck turned 10 cases down to 0.011" wall thickness to test shoot and fully expect any pressure signs to go away.
To say I was lucky to find my Pmax with the Rem and Win brass first is an understatement. Things could have gone much worse had I used Lapua brass to start and had very hot loads.
6x250 on left, 260Rem on right
In full disclosure, I did hours of research on the burn rate of XMR4350 that I could find, measured brass volume, compared powders of similar characteristics and designed a custom template in GRT to get an idea of where I needed to be, but it was still very hot with my first two rounds giving very distinct ejector marks, flattened primers and I only shot 2 rounds then stopped.
So do yourself a favor, cast unknown chambers and measure! Or, pull the barrel and use pin gages. Verify before you trust it. Even as a seasoned reloader, this error sure gave me a reason to pause working on a load.
When I saw the price was finally lowered to $495, I brought it home. Expecting to toss the barrel, I cleaned it and bore scoped it. It looked like it had barely been broken in! So now I had to try and shoot it. Took a couple pieces of fired Rem and Win 22-250, necked it up and tried them. Fit snug, but could force the bolt closed. Ok, close enough. Checked freebore with some Hornady 105 and 108s, it had enough length, and was a 1:8 twist. Had a full keg of XMR4350 sitting on the back of the shelf that would work perfect for this.
Found a RCBS 6mm-250 FL die on ebay, pieced together a seating die from a Hornady custom with a new sleeve and stem, and got to loading.
After trashing a couple cases with an educated guess on charge weight and a 108° day, I finally found its load range. Picked up some Lapua 22-250 brass and got to loading a ladder.
This is where the caution should have been inserted, however for whatever reason it just passed me by this day.
I never measured loaded neck diameter and fired neck diameter of the previous Rem or Win brass and just went ahead with the Lapua. Well, tonight while loading some fire form ammo for another gun, that box of 6x250 brass was sitting there and I finally decided to inspect it closer. Fired inside neck diameter was ~0.2415"! A bullet would not fit in a fired neck! I have EPS 106 bullets for this gun and they measure 0.2436" at the pressure ring. (Please excuse the calipers for measurement, thats just what would show the diameter in the pic the best)
So now I've neck turned 10 cases down to 0.011" wall thickness to test shoot and fully expect any pressure signs to go away.
To say I was lucky to find my Pmax with the Rem and Win brass first is an understatement. Things could have gone much worse had I used Lapua brass to start and had very hot loads.
6x250 on left, 260Rem on right
In full disclosure, I did hours of research on the burn rate of XMR4350 that I could find, measured brass volume, compared powders of similar characteristics and designed a custom template in GRT to get an idea of where I needed to be, but it was still very hot with my first two rounds giving very distinct ejector marks, flattened primers and I only shot 2 rounds then stopped.
So do yourself a favor, cast unknown chambers and measure! Or, pull the barrel and use pin gages. Verify before you trust it. Even as a seasoned reloader, this error sure gave me a reason to pause working on a load.
