so ive been back and forth on the AI thing for a year or so and finally decided to go ahead and see whats what for myself..yes im board and ready for some testing LOL
ive read a LOT of mixed reviews on the 260AI and there seems to be about a 50/50 split...a lot of the reviews say they were not getting the claimed AI speeds..others saying its not worth the added work ECT...anyway i figured id start a tread from start to finish,keep it updated as i go and give my thoughts on the subject....for what their worth.
so i sent jim a barrel to have set back in july this year and told him i was in no hurry so when ever he could get to it would be fine...id pretty much forgotten about it and he called last friday very apologetic and said he was getting ready to chuck it up and if i wanted to do anything different...so i told him AI it with .190-.195 free bore and thread it for a break...im hoping to see it by friday(wednesday would be better)so i can get going on this.
i also spoke with Dean(scopeeye)on the phone about this and got some great info from him...thanks Dean!
im going to start on the cheap with this until i decide if im going to stick with the AI or not so heres what i got so far...
barrel...$100 bucks...shilen select match S8 with 2800 rounds throught it...set back and AI'd finished at 26" .190/.195 free bore threaded for a break...this is the first 260 barrel from when i put my short action together...it had a very short free bore so it was never hot rodded and the reason i kept it.
100pcs 243 winchester brass...$54 bucks
redding body die and seater die...$102 bucks
lee collet die....i had but $20 bucks?
JP enterprise recoil eliminator...$99 bucks
i weighed all 100pcs of the win brass looking for the lightest piece and the heaviest piece of the 100...heaviest was 160.4 lightest was 156.3...i then took those two and weighted with H2O and was surprised...the 160.4 piece had and internal capacity or 54.4g and the 156.3 piece was 54.3g before being necked up...260 lapua brass is about 53g so the 243win brass had 1+g more internal capacity before being necked up. i weighed the heaviest and lightest pieces with H2O just to see if there was a big spread and if there had been i would of weighed all with H2O and separated them.
next i measured about 20 neck walls and they were pretty bad before necking up...several were from .0135 up to .015.5 but after necking up they straightened out enough(for now) that im not going to turn them as the came out to .014 to .015 with most being .0145 to .015...the case OAL did shorten quite a bit as most cases measured 2.0345 and after necking up they were 2.0265 which is about right in a 260 but ive heard they shorten with fire forming so i will check after and post what i find...
i use graphite on the necks when i size...works great and no greasy mess to clean up...
i started with a 25cal expander and did 4 cases then ran them through my FL die...then i just ran 4 cases through the FL die...the 4 that went through the FL die only had more consistent neck wall thickness so i just ran the rest through the FL die...before and after necking up...
next i uniformed the primer pockets...i had 15 or 20 cases that the PPs were so tight that my K&M tool took a little off the PP walls near the bottom which made them real hard to hold on to...
before....
after...
tonight i will anneal all the cases so they are soft and fire form well...im going to fire form with 47g of H4831sc,CCI 250 mag primers and 142gSMKs jammed .005 into the lands...my goal is is to get 139g lapuas...140g something or 142gSMKs up around 3000fps accurately.
i will have the dies by tomorrow and hopefully the barrel...im going to use my long action for all of this and if it goes as planed i will order a 260AI reamer and have my barrel thats on my long action now set back and chambered as it only has 705 rounds through it and keep the barrel from jim for fire forming.
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