Home Forums Hunting & Shooting Single Shots Picked up my No. 1 this weekend.

Picked up my No. 1 from the gunsmith on Friday. It was a .243 win that I had rechambered to .243 AI. I loaded up some rounds just to fire form some AI brass and I was surprised with the accuracy. 40 grns H4350 under an 87 gr Hornady BTHP shot consistantly under 2.5" I'm not sure why, but I wasn't expecting anything better than staying on paper with the fire forming loads. This is my first AI caliber, and I'm really looking forward to working up a load with it. Anyone have any reccomendations as far as different powders to look at. I picked up a box of the 85 grn TSX bullets. I'm thinking this rifle will be my antelope rig.

I cannot give any advice. But I am quite interested in getting some from you. I have a #1 in 243 win. What was involved in rechambering to 243 AI. Just a gunsmith to use an AI reamer?

Since these are known to have long chambers, seems changing that would be a good choice. Mine shoots okay, 1.5 inches or so with off the shelf ammo. Would be nice to tighten that up a bunch.

I would bet a cup o' Joe, that just improving the chamber to a 243 AE will not change your groups any from the 243 Win. I read the experts to say that a 243 Win is already an "improved" case because the case taper has been largely removed and the shoulder is pretty steep as is. Anyway, if you have the cash and want to spend it, I'd go ahead and see what happens. Let us know the results, please.

All that was required was the gunsmith to run the AI reamer. The cost was right at $100. One thing to consider is the quarter rib on the No. 1. The way the smith explained it to me is they usually turn the barrel during the rechambering process in order to "clean up" the chamber. I'm not sure of the exact reasons for doing so, hopefully someone who is more knowlegable on the subject can clarify on this. To do this step on a No. 1 would be more difficult and more expensive. All this means is that my rifle is not capable of firing factory .243 Win ammo. In order to fire form the brass, I had to create a false shoulder, which is a little more work. All in all, I'm really happy with the rifle so far, it has definetly been a learning experience but I'm enjoying it.

it will probably change nada!!

My fireforming loads in my 223 AI were about the same asthe regular ones

Thanks for the info elchsr.

Just what I wanted to know. And how it shoots now of course.

Good luck with it anyway. I do like my #1's. Feel like everyone should have one at least.

The barrel (on a proper AI rechamber) is turned in so the new chamber can be cut to be snug on a standard pre-AI cartridge. This is done to avoid the precise situation you're in with having to form false shoulders, et cetera.

Thanks for clarifying that mathman. I'll be sure to post the results when I work up a load for it, but for now the salmon flies are hatching on rock creek, and the bugs on the Big Hole can't be too far behind.

to do it correctly the barrel must be set back 1 turn I have had bolt guns in 243 ack and love the chambering my best 5 shot 68 gr berger .087 @100 I dont rember the powder charge but it was n150 vitavouri
the next 243 #1 i pick up will go straight to the gunsmith.