I am in the process of selecting a caliber for my next upper build, I am leaning toward the 243 LBC. I would like to hear from some of you running this cartridge how you like it and what I should know about loading for it. I am planning on running 95-105gr bullets. What bushing, brass, powder and bullets is everyone running? Thanks for any input.
243 LBC/ 6mm Grendel
- Thread starter 308Garand
- Start date
204 AR
Well-known member
I'll chime in here. I think it's a great choice, it's probably my favorite upper. Here's what I learned about it, some from trial and error and some from Ritch.
I finish with a 268 bushing, using Lapua and Norma brass. On the first neck down I go with a 271 or 272 iirc, you can do it in one but it leaves your necks under sized for some reason with a funny kind of belled mouth. Hard to explain but getting them close on step one and finishing on the second step leaves them nice. I started with less neck tension but that was a mistake that took a while to figure out.
My go to is the 87 vmax at 3000 fps, just because they kill well and I bought 1k of them as seconds for under $6 a box. Before that I loaded 75 hdy hp's, 58 vmax, 55 varmageddons, and 55 ballistic tips. Everything tried shot well to very well. 75's will go 3250 or so, and the 55's can get up to 3600. IMR 8208 is your friend on this one.
A couple tricks to do to your bolt to get it to run right, slightly round the corners of the extractor. It allows it to release the case easier and eject properly. And very important to bevel the ejector rod edges. I pretty much rounded the edge off of mine. If you don't do this the ejector rod catches the edge of the case as it's feeding and it gets hung up.
I finish with a 268 bushing, using Lapua and Norma brass. On the first neck down I go with a 271 or 272 iirc, you can do it in one but it leaves your necks under sized for some reason with a funny kind of belled mouth. Hard to explain but getting them close on step one and finishing on the second step leaves them nice. I started with less neck tension but that was a mistake that took a while to figure out.
My go to is the 87 vmax at 3000 fps, just because they kill well and I bought 1k of them as seconds for under $6 a box. Before that I loaded 75 hdy hp's, 58 vmax, 55 varmageddons, and 55 ballistic tips. Everything tried shot well to very well. 75's will go 3250 or so, and the 55's can get up to 3600. IMR 8208 is your friend on this one.
A couple tricks to do to your bolt to get it to run right, slightly round the corners of the extractor. It allows it to release the case easier and eject properly. And very important to bevel the ejector rod edges. I pretty much rounded the edge off of mine. If you don't do this the ejector rod catches the edge of the case as it's feeding and it gets hung up.
204 AR
Well-known member
Mine is a 22" to give you an idea. Not sure how much you gain but I'd guess 50 or 60 fps for 2 more inches. Mine is 1-8 but actually ordered 1-9 I thought but it shoots so well I'm happy with it for sure.
I have roughly maybe 1650 down the tube? I figured 1400 last fall when I broke my bargain basement bolt. It's still shooting 1" sized groups at 200 yds with good brass. I get some fliers with my 12 time loaded Lapua but none with new Norma. I'm ready to order a replacement to have on hand as this is about the sweetest ar caliber I've seen.
I have roughly maybe 1650 down the tube? I figured 1400 last fall when I broke my bargain basement bolt. It's still shooting 1" sized groups at 200 yds with good brass. I get some fliers with my 12 time loaded Lapua but none with new Norma. I'm ready to order a replacement to have on hand as this is about the sweetest ar caliber I've seen.