OnePivot

Lots of people have tried, they just don't cut the new ultra hard barrels. The barrel ends up smashing the reamer instead. Really have to use a carbide reamer. Mine won't cut into my xd barrel for that matter.

I plunked my PCC barrel when I bought it and ended up reaming it before installing. I would have ran into weird problems, I'm glad I checked.

I was pretty concerned about this, but the reamer makes a significantly different feel once you're at the end of the chamber. It's very obvious and easy to catch. I didn't even cut into the finish.

If it's plunking smoothly and easily it should also spin pretty easily. While yes it's technically headspacing off the extractor, that's not really how you want ammo fitting in a barrel, and passing the plunk test definitely doesn't add too much safety margin. If some brass has a thinner or thicker rim, you still want that ammo cleanly fitting the chamber. How short are you needing to load them?

I used a clymer finish reamer, it cuts to about 1.14" on a regular fmj. I believe Manson finish reamers go closer to 1.17. Just have to be careful to not cut the chamber any deeper. A regular throat reamer will do any depth you want though. I did want to clean up the chamber while I was in there.

There's powder combos that work, but you're closer to pressure spikes, running less gas to the comp, and just increasing recoil for no reason. A moderate +p 147gr load is easy with most powders. Going beyond that is sketchy without a benefit.

I reamed all my guns and load to about 1.12 with a RN. But now 1.12 works with every bullet brand or profile I can find. Before I was loading some to 1.140 and some to 1.090, depending on profile. Now, 1.120" works no matter what. It just makes life easy. I mostly load minor, but not always. Working up an occasional +p load with certain bullets and powders can be sketchy when your OAL is far under any load data. Theres safe workarounds, but reaming takes out guesswork. I bought my own finish reamer, and another thing I'm finding is that a lot of barrels are finished like crap, with out of spec burrs and edges, or poor taper angles into the rifling. Can turn an occasionally wonky gun into one that just works like it should.

The profile is different between brands. Missouri and bayou are fat and need to be loaded shorter than other brands. Blues are probably the slimmest. Summits are on the slim side. Brass monkey might ship you .365" bullets. I shoot 95% coated bullets now. They go faster with less powder, they're cheap, and they're plenty accurate. Not the most accurate, but easily better than nearly any off the shelf ammo.

$240/k is a good price, especially for local ammo with no shipping.

I've shot thousands of summits now. I've shot most coated bullets. Summits are good, the bullets you order will be the same every time. Same size, same finish, same about a grain weight variance. 124s actually weigh 124gr (not 128 like brass monkey). They're on the big side, maybe .3562, but it's not a problem. If for some reason you absolutely need <.3555 bullets or something, summits aren't it. Also the profile is the modern slim profile. Blues might be less fat, but the summit profile is appropriate for short throat guns.

Any of the popular 9major powders will do it. I'm guessing that was 1.080" oal. You're incredibly short for your velocity goal. Dangerously so. Your Glock mags are going to max out around 1.150, and it would be good to use the whole 1.150. Barrel reaming is probably necessary as well. My g3 17 will do xtp's out to maybe 1.130.

Supervel select 124gr is 1050fps/130pf. A 34 might be 135 pf. Its reliable and cheap.

I lightly scuff my lee pins and crank them down. I don't want them slipping, ever. Squirrel daddy pins will punch out norma brass too. Sometimes lee dies need a little polish, but they work incredibly well.

That's a very stubby hp! Xtp's are 0.654, or 0.054" difference. Autocomp load data lists 147gr xtp's at 1.100, so at the same insertion depth, your loaded ammo will be 1.046". I think you need to redo your oal using the plunk method. Fired cases have basically no tension and the bullet gets hammered into the case further than the real max oal. Definitely measure with the barrel out, and using a sized case, gradually pressing in deeper until it plunks. Either way, your 1.04 loads do basically match book loads exactly, so you're not wildly in the weeds or anything. Autocomp is pretty slow too, but if it's what you got there is data. Faster powder would work out better. There's also nothing wrong with a compressed load.

I definitely had less than a 1/4 inch. I ended up short stroking it and don't have lock back anymore, but I don't think I like it. I have a 3d printer and just made a spacer.

I can give that a try, it's easy enough to swap around. Is the difference significant? I figured weight from either would be the same.

That did it. Removed 2 tungsten weights and replaced with steel. 22.3oz now, and runs great. Blowback9 has been spot on besides this. You definitely can go too heavy on bcg/buffer mass.

What's unique about the bcg? Does the article mean it's just a regular ar9 unit, unique from the normal 223 carrier? All the DD stuff I've seen or built has been very well made and finished, but in ways that are inconsequential to actually shooting the gun... It sounds like a regular old ar9 with a kynshot.

Thanks! I think that'll be my next step, to pull some weights out.

Hey everyone, could use some tuning help with my AR9 I just pieced together. Milspec lower and PSA upper. Bk 16" barrel (probably a BA?). BK 14.6oz bgc, kak k spec 9.5oz buffer and flat spring kit, in a carbine tube. 24.1oz total. R&D Colt magwell properly installed with divots for the set screws. Tuned the ejector to sit snugly at the top of bcg. I'm shooting 124gr Everglades plated. They go about 1005 fps in my Glock 17, 125pf on average. Did not chrono in the AR9. Shot 200 rounds today, recoil feels great! I only have a sub 2k to compare to, and the sub 2k kicks like a horse. This AR9 is pleasant and mild. I had 5 or 6 malfunctions total. All were stovepipes, all jammed right at the front corner of the ejection port, locking the bolt shut but sticking out of the gun. Just the brass rim jammed into the port. I had to pry the brass out with a tool. I wanted to write this off as it being a AR9 and I simply needed to tune the ejector that one last bit... But on a whim, I started monitoring ejection, and my brass is dribbling out! Maybe 2-3 feet max. Lrbho works every time without issue. Is my bolt too heavy? Spring too stiff? Both? I don't 100% understand the bcg weight relationship, especially since the bolt locks back and ejection is weak anyway! I don't want hotter ammo. Id actually prefer to go even weaker, it's probably going 1200 fps in the rifle, and 1050fps would be more ideal... But I want to take calculated steps to ensure this gun runs and I already have weak ejection. Blowback9 has been incredibly helpful getting this to 90%. Just not sure how tuning goes when minor of ammo gets mixed in. Thanks!

Honestly, I like plated bullets. They resist shaving more than coated (not really an issue if you flare appropriately anyway) and they don't smoke. You shouldn't crimp the hell out of 9mm regardless of bullet construction, it's not really something unique to plated. I got 2500 Everglades for $125 shipped last year. I'd gladly shoot those exclusively if that was the normal price!

Every time I hear about someone using a MA die, it's involving some type of reloading malfunction caused by the MA die.

Getting below 120pf with whatever you have on hand is going to be very very light ammo. Ive had better luck with 124s cycling really slow, even with lighter springs. <900 fps with a 124 is comically light. E3 powder will build enough pressure and keep speeds down.

My two least favorite powders ever! TG smokes a ton and heats up brass insanely hot. Unique just makes a mess everywhere and still smokes, and really needs to be loaded pretty hot to seal up and burn. I wouldn't give up on coated quite yet. Try basically any other powder besides unique or titegroup. 244 and 231 work, or cleanshot, aa2, sport pistol, n320, n330. There's more, but those all work well and don't billow smoke out.

I'm using a lee six pack with wobbly lee dies and I get .008 max with mixed range brass and almost any bullet. It's not a big deal, sure, but getting .017" seems like the press isn't setup right. Make sure the sizer is set correctly and touching the shell plate. Double check it still touches with brass in there.