I have 2 AR's with what seem to be tight chambers. I always have problems with the bolt not going into full battery and I have a hard time ejecting the unfired rounds. But they work fine with new ammo. I started with the Lee dies, full sizing and crimp die at the end, but no good. I have checked and adjusted the Ogive length with the Hornady overall case guage. I have trimmed the cases, I have used the Redding body die (small base), the COAL is at the minimum. The only thing that I think is left, is the shoulder. Could this be my problem? If so, what is the best way to measure and what is the best die to use?
-
Having trouble using the site?
Contact support
Problems Reloading for a tight-chambered .223
- Thread starter SniperJoe
- Start date
Yup, that's why I don't buy Lee dies unless I absolutely have to, they make their dies with min headspace, you might have to send that sizing die back to them and have them shave the bottom off a bit. Had to do that with my 06 and 270 Lee dies, the 270s still aren't quite right, but work for now. You can also take a couple thou off your shellholder if you know a machinist. Yeah, and do not crimp. You're not shooting a firty firty.
Last edited:
Paint a couple cases with a sharpie and chamber them to see where the ink rubs off. Also chamber a dummy round as you go thru your reloading process- after full length sizing, after bullet seating, and after crimping. You could be over crimping which will deform the shoulder enough to not chamber.
Have you got access to a Hornady Headspace Gauge?
You could compare the fire-formed cases to a pulled factory case.
Also have you checked the diameter of the cases you are having troubles with? You could check them with a pair of callipers.
You could compare the fire-formed cases to a pulled factory case.
Also have you checked the diameter of the cases you are having troubles with? You could check them with a pair of callipers.
If you're using the Lee Factory Crimp die that'll be OK, but if you're crimping with the seating die you could be collapsing the shoulders a bit. Or just don't crimp and try a few rounds.
I now use a JP Rifles case gage for a final plunk test on every round before it goes in the ammo can. These are the only gages I found that are actually made with a chamber reamer. MOST others are headspace check gages and are straight-walled inside while the JP's have a tapered interior like your chamber. If it won't go in the JP gage it won't chamber in your gun either. What I'm saying is a regular gage may not catch a bulged shoulder or something that would prevent the round from chambering. I got mine from Brownells.
JP - Gunsmithing and Maintenance
I now use a JP Rifles case gage for a final plunk test on every round before it goes in the ammo can. These are the only gages I found that are actually made with a chamber reamer. MOST others are headspace check gages and are straight-walled inside while the JP's have a tapered interior like your chamber. If it won't go in the JP gage it won't chamber in your gun either. What I'm saying is a regular gage may not catch a bulged shoulder or something that would prevent the round from chambering. I got mine from Brownells.
JP - Gunsmithing and Maintenance
I have a friend who insists on over crimping his 5.56 with Lee dies.
So much that I have seen the necks bloat out with my naked eye.
He has the same problem as you every so often for entire batches of pressed bullets.
Perhaps check the neck of some factory ammo compared to yours with a set of calipers.....or try like mtrmn said and try no crimping on a few.
So much that I have seen the necks bloat out with my naked eye.
He has the same problem as you every so often for entire batches of pressed bullets.
Perhaps check the neck of some factory ammo compared to yours with a set of calipers.....or try like mtrmn said and try no crimping on a few.
I had the exact same problem with my .308 gas gun. I'll share in case it helps you.
In my particular case, I found that my sized cases had a headspace of a fired case. Meaning that even though I was sizing them, I was not sizing enough.
I was using 1x LC .308 that was fired in something that IMHO resembles a football. Seriously, it's a bitch to FL resize these things. I used a Hornady headspace gauge to figure this out. I found measurements as follows:
Factory Hornady 168 MATCH : 1.621 - 1.622
LC 1X in a football chamber: 1.635 (worst case)
Fired brass from my gas gun: 1.624
My original target was 1.624 and that allowed some to chamber and some not to chamber.
I've now set my FL (small base because that's what was in stock) die to size to 1.620. That gives me a few tho of play depending on on the brass or whether I push the handle down all the way, etc.
I loaded 5 cases this way and seated a bullet to 2.800 (which actually varied from 2.799 to 2.804 with a 175SMK). I loaded these up in mags and cycled the gun. Everything ran just fine.
I highly recommend the Hornady case gauge. The embarrassing part of this story, I know better and I've been using these for years for my bolt guns. I just have to learn the hard way.
Hope you get it figured out and running!
In my particular case, I found that my sized cases had a headspace of a fired case. Meaning that even though I was sizing them, I was not sizing enough.
I was using 1x LC .308 that was fired in something that IMHO resembles a football. Seriously, it's a bitch to FL resize these things. I used a Hornady headspace gauge to figure this out. I found measurements as follows:
Factory Hornady 168 MATCH : 1.621 - 1.622
LC 1X in a football chamber: 1.635 (worst case)
Fired brass from my gas gun: 1.624
My original target was 1.624 and that allowed some to chamber and some not to chamber.
I've now set my FL (small base because that's what was in stock) die to size to 1.620. That gives me a few tho of play depending on on the brass or whether I push the handle down all the way, etc.
I loaded 5 cases this way and seated a bullet to 2.800 (which actually varied from 2.799 to 2.804 with a 175SMK). I loaded these up in mags and cycled the gun. Everything ran just fine.
I highly recommend the Hornady case gauge. The embarrassing part of this story, I know better and I've been using these for years for my bolt guns. I just have to learn the hard way.
Hope you get it figured out and running!
Sharpie won't work. Use smoke from a candle instead and smoke the ouside of the case or get some Dykem (layout fluid). Either of those options will work but are shitty compaired to simply buying a headspace gauge. You shouldn't have to crimp at all unless you want to but not out of necessity. If you're having to crimp to solve problems your simply putting a bandaid on a much larger problem...
(hint: Buy a headspace gauge!)
You need to determine whether or not you are sizing your cases enough and setting the shoulder back to an appropriate level. If you truly have a small chamber, a small base die may be necessary. However, the most likely case if is that your chamber was cut a bit on the shorter side and you need to bump the shoulders back more than you are doing currently.
Do you have any known ammo that chambers and extracts reliably? If so, measure the dimensions of it including the use of the hornady gauge to measure where the shoulder is and compare that value to what you've measured from your problematic cases. I can almost guarantee you that you'll see what I am talking about with your shoulders not being set back enough.
Do you have any known ammo that chambers and extracts reliably? If so, measure the dimensions of it including the use of the hornady gauge to measure where the shoulder is and compare that value to what you've measured from your problematic cases. I can almost guarantee you that you'll see what I am talking about with your shoulders not being set back enough.
Similar threads
