bc, spend the $20-30 and buy, or borrow, a go-gage and stick a peice of scotch tape on it to check your headspace. At least you will know if that is the problem! If you were close I would lend you mine but for the cost of shipping you might as well buy one. Then, and only then, the correct advice can be given!
223 improved 40° shoulder help.
- Thread starter bobcat93
- Start date
CatShooter
bobcat93 said:
PTG "GO" gauges do not come with the actual headspace measurement on it - when you order it, tell them you want the actual measurement on it - there is no extra charge for it.
Without the measurements, you are no better off than you are now.
MarkS
Silver $$ Contributor
bobcat93,
I have a 223AI, my new cases are tight when chambered. If you have a AI chamber, new brass should be tight. If not you can hold the case tight with the bullet. Hold the bullet tight and jam 0.020" to 0.030" into the lands. I fireform for a 6BRX, it blows the shoulder out 0.100".
Don't use fired brass for a AI, the once fired brass is most likely your problem.
Mark Schronce
I have a 223AI, my new cases are tight when chambered. If you have a AI chamber, new brass should be tight. If not you can hold the case tight with the bullet. Hold the bullet tight and jam 0.020" to 0.030" into the lands. I fireform for a 6BRX, it blows the shoulder out 0.100".
Don't use fired brass for a AI, the once fired brass is most likely your problem.
Mark Schronce
If your die is set correctly to your chamber it wouldn't matter. I typically just use an expanding mandrel to smooth out the necks.
Ackman
Gold $$ Contributor
bobcat93 said:
Your headspace is screwed up. Maybe the chamber wasn't done properly......lots of "gunsmiths" don't know how to cut an AI chamber. Or, you made the brass too short when fl sizing. For your AI chamber, use new brass and don't screw around with once fired stuff. And with new brass DON'T fl size, necksize to make it round and that's it....use a necksize die with an expander ball. Unless it's a tight neck chamber, neckturning isn't gonna do anything. If a new case doesn't chamber with some felt resistance on the bolt handle, it's chambered wrong.
When fire forming used brass you should anneal the case first. I never seen a case separate where yours is on fire forming. The problem I see happens after a few firings happens with over working the brass due to wrong dies or pushing the shoulder back too far. Larry
The headspace on the AI is shorter. A go-gage is more useful and the scotch tape trick will be the no-go.bobcat93 said:
CatShooter
bobcat93 said:
Cuz the neck/shoulder junction is shorter, and the shoulder/body is longer. When you chamber a new, un-formed case, the neck/shoulder junction gets pushed backwards - that is the resistance.
When it is fired, the shoulder/body junction is blown forward (and sideways) - that is where the "improved" part comes from.
searcher
Gold $$ Contributor
I agree with what others said about checking out the gun - and, even if fired in a machine gun, it is possible, but unlikely you would encounter the problems you are having if 1)The brass is annealed prior to the fireforming
2)Bullet is jambed with enough tension so the firing pin doesn't push
the case forward.
3)The load is not overpowered
4)Full-length sized prior to fireforming
Because you are losing so many when fireforming and before the bad effects of continuous excessive shoulder setback can really show themselves in the same manner, I'd look strongly at the above. When setting your shoulder setback clearance, the brass should already be blown forward a great deal as compared to factory new brass, greatly minimizing the amount of shoulder blowout needed when fireforming. To determine whether the brass was damaged, I'd look at the bases for signs of excessive expansion. I used to get case failures on Lake City when fireforming brass newly made into .20 caliber. Doing the annealing first solved the problem. Than I anneal again afterwards. Be sure you are not overheating your cases or that alone could weaken them. When fireforming a lot of calibers - such as to an ackley or 6BR to Dasher, etc., there is a lot of brass being moved around and forward. The same things will happen with those, even with Lapua brass, if everything is not as it should be.
2)Bullet is jambed with enough tension so the firing pin doesn't push
the case forward.
3)The load is not overpowered
4)Full-length sized prior to fireforming
Because you are losing so many when fireforming and before the bad effects of continuous excessive shoulder setback can really show themselves in the same manner, I'd look strongly at the above. When setting your shoulder setback clearance, the brass should already be blown forward a great deal as compared to factory new brass, greatly minimizing the amount of shoulder blowout needed when fireforming. To determine whether the brass was damaged, I'd look at the bases for signs of excessive expansion. I used to get case failures on Lake City when fireforming brass newly made into .20 caliber. Doing the annealing first solved the problem. Than I anneal again afterwards. Be sure you are not overheating your cases or that alone could weaken them. When fireforming a lot of calibers - such as to an ackley or 6BR to Dasher, etc., there is a lot of brass being moved around and forward. The same things will happen with those, even with Lapua brass, if everything is not as it should be.
CatShooter
searcher said:
The firing pin does not force the case forward, the primer firing forces the case forward... like a RamSet cartridge.
The force of a primer by itself, is amazing. I set off a primed case in a heavy stainless steel pot, and the force of the primer alone made a huge, deep dent.
Excessive headspace is your issue I would say. If it's your only gun I. This chambering you can get away with a false shoulder method of seating the bullet firmly into the lands with enough neck tension to hold the case against the bolt face while it forms. This would be the same method you'd use for a dasher or BRX.
I reloaded 100 rounds using Remington new brass. I didn't size it at all. Right out of the box I loaded it, I used kroil and a cleaning patch and wiped each case before firing. Shot all 100 rounds every case looks good with no sign of future issues. I will reload and shoot with out lube and see what happens.
On another note I use redding competition bushing neck dies. I'm only going to size the necks 3/4 of the way.
While using this method will this die bump the shoulder?.. I don't think it will
Does any one use these dies ? I think they are made to only size the neck and leave the rest of the case including the shoulder as is.
Am I correct? That is what the shoulder die is for , correct?.. Thanks.
I was shooting 77 gr. Bthp nosler custom competition bullets, 23 gr. Of reloader 15, Remington 7 1/2 br primers, in Remington new brass. I was getting 2570-2590 fps.from a 24" barrel.
On another note I use redding competition bushing neck dies. I'm only going to size the necks 3/4 of the way.
While using this method will this die bump the shoulder?.. I don't think it will
Does any one use these dies ? I think they are made to only size the neck and leave the rest of the case including the shoulder as is.
Am I correct? That is what the shoulder die is for , correct?.. Thanks.
I was shooting 77 gr. Bthp nosler custom competition bullets, 23 gr. Of reloader 15, Remington 7 1/2 br primers, in Remington new brass. I was getting 2570-2590 fps.from a 24" barrel.
CatShooter
bobcat93 said:
"While using this method will this die bump the shoulder?.. I don't think it will "
No... even if you screw the die all the way down, it will not touch the shoulder.
Don't worry - be happy
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