.223 cases not fitting chamber well

[Kenny2001]

Hi all, I have looked all over for somebody having a similar problem and havent had much luck so far. I am reloading .223 from a combination of range pick up brass and my own previously reloaded brass. After I have cleaned, resized, trimmed, deburred, chamfered, and swaged all my pickup brass they all fit perfectly in my Hornandy case gauge.

After seating the bullets about 1/4 of them (seemingly at random) will only go into the case gauge so that the rim of the cartridge is still sticking out. Another 1/4 of them will go that far and the rest of the way with light pressure, and about 1/2 still fit the case gauge perfectly.

I have taken case measurements with a caliper at the neck and shoulder and they seem to be fine, and I know my OAL is good. I am using a Hornandy Lock n Load AP press so I checked it in the case gauge after every step and if its going to go bad its always after bullet seating. I know some brass is thicker than others, but I have had some pieces fit and others not from the exact same manufacturer.

The bullets I am using are Hornandy 55gr sp. I just cant find any reason why they all fit before and afterwards some fit and some dont, regardless of the brass headstamp. Anybody seen this before or have any ideas? I have used a factory crimp die to fix a similar problem on pistol rounds, especially cast bullets, but I dont think I should need to crimp .223.

 

[nicholst55]

"so I checked it in the case gauge after every step and if its going to go bad its always after bullet seating"

To me, this indicates that your bullet seating die is probably turned down too far, and is bulging the case at the shoulder junction. Back it off a full turn, readjust for COAL, and try again.

 

[Straightshooter1]

Hi all, I have looked all over for somebody having a similar problem and havent had much luck so far. I am reloading .223 from a combination of range pick up brass and my own previously reloaded brass. After I have cleaned, resized, trimmed, deburred, chamfered, and swaged all my pickup brass they all fit perfectly in my Hornandy case gauge.

After seating the bullets about 1/4 of them (seemingly at random) will only go into the case gauge so that the rim of the cartridge is still sticking out. Another 1/4 of them will go that far and the rest of the way with light pressure, and about 1/2 still fit the case gauge perfectly.

I have taken case measurements with a caliper at the neck and shoulder and they seem to be fine, and I know my OAL is good. I am using a Hornandy Lock n Load AP press so I checked it in the case gauge after every step and if its going to go bad its always after bullet seating. I know some brass is thicker than others, but I have had some pieces fit and others not from the exact same manufacturer.

The bullets I am using are Hornandy 55gr sp. I just cant find any reason why they all fit before and afterwards some fit and some dont, regardless of the brass headstamp. Anybody seen this before or have any ideas? I have used a factory crimp die to fix a similar problem on pistol rounds, especially cast bullets, but I dont think I should need to crimp .223.

Sounds to me like it's very much having to do with the thickness of the various brass. All brass of the same manufacturer can have a wide variance in their thickness (some manufacturer's brass is worse than others). So, it would be no surprise that some would fit your case gauge and other's don't.

What you can do is check the neck tension of each case to see what kind of differences you're getting. Measure the neck diameter before you seat the bullet and then measure the neck again right after. Then you should see what the range in difference you're getting.

You can always sort your brass by measuring the neck thickness with a micrometer, being sure to use just those that stay within a parameter that avoids your problem. Or . . . you can turn all the necks so they're all the same. Then you shouldn't have this problem.

 

[Kenny2001]

Thanks for the replies, I already tried backing off the seating die and that didnt make a difference. I have checked the neck diameter of rounds that fit and rounds that dont and they are both always under sami spec but I will try checking the neck thickness as well next time I do a batch. I thought maybe the neck tension was high enough that seating the bullet was causing the round to bulge at the shoulder but I measured there and on both good and bad rounds its only about .001 above spec.

I have a heavy buffer spring on my primary AR15 so it will actually chamber them all just fine and I havent had any failures to extract but some of them are extremely difficult to extract unfired. I took out my firing pin and ran a few of the worst ones through my AR and they are really tough to get back out. On the bright side they usually fit the chamber gauge better after cycling through the chamber of my gun.

 

[DngBat7]

I could be missing what you are saying, but have you tried a small base die? Maybe it’s not the necks getting stuck, but the bases. Especially since it’s all assorted range brass.

 

[Kenny2001]

I have not but they always fit the case gauge after sizing so I am pretty sure my sizing die is spot on. Its only after seating that they randomly dont fit. I did a batch of 170 or so recently, checked every one in the chamber gauge and sorted them accordingly. There is no consistent pattern of which fit and which dont. A 5.56 is just as likely to fit or not fit as a .223. Some Hornandy .223 rounds dont fit, some Wolf .223 rounds do. Its a head scratcher. My next step is going to be to try measuring the case wall thickness at the neck. The problem is I dont know whether it will fit or not fit until I seat a bullet, but I guess thats what bullet pullers are for.

 

[SmokinJoe]

It is possible that you are getting some spring back at the base between the time you do the initial sizing/checking and when you do your loading, especially with range pickup brass - just a thought. I agree with the above that it sounds more like the problem is at the base. Next time you get some "fat" rounds, paint them with a marker pen, let them dry and try them in the gage again pushing them in nice and tight. After you take them out examine them for where the ink is ribbed off and that should tell you where the problem is.

 

[243winxb]

What the case gauge checks is different between brands. Some only check head to datum.

Range brass = RCBS small base die may be needed.

 

[243winxb]

On the bright side they usually fit the chamber gauge better after cycling through the chamber of my gun.

I have a heavy buffer spring on my primary AR15 so it will actually chamber them all just fine

The rounds are being sized by the chamber on loading. I have measured a change in the head to datum measurement after chambering a round in a M16A1.

The test round must be sized to get a head to datum measurement longer then your rifles chamber. A shoulder set back of over .001" is possible after chambering.

The short answer is turn the fl die down more. Make sure shell holder/plate & fl die are in full contact at the top of the rams stroke.

**Hornandy Lock n Load AP press - A shell plate may give a different fl sizing, head to datum, at each station. **

The platform/shell plate may flex on sizing. Shimming has fixed some.

 

[Kenny2001]

What the case gauge checks is different between brands. Some only check head to datum.

Range brass = RCBS small base die may be needed.

Willing to give that a shot, for .223 I am using Lee dies and a Hornandy Case gauge.

 

[mikecr]

Perhaps the necks with the range brass had expanded more on their firing. Enough so to cause a false shoulder and prevent interference free insertion into your case gauge. In that event the necks would need to be FL sized.

 

[Kenny2001]

It is possible that you are getting some spring back at the base between the time you do the initial sizing/checking and when you do your loading, especially with range pickup brass - just a thought. I agree with the above that it sounds more like the problem is at the base. Next time you get some "fat" rounds, paint them with a marker pen, let them dry and try them in the gage again pushing them in nice and tight. After you take them out examine them for where the ink is ribbed off and that should tell you where the problem is.

Looks like most of the rubbing is just below the shoulder. Again though it fits the gauge before seating. I have a hard time imagining that there could be enough neck tension during seating to bulge below the shoulder like that, it certainly doesn't seem to take much effort to push the bullet in. Its not impossible though, I did have fewer instances of this problem with the Berry's FMJBT bullets I was using before I ran out and couldn't find more and the boat tail bullets do go in a little easier.

 

[Kenny2001]

Perhaps the necks with the range brass had expanded more on their firing. Enough so to cause a false shoulder and prevent interference free insertion into your case gauge. In that event the necks would need to be FL sized.

Thanks for the idea, I am using a FL sizer and the part of this whole thing that is confusing me is that they always fit the Hornandy case gauge after sizing but randomly do not after bullet seating.

Going to try everybody's ideas, I already had a lee FCD on order but just ordered an RCBS small base die set as well. I had the sizing die cranked all the way down to the shell plate plus a half turn but going to try a little further to account for flex. Also going to pull the bullets on a few of the offenders this afternoon and check their case wall thickness at the neck and outer neck diameter before and after seating.

 

[Uncle Ed]

Your rifles chamber is your best gauge, color a case with a black felt tip marker and chamber it and check for rub marks.

For all you know you might have a defective case gauge. On a tight gauge at SAAMI minimum dimensions if the case mouth is not deburred properly it could hang up in the gauge. Wet tumbling can peen the case mouth and this must be removed or else the case mouth will be larger.

I buy bulk once fired Lake City 5.56 and 7.62 brass and size it first with a small base die to bring the case back to minimum dimensions. The reason for this is the cases were fired in a multitude of different and brass spring back after resizing can be a problem. And pausing a few seconds at the top of the ram stroke reduces brass spring back.

On a semi-auto the resized case should be .003 to .005 smaller in diameter than its fired diameter. This allows the case to spring back from the chamber walls and extract reliably. And ball park shoulder bump on a semi-auto is .003 to .006. Meaning the case needs to be smaller than in a bolt action in diameter and headspace length.

Below look at the chamber reamer dimensions and you will see the AR15 has a large neck diameter. Meaning you do not have a tight neck chamber and you gauge may have a minimum neck diameter.

Below are a Wilson, Dillon and JP Enterprise .223 case gauges with cases reversed and placed base first into the gauge. The JP Enterprise gauge is at minimum SAAMI dimensions and you can see the case does not drop as far into the gauge.

So again color two problem cartridges with a black felt tip marker. Drop one into the case gauge and check for rub marks and chamber the second in your rifle and check for rub marks. Both loaded cartridges will tell you about your problem.

 

[piie]

Just a random thought- could you have some “mild donuts” that is causing just enough tension to cause buldging?

 

[Bill K]

I would say make sure your brass is trimmed to tolerance, after sizing and use a small base die on all the range picked up brass your are using. If it was fired in a AR type rifle, it more than likely has a little too much growth in the base/side of those cases.

 

[243winxb]

they always fit the Hornandy case gauge after sizing but randomly do not after bullet seating

This PTX thing needs adjustment?? Looks like it expands the case neck & drops powder. A powder drop station problem?

I have old Dillon, so just a guess.

This for pistol, but 223 may be about the same?

 

[Kenny2001]

Your rifles chamber is your best gauge, color a case with a black felt tip marker and chamber it and check for rub marks.

Below are a Wilson, Dillon and JP Enterprise .223 case gauges with cases reversed and placed base first into the gauge. The JP Enterprise gauge is at minimum SAAMI dimensions and you can see the case does not drop as far into the gauge.

So again color two problem cartridges with a black felt tip marker. Drop one into the case gauge and check for rub marks and chamber the second in your rifle and check for rub marks. Both loaded cartridges will tell you about your problem.

Its definitely rubbing around the base of the shoulder and just a little bit around the base of the case, about 1/8" up from the rim. Also I tested my Hornandy case gauge by sticking in the round backwards and it sticks out very far like the JP enterprise one. Hoping that a combination of small base dies and a FCD will get me where I need to be.

 

[Uncle Ed]

What make seating die are you using?

And do you feel a lot of pressure seating the bullets.

Have you tried a VLD deburring tool for the inside of the case necks, this deburring tool will aid in smoother bullet seating.

 

[Kenny2001]

What make seating die are you using?

And do you feel a lot of pressure seating the bullets.

Have you tried a VLD deburring tool for the inside of the case necks, this deburring tool will aid in smoother bullet seating.

Its a Lee die set, but I just ordered an RCBS small base die set and factory crimp die. I actually have a Lyman powered case prep station so I chamfer and debur my cases pretty thoroughly. There is some pressure when seating the bullets, definitely more than the 300 BLK or pistol cartridges I do but it doesnt seem excessive. The Berry's .223 boat tail bullets went in very smooth, the Hornandy soft points take a little more force.