Resizing primed brass with SB 5.56mm RCBS die

[akbluz]

Here is one for the "Brain Trust" reloading folks.

I have a Ruger AR556 stock rifle. I have been reloading for it for a couple of months. I reloaded some .223/5.56 brass and checked them with my case gauge and the rounds seemed to me like they should feed/fire OK (these were sized/reloaded with regular RCBS dies). When shooting I had several rounds that didn't chamber completely. However these rounds fired just fine when I tried them a 2nd time. (I also tried different magazines with the same results.)
I now have a set of Small Base RCBS dies to use but I have quite a few rounds that I have already sized with my regular dies & primed. I plan to resize this brass with the SB dies. I could remove the Decapping Rod, Pin Holder, and Decapping pin assembly to protect the primers while resizing. My concern is that the mouth of the brass will be "squeezed down" and won't be expanded out to size to accept a bullet when seating.
Should I leave the Decapping Rod Assembly out and not worry about being able to seat 55grain FMJ bullets - or - should I remove the Decapping pin from the bottom of the Expander/Rod assembly in the die so as to expand the mouth of the brass to accept a bullet without incurring problems with bullets seating.

I planned to contact RCBS today but I waited too late. I can call/email them on Monday to see what they say.

I'd be interested in your thoughts.

akbluz

 

[contender]

I'd remove just the pin & resize them, allowing for the neck expansion.

 

[Jimbo357mag]

I think the decapping pin is there to take irregularities out of the case mouth and not to expand it. Pull the de-capping pin out and try a couple and see.

 

[Chuck 100 yd]

Don't forget to lube those cases. Small base full length sizing dies will jam tight
easily. Removing the primer pin will allow you to resize without removing the primer.

 

[mikld]

Yep, like the guys above said, just remove the pin but leave the stem with the expanding ball...

Kinda curious about this though;

However these rounds fired just fine when I tried them a 2nd time.

Did the feeding of the case into the chamber allow for a second try to fully chamber the round? Did the rounds chamber OK on the second try? I might look for something else, another reason for chambering problems...

 

[Clovishound]

Yep, like the guys above said, just remove the pin but leave the stem with the expanding ball...

Kinda curious about this though;

However these rounds fired just fine when I tried them a 2nd time.

Did the feeding of the case into the chamber allow for a second try to fully chamber the round? Did the rounds chamber OK on the second try? I might look for something else, another reason for chambering problems...

I would be checking for the bullet contacting the lands, and then getting set back. I had lots of problems with bullets not having enough tension to properly hold them using RCBS dies in 30-06. Tried everything including calling RCBS. Ended up adding a collet style crimp die and that solved the problem. Not saying all RCBS dies have this issue, but mine did. Bullets contacting the lands when chambered are a recipe for over pressure.

 

[akbluz]

After seating the bullets with my regular RCBS die, I used the Lee FCD to put a crimp to hold the bullets in place in the brass. These cartridges were mic'd at about 2.240 OAL - less than the max 2.260 by 0.020. I did not mic the rounds again in-between the first time they fed into the chamber from the magazine but when some did not go into battery versus the 2nd time they fed into the chamber from the magazine OK. (I used the "mortaring" technique to eject the rounds which were not fully chambered). The I reloaded them into the mag(s) and they chambered fine the 2nd time. All the rounds had plenty of room when I loaded them into the magazine(s) each time. I used both the supplied P-Mag that came from Ruger and also a Lancer mag I bought later.
Needless to say I was a bit puzzled. But I think it probably goes back to the brass being properly sized.

The rifle feeds/fires the factory ammo I've tried just fine - I've only had problems with some of my reloads. But most of my reloads have fed/fired just fine.

 

[Mobuck]

It should be safe enough to resize the cases by simply removing the decapping PIN (leaving the neck expanding rod in place).
Regarding not expanding the neck: my "sequential" loading set-up works very well w/o the decapping assembly(all of it) when seating boattail bullets or bullets with a noticeable radius at the heel.

 

[mikld]

Hmmm. I think I'd measure the "bad" rounds and see where the cartridges are too big. Mike the OD in several places, or perhaps mark some rounds w/marker and see where the cartridges hit that keeps them from chambering. Mebbe it isn't a sizing problem...

 

[Jimbo357mag]

When shooting I had several rounds that didn't chamber completely.

I found this thread interesting because I have 4 rounds of 308 that won't chamber in my bolt gun. hmmmmmm I pulled the bullets and powder and checked the case OAL and then pulled the de-capping pin on my sizing die and re-sized the cases and the cases still will not chamber except for one that was real hard to close with the bolt. I am going to trash them. I have spent enough time on them.

 

[Mobuck]

I have a complete "batch" of .223 ammo loaded in cases that didn't get properly sized due to a worn die. About 10-20% would either not fully chamber or would chamber but could not be extracted unfired from most of my AR rifles. I marked the entire "lot" for use in my "never chokes on anything because it has a loose chamber" rifle(it's a COLT btw) and moved on. I could mess around running the batch through the sizer again and charging/re-seating bullets but I'm not sure it's time efficient when I can just shoot them through the designated rifle and start over.

 

[mikld]

FWIW; I had "problems" with some of my Garand brass no fitting in a Hornady gauge. I tried adjusting the sizing die, sorting the brass, sizing, turning the case 1/3 turn, size again, turn and size again. I still got brass that would not "gauge". After some frustrating attempts I noticed a small dent on the case rim. The cases were hitting the Op Rod handle on their way out and the resulting ding would keep the cases from fitting into the gauge. Various loads would eject differently so the ding was not consistent which caused confusion too. I put the gauge away...

 

[akbluz]

Thanks for all your replies. I'll be resizing a bit of the brass with the depriming pin removed. After checking with the case gauge, I'll load some powder/bullets and see if the rounds feed/chamber/fire OK. I've got my fingers crossed that will solve the problem.