Brass lengthening- is this about right?

[callgood]

I have recently begun reloading .223 Remington. I started with some new brass (Winchester) and began by trimming it back to 1.75". Most of the untrimmed lengths were 1.752" to 1.756" and I'd say the majority were around 1.753."

After firing, I cleaned up 50 of these to reload, resized them and checked the length. First few I checked were 1.75" to 1.77." From reading my manuals, I knew they would lengthen, but after one firing, this seems like a "lot."

I'm loading 69 grain SMKs to 2850-2850fps and am trimming them to 1.75" to ensure uniform length for crimping with a Lee FCD.

Is this about what you experience after one firing, and given this, how many cycles would you expect before I have to scrap them?

Thanks for reading.........

callgood

 

[mete]

Much of this depends on the chamber dimensions of your gun. You should size the cases to YOUR chamber not anything else. You can also get 'neck sizing only' dies.

 

[callgood]

I should have added, I have a (<1000 rounds fired) Bushmaster. I am using a body die and a Redding Competition Neck sizing die. I checked them with a case gauge before I dropped the powder and they were all ok.

I could seat a bullet in one of the cases I haven't resized and see if using the body die after firing is necessary, but my understanding is that they might not cycle unless they are resized after firing.

 

[Ol` Joe]

Cases in my experiance seem to expand more on the initial fireing then they do per shot with further use.
Always trim after sizeing. The brass "grows" when sized, not when fired. The cases expand outward when fired and sizeing squeezes them down forcing the brass to flow upward lenghtening the case. I usually get 3 or so fireings from full sized brass before it needs to be trimmed. This is brass fired in a bolt rifle and not a semi-auto. Semi-autos have large(r) chambers to insure feeding and this causes the brass to expand more then it normally will in a bolt or single shot. Useing a neck sizer, if possible, will almost eliminate the need to trim. Especially if you use the Lee collet die. You should still check case lenght when reloading but should find you only need to trim every 10 or so fireings.

 

[callgood]

Yes, I know that when I trim pistol brass, I always size first and then trim, and I trim .0005 short because my Lee FCD sizes when it crimps, lengthening the case back to where I want to end up.

In this case, I measured the brass after it had been fired and before I sized it, and found the "growth." I use a neck sizer, but since it's a gas gun I'm having to also use my body sizer (as I said, I'm going to try and chamber one without using the body sizer die, but I'm thinking it will be too tight to chamber).

Good to hear the first firing will grow it the most. If it keeps it up at this rate I'll run out of brass fast.

Any gas gun guys out there who can tell me how many firings they get on average?

Thanks.......

callgood

 

[30Cal]

Any gas gun guys out there who can tell me how many firings they get on average?

A 7.62 Lake City case will go six or eight times. I've also seen complete head separations at four firings. Case life is highly sensitive to the sizing die setting. One sixteenth of a turn on the sizing die will make all the diffence in the world.

Mine grow by ~0.005" each time around.

 

[Nhsport]

Are you cleaning/lubeing your neck insides? I have found a inside neck resizer ball dragging on an dirty/unlubed neck will "drag" and draw out some brass .

 

[callgood]

When I start with new brass I run a neck expander through the necks to push any high spots out. Then I turn the necks to .012 and trim them to 1.75". I began by running them through a body size die (sizes body, bumps neck) but the new stuff isn't touched by the die, so this may be a waste of time. (I reload 9mm, so you can see my spare time isn't real valuable).

I just finished the 50 rounds I referred to above and here's an update.

The two long rounds I mentioned above were the exception. After running the 50 rounds through the body die, only 10 were longer than the original trim length of 1.75." The rest were SHORTER. From 1.745" (shortest, and not many this short) to 1.749." Most were around 1.747-1.748". I use the Possum Holler Kwik Trim (Sinclair) and it suggests using it on once fired brass, but I had wanted to trim the new brass to uniform length so I could compare crimp/no crimp preformance.

I noticed that, although the new brass and the processed once fired brass all went in the case gauge fine, when I trimmed the once fired brass in the trimmer, it was MUCH snugger when I inserted it. I'm thinking the new Winchester stuff is slightly undersized circumfrence wise. I have some new Remington to process and I will compare it with the above experience.

I'm finding in reloading for .223 that, even tho things wind up where they're supposed to it's not always by the route I thought they would take.

 

[Bullet]

callgood

You need to get one of these to measure headspace –

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=477756

You only need to bump the shoulder .002 or .003. This will make your brass last longer. Since you have to bump the shoulder and size the neck you would probably be better off with a full length sizing die (do both at the same time) and save your other dies for a bolt gun. I don’t think you would see a difference if you don’t neck turn either and I don't crimp the bullets either (69gr SMK’s don’t have a crimp groove).

 

[P0832177]

I have to echo the sentiment that you sure do not need to crimp SMK bullets. They were never designed to be crimped! :banghead:
Unless you have custom chambered rifle, of the bolt action variety turning nexts for a factory chambered gun is point less. I mean totally pointless! The chambers are sloppy, and it a semi auto?
Get a headspace gauge, and then use a Type S FL die if you want to control neck tension, but set the shoulder bump for 0.002 to 0.003 shoulder set back enough for reliable chambering.

Heck I have BM 20" A2 upper that with very little tweaking and 69 SMK's and Varget shoot tight groups 100 off the bench. And, that is with segregated LC brass. We all know how sloppy Rem 700's are, and I have had one hole groups with several bullets with little or no work!

You might be making loading hard then it needs to be!

 

[callgood]

Bullet, I'll look into the Precision Mic. I'm familiar with it. It would give me a better understanding of the shoulder issue.

I've about ruled out crimping. One thing I was looking for was setback in my semi-auto, but the Varget I'm using is compressed, so I don't think setback is going to be a problem. I do want to be able to tension the necks so the bolt won't move the bullet forward (or only a short move). I was seeing .002-.003 last trip to the range. Seated to 2.260, this should not be a problem.