# Splitting cases



## KineKilla (Jan 28, 2011)

I have a Model 700 .270 BDL that appears to be splitting cases after 2 firings even with neck sizing only. I also noticed that the cases grow quite a bit and have to be trimmed back to the Hornady Trim Length each time.

Don't these cases space off the shoulder? If so, wouldn't that help minimize or prevent stretching by neck sizing only? Seems weird to have to trim when neck sizing and that the bright ring (case/head separation) starts to appear after 2 firings (modest powder charges).

Anyone else experience this at all? You suspect I'm doing something wrong?


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## DallanC (Jan 13, 2009)

Sounds like it has a sloppy tolerance in the chamber. You might want to anneal more frequently to keep the neck brass soft... but if its flowing that much material forward that you have to trim each time, that brass isnt going to last at all due to the chamber. 

Mic a spent case and compare it to SAAMI specs (chamber cast is better if you have the means).


-DallanC


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## KineKilla (Jan 28, 2011)

DallanC said:


> Sounds like it has a sloppy tolerance in the chamber. You might want to anneal more frequently to keep the neck brass soft... but if its flowing that much material forward that you have to trim each time, that brass isnt going to last at all due to the chamber.
> 
> *Mic a spent case and compare it to SAAMI specs (chamber cast is better if you have the means).*
> 
> -DallanC


Can you elaborate? I don't have the means to make a cast of the chamber but I have lots of tools for measuring cases.

Unfortunately I think I've found a good recipe for it finally, albeit a bit on the slow side (2,890fps +/- according to the Nosler data)...shoots 3 rd. groups into MOBC (Minute of Beer Cap)

130gr. Nosler Accubond, 52.0g IMR4350, Win Primers, Hornady Brass loaded to published seating depth.


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## swbuckmaster (Sep 14, 2007)

Fire it once is how you make a mold of the chamber. The cartridge will be a perfect replica of the chamber.

Then measure it and see if your pushing the shoulder back to far on your reloads 

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## DallanC (Jan 13, 2009)

KineKilla said:


> Can you elaborate? I don't have the means to make a cast of the chamber but I have lots of tools for measuring cases.












Measure a spent case, see what dimensions are off. Brass will "relax" a little after being fireformed to the max case dimensions, but its a good place to start atm. Chamber cast will get you the actual dimensions, something you can investigate later.

As it is, if its shooting good then great... thats the most important thing. Long brass life is a bonus... but if you are only getting 2-3 firings its not a deal breaker, how many times do you shoot your 270 in a year... its not like a AR15 where you can shoot hundreds in an outing.

-DallanC


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## KineKilla (Jan 28, 2011)

swbuckmaster said:


> Fire it once is how you make a mold of the chamber. The cartridge will be a perfect replica of the chamber.
> 
> *Then measure it and see if your pushing the shoulder back to far on your reloads *
> 
> Sent from my SM-G900V using Tapatalk


I can do this with some of the ones I shot this weekend through it.

*I guess I was naive in thinking that neck sizing only wouldn't bump the shoulder back and thereby reduce or eliminate any further stretching of the case.* I'm using an RCBS Neck Sizer die.

Could also be that the ring I think I'm seeing is not actually the CH separation starting. I have had brass actually split in that same spot in this same rifle before but it was brass I'd shot 3-4 times in a different Mod.700 and FL sized each time.

Because I had experienced CH Separation in this rifle before, I made sure I used brand new brass and neck sized it only after the first firing...brass for this rifle is for this rifle only at this point.

I have a total of 3 - .270 WIN rifles. I have a BDL, an ADL and a Mod. 783. I do not share brass between them anymore.


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## wyogoob (Sep 7, 2007)

Are you using a neck sizing die or neck sizing with a FL die?

.


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## Loke (Sep 7, 2007)

Can you post a picture of the cases that are splitting?


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## KineKilla (Jan 28, 2011)

I'm using an RCBS Neck Sizing die...didn't trust my ability to be effective using a FL sizing die.

I'll get some pics when I get back to town...on the road to Cedar City today.


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## KineKilla (Jan 28, 2011)

These shiny ones have now been fired twice from the same rifle. FL sized when they came new from the box, then neck sized after the first firing.

The third pic is of a split one that was fired in this gun a while back after reloading it 3-4 times with a FL sizing each time. 

That is what has me worried, and what made me start neck sizing fire formed, rifle specific brass in the first place....don't want that to happen again!


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## DallanC (Jan 13, 2009)

Woah I thought you were splitting necks. Head seperation is bad mojo... usually its due to a very sloppy oversized chamber. You might be getting so much stretch after the first shot the case is nearly compromised. What does the base of the case to the start of the neck mic out at?


-DallanC


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## Loke (Sep 7, 2007)

Probably a headspace issue. Take it to a good gunsmith and have him check it for you. They should have a set of go/no go gages that should identify the issue. Then they can set the barrel back a thread and rechamber to the proper headspace. I've heard good things about Night Owl gunsmithing. I think they are in Salt Lake county.


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## KineKilla (Jan 28, 2011)

Sorry, thought I mentioned case head separation in post #1.

The one I had actually separate was fired a few times in a different rifle then full length sized each time prior to shooting it in this rifle, that's when it separated.

The other ones pictured have been fired twice and neck sized only. Only fired in this same rifle as well. I really didn't expect this much stretch when neck sizing as I was under the impression that after the first firing it was kind of done and formed to the chamber so no more room to stretch.

I'll get a hold of a gunsmith and have them check the chamber specs. It was my dad's rifle for years and passed to my son when he died but my dad only shot factory loads. Now that I've found a good load that works in this rifle, I suppose I could just load virgin brass for it and toss them after one use...not ideal but I'd still get better than factory loads for less cost.

Base to neck appears to mic at 2.1750. if I use my Hornady case comparator it shows 2.043 but that's further down the shoulder.

*EDIT: Night Owl GS doesn't answer their phones and it specifically says not to leave a message. Any other good smith's in town I could try? *

*Edit Edit: Got a hold of them ad tried to explain the problem. First thing he said was "Well the first thing to do is make sure the barrel is still good." Can't say that boosted my confidence in them, but I'll take it down there anyways. I'm not buying a new barrel for a gun that shoots great.*


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## KineKilla (Jan 28, 2011)

Because I found myself with spare time last night, I took my dremel and opened one of the suspect cases up to see just how thin it was getting.

It's hardly thinned at all and I loaded 10 of them and they shot great at the range. I think I won't push my luck any farther than 3 reloadings in this rifle though just to be safe.

I believe this load is the sweet spot for this rifle. It's putting 5rd. Groups in about an 1" and 10 round in less than 2" even in today's wind. I don't have a lead sled, just a cheap rest.

.270 WIN
130gr Accubond
52.0g of IMR4350
Winchester LR primer
Seated 2.751 (to Ogive), 3.32 OAL
Estimated 2,890fps

*This is only 1gr. above published minimum for this load and powder.

I think those light marks are from the chamber scratching the case or from the die since I FL size them when I take them out of the box. Maybe the chamber has some rough spots there from when a previous round actually had case/head separation.

I'm still going to drop it off for a full inspection just to be sure. Maybe they can clean up the chamber if nothing else.


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## swbuckmaster (Sep 14, 2007)

KineKilla said:


> Sorry, thought I mentioned case head separation in post #1.
> 
> The one I had actually separate was fired a few times in a different rifle then full length sized each time prior to shooting it in this rifle, that's when it separated.
> 
> ...


JD presision arms did my rifle. He lives in west valley. Took about a week to do. You can look him up on face book under JD presision arms.

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