Neck turned brass measures .342 and unturned brass measure .343. Both are when loaded with a ..310 180g boolit of the Lyman design 041.The load is 15g of 2400. Both rounds chamber in the Savage mdl11 ok however the .343 round had a little stiffer bolt closure.The question is it safe to shoot this light cast boolit load when the neck diameter as loaded is at the SAAMI max?
.308 Win neck dilema
- Thread starter shuz
- Start date
Joshua
Taco Aficionado/Salish Sea Pirate/Part-Time Dragon
I colored my necks and bullet with a Sharpie marker to locate where the rub was. In my case it was the necks that were too large for my chamber.
I shot a lot of these 7.7x58mm (cast 215gr, over 16gr of 2400) loads before I realized what was going on. I initially thought the bolt closing resistance was caused by jamming my cast bullets into the rifling lands, I was wrong.
In my situation well annealed cases weren’t cracking at the shoulder when fired. However, with non-annealed reformed cases I was loosing 50 percent to cracked shoulders. I thought it was the old brass. So I thought that annealing was the solution.
I now believe that the cracks were caused by the combination of old brass AND the high pressures created by the overly thick necks/oversized cast bullets.
So, in my case both annealing and reaming the necks seems to be the solution.
I shot a lot of these 7.7x58mm (cast 215gr, over 16gr of 2400) loads before I realized what was going on. I initially thought the bolt closing resistance was caused by jamming my cast bullets into the rifling lands, I was wrong.
In my situation well annealed cases weren’t cracking at the shoulder when fired. However, with non-annealed reformed cases I was loosing 50 percent to cracked shoulders. I thought it was the old brass. So I thought that annealing was the solution.
I now believe that the cracks were caused by the combination of old brass AND the high pressures created by the overly thick necks/oversized cast bullets.
So, in my case both annealing and reaming the necks seems to be the solution.
CZ93X62
Official forum enigma
Once that spec is known, I like at least .0015" of diametric clearance on a fired case, and .002" is even better.
No cast bullet experience in 308 Win, but LOTS in 30/30 WCF and 30-06. All of my rifles so chambered have had sufficient neck clearance using factory brass and have yet to require turning or reaming.
No cast bullet experience in 308 Win, but LOTS in 30/30 WCF and 30-06. All of my rifles so chambered have had sufficient neck clearance using factory brass and have yet to require turning or reaming.
Kevin Stenberg
Well-Known Member
Could you pull a bullet from a case that has a tight bolt cam. And see if it is shoulder or bullet problem.
Or if you have a gauge to check shoulder length.
Or if you have a gauge to check shoulder length.
Ian
Notorious member
Where did you find .308 brass with .0165" neck wall thickness? I had to cut; form, trim, and turn military blank brass to get that, and five headstamps of military NATO brass all loads around .336-.337" without turning or even cleaning up the thick side. Commercial runs about .013". Real fun to try and snug up a .345" x .3465" chamber neck.
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SWISS SHOOTER
Banned
I load FedGMM cases with .312 bullets. Size fully prepped case as normal, bell with NOE, seat, fire.
No idea what all the drama is about.
3rd down is 308.
No idea what all the drama is about.
3rd down is 308.
Catshooter
Member
Very nice set! What are the others?
Ian
Notorious member
Pushing 24-2600 feet per second with consistent small groups tends to create drama and an awful lot of hard thinking late at night.
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SWISS SHOOTER
Banned
The M 70 Target rifles are from top 220 Swift, 270 Win, 308 Win and 300 H&H (Bull Gun). Recently added 30-06 as well. IMHO the 2" Unertl scopes they all carry are the best scope for shooting off a bench one can buy for < $2000.
Back in the day, Winchester would make you one in ANY chambering offerred. I missed one in 22 Hornet recently that went North of 5 Grand.
Due to WRA collector snobbery the post 64 push feed models are real bargains.
For example this 30-06 was bought last month from a major auction house. for $650 carrying $250 worth of sights ! With VIG and shipping TMD < $1000 ! I'll sell off the sights, put another 2" Unertl on it and shoot it.
In the same auction a pre 64' twin went for $2700 w/no sights. I want to shoot not impress collectors !
Back in the day, Winchester would make you one in ANY chambering offerred. I missed one in 22 Hornet recently that went North of 5 Grand.
Due to WRA collector snobbery the post 64 push feed models are real bargains.
For example this 30-06 was bought last month from a major auction house. for $650 carrying $250 worth of sights ! With VIG and shipping TMD < $1000 ! I'll sell off the sights, put another 2" Unertl on it and shoot it.
In the same auction a pre 64' twin went for $2700 w/no sights. I want to shoot not impress collectors !
SWISS SHOOTER
Banned
Ah I see. When I want to shoot faster than traditional cast velocities (rarely).I reach for the Bergers. I know Larry Gibson over at CastBoolits.com has done a lot ot of HV research.
.343 round had a little stiffer bolt closure. Unturned neck, is it round? So your chamber neck is more like 345 and the case shrinks. You also might be jamming the nose on a few. Soft alloy can 'expand' the nose a bit when seating. But yes, safe to shoot if the bolt closes OK.