Is this normal?

[Pigdog]

Hey guys I got a new/second hand 6.5x47lapua that came with 50 pieces of lapua brass. I just measured the fired brass today and they measure .282-.283. The bushing in the Wilson neck sizer that came with it is .281. I did a search on here and most people reccomend a .288 bushing!!!! A .288 bushing wouldn't even size my brass!!! I sized around 4 cases and they measure .280.5 the previous owner did say the brass was neck turned but I don't have a device to measure neck wall thickness. Is this brass super thin does this seem way out to you guys? I have some lapua scenars arriving this week to see what the neck measures with bullets seated. The other issue is of the 4 cases I sized one ended up with a slight ding right at the edge of the case mouth I used lube on the necks in the Wilson sizer is this likely to happen with necks this thin???

Thanks

 

[spclark]

At mininum those necks have been turned, yes. Ding won't hurt if you can re-round the neck with a sizing mandrel or expander ball. Dings aren't typical but they do happen when cases aren't exactly centered up as they enter the neck bushing.

You can get a rough idea whether necks have been turned by measuring their thickness with a standard caliper, but for more accurate numbers - when turning for instance - you ought to use a ball micrometer.

Best you get/make a chamber cast so you know for sure what your chamber's neck dia. really is, otherwise you won't know 'till you try unturned brass whether you need to invest in a neck turning tool or not. It's easy enough if you can get the barrel dismounted and some Cerrosafe alloy handy.

I have to wonder what happened to the other 50 cases.... They're sold in boxes of 100, unless the seller split a box maybe with someone else?

 

[leatherstocking]

Excess lube can cause dents. You want a very thin coating.

 

[dkhunt14]

You can get close to the thickness of the brass by measuring a loaded round and then subtracting the bullet diameter. Then divide by 2. If your careful with your calipers this will get you close. Isn't the neck diameter of chamber stamped on barrel? Matt

 

[Keith Glasscock]

I'd second the chamber casting. Looks to me like you have a tight necked chamber. If so, you will have to be really good about your loading practices and shoot only ammunition that is correct for that chamber.

From what is in your post, I'd guess that your brass has a .009 thick neck (.018 + .264 = .282). Based on your other information (fired necks .282-.283) Id guess that you are looking at a .284 neck chamber.

If you are not comfortable with that thin of necks, get a good, reputable gunsmith to open up the neck for you.

 

[Ggmac]

If it's a tight neck chamber and you don't want to cut necks , you can have your smith open it up .

 

[hogpatrol]

Checked some Lapua 6.5x47 new and unturned brass. Neck wall thickness is .013 + or - for a loaded round of .290 + or -. That corresponds with your .288 bushing recommendation. More than likely your rifle has a tight neck chamber. If you prefer to just use factory size brass, as previously posted, a trip to a smith can fix that for you.

 

[Pigdog]

Thanks guys as long as when I get the bullets my neck tension is still within normal amounts I will be ok. I was worried that a .281 bushing was going to be wayyyy to much tension but it looks like because the necks are turned that it won't be so bad. I want to soft seat the bullets so I will report back in this week once my bullets arrive to see what sorts neck tension it has.

Thanks

 

[BoydAllen]

FYI, while the tips of your zeroed dial calipers are not the correct tool to measure case neck thickness, just for fun I pulled out a fired Lapua 6.5 x 47 case and measured its neck thickness with my neck mic. and compared those measurements with those taken with a dial caliper. The mic, gave me a range from .0127 to .0135 depending on where I measured around the neck. The caliper was very close with light pressure on the adjustment roller. If you have nothing better, and only looking for a rough answer the caliper is better than nothing, but I would not use it for serious work, like setting a neck turner, or doing accurate measurements of bullet diameters.

 

[spclark]

Pigdog do you have any of those 50 cases fired but not sized?

How do any 6mm bullets you might have fit those fired but unsized necks?

If they're a loose fit (fall right in) your chamber neck may not need turned brass.

If they're a slip fit (tight but still fall in with moderate finger pressure) it's a turned-brass neck. Minimal neck sizing's all that's needed until rounds start resisting being chambered, at which point a body die'll be needed.

If they won't fit easily up onto the bearing surface, but can be pushed in with fingers alone, you're on the edge of not quite enough neck clearance.

A chamber cast will tell you & your gunsmith a lot more than fiddling with just calipers with what you have now.

Where're you at? Maybe somebody here close by you can help...:

 

[Pigdog]

Thanks again guys I do have fired cases that haven't been sized yet and I plan to do what you say I just don't have any 6.5 bullets ATM but will have some this week to try. Thanks for all the tips and advice from others. There is a sticker on the barrel that says 6.5x47l .286nk what would this .286nk mean?

 

[hrlincoln]

I would think it means you have a chamber with a .286 neck.

 

[dkhunt14]

That should be what it means and brass needs to be turned for that chamber. .283 loaded round and .095 neck wall thickness. Matt

 

[Brians356]

An alternative to a chamber cast is to obtain a few pin gages, say .283 through .287 "minus .0002" type, to probe the neck ID. I use a cleaning rod through the muzzle to determine how deep into the neck each gage will go from the breech. You find out the largest gage that goes in all the way to the end of the neck.
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[Brians356]

Best you get/make a chamber cast ... It's easy enough if you can get the barrel dismounted and some Cerrosafe alloy handy.

You need to remove the barrel to cast a chamber? Really?
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[Pigdog]

Thanks guys I will make sure I'm future if I get new brass to turn it so it measures no more than .283 with a loded round.

Another question as this seems to be a tight neck chamber I read in here that the Sinclair chamber length gauge doesn't work properly on tight neck chambers?? I was planning on using one of these to Get an accurate trim to length some of the brass is 3 though over Saami max but most likely is still well within spec if I can use the Sinclair gauge to accurately measure the actual length!!!

 

[rocketron]

the gage dia. is the problem it's to large for the .286 chamber.

 

[spclark]

You need to remove the barrel to cast a chamber? Really?
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No, not always... but it sure makes it easier than if it's on the receiver.

 

[spclark]

Another question as this seems to be a tight neck chamber I read in here that the Sinclair chamber length gauge doesn't work properly on tight neck chambers?

Depends on how tight.

The ring diameter at the forward end can easily be reduced with the gauge in a lathe (best) or drill (do-able but not as easy) with either a cutting tool or fine file. The material they use is a lead-bearing alloy, rather soft.

Knowing when to stop's the trick & for that you need to know what your chamber neck's ID actually is. Casting or pin gauge both work for that.

Not forming a taper on that ring is best too, why the drill idea's a last resort. Typically the transition from chamber neck to leade is cut to an angle so tapering that ring will induce a measure of inaccuracy. More important is keeping your brass a minimum of 0.010" shorter than whatever you find your chamber's length actually is. SAAMI'S more like 0.025" or a bit more depending on cartridge.

Pin gauges can be both hard and sharp at both ends, use with care to avoid scratching your chamber's surfaces if used.

 

[Brians356]

The Sinclair plug is sized to contact somewhere in the middle of the 45-deg transition between the chamber neck and the leade. You'd have to have an awfully tight neck for the Sinclair not to fit easily.

If a pin gage has a sharp edge I use a fine diamond hone to soften it with the gage chucked in a drill press.
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