It could well be, that's about 6.7 thou"
I'd fit a bullet, measure the neck diameter, remove the bullet and re-measure, if it's the same try carefully loading the empty case with the expanded neck and see if it chambers.
What's the neck wall thickness on both old and new cases?
Rounds won't chamber
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All handloading data posted on Full-Bore UK from 23/2/2021 must reference the published pressure tested data it was sourced from, posts without such verification will be removed.
Any existing data without such a reference should be treated as suspect and not used.
Use reloading information posted here at your own risk. This forum (http://www.full-bore.co.uk) is not responsible for any property damage or personal injury as a consequence of using reloading data posted here, the information is individual members findings and observations only. Always verify the load data and be absolutely sure your firearm can handle the load, especially older ones. If in doubt start low and work your way up.
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phaedra1106
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Re: Rounds won't chamber
There's room for all Gods creatures, next to the mash and gravy :)
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wildrover77
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Re: Rounds won't chamber
The new brass is .17 mm thicker( on two sides) as that is how larger diameter the neck is on a loaded round.
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phaedra1106
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Re: Rounds won't chamber
Yes, the difference in total is .17mm, but what is the actual wall thickness of the neck?, I think they're usually about .012".
The spec for the case gives an OD of 9.11mm so 9.33 seems rather large, if you measure then chamber and re-measure an empty case is there a difference in the neck diameter, ie. is the chamber squashing it to fit but isn't able to do so with a bullet inserted into the neck?
The spec for the case gives an OD of 9.11mm so 9.33 seems rather large, if you measure then chamber and re-measure an empty case is there a difference in the neck diameter, ie. is the chamber squashing it to fit but isn't able to do so with a bullet inserted into the neck?
There's room for all Gods creatures, next to the mash and gravy :)
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wildrover77
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Re: Rounds won't chamber
Started neck turning the cases to the correct dimension.
Bought a Lynn case trimmer to take .4 mm of case length. Now the problem apparently .33 pilots are out of stock in uk and the USA. Have order a .45 pilot and will have to get it machined to size.
Bought a Lynn case trimmer to take .4 mm of case length. Now the problem apparently .33 pilots are out of stock in uk and the USA. Have order a .45 pilot and will have to get it machined to size.
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phaedra1106
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Re: Rounds won't chamber
Be very careful how far you turn down the necks, try and keep around .011" of wall thickness.
Did you measure an empty case neck O/D before and after chambering it to see if it was being compressed by the chamber?
Did you measure an empty case neck O/D before and after chambering it to see if it was being compressed by the chamber?
There's room for all Gods creatures, next to the mash and gravy :)
Re: Rounds won't chamber
One of the problems with neck turning to below standard brass thickness is resizing and accordingly neck tension, reducing the neck thickness to 0.011" will almost certainly mean you will need sizing dies with separate bushings such as Redding, Forster or Wilson to get the beck tension you require.
Lapua brass is usually around 0.0145" to 0.015" at the neck so using the .338 as an example:
0.338 + 0.15 + 0.15 =0.368" so your neck bushing needs to be around 0.368" - 0.002" so 0.368" or maybe 0.367" depending in the tension you require and factory dies will be built along these lines. reduce the overall diameter to .360" and you need a .358" bushing or ten thou smaller.
I usually buy my bushings in sets of three when building this sort of thing so I can get the desired neck tension and I will resort to machining my own bushings in .0005" increments if things are still not where I want them to be.
Lapua brass is usually around 0.0145" to 0.015" at the neck so using the .338 as an example:
0.338 + 0.15 + 0.15 =0.368" so your neck bushing needs to be around 0.368" - 0.002" so 0.368" or maybe 0.367" depending in the tension you require and factory dies will be built along these lines. reduce the overall diameter to .360" and you need a .358" bushing or ten thou smaller.
I usually buy my bushings in sets of three when building this sort of thing so I can get the desired neck tension and I will resort to machining my own bushings in .0005" increments if things are still not where I want them to be.
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WelshShooter
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Re: Rounds won't chamber
I don't want to nitpick, Ovenpaa but I just wanted to correct the statement to 0.366" to 0.367" for OP's sake.Ovenpaa wrote:0.338 + 0.15 + 0.15 =0.368" so your neck bushing needs to be around 0.368" - 0.002" so 0.368" or maybe 0.367" depending in the tension you require and factory dies will be built along these lines.
Re: Rounds won't chamber
Well spotted, that should have read .366"/.365" - Not enough coffee!
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wildrover77
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Re: Rounds won't chamber
Problem solved.
Have neck turned the brass. With a bullet in place the neck diameter is now 9.1mm.
The thickness of the brass at the neck is about .3mm
The rounds now chamber perfectly.
They are still about .4mm to long but that will have to wait until i get a Lyman pilot that fits.
Have neck turned the brass. With a bullet in place the neck diameter is now 9.1mm.
The thickness of the brass at the neck is about .3mm
The rounds now chamber perfectly.
They are still about .4mm to long but that will have to wait until i get a Lyman pilot that fits.
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phaedra1106
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Re: Rounds won't chamber
Good work :)
There's room for all Gods creatures, next to the mash and gravy :)
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