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.338 LM shoulder bump gauge inner diameter?
Posted: Mon Jul 09, 2018 8:51 pm
by Brian838
I was wondering if anyone uses a shoulder bump gauge for .338LM, could tell me what inner diameter should be?
I have a Hornady comparator body already so I bought the shoulder bump insert recommended for magnum cartridges (.420 ID). This only measures a few mm past the neck at the start of the shoulder though.
Cheers,
Brian.
Re: .338 LM shoulder bump gauge inner diameter?
Posted: Tue Jul 10, 2018 9:37 am
by rox
Brian838 wrote:I was wondering if anyone uses a shoulder bump gauge for .338LM, could tell me what inner diameter should be?
I have a Hornady comparator body already so I bought the shoulder bump insert recommended for magnum cartridges (.420 ID). This only measures a few mm past the neck at the start of the shoulder though.
There's a Sinclair 'bump gauge insert' that is based on a 20 degree shoulder angle, rather than a diameter.
https://www.brownells.co.uk/SINCLAIR-BU ... -749011478
There's also a Giraud comparator, but I can't find out how it indexes - maybe worth asking them.
http://giraudtool.com/338comp.htm
Looks like the SAAMI datum (corresponding to headspace datum) would be .476, but it has no corresponding CIP dimension (being a CIP standardised cartridge).
https://saami.org/wp-content/uploads/20 ... f#page=128
..
Re: .338 LM shoulder bump gauge inner diameter?
Posted: Tue Jul 10, 2018 5:50 pm
by Brian838
rox wrote:Brian838 wrote:I was wondering if anyone uses a shoulder bump gauge for .338LM, could tell me what inner diameter should be?
I have a Hornady comparator body already so I bought the shoulder bump insert recommended for magnum cartridges (.420 ID). This only measures a few mm past the neck at the start of the shoulder though.
There's a Sinclair 'bump gauge insert' that is based on a 20 degree shoulder angle, rather than a diameter.
https://www.brownells.co.uk/SINCLAIR-BU ... -749011478
There's also a Giraud comparator, but I can't find out how it indexes - maybe worth asking them.
http://giraudtool.com/338comp.htm
Looks like the SAAMI datum (corresponding to headspace datum) would be .476, but it has no corresponding CIP dimension (being a CIP standardised cartridge).
https://saami.org/wp-content/uploads/20 ... f#page=128
..
Awesome, thank you! I think I will look into the Sinclair insert.
Brian.
Re: .338 LM shoulder bump gauge inner diameter?
Posted: Wed Jul 11, 2018 8:39 am
by ovenpaa
The bump comparator gauges we manufacture are sized at 11.62mm bore for the .338LM
Re: .338 LM shoulder bump gauge inner diameter?
Posted: Thu Jul 12, 2018 5:38 pm
by Brian838
Ovenpaa wrote:The bump comparator gauges we manufacture are sized at 11.62mm bore for the .338LM
