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  #1  
Old 09-16-2020, 11:42 PM
mefizto mefizto is offline
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Default VarTarg neck size help

Greetings all,

I am getting ready to order a VarTarg reamer, and there appear to be a lot of contradictory opinions regarding the neck size and free bore. So, to get some more (confusing) information, the following is my reasoning and question.

I have measured several Lapua .221 FB cases and the outside neck diameter is rather consistent at 0.248 inch. Therefore, if the case is resized to 0.20 inch , the outside neck diameter will be 0.228 inch. Since some opine that 0.004 inch tolerance is acceptable, that would translate to a 0.232 inch neck chamber. Yet, some of the recommendations are for 0.234-0235 inch chamber.

The only explanation I can think of is to ensure tolerance for a different lot. However, this pre-supposes that the lot will have thicker brass.

To add to the confusion, JGS sent me a drawing that shows the neck size 0.224 inch.

Regarding the free-bore, the general consensus for 32-35 gr bullets is zero free-bore, there does not appear to be any consensus regarding 40 gr bullets.

Could you please clarify?

Kindest regards,

M

P.S. Would it be advisable to rent the reamer? I understand that it has to be really sharp.
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  #2  
Old 09-17-2020, 03:53 PM
Ganderson Ganderson is offline
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You have to measure the neck diameter of a loaded round...neck down the cartridge, seat a bullet and then measure the neck diameter. I think you will find that blue box Lapua brass with a 20 cal bullet seated will measure right at .232 so therefore a .234 or .235 chamber neck is what you will want. In regards to freebore, JGS should be able to make the best recommendation based on the bullet that you are wanting to shoot.
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  #3  
Old 09-17-2020, 05:11 PM
mefizto mefizto is offline
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Hi Ganderson,

yes, I understand that, the bullet increases the diameter by 0.004 inch. Hence my confusion that some of the reamers specify 0.232 neck, and, as noted, the print that I received from JGS is even smaller at 0.224.

Kindest regards,

M
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  #4  
Old 09-17-2020, 06:03 PM
JohnHenry JohnHenry is offline
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M, See following link.
http://www.saubier.com/forum/showthread.php?t=28593
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John
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  #5  
Old 09-18-2020, 12:45 AM
dungheap dungheap is offline
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I rented a reamer some time ago from CH4D -- excellent service, worked fine and did not break the bank.
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  #6  
Old 09-18-2020, 01:47 AM
Ganderson Ganderson is offline
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Quote:
Originally Posted by mefizto View Post
Hi Ganderson,

yes, I understand that, the bullet increases the diameter by 0.004 inch. Hence my confusion that some of the reamers specify 0.232 neck, and, as noted, the print that I received from JGS is even smaller at 0.224.

Kindest regards,

M
Yes, .232 was the "normal" neck diameter for most any brass...OTHER than Lapua...Lapua necks are thicker. A .224 neck would be a tight neck chamber and would require neck turning...tight neck chambers are supposed to squeak out a little more accuracy.
If you don't want to turn necks down and use Lapua brass, a .234 or .235 neck will be what you want.
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  #7  
Old 09-18-2020, 02:04 AM
L.Sherm L.Sherm is offline
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Call JGS and tell them you want a print for the Lapua fireball brass. It should have a .235 nk little bigger at the .200 line than for Rem brass and in my opinion zero freebore.
Just about all the Lapua brass I have measured has been .2315 give or take .0005 necked down.
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  #8  
Old 09-18-2020, 02:25 AM
mefizto mefizto is offline
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Greetings all,

I am getting the false impression that understand the issue. Thank you very much for your patience.

Hi dungheap,

thank you for the recommendation. Would you recall the approximate price? You can p.m. me if you do not want to publicize it.

Hi L.Sherm,

I did and asked to speak to technical personnel, but the secretary said that she would send me a print and if I did not like it, to change the dimensions and they would re-draw it and make it. She found the one with the .224 inch neck; thus they appear not to have yours on file. Of course, any change will make it a new item with the maximum charge. That is not very accommodating, is it?

Kindest regards,

M
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  #9  
Old 09-18-2020, 05:36 AM
strkr strkr is offline
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That .224 neck was one of the very early ones. If my memory is right, .229 was next, but .232 was then pretty much standardized before pooie brass came out and people had to fit their barrel chamber to accomidate overpriced brass. Why not go with a .237? or so, and just use reformed lc with no turning.
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  #10  
Old 09-18-2020, 05:02 PM
mefizto mefizto is offline
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Hi strkr,

thank you for the suggestion. I will go with no turn neck. All my inquiries were meant to clarify my confusion about the different necks, which I now believe to understand.

The last issue I need to understand is what is the maximum allowable/safe tolerance. Let us say that I specify a neck size of 0.235. Then I get a batch of cases with a neck size of 0.228. Is it safe to fire? Will it have negative consequences, i.e., neck splitting?

Kindest regards,

M
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