I received a new comparator nut from Sinclair after donating my other one to a "worthy cause" which I will not get into. After starting to handload for my 300WM I noticed my ogive measurements had changed drastically. I tracked the problem to the new nut and promptly fired off the E-Mail below. Please notice all the measurements are a little small. Their response is included also.

>> I just purchased a Sinclair comparator nut. All the measurements seem small. They measure .212,231,244,254,273,297.
> I noticed it when all of my cartridge measurements changed from my last comparator. What's up?
>
> B1: Submit

From: "Sinclair International GE" <support@sinclairintl.com>
To:
Subject: comparator discrepancies
Date: Friday, July 27, 2001 8:17 PM

The measurement is still a relative one. As long as it is the same each
time. Our newer comparators are designed and cut with rifle throating
reamers - even know the numbers may be a bit smaller, it simulates what a
real rifle throat measures now. Older holes were cut making sure they were
just a bit smaller than bullet diameter.

If you are not happy with the new design, please feel free to return the
comparator for a complete refund. We want to make sure our customers are
pleased with every Sinclair purchase.

Any additional questions or inquiries, please feel free to contact me
directly.

Thank You,
Geoff Esterline
Sales Manager - Sinclair International
http://www.sinclairintl.com
(219) 493-1858
Fax (219) 493-2530>
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[This message has been edited by ssleefl (edited 07-29-2001).]

ssleefl,

I would expect the 30 cal hole to be .300, to match the typical land diameter. The groove is 308, so your bullet would just slide through. to keep from cutting the bullet there needs to be a radius or slope at the edge, and that's where the problem lies. Also, .308 bullets tend to stick in a .300 hole, unless you are careful.

I'd try to trade back with the worthy cause, so all my data matched my nut. (There's a joke in there somewhere.)

I have a an RCBS mic, and it apparently compares length at .280 !!!

Don

I totally understand your point.

However, I find it to be less of a problem because, I seek a measurement off the lands and handload at different lengths, until I find a sweet spot. Once I have achieved that sweet spot, I only need a consistent measurement to keep my loadings perfect. All following loads would have to compare to that length. As long as the comparitor is consistent, which I have always found them to be, there is no need of worry on OAL. The consistency is always there.

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