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Posted: 6/16/2009 3:43:13 PM EST
If you have some factory loaded rounds would you please measure the neck diameter.

What is considered the proper neck diameter for the 6.5/308 AKA .260 Remington?

Thank you in advance.

D
Link Posted: 6/16/2009 4:16:59 PM EST
Don't own a .260, but my Sierra manuel shows 0.297 on the .260 diagram. Here's a link to decent spec sheet.

http://www.6mmbr.com/cartridgediagrams.html#260REM
Link Posted: 6/16/2009 5:24:31 PM EST
Thank you, great link
Link Posted: 6/16/2009 6:48:06 PM EST
0.0135" neck wall thickness and a 0.264" diameter bullet yields an overall neck diameter of 0.291". I'll go measure some of my reloads and get back to you later.
Link Posted: 6/16/2009 7:05:33 PM EST
Thank you Mike, I would be loading my own...
Link Posted: 6/16/2009 7:09:17 PM EST
If you're ordering bushing dies, then don't forgot to account for some neck tension.

If you're ordering a reamer, a .297 neck would work very well.
Link Posted: 6/16/2009 7:19:55 PM EST
[Last Edit: 6/16/2009 7:20:42 PM EST by 308Sako]
double tap


Link Posted: 6/16/2009 7:20:24 PM EST
The man is clairvoiant... still at the reamer stage with this one. And I am familiar with bushing dies.. wouldn't use any other type.
Link Posted: 6/16/2009 7:49:13 PM EST
Ah.

My .260 reamer has a .294 neck, and I can shoot factory ammo in it with no problem.
The plan is to use necked down Lapua .308 brass, for which I've been told I'll need to turn the necks.
I haven't done this yet, but it's coming... soon as I get some dies.
Link Posted: 6/17/2009 5:15:32 AM EST
Zia, I have the Redding .308 bushing dies and plan to use them with my 6.5/284 Win's bushings... That rifle has a .295 neck as it was made before Norma nad Lapua made brass for same.

I also think that either necking up .243 Lapua or down with the .308 should be nice. I am going to test some brass later with said theory. My local gunsmith recomends going up not down...
Link Posted: 6/17/2009 5:21:49 AM EST
I think most agree with your smith. My smith says to go down and turn necks for custom fit. I cheated, I broke down and ordered a bunch of black hills .260 from GAP. No muss, no fuss and come with a lapua bullet.

I'm hearing the rem .260 brass has gotten a bit better in their qality.
Link Posted: 6/17/2009 7:35:11 AM EST
[Last Edit: 6/17/2009 7:36:16 AM EST by Mike_Mills]
I made some measurements on my gear for you.

The Hendricksen (sp?) chamber reamer used by McBros on my barrel supposedly has a 0.298" neck diameter according to the chambering reamer drawing.

Fired brass, after several firings (but not a lot of firings) measures 0.296" diameter (0.002" spring back?).

Loaded rounds using the 107 gr SMK, measured 0.291" to 0.292" diameter for Remington brass.

The batch of Remington brass I have is surprisingly good quality in terms of case weight uniformity and neck wall thickness uniformity. Watch out, though. I found a HUGE, multi-grain weight brass shaving (curled brass trimming) inside one case. I only found this because I took the time to do some weighing of the cases. Normally, the case would have been loaded and fired with this HUGE shaving inside. In another case, I found the flash hole punching pin from their brass forming die which was broken off and stuck in the flash hole of one case. After inspecting these defects out of the brass, it was great.

I hope this helps in some way.
Link Posted: 6/17/2009 9:06:06 AM EST
[Last Edit: 6/17/2009 10:28:24 AM EST by CCW]
I don't have one, but someone told me the .260 is basically a 6.5mm-08, between the .243 (6mm-08) and the 7mm-08. That being the case(no pun intended), I would submit that the assembled neck diameter should be bullet diameter + 2 x 0.015.
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