6.5-300 loaded neck diameter

[fmuguira]

Anyone have a loaded 6.5-300 factory round they could measure outside neck diameter on? On a different forum a guy helped me with his reload; said it was .2915.

I ve necked down some 300 WB brass to 6.5-300 and I m seeing .294-.2945 so trying to see if I need to turn the necks a couple thousandths. After firing one of my loads with a beginning charge I m only seeing neck expansion at .295-.2955. Worried I might be a little too tight on clearance and not wanting to step up pressure til I can get a better handle on diameter of 6.5-300 factory brass loaded diameter.

I got tired trying to find brass thus my reason to step down some 300 Weatherby brass; I was lucky enough to locate that!!

Thx in advance to anyone who can help!

 

[dok7mm]

Not familiar with 300 WB brass thickness, so I can't guess the thickness when necked down to 6.5. Check some fired rounds to see if new bullets will slide thru the neck easily. If not, you'll need to turn necks.

I like to have .003"- .004" clearance in chamber neck. If you have any factory rounds fired in your chamber, you can check the neck OD and add .001" to get close to your chamber neck spec. It should give you a good idea on how much to turn.

 

[MagnumManiac]

It will depend mostly on maker of brass.
Norma run right around .013" wall thickness, Rem runs around .0145-.014" with my 300 Bee brass.
I have never had an issue running either.
I have .004" clearance with Norma brass, .0015" less with Remington.
As long as there IS clearance, you shouldn't run into too many issues.
A light skim turn may be needed, but if a bullet slides back into a fired case, then I wouldn't worry about it too much.

Cheers.

 

[fmuguira]

Bullet doesn't slide into fired case… has some interference …. Fired case inside diameter right at .264 ish …. I agree that a partial skim cut, maybe .0015 or .002 would most likely be max. Would just like to know what actual 6.5-300 WB brass is measuring at vs my 300 WB necked down brass. (It's Weatherby head stamped)

When I seat a bullet my neck diameter is right close to the Saami drawing.. .295, thus my concern.

Thx to any other input if someone has a loaded round of 6.5-300 stamped brass regarding OD of neck!!
Appreciate everyone's help

 

[MagnumManiac]

If it's Weatherby stamped, then it is made by Norma.
Because you have used a mild load, it is very possible the resistance you feel trying to slide the bullet into the case neck is actually the case mouth being slightly curled inwards. This happens to me when I do seating depth tests with mild loads.
If you look very closely at the case mouth, you can tell quite easily if it's curled in.

Also, .295" sounds right to me, as I necked down a Weatherby 300 Bee case to 6.5 and wound up the same with a 142g ABLR seated in it.

Cheers.
P. S. Hopefully Aussie Hunter Steve chimes in, I know he has one.

 

[bsnyder]

Just measured my handloads at .290 that's with a 124 hammer loaded in it.

 

[fmuguira]

bsnyder , thank you !! Do you have a fired case that you could measure to see how much expansion your setup/rifle has? My rifle is a Vanguard Wilderness.

 

[bsnyder]

I have the same rifle. Fired case is .30

 

[fmuguira]

Great, thanks!! Sounds like my loads (starting) may not be even expanding the case fully. Still doing barrel breakin so will go up in charge and watch closely.

I m thinking of trying the 143 Eldx for deer and coyotes. What load/reload are you using if you don't mind me asking. I ve got some US869 that seems to get good velocity and accuracy with the heavier bullets. Think I ll try it first.

 

[MagnumManiac]

Hmmm, I just re-did a case with both Remington brand and Norma brand….I got .2915" with Remington and .290" with Norma. I also get .2915"-.290" with 6.5x47, 6.5x55 and 264WM with various brass brands.
Something is up with your measurement.
I noticed my first measurement with a calliper was too close to the case mouth. So I repeated with a micrometer after measuring the above rounds in 6.5.
I have never seen a neck thicken necking down. I neck 7RM to 264WM all the time because brass is virtually impossible to get here. I've seen it lengthen, but not get thicker in any measurable way.

Cheers.

 

[fmuguira]

Mine lengthened .010 after necking down. 2.835" from 2.825"

I annealed them prior to trimming. I ve measured up and down the neck and get the same measurements…. Measured 17 cases ( how many I have right now) and they were all consistent.

 

[bsnyder]

I run 91 grains of lrt with a 124 hammer hunter. Can't remember my previous as with us869 and 127 lrx. My oal with the 124 is mag length. Remember if trying this load start low and work up this load is safe in my rifle with my conditions. Thanks and shoot safe.

 

[fmuguira]

 

[Wrenches]

Maybe this will answer your question. When first available I purchased a MK V Accumark in 6.5 X 300 Wby Mag. Reloading supplies were not available at that time to I purchase 200 rounds of factory ammo. 100 Swift 130 Sirocco's and 100 140 grain A-Frames. That is all that was available. I just now went and measured the neck diameter of both factory loads and all are between .2905 and .291 from 89 samples. HTH