300-221 chambering issue

[azfred]

I bought a model 1 upper, when I feed a round out of the magazine the bolt wont close all the way and I have a fight to get it open, when i load a round single and close the bolt it closes and fires, any suggestions?
Fred

[Pitt300]

what bullet & what COAL?

[azfred]

sorry, thought I typed that, 200 smk 2.25

[Pitt300]

Do you have a Stoney Point bullet comparator?

[Pitt300]

As has been mentioned all "throats/chambers" are not exactly the same w/all 300-221/300 Fireballs/300 whispers.
I've been loading my 220 & 240s to 2.14 to get them to load properly in the mag & cycle.
I just bought a PMag & will be loading some cartridges longer now that they will cycle. These are great mags & only $14-$17.
Hopefully will reload/shoot this weekend & will update you on my "new" COALs.

[azfred]

Yes, I do, but I give the coal with out using it as not everyone has one

Originally Posted by Pitt300

Do you have a Stoney Point bullet comparator?

[Pitt300]

I apologize.
What I meant was do you have a Stoney Point Cartridge length gauge?
Hornady now owns rights to this product.

https://www.hornady.com/shop/?ps_ses...a34eaef6e83165

[Gelandangan]

I had the same problem in the begining of my live with a 30-221.

I use PTG reamer and Hornady dies.

It turn out that the case neck is too thick as I am using 223 necked down cases, bought from Keith Davis.

The problem solved itself when I turn the neck thickness down by 0.002.
Now everything feeds nicely.

[azfred]

what should the neck thickness be? and where is the best place for p mags?
Thanks Fred

[Gelandangan]

Originally Posted by azfred

what should the neck thickness be? and where is the best place for p mags?
Thanks Fred

The thickness should be
(whatever your chamber size is (cast and mike it out) less the bullet size (0.308) )divided by two (two layers) less the tolerance you want to live with confused? me too.. cant write formula here

I am using about 0.013" thick neck and that gives me about 0.005" tolerance on my bolt gun.
If you are using it in a semi/auto guns, better get about 0.008 or more tolerance.