Concentricity Variance Between Different Brass Manufacturers

[Zia Hunter]

A friend of mine recently returned from a sniper school and brought back several hundred once fired .308 cases consisting of FC and Hornady Match brass. These cases were fired through both bolt and gas guns.

While sizing 50 random cased with a Redding Type S die, I checked the runout on the case necks after sizing. Although not all FC cases showed more runout (maximum .0035) the majority exhibited greater runout than the Hornady which typically were .0015 or less. This same die consistently achieves runout of .001 or less with Lapua and neck turned brass so I don't believe the issue is with the die. I did check a random sample of the case necks for thickness and they ranged between .0135 and .015. Neck bushing used in the die was .334.

Has anyone else experienced this and would be interested in your comments.

 

[fdshuster]

I don't place much faith in range pickup brass, ( you have no idea of the history of that brass/ was it once fired (?), loaded ? times, subjected to oversizing, etc. etc.), but if I did, I would segregate the brass between what I thought was acceptable, and toss out whatever did not meet my standards.

I will not risk the chance of headcase seperation with possible damage to my rifle(s), (and me), to save a few pennies. Like driving a Mercedes with $29.95 "Made in China" tires.

 

[necchi]

Well there is a huge difference between the chambers on bolts and the Gas guns the military uses. I have seen some brass out of the full autos really expanded.
The amount of movement made by a single FL sizing and spring back of the brass from the Auto guns could be a big difference itself.

And the brass you mention each has a different alloy,,all these things can contribute to sizing conditions.

 

[Zia Hunter]

Thanks for the replies and comments. For the record, the brass was all once fired and new in the box from the original manufacturer. Plan on segregating the brass by head stamp and carefully inspect each case. I checked each case for proper head space after sizing and all within tolerance. The XRF analysis was quite informative and thanks for sending. Thanks again.

 

[Nomad47]

Just curious. How do you know all the brass is "once fired" when you are picking up other shooters' brass at a range? Nobody at a Sniper school handloads?

 

[kraky]

Fwiw...although I like federal brass vrs win or rem I'd bet that hornsdy has more consistant neck thickness. This just from my experience with hor
nady brass in the 300wby.

 

[Zia Hunter]

Nomad 47:

To answer your question, policy dictates using factory ammo only for liability purposes.

 

[Nomad47]

I see, thanks. Seems to me there would be a mad scramble for a bunch of free once fired brass.