Neck Tension Effect on Accuracy

[cape cove]

I have both type gauges so I can argue with people like Mikecr.

The Hornady gauge holds the case just like a chambered full length resized case in the chamber.

It is supported by the bolt face in the rear and the bullet in the throat. And the body and neck of the case never touch the chamber walls. Because the full length die reduces the body diameter .003 to .005 in the average die.

Meaning even if the case body is slightly out of round the body of the case has no guiding effect on bullet alignment. (rat turd in a violin case)

Thank you

 

[bigedp51]

Thank you

Thank you. cape cove

I thought I was going to hear no one gave a rats ***, or never saw a violin case.

All joking aside I collected mil-surp rifles and know how badly these longer and fatter chambers can torture brass. Then next down in size is SAAMI chambers and then smaller custom chambers.

The "smaller" chambers and "uniform" Lapua brass get along great and this keeps case distortion to a minimum. "BUT" a SAAMI chamber with Remchester brass can be another story. Example, I have Remington .223 cases with .009 neck thickness variation. And when I check the case body for variations many times they are as bad as the case neck.

I sort my cases using a simple Redding neck thickness gauge and with one twist of the wrist it tells me the quality of the case. Meaning if the neck is a uniform thickness normally the body of the case is also uniform.

Also a standard V-block type concentricity gauge "if" you can move the gauge to the base of the case and shoulder it will tell you if the case is egg shaped.

Besides the hornady gauge I have the RCBS case mastering gauge and is the Swiss army knife of gauges. Meaning its not the best of gauges but it does many jobs good enough.

This is why I said the two types of gauges give different readings with the Hornady gauge reading over half of what a V-block type gauge does for bullet runout.

Its too bad I'm retired, in my "golden years", have chronologically gifted eyesight, the start of cataracts and drink too much coffee to say runout matters.

 

[cape cove]

As I said thank you. I have the RCBS and Hornady units. I wondered why the Hornady guage most always read less run out than the RCBS unit. Now I know. Must say that I'm not completely sold on the V- type blocks. I believe a bearing unit like the Redding one might be easier to use. As you said the RCBS one is quite flexible. I've got mine set up with 2 dial guages for neck and bullet run out as well as neck thickness without moving anything. Again TKS for the info.
CC

 

[Greyfox]

I also have both the Hornady and the RCBS gauges. While I agree with the measurement methodology differences between the two approaches, I prefer using the Hornady becaudse of the convenience. As long as the measurement is under .003'(most are under .002'), I'm confident,based on experience, that excessive runout will not be a cause of inaccuracy with the several calibers I reload.

 

[cockednlocked]

I have the 21st century gauge any thoughts on where they rank with the others ? I looked at the hornady guage and figured the 21st was better for my needs but have not actually used the hornady or rcbs

 

[cockednlocked]

Wow just realized how old this thread was

 

[ShtrRdy]

Wow just realized how old this thread was

Thanks for kicking this thread up. I have been using an old Sinclair Concentricity Gauge. My thoughts on the V-block are that a case that has been fired should be very concentric on the outside due to the chambering reamer being rotated on an axis guided by a alignment pin.

I'd like to mention something I noticed recently when using a Redding Full Length Bushing die. This is for a .308 Win case. The fired case neck diameter is 0.344". I need to size it down to 0.335". I do this in two steps. First step takes it down to 0.340" and the second takes it down to 0.335". Measuring the runout at the neck on a fired case I see less than 0.0005" runout. After sizing down to 0.340" the runout is 0 to 0.001". Then sizing down to 0.335" the runout was frequently 0.004". During previous case prep sessions this step has resulted in runout less than 0.002".

What i found that I could do is to first just start the neck of the case into the bushing, then pull it back out, and then go the full stroke. This would result in less than 0.002" runout.

 

[DUSTY NOGGIN]

Wow just realized how old this thread was

your deserve a trophy , im excited to see a new guy that used the search function

 

[cockednlocked]

Heading to Montana in a couple weeks looking for that trophy.