Pin tumbling experiment On peening

[swampratt]

Ok so some say no issues with peening with stainless pins.
Some say it is the other cases in the over stuffed tumbler doing the peening.
Some say you need to tumble for less time
I had to know exactly for myself.

Experiment #1
1time fired Hornady 30-06 case..I took a picture of the fired case.. this case never touched the ground it went from box to gun and back into the box.
I took a few pics sorry an old sony cybershot 3.2 mega pixel camera.
I then polished the case with 0000 steel wool and then some tissue paper and polishing compound.
Took some pics of that.

Then into the tumbler all by it's self with only stainless pins in it..My tumbler is a 2 quart plastic V8 container.
I filled it full of water and a sprinkle of Lemishine and 2 drops of dawn.

More pics taken.
First picture is fired case.

Next picture is the same case polished.

Now after 1 hour in the tumbler by itself.

another pic after pin tumbling.

My pins peened the case.
I will try and score some smaller pins and do the test with them.

 

[Pokinfun]

you would have a greater chance of the case hitting each other and peening a case than the pins.

 

[swampratt]

So I need to polish a few cases and stick them into the tumbler in a group without pins.
You may be correct.
But my issue mostly is the inside of the cases to be specific the case mouth where the bullet is seated.
This creates extra drag on my expander mandrel and pulls the case shoulders ever so much more.

I can read the differences as much as .008" difference in where the shoulder datum is at between cases.
So slicking the insides of the case necks tightens these tolerances.

That is why I brush my case necks before and after sizing and doing so has greatly improved my groups.
Not only that but I like to push my shoulders back .001" or less , when the case is rough this does not happen..many times It will pull them past where the fired round was at.
That makes for "CLICK" in an ar 15 at the worst time.
Not quite seated all the way in and the assist is of no help.

These are things I noticed..YMMV

 

[Mad Professor]

That makes for "CLICK" in an ar 15 at the worst time.
Not quite seated all the way in and the assist is of no help.

I’m slightly surprised you are not case gauging finished rounds.

 

[Pokinfun]

the speed of you tumbler is going to matter more than the pin size or case size, or that's what she said.
There are dozens of things that could cause a case to be peened in any sort of tumbler.
But, if you wish to believe that you can feel .008 difference, then believe what you wish.
I am disagreeing with you about peening of the cases.

 

[Shadowrider]

I can read the differences as much as .008" difference in where the shoulder datum is at between cases.
So slicking the insides of the case necks tightens these tolerances.

That is why I brush my case necks before and after sizing and doing so has greatly improved my groups.
Not only that but I like to push my shoulders back .001" or less , when the case is rough this does not happen..many times It will pull them past where the fired round was at.

It’s not the peening. If anything it would decrease friction due to the expander mandrel only contacting the high points.

You need to use a dry neck lube like graphite or mica on your brush. I went to a Dillon sizer die to fix the same problem. It has a carbide expander and It’s also only a few thousands in length (the engagement part) instead of full length engagement with the neck like my Hornady was.

Fixed it for me.


Sent from my iPhone using Tapatalk

 

[swampratt]

I can measure .008" difference in how far the shoulder is from the base of the case.
This hinders chambering in some guns and hurts accuracy even more.
Read.
https://www.longrangehunting.com/threads/how-to-measure-shoulder-bump.40567/

I was going to order some dry lube kit but it slipped by me when I made my last Midway order..I wish locals would carry some of this stuff.
I have been wanting to try a different type sizer die, I will look into the Dillon sizer.

 

[Snake]

I can measure .008" difference in how far the shoulder is from the base of the case.
This hinders chambering in some guns and hurts accuracy even more.
Read.
https://www.longrangehunting.com/threads/how-to-measure-shoulder-bump.40567/

I was going to order some dry lube kit but it slipped by me when I made my last Midway order..I wish locals would carry some of this stuff.
I have been wanting to try a different type sizer die, I will look into the Dillon sizer.

I believe H&H carries that.

 

[swampratt]

Easy to make them also. You can use an old pistol case..just find one that rests on the datum of the shoulder where you want it to.
You can also make bullet comparators quite easy.
https://www.sinclairintl.com/reload...r-hex-style-bullet-comparators-prod83792.aspx

Of course I like to make things..I made my own bullet mold and handles from stuff I had laying around.
I made it for 50 cal muzzleloader to mimic the 295gr powerbelt bullet, mine came in at 326 gr and shoots decent.

 

[Pokinfun]

Easy to make them also. You can use an old pistol case..just find one that rests on the datum of the shoulder where you want it to.
You can also make bullet comparators quite easy.
https://www.sinclairintl.com/reload...r-hex-style-bullet-comparators-prod83792.aspx

Of course I like to make things..I made my own bullet mold and handles from stuff I had laying around.
I made it for 50 cal muzzleloader to mimic the 295gr powerbelt bullet, mine came in at 326 gr and shoots decent.

I made my headspace gauge that way.