6PPC ammo questions

S

stevenorlando

Guest
Hello All,

I just got a 6PPC rifle. I was told the chamber thickness at the neck part is .262". I also got some brass, and I measured the neck thickness and it measured 0.0035". That seems a bit low to me. Am I measuring right. According to this data, I would need bushings around 0.250", that seems a bit small, considering that the chamber is 0.262".

The ID of the necks are 0.246"..

What diam should I size my necks to?

Steve
 
seat a bullet and measure the neck at the base of the bullet
take the gun apart and see if the neck dia is marked on the bbl
 
Before you go further, find out, by whatever method, what the actual chamber neck diameter is. Then go from there.

Generally 0.002"-0.003" is the accepted clearance between the loaded cartridge neck diameter and the chamber neck neck diameter.
 
Normally .002 or .003 smaller than the neck diameter of a loaded round is a good starting place.
How are you measuring neck thickness? .0035 is really thin.

I started off with a 262 neck in the beginning and at that time I used a .256 or 257 bushing.
If you add .007 (2 x your neck thickness) with .2432 (243 bullet with a .0002 pressure ring) you will come up with .2502 which is really to small for a 262 chamber.
What you want is a loaded round that is about .260.

Ted
 
What sort of tool did you use to measure neck thickness? Your statement that your neck thickness is .0035 looks like either a typo or a measuring error, since necks that have been cut for the usual loaded round clearance for a .262 chamber neck diameter are usually over .008, and less than .009. Do you know anyone that loads for a tight neck chamber? it might be good to have someone local look over your setup.
 
"Your statement that your neck thickness is .0035 looks like either a typo or a measuring error, since necks that have been cut for the usual loaded round clearance for a .262 chamber neck diameter are usually over .008, and less than .009."


Steve, check to make sure you didn't measure .0085...............Rather than .0035.

IF....... Neck thickness is Between .008 and .009 (where it should be for a .262) then .257 / .258 / .259 bushings will get ya going.

cale
 
Thank you all for replying. I'll try to answer all the questions asked :

First of all, I thought that 0.262 is the chamber neck diameter. I got that from the person I bought it from. However, I'll look over the whole barrel when I get a chance. If I am in error, can someone please point that out and steer me in the right direction of measuring the chamber neck diameter (or getting it)

Next, I took a caliper (http://www.midwayusa.com/viewProduct/default.aspx?productNumber=604242 to measure the neck thickness. It was difficult to get the caliper inside the neck After checking Midway it turns out I have the wrong tool, which may be my problem. I need to get a ball micrometer. In the meantime, I'll have a gunsmith measure it. I'm sure he has a ball micrometer.

Will get back with the measurements.

Steve
Steve
 
Steve,
I am not a big fan of cheap digital calipers. I would rather have a cheap dial caliper. You also need a 1" micrometer that reads to .0001 as part of your basic tool kit. If any of your cases have enough neck tension to hold a bullet, you can use the micrometer to carefully measure the maximum diameter of the bullet and the OD of the neck with the bullet seated in it. By subtracting the bullet diameter from the total, and dividing the difference by two, you will end up with the thickness of the neck. I would brush out the neck with a couple of passes with a bore brush, but not down to clean brass. Leave a translucent haze of powder fouling. While you are at your gunsmith's, have him check out your calipers, if they are not accurate to a half thou. I would return them to Midway (assuming that you have not dropped them) and see if you can trade them in on a mechanical one, that has a dial. Years ago I traded into an old German made Craftsman vernier caliper, that has no gears or linkage to induce errors. Although it is more of a pain to read, it checks out very well against a good micrometer...every time. Do you know how to read a micrometer to .0001? No one is born knowing how to do this, so if I can be of any help let me know.
Boyd
 
Steve, you might want to purchase Cerrosafe for chamber castings. Sinclair's No. is CERR
Brownell's has it also.
Should solve your problem.
Centerfire
 
Steve you should contact the person you bought the rifle from. He may have loads of information that would help you get that rifle shooting tight.
 
Once again, thanks for responding. I have spoke with the person I bought it from, and all he was able to tell me is that it shoots in the .2 groups, and the chamber diameter for the neck is 0.262", and the RCBS dies worked well.

I remeasured them and came up with an avg ID of the neck of 0.246, and an avg neck thickness of about .007-.008. That data makes more sense.

It was recommended to me that I purchase redding comp-s busing dies and get bushings 0.256, 0.257 and 0.258 (however, I'll probably get more sizes). I will probably have the chamber cast and have someone show me how to separate the stock from the action, since it isn't obvious to me (not done by screws, I can only figure out that the trigger is held in by a long pin).

Steve
 
"I will probably have the chamber cast and have someone show me how to separate the stock from the action, since it isn't obvious to me (not done by screws, I can only figure out that the trigger is held in by a long pin)."

Steve, no need to take the action out of the glue-in..... I wouldn't recommend it and for your try'n to find out, this won't help ya, just cost more $$$ to get glued back together PROPERLY... And it still shoot...WELL...

Either........

Have the BR smith (hopefully he has this experience) with his tools remove the barrel to "check" the chamber....

Or,

Buy an action wrench and barrel vice to remove the barrel from action.... You'll need these tools eventually anyway.

On the die, I'd recommend a Redding S-bushing Small Base FL resizing die.. The .257 / .258 / .259... Will be all that you'll need but..... If your necks are on the thin side, a .256 bushing "may" be needed...

Good luck,
cale
 
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