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View Full Version : 6PPC Need Some Help Guys



cwood3
03-19-2009, 08:28 PM
My 6PPC is chambered with a Kiff reamer, 0.269" neck, 0.045" freebore. I use A Redding FL bushing die (0.264" bushing installed with the marked side facing downwards). When resized, they chamber silky smooth. Now, I use 68-grain Bart's Ultra's. Let's not worry about N133 charge yet. I'm hearing things about when seating the bullets into the lands, and trying to extract without firing, oft times the bullet gets stuck and ya pull out the primed case and spill powder and stuff. So I'm messing around with my Wilson SS Micrometer Seating Die, trying to see how far I can back it off until an unprimed, but resized and bullet seated cartridge has the bullet get stuck. Well, the out come is that I cannot make the bullet get stuck. I'm all the way out (well maybe 0.020" of bullet in the case). What have I got here? I just barely see square marks on a Sharpie-colored bullet indicating lands. The bullet, even at this very shallow seating depth seems to hold OK, although I can wiggle it and pull it out by hand. Is this due to the 0.045" freebore as related to this bullet? If a PPC is supposed to perform well when jammed, I just want to make sure I can "jam". Too much neck tension..? I wouldn't have thought so. I'm open for thoughts and ideas.

Thanks guys (and ya know who ya are).

curtis

jackie schmidt
03-19-2009, 08:47 PM
Granted, The Ultra, which is a double radius design bullet, does not get "tight" in the lands as does more conventional bullet with a 7 to 7 3/4 ogive. You can make the marks appear twice as long as they are wide before it will ever stick. What we are talking about is a bullet that is moved out about .025 from just touching.

Heck, I can actually feel the things "crunch" in when I close the bolt, and they will not stick, (well, most of the time).

Are you sure your reamer is a .045 freebore?? Personally, I think a .035 is perfect for an Ultra, just like a zero is just right for a Bruno 00 Boat Tail.

We will all be at Tomball this week end, if you make it, we can sure sort this out.

There is a possibility that everything is just right.........jackie

cwood3
03-19-2009, 09:22 PM
Yepper............I have the reamer, and it's ID'ed with the numbers. Actually, I don't it's an issue. I'm just all cocked around by a lot of information and sorting things out. Heck, Spring is here and I'm likin' it (what was that crappy weather last weekend???). When you guys load in that upper range, how much bullet do you have inside the neck ?

curtis

abintx
03-19-2009, 10:49 PM
The below info is taken from:

Benchrest Central,
Tips, Tricks & Info, Case Preparation
How much neck clearance do you try to achieve and what kind of neck tension do you like ? - Multiple

Bart Sauter
With a .262 Chamber and I trim my Brass to 8.8. So with a 243.5 bullet that gives me a little less then a thousands clearance. I use heavy neck tension 257. Carbide Bushing.

Billy Stevens
I use Lapua brass and cut it to .0088 for a 6PPC with .262 neck which gives me just under .001 clearance on bullets with a .2435 pressure ring. I don't run into any problems if I keep the necks clean and occasionally check to ensure that I maintain at least .0005 as the necks grow from the brass flowing forward from firing. I only use a set of brass for about three matches and then trade them in for some new ones. I shoot V133 powder with the PPC and like to use a .257 button which will give a fairly heavy neck tension with the above setup. For me, V133 will not shoot as well unless you have heavy neck tension.
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Billy Stevens is building me a 262 neck 6PPC and I'm using Bart's bullets so I'm pretty much following Billy and Bart's lead on neck tension for my 6PPC. I already have a .257 bushing. With a .257 bushing or button, a .262 neck and a loaded round using their specs you wind up with about .004" of neck tension. .0088" + .0088" + .2435" = .2611" (just under .001" of neck clearance) - .2570" = .0041"

With that kind of tension, no one should have trouble spilling powder in the chamber or keeping a jammed bullet in the case if you need to extract the round for some reason.

I’m using .0085 + .0085 +.2435 = .2605 (loaded round) + .0015 (total clearance) = .2620 (chamber)

.2605 (loaded round) - .2570 (bushing) = .0035” (neck tension)

Figuring out what bushing you might need to apply that kind of tension to your necks, might give you pretty close to the same type of results they’re getting, with your .269" neck.

Perhaps: .2690 (chamber) – 0015 (total clearance) = .2675 loaded round diameter

.2435 (bullet) + .012 (neck brass thickness on one side) + .012 (brass on the other side) = .2675 (loaded round)

.2675 (loaded round) - .0035 (neck tension) = .264 bushing

Jackie: What are your thoughts ???

Steve Nash
03-20-2009, 01:46 AM
Curtis,

As far as I am aware the bushing should have the numbers at the top not facing down. Will give you more neck tension if the bush is upside down.

Steve

cwood3
03-20-2009, 06:28 AM
All sounds logical to me. I believe I have the right stuff, just need more experience on the bench to get that intuitive, touchy, feely end of things in line. Thanks all.

curtis