Author Topic: full or neck (Read 2157 times)

T/C nimrod · « **Reply #30 on:** October 23, 2003, 06:17:24 AM »

Kyode - do you (or do you have to) trim your bottleneck cases after each firing? I ask that question to see how much brass you're moving. I do run each case through the trimmer just to square the mouth, but usually don't take a full cut off. By this I mean only the high spots around the mouth are removed - so I may have a case mouth that has one or two shiny spots where brass was removed, but not the whole way around case mouth.

Now you have my curiousity spiked. I'm wondering if this may be related to individual barrel to frame gaps?

T/C nimrod · « **Reply #31 on:** October 23, 2003, 07:05:20 AM »

haroldclark - we must have been typing at the same time.

Ok, that's why it's not more work for me to neck size versus full length. I tumble my cases during each reload even when neck sizing. I throw them in treated corn cob right after a range session, let it run for a few hours, then I'll spend some time sizing and de-priming. Right out of the first die, the brass goes for a second ride in Lymans Tuff Nutt overnight.

So.......I spend as much time on cleaning necked cases as I would full length cases.

KYODE · « **Reply #32 on:** October 23, 2003, 08:29:42 AM »

lately, yes i have been trimming each and every time i load. i don't necessarily have too, but i like to keep them really close. i doubt if i could go 2-3 firings before they grew over specs. plus, for me it's easier and faster to trim a few thousandths off each time, rather than several thousandths.
remaining lubricant is possible maybe(although it would be slight), as i seldom tumble. i consider myself a low volume loader, and i mostly wipe each and every case after sizing.
the headspace indicator(which i just ordered) has a dial indicator, and is specially made to read how much fired case sticks out of a removed tc barrel. then, if you know how much the barrel to frame gap is, you size until you have .001" less case protruding than what the case sticks out. it's made to work with break open single shots.
i have 5 contender frames, and two encore frames. yes, they have varying gaps which i havn't actually measured yet. as soon as i find some plastigauge, i'll check them all.
:grin: wow! i have loved this whole thread, thanks everyone.

Steve P · « **Reply #33 on:** October 23, 2003, 09:57:51 AM »

Great posts above. Lots of good information. Lots of it relates exactly to my experience.

My 7tcu can be fired 3-4 times neck sized, then has to be full length sized, trimmed, etc.

My 6.5 tcu has to be full length sized every other time.

My hornet groups better full length sized every time.

My .30-30 and 7-30 waters barrels dont care. They just shoot.

My 357 max brass is never full length sized for the contender. I keep it polished good and size the end of it to accept the bullet. I have seen the "coke bottle" effect of full length sizing these long brass. I can get in an extra grain of powder by only partially sizing them. Never a problem with any misfires.

I think of all of the posts above, we have all come up with the same answer. Yes, and, No. Your barrel, your frame, your brass, your dies. You may have to neck size, or you may have to full length size. You have to be the judge. Your gun will tell you if you are wrong.

Shoot straight and have fun.

Steve

Bullseye · « **Reply #34 on:** October 23, 2003, 03:41:49 PM »

I need to add some more about why neck sizing is easier. I tumble my brass before sizing. If neck sizing I then dip the neck end of the brass in mica powder as a lubricant for neck sizing. The excess powder wipes off after sizing without any mess from a liquid lubricant. No need to tumble after sizing and lubricating for sizing is much cleaner.

drdoolittle_1 · « **Reply #35 on:** October 26, 2003, 04:54:52 AM »

This a must read for all T/C owners. I learned soooooooo much more about my Contenders after purchasing a depth gauge. Still have to try plastigauge on one barrel with scope base that does not allow me to measure with feeler gauge. Just my $.02
Cheers,
Dave
(sorry so long, couldn't get link to work)

The Experiment Every Contender (and Encore) Shooter Should Perform

--short version--

When the Contender (or Encore) is fired, the frame stretches within its limits of elasticity, then relaxes when the pressure drops. This leaves the fired case longer from shoulder to head than it was before it was fired. You will never see this with the extractor installed, but shooting the barrel without the extractor will show you clearly what happens when a round is fired.

This additional length must be removed when the case is resized, or it will interfere with lockup and cause misfires and accuracy problems.

DO THIS:

Take the barrel off the frame.

Remove the extractor by tapping out the 1/16th roll pin that holds it in.

Drop one of your sized bottleneck cases into the chamber.

The case head should be flush with the end of the barrel. If it isn't, you need to adjust your size die down in small increments until the case head is flush with the end of the barrel or protrudes no more than about .002." If the case head falls below the end of the barrel, you have pushed the shoulder back too far and created headspace. You can rely on "feel" as you run your finger across the end of the barrel and case head, or hold the end of the barrel up to eye level and sight across the end of the barrel to determine that the case head is not sticking out of the end of the barrel. .002" is difficult to see..... it is not much.

Now load this case with a full normal load, and shoot it.

When you open the barrel without the extractor installed, the case head will be in the position it was when fired.

Take the barrel off the frame and look at the case head again. It will usually be sticking out of the end of the barrel about .010" or more.

This excess length must be removed. Ie., you have to bump the shoulder back in a full length size die. Neck sizing is out. If you insist on neck sizing or just partially full length sizing and have misfire problems, this is the reason.

Typical barrel to frame gap is normally from 0 to about .004." Some will be up to about .006" or so. To be more precise, close the barrel on feeler gauges to determine exactly what the gap is.

Your sized cases should not protrude from the end of the barrel more than the amount of the barrel-to-frame gap.

Failure to understand the above is one of the two main causes for misfires and accounts for a big percentage of the questions I get.

So at the first hint of misfires, CHECK YOUR SIZE DIE ADJUSTMENT.

Cases grow in length when fired in these break open guns. DO NOT TRY TO CRAM THEM BACK IN BY SLAMMING THE BARREL SHUT. It is like trying to drive a square peg into a round hole. Just don't work

KYODE · « **Reply #36 on:** October 26, 2003, 05:54:42 AM »

i tried plasti-gage(made by sealed power)(from auto parts store) last night. i measured all barrel to frame gaps. it works great and is cheap. just measure the thickness of the plasti-gage with dial caliper, after closing the frame/barrel on it. if a scope base hangs over, it prevents using feeler gages to get the measurement. the plasti-gage does work, and it's only about $1.79 for a stick of it.

clodbuster · « **Reply #37 on:** October 26, 2003, 06:53:12 AM »

Hi guys-- this discussion is too good!!!!!!!!!!!! One subject triggers another-sorry about the trigger pun. Anyway I have a 357 max 10" factory barrel
that I have never been able to get decent groups from and was wondering if the barrel frame gap is right and how to measure it. Is this done with brass in the chamber (please pardon my ignorance) and a piece of plastigauge on the case head? Or does the plastigauge go on the end of the barrel that butts against the frame?
I've tried Hornady 180 SSP, 158 and 180 XTP, various cast bullets of high quality, gascheckedand not. Powders-WW296, AA9 and 1680 all with small rifle CCI primers. What am I doing wrong? P.S. I have a 4X leupold mounted in 3ring base and shoot from benchrest and sandbags.

drdoolittle_1 · « **Reply #38 on:** October 26, 2003, 07:22:52 AM »

Clodbuster,
Measure between chamber end of barrel and frame without case in chamber. This is the frame/barrel gap. Let's say for example that it measures .004". Then with a fired case in the barrel(removed from frame) measure how far the case protrudes from the barrel. Let's say for example that this measures .006". Back your sizing die out a bit and size case. Return it to the barrel and measure again. Keep doing this turning in the die body in small increments until the case measures .003" protrusion from the barrel. This will have you headspaced back .001". About as good as it gets! Once you have this measurement, you can do the same thing for checking seating depth for any particular bullet. Just partially seat the bullet and measure case protrusion. Say for example it measures .010". Keep seating bullet in small increments until it measures .004". This is COL seated directly on the lands. Measure your COL at this point. Let's say for example that it measures 2.260". If you then seat bullet for COL of 2.240" this should leave you .020" from lands. Hope this helps! If I don't have math right, guys....please chime in and correct me!!!!
Cheers,
Dave
Note *These measurements will only be good for this particular barrel with the same frame and bullet*

KYODE · « **Reply #39 on:** October 26, 2003, 08:43:31 AM »

clodbuster, this plasti-gauge will measure the barrel to frame gap, but since you're using a straight wall case that headspaces off the rim, your gap shouldn't affect anything. the plasti-gage will measure the gap, so you can adjust your sizing die to bump shoulders back to the correct place on bottleneck rounds. which should prevent MOST misfires and excessive brass working.
it could be possible you're doing nothing wrong, but havn't found the powder, bullet combo that barrel likes. looks like 296 would work in the max though.