Reloading for Contenders

[BruceP]

I need some more help guys. When reloading for a contender what is normally the first high pressure sign to show up. I have reloaded for maybe 15 years now, mostly for rifles, and the sign to show up first most of the time seems to be with the primers so I usually give a hard look at them when working up a new load. Now dont take this the wrong way. I dont want to push things to the limit here, but being new to loading for the TCs I was just wanting to know if maybe something else usually showed up first, like the action being harder to open or cases not extracting as well as they should. I dont know, these things might not show up until after other signs and until you are way to high. Thats why I'm asking you guys. I also dont plan on looking just for one sign but if one thing seems to show up first most of the time I would like to know what it might be.
Thanks in advance.
BruceP

[josiah719]

I sometimes start getting sticky case extraction before I see any flattening of the primers.  But then I use CCI primers and I've been told ther are the hardest of the popular brands.  On medium pressure cartridges like the 30-30 I use pistol primers because they will start getting flat about 10,000 CUP earlier, and that gives me an early warning.  I also watch the chronograph, because when pressure starts getting too high then the numbers sometimes get wierd.  They don't continue their steady and orderly progression.  I also keep in mind what the loading manuals claim that I can get with that powder and bullet combination.  Be careful and go up slow.

J. R.

[T/C nimrod]

Case head expansion as compared to a known pressure load (factory loading). See Pet Loads by Ken Waters for an explaination of the process, or I believe any loading manuals now have a chapter on pressure signs.

[BruceP]

T/C nimrod you probably named the best way but I'm loading for the 300 whisper. I guess I could break down and order a box from Corbon as for as I know they are the only factory load.
josiah719 you just had to bring up watching the cronograph. If I had been watching the cronograph I would not have shot my skyscreen while working up loads the other day. Anyway that too is a point well taken and  when I get a new skyscreen I will be watching. Thanks also for the extraction tip. I was also using CCI primers for these loads.
BruceP

[chazgin]

Bruce, I'm afraid you've opened a real can of worms here. Overpressure readings are very difficult to deduce in any firearm without strain gauge instrumentation. The combustion process in the cartridge produces a peak (spike) pressure that must also be accounted for in developing a safe load. The ammuntion (powder) producers take this into account when producing acceptable load tables. I don't want to start a flame war here but Ken Waters' old method of measuring case head expansion has been pretty much abandoned by the high performance crowd. There are too many variables that lead to inconsistent results. One major one is that this method depends on the temper (hardness) of the brass. This variable changes between case manufacturers, manufacturing lots, how many times the case has been fired, etc. A load developed in hard cases maybe too hot and not show excessive expansion. It has also been observed that brass yield is not linear with pressure, meaning that no pressure sign may be observed until the load is too hot. This is especially true with cartridges operating on the lower end of pressures. A near certain sign of overpressure is loose primer pockets. You can feel for these when you punch out the fired primer in your press. Unfortunately this result is also cumulative over repeated high end loads as the brass flows forward. You must go slowly if you are trying to approach max loads while seating the bullet out towards the lands. I've seen an OK load developed on a mild day go overpressure after sitting in sunlight on hot day.

[Bug]

Thinking! But, what I think T/C Nimrod is talking about, is measuring case-head expansion against a factory load. You fire a few factory loads, and measure their average expansion. Then you pull bullets, powder, & primers from a few cartridges out of the same box, and substitute your test loads. You DO NOT full-length resize in the process. Equal expansion equals similar pressures. This is to ensure you do not exceed a factory-load pressure in your weapon. Or so this is my take on this process.>>>>Bug

[T/C nimrod]

There are too many variables that lead to inconsistent results. One major one is that this method depends on the temper (hardness) of the brass. This variable changes between case manufacturers, manufacturing lots, how many times the case has been fired, etc

Very true - which is why you can only base expansion readings off exact components. If any components are changed, you have to start from scratch. One should keep in mind that case head expansion by itself is just that. Like primer appearance by itself is just primer appearance. That brass hardness variable can be applied to every single component we use for our handloads. Aren't we all careful even with a different lot of powder? I am - never had a reason to be, but I still am. Pressure signs will always be open for debate by themselves, but used together they will tell the truth.

I use primer appearance(by this I mean metal appearance under a magnifying glass -not flattened primers), case head expansion, felt recoil, and velocity as indicators as to where I am in regards to pressure in my handloads. When one sign shows up, I'll start watching for another, when I have 2 out of 4 I stop. My experience with Project 41(using published loads) educated me. I've just recently added head expansion to the list, and I won't stop watching it.

T/C nimrod you probably named the best way but I'm loading for the 300 whisper. I guess I could break down and order a box from Corbon as for as I know they are the only factory load.

I had the same question about my wildcats. My theory (and for GB's sake I stress it's a theory - not a sound fact) is that published starting loads will give me a good baseline to work with. I proceed alot slower and with more reserve when working this way. Bottom line is case head expansion will (and always has the little amount of time I've worked with it) have a "plateau". When you begin expanding cases past this plateau it's time to back down.

I've been doing a lot of pressure research over the last few months to try and get a true understanding of it's dynamics. There is nothing cut in stone - too many variables. Just my ideas and experiences and what can be deduced from them. This topic is a can of worms, but not a big one - there aren't enough consistencies to make it an arguementative point.

[T/C nimrod]

Bug - no I'm taking factory brass expansion measurements as a baseline and comparing that measurement against my handloads. Anything showing .0003 to .0005" expansion over the factory baseline is the stop and back-up point. I believe the theory is based off the idea that factory loads are made up to and not exceeding over pressure in the "average" gun design. ( I say this "average" because every gun is different - we all know that). This is done with the understanding that Norma brass is a different component from using Remington brass. Any time a component is changed, the baseline must (should be) corrected.

[chazgin]

T/C I don't disagree in general with what you say, about using several indicators. In bolt rifles that have had their lugs lapped and with smooth chambers the most reliable indicator of high pressure is increased bolt lift effort. This method seems very qualitative but to the experienced hand is a very reliable sign to backoff. How about the Contender with its standing breech? I don't think there is anything comparable, at least I have not been able to figure one out. Bruce was asking for something similar. I shoot an SSK 45/70, a 7mm Bellm (444 necked to 7), and a 357 Herret. The head expansion will not work with any of these. Two of them have no factory loaded cartridges and the 45/70 factory fodder is anemic compared to JD's load data. Believe me that I approached max very carefully and with the bullet well off the lands on that one. You could definitely feel the diference in the loads as you resized the cases after firing. That was the only indication that pressure was going up. I stopped seating the bullet out when I saw the group open up. In this particular barrel best accuracy at max velocity was .025" of the lands. There are no pressure signs other than the pockets are toast after 3 reloadings. The bottleneck rounds behaved differently tending to "grow" and require body resizing as the loads got hotter. But this is all bench work, I could not reliably tell at the range ( I mean I couls see the velocities go up, but not past the max listed). I don't know of another way with wildcats short of instrumenting the barrel. Ohler has a strain guage setup but I haven't sprung for one yet, because I don't see how you would run a cal curve with it. You can't buy certified pressure rounds (not proof loads but rounds that generate a certain level), so I don't know how much I would believe the readings. Maybe someone on this board has an Ohler setup and can correct any misimpressions.

[T/C nimrod]

I shoot an SSK 45/70, a 7mm Bellm (444 necked to 7), and a 357 Herret. The head expansion will not work with any of these.  

Can't speak from experience on the 45/70 or the 7mm Bellm, but I can with my 14" .357 Herrett. I shot a few yesterday after reading your post, just for experimentation reasons. Took a baseline measurement from a beginning load, and started working up to two loads over published data. With this baseline, the brass held within .0002" (average of three measurements on each shell) until I hit one .4 grain load over published max. This took the brass to .0004" (again average reading). I took this as being the point of max pressure - in my barrel.

Just thought it would be interesting, and I found it to be.

You could definitely feel the diference in the loads as you resized the cases after firing. That was the only indication that pressure was going up.  

This tidbit I found really interesting. Maybe if you would have been watching head expansion you would have caught an indication before you got back to the reloading bench? :roll:

Geez, now I sound like I'm trying to justify my means. I'm really not  :roll: well ,ok I am. Thanks for the thoughts - keep posting if think of some more, I like others views - keeps me on my toes.

[chazgin]

T/C, the 45/70 loads were not overpressure. I mentioned this because there was a world of difference between Trapdoor Springfield type loads and JD's data.

[/quote]With this baseline, the brass held within .0002" (average of three measurements on each shell) until I hit one .4 grain load over published max.

I don't go over published data with wildcats using canister powder. Mil surp 1680 is quite a bit slower than AA1680 and that is an exception I make.

[T/C nimrod]

I don't go over published data with wildcats using canister powder. Mil surp 1680 is quite a bit slower than AA1680 and that is an exception I make.

Don't get me wrong - I went over just to get some good hard data for you and I to compare. I usually find the most accurate loads around the middle of published data. But, I still start at the beginning charge and work up to published max. I feel comfortable with my barrel to do the test I did, and the results were pretty much what I expected.  

I've found myself recently going to five or six manuals for load ramps. (using the same powder, bullet, primer, etc), because the older manuals I have tend to list slightly higher charge ramps then the new books. Another thing I do is work up in .4 grain increments. I do this for two reasons - 1) I can keep a real close eye on what is going on, and 2) I can narrow the best load down a little easier. If 10.0 grains of powder is the tightest group up to that point, and at 10.4 grains the group begins to open up - I know I can find the best somewhere in between. Just a little easier Then trying to figure out where the sweet spot is between 10.0 and 11.6 grains.

(These grain weights reflect no particular powder and are used as examples only)

[chazgin]

I agree, I look at several manuals myself. I have an old Lyman spiral bound book from the late 60's - early 70's and the ramp is indeed steeper. Most of the data is still valid and then some of the powders have changed formulation, haven't they? LOL I bet old Elmer K wouldn't like his old 44 Mag load anymore!

[Questor]

Eeek! You should never see pressure signs with the contender unless there's something wrong with the gun. Stick to published load data.

[T/C nimrod]

Eeek! You should never see pressure signs with the contender unless there's something wrong with the gun.

I don't understand that. Could/would you elaborate your ideas? That's a pretty steep statement to make about a closed breech gun. I'm not sure I understand why I can have pressure signs in a bolt actioned firearm and not in a Contender?

[The Duke]

I agree with Questor.  The Contender is operating at a pressure range (depending on the size of the case head and body taper) where flattened primers and sticky extraction may be way past that limit.  It just isn't worth it. Want more horsepower, get an Encore.

[T/C nimrod]

Duke and Questor - Don't know how to project my tone on this, but I don't wish it to sound harsh.  :-)

If you have sticky extraction and flattened primers - we'll go with the understanding that the primers are flattened due to pressure, not because of metal characteristics - you already are beyond max pressure......in any gun; lever action, bolt action, revolver, auto, pressure doesn't care what it's in - all it wants to do is get out.

I believe the discussion is dealing more with safe reloading practices and what to look for - not "hot-rodding" loads. If you believe max published loads are safe in every gun, pull up a chair - I've got a story for you regarding a 14" .41 magnum with published loads. In short, 1860+ fps w/a 210 grain XTP is a stiff load, and that was one charge under published max.

I'd still like to know how you can't have pressure signs in a Contender frame unless you have a gun problem..........

[BruceP]

T/C nimrod is correct in that the reason I started this thread is to help in my loading, safely, in a "type" of firearm I have not loaded for before. Questor I agree that using published data is best but I wanted to try Lil' Gun powder in my 300 whisper and even though its burn rate falls right in with all the listed powders I have found no data with this powder from any powder or bullet Co. Just a little info on the net, and I tend to be careful when no published data is available to compair to. In most published data for Lil'Gun ( in other cartridges ) it seems to give higher or the same velocities as H110 at lower presures. Notice I said in MOST data. The main thing with our hobby is always safety and while all the replies given so far may not agree, all have been helpful in one way or another so please keep it comming.
BruceP

[less9toes]

:grin: aw, just work up till a bit of smoke curls outta tha action,back up a couple of grains, runnem and see what your case life loks like. actually your on pretty safe ground with the 300 whisper.

[Tony D]

T/C nimrod is correct in that the reason I started this thread is to help in my loading, safely, in a "type" of firearm I have not loaded for before. Questor I agree that using published data is best but I wanted to try Lil' Gun powder in my 300 whisper and even though its burn rate falls right in with all the listed powders I have found no data with this powder from any powder or bullet Co

If the bullet leaves the barrel, you've got signs of pressure!  

Bruce, what I've done with L'il Gun is use a starting load for H110, work your way up in increments you're comfortable with.  Watch the velocities as you go.  When you start getting to the published max velocity, you're probably pretty near the max load for that gun, bullet and powder combination.

[BruceP]

Tony D, The way you say you work with Lil'Gun is what I was doing until my chronograph accident. Just looking for more info with my question.
Have you loaded the 300 Whisper with Lil'Gun?
BruceP

[less9toes]

just pullin your leg the other evening. ball powders have a somewhat narrow opererating band,h110 & lil gun are ball powders.don't get them up to proper pressure they are filthy and have been known to cause detonation(or whatever you want to call it),read warnings on ww296(alias h110). push above the pressure level designed for, velocity seems to stabalize or even regress and they can become highly erratic potentially causing extremely high pressures, much more than warranted by increase in charge.

[Lone Hunter]

http://www.ourpeak.com/ralphw/tc/
  I know this tread is not about pushing the limits of a Contender. But
I like to take a look at these pics every now and then to remind myself of what could happen if some thing does go wronge.  Lets all be careful