signs of excess chamber pressure in the contender

[goodtime7]

Just curious as to what others are thinking about detecting excess pressure in the contender, either the original or G2.   You hear and read about the variability of reading excess pressure signs in bolt action rifles, etc.  Most any reloading manual discusses the need to be aware of flattened primers, difficult case extraction, and other signs of excessive chamber pressure.  But, you frequently read that these signs may be a irregular manifestation of excess pressure, and you might be actually operating at very high pressure, before you realize it.  Is it safe to assume that we can use these same parameters in the contender?  There are those that believe with good velocity data, and a chronograph, you should never exceed the anticipated velocity, and if you do, something is going to happen:  and it probably won't be a good thing.  But I have seen excess pressure not reflected in excess velocity...ie a VERY copper fouled 25-06 Mauser.   I load the TCU series, Herrett series, and have never had any trouble.  Have just ordered a MGM 30-30 AI barrel, and there isn't a whole lot of data out there, and not much on appropriate velocity for a given load, etc.   So, was just thinking about this issue.   Any thoughts out there?  Do we really have any good objective information?    Have a great Holiday Season!!

[Bigeasy]

I am relatively new to contenders, but will tell you of an issue I had.  With both a 223 and a 30-30 barrel, I had sticky, hard opening, with "swipe" marks on the slightly cratered primers.  Sure looked like high pressure, but it was with certian factory loads.  Turned out my gun was sensitive to soft primers.  I finally replaced the firing pin return spring, and that made the difference.  No problems with any load now.  The usual pressure signs can sometimes be misleading in a contender.

I would think other signs, like excessive case head expansion, sticky extraction, and overly high velocities for a given load would still stand.

Larry

[sr sawyer]

I have been loading for the Contender 30 Herrett, 22 Hornet and 218 Bee for a long time.  Never had a problem with soft primers but when you reach sticky extraction, and all other things being normal, you have probably exceeded your max load for these calibers.

Even if you have not exceeded book Max and get sticky extraction you shoud back off at least 5 percent.  IMO sticky extraction in the single shot TC, if you are working up "slooowly", will most probably be your first sign of excess pressure.

Ken

[Richard P]

Rather than try to detect ''excessive pressures'' in a Contender, why not simply stay within published data for your selected cartridges ?  If you review several sources you'll probably find a load with a powder that suits your need. I'd rather select a powder or a charge that will not produce the highest pressure. Contender frames will stand a lot, but they eventually succumb to stretching and unlocking on firing. Contenders are hard to deal with on this as normal pressure in a small diameter case as 5.56 will be over presure in those with sharper body taper as 30-30 or large diameter as 45-70.  Changing to Improved designs with less body taper is a way of reducing the thrust applied to the breech face.

[Grumulkin]

I've never shot a G2 Contender so my comments only apply to the older style.  The first thing that happens with larger diameter cases is sticky extraction.  With smaller diameter cases like the 222 Remington, you can get a pierced primer.  You don't see primer flattening to speak of.  I don't use a chronograph in load workup since I think it gives undependable indirect information.

[Javelina]

You've asked for and received some good advice here.  Most importantly, check several respected reloading sources that publish information when possible and don't exceed their maximum recommendations.  Although they may only seem like recommendations, you should consider them the law.  Also, don't try to extract the maximum velocity from any metallic cartridge that you're reloading, if you need more velocity or a larger bullet for more performance. . .simply use a cartridge better suited for the job.  It's always tempting to squeeze the last drop of performance out of any firearm, but listen to the voices of logic and reason here - DON'T DO IT!  By not being foolhardy with reloading components, you'll never have to depend on luck to keep you and those around you safe, luck is a fickle friend and not always around when you need it.

Another important consideration is not to depend on any one over-pressure sign too much.  Learn to use a combination of various factors since you can't always depend on any one single part of the equation to tell you the entire story of where your handloads are pressure-wise.  Even the sticky extraction issue cannot always be depended on due to various degrees of case taper, the degree of roughness (or smoothness) of a given chamber and other elements such as case wall thickness, work-hardening of your brass, etc.  I have seen some serious mistakes made with a highly tapered case that was reloaded at maximum levels and fired in a chamber that had been highly-polished by a T/C's previous owner, all the while this issue was completely unknown to and not considered by the current owner who was surprised and amazed by a serious over-pressure situation that could have resulted in very serious injury.  Fortunately, all this fellow had to do was buy a new barrel and learn from his experience.  On another day he and those around him may not have been so lucky.

Use all the pressure signs and safety practices available to you and don't exceed reasonable maximums, by doing this, you'll be able to continue to read and reply to all the cool information and discussion here in Graybeard's forums here instead of having them read to you and having someone type your replies for you.

Stay safe.

Javelina

[goodtime7]

thanks for all the ideas/thoughts on this subject.  I hope that I didn't give the impression that I like to push reloading data, etc to the max.  In fact, I tend to be pretty conservative (for the reasons we all know).   I think it is relatively easy to load for common calibers, but when you start talking about wildcats with minimal data, more information is obviously better.   Appreciate all the responses.  Best in the Holidays.   

[David D.]

This is my thoughts and my way. Follow all the Golden Rules on reloading. Like many have said sticky extraction will usually be the first sign of high pressure. But still watch all the other signs. Working towards Max loads isn't such a bad thing as I'm sure for liability purposes they wouldn't be listed in the manuals, but should be done in a safe way. I know compared to a good bolt gun the TC is a weaker action. I have taken a TC past listed max with no ill effects or signs of high pressure and have seen signs of high pressure before max on some. But not all barrels, or guns are the same that's why you have the starting load and rules and guidelines for reaching max. Never shoot loads developed for one gun in another as their max may be different! I know not everyone has dedicated frames for each barrel so I would keep records for barrel/frame combos and always match them the same. I myself dedicate a barrel to a frame. Most my TC's shoot their best at or near listed max loads. I do have an Encore 14" pistol  22-250Rem. that it's best accuracy comes way under listed max.

I,m sure I haven't said anything here that you and most us didn't already know!

[shot1]

Start low and work up your loads. DO NOT JUST FOLLOW PUBLISHED DATA. Most data for pistol rounds like the 357 or 44 mag were done with revolvers and that can get you into trouble quick with a closed breach like the Contender. It happened to me years ago with my first 357 mag barrel contender. The rounds that worked perfectly and accurately in my revolver were tried in my Contender. I thought a 357 mag was a 357 mag.    I had to use a pocket knife to pry the cases out of the chamber.

If you have a wildcat round like the 30-30AI you get to find your own way down the dark path  . I have found a Chronograph to be very useful in finding loads. You know by the velocity you are getting when the pressures are getting up there even though you might not be seeing some of the standard "signs" of pressure on a case or primer. I have found this to be especially true with custom barrels. Their chambers are usually much tighter and better than the average production chamber. You reach the high velocity with less powder in custom chambers so start low and work up and watch the velocity on the chronograph. When you start to get to or above the average velocity for the round you know that your pressure is getting up to about max.