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  #81  
Old 07-07-2016, 01:06 AM
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Quote:
Originally Posted by Sheepherder View Post
To UncleNick and others,

I have a new S&W M29 with some 80 rounds through it. In one range session, using True Blue, at moderate loadings (13.2 gn, 13.7 gn and 14.3 gn) -- max is 15. 3 grains) with Sierra 240 gr jacketed hollow points in new Starline cases that had been resized before loading and using Winc. LP primers I had sticky cases for some of the powder charges.
Terminology here is important. You had cases that were hard to extract if I understand you correctly.

Quote:
Others who have commented said sticky cases means over pressure. The low loads (13.2 g) did not stick. The next load, 13.7 and 14.3 grains both were sticky to get out. Had to hit ejector with the ammo box to break the contact and extract cases. After I resized them some 5 cases were very hard to get into a case gauge. I tossed them as they seem over expanded at the base. I ran a couple through the press and they finally came back to spec. I assume this is another sign of over pressure in higher pressure and thus higher powder charges. Do some powder jump that far from the norm in certain guns?

Yes in my case it would normally be .45acp. Titegroup is typical for quickly going over pressure.

Quote:
Of the 100 Starline cases from that batch of brass, 24 or so had flattened Winchester LP primers. That is about the number of rounds I loaded with the True Blue at 13.7 or 14.3 gr. I looked at the primers after firing and since I am new to this I thought they were a little flattened, but am aware of different hardness so I did not know what to make of it. After I popped the primers you can see the ring on the top on some 25% of them.
Flattened primers and cratered firing pin strikes are typical indicators of pressure problems.

Quote:
1. Has anyone had a similar result with True Blue and .44 mag loads? The Unique loads I shot before the True Blue had no issues; they were subsonic for the most part.
Sorry never used it. This is a good indicator that it's probably not a good powder for your caliber.

Quote:
2. Was sticking do to fouling of the cylinder with the Unique loads, and the increased pressure from hotter True Blu loads that embedded in the hotter loaded cases in the grit?
Hard to tell unless we were there, but the flattened primers are an indicator that your pressures were high. I use Win LP primers and I have noted they're a touch hotter than Federal LP primers. But they work fine for the pistols I use them in since I balance the loads.

Quote:
3. How about crimping to hard and increasing pressure? I put a pretty good roll crimp on the cases using a RCBS carbide die. Trying to find a metric for a hard crimp versus a mild crimp. It seems to me it is the width of the band at the case mouth. Mine were about a millimeter in width. I have since back off till it is hardly noticeable as a line, but you can see under magnification the contact of the case with the cannulure.
Hard crimps (taper or roll) will increase pressure, trying to explain it doesn't really work well. Ought to talk to the tech support at Sierra about this one, they're good guys and the one person you ought to try for on this is Rich. He's a good guy for helping pin down the problem and they have a great knowledge base for a wide range of powders.

Quote:
What I did not do:
1. shoot factory loads to know if this is a common problem for the gun.
I think the other reloads I made and shot suggests this is not the simple answer as other cases even with True Blue did not stick. Perhaps a combination of physical things near the margin of being out of spec. combine to push the pressure and the thus the cylinder imperfection comes into play
Trying to really isolate the problem can be a problem given we aren't there to see things or inspect things. First thing I'd do is call Sierra and ask them about the problem and reference for a better powder. I have no experience with the powder you're using, but there are powders that preform more reliably with your caliber.

Quote:
I have several powder choice so don't need to push the True Blue. I am wondering if the issue I had is powder specific or gun specific when the fps gets pushed up. This could be a gritty cylinder or a atypical small bore. Leave True Blue alone or figure out the issue?

Relating similar results and fixes would be helpful.
Given it's a Model 29, I'd be real careful about pressure problems and go very slow after you talk to Sierra and get a better handle on it. Model 29's are not really built to take a lot of abuse from pressure. I've seen the top ends blow off with bad loads. Go slow, go CAREFULLY!

Last edited by rojkoh; 07-07-2016 at 01:08 AM.
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  #82  
Old 07-22-2016, 06:13 AM
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Here is a very recent article on the subject. I found it extremely helpful.

Primal Rights, Inc :: Understanding Pressure
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  #83  
Old 07-30-2016, 03:19 PM
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You have been given lots to look for, some good and some not necessary..I do as follows:

1. Keep it simple

2. start a couple of grs. below book max. Use several books. and work up from minimum recommendation 1 gr. at a time at least until you get close to max then go 1/2 gr. at a time..

3. Probably the first sign you will see is a flat primer, but that's an iffy sign as primers vary in strength, then comes the cratered primer, and that's the same deal, its iffy, but if it has a black ring around the outside, its time to cut back..

4. While doing #3, watch for an extractor mark on the case head, if you get one your about agrain too hot so cut back 1 gr. and call it good...a stiff bolt lift is another indicator or pressure, a crack as opposed to a boom is an incicator of pressure, sticky extraction is a sign of pressure...this is all stuff to look for and cut back a grain or two on..Do this and you will never injure yourself or the gun.

Go beyond 4 and you may blow a primer, so wear glasses, you can blow off the extractor, and blow a case in half..All of this is bad stuff but seldom results in injury however you don't want it to happen...Most good bolt guns have been tested at 180,000 PSI and that's about double what we need to be working with on max loadings..I use a chronograph and I know where velocity max should be and Im striving for that more or less, I use one case to work up loads and I check for "0" expansion at the base with each fired load, I do not want expansion.. I trim the case and reload it and watch for a loose primer as that also tells me the load needs to be cut back a grain or two..I expect to reload a case at least 10 times and in many cases 15 or more isn't uncommon....

That's how I do it, but I am only looking for where max is with my rifle, I don't load it max, nor hunt with max loads, just near max...a 100 FPS makes no difference to a game animal, so strive to load where the accuracy is best..sometimes that's very close to max is the problem..but good advise is never to go beyond 2 grs over "book max" and approach that very carefully 1/2 gr, at a time ....I say this because many reloading books have that edge written in to protect them from frivolous law suits...follow the rules..never get over confident..

On occasions a load meets all the criteria as a good load, but after two or three firings you get some pressure indications, time to back off a grain if you do...

I have followed this system for near 70 years with only a few minor incidents such as a couple of blown primers, a sticky bolt or two, and one case separation in a 25-35 that had head space..

Last edited by Big 5; 07-30-2016 at 03:27 PM.
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  #84  
Old 07-30-2016, 11:26 PM
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Quote:
Originally Posted by Big 5 View Post
You have been given lots to look for, some good and some not necessary..I do as follows:

1. Keep it simple

2. start a couple of grs. below book max. Use several books. and work up from minimum recommendation 1 gr. at a time at least until you get close to max then go 1/2 gr. at a time..

3. Probably the first sign you will see is a flat primer, but that's an iffy sign as primers vary in strength, then comes the cratered primer, and that's the same deal, its iffy, but if it has a black ring around the outside, its time to cut back..

4. While doing #3, watch for an extractor mark on the case head, if you get one your about agrain too hot so cut back 1 gr. and call it good...a stiff bolt lift is another indicator or pressure, a crack as opposed to a boom is an incicator of pressure, sticky extraction is a sign of pressure...this is all stuff to look for and cut back a grain or two on..Do this and you will never injure yourself or the gun.

Go beyond 4 and you may blow a primer, so wear glasses, you can blow off the extractor, and blow a case in half..All of this is bad stuff but seldom results in injury however you don't want it to happen...
This is a seriously flawed piece of information. Start two grains under max? You're trying to get people to do something that may well do damage to them and/or their rifles. No sane shooter I know starts 2 grains under max. You start well below that and work up carefully, that's called common sense and doing it smart and safely.

Quote:
Most good bolt guns have been tested at 180,000 PSI and that's about double what we need to be working with on max loadings..
You've posted this figure before, I called you on it and so did Unclenick, it's pure horse ****e. NO SAMMI chambered rifle is tested to 180,000 PSI. John Garand only took the M1 up to 125,000 just to see what it would do, and the Garand is built tough for battle.

Quote:
I have followed this system for near 70 years with only a few minor incidents such as a couple of blown primers, a sticky bolt or two, and one case separation in a 25-35 that had head space..
Frankly with this "advice", I'm surprised you're still around.
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  #85  
Old 08-03-2016, 05:11 PM
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MZ5 MZ5 is offline
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Rocky Raab's advice was appropriate and prudent:
Stop at book-max charge weight or book-max velocity, whichever you reach first.

It's simple, fairly inexpensive (you do need a chrono), effective, and conservative.
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