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Sticky bolt. Definion?
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Hi

When I started reloading, a long time ago, I was told that a sticky bolt is a sure sign of excessive preasure (if chamber, brass, firing pin and so on are in order).
I have lived by this rule and I have not had any preasure related issues with my reloads so far. I have also not had the fastest loads in hunting camp...

I now have QuickLoad and the program tells me I should be able to reach quite a bit more velocitie with most of my loads and still be on the safe side regarding preasure. (Yes, I have plugged in my actual values for OAL, case capacity and so on).

Testing this I, as predicted, can reach the higer velocities with out any preasure signs on the brass/primer but the last few degrees of bolt lift on my M70 Winchester gets noticably harder as the loads increase. Not that i need to realy force it or hit the bolt handle to open the bolt. It's more like a litle "click" as the bolt opens that last bit and not as smooth and effortless as with the milder loads.

My question is; should the bolt open as easily as when cycling an unfired cartridge, after the round has been fired? In other words, what is the definition of a sticky bolt lift caused by excessive preasure?

I appreciate any input you have on this!
//Klein
 
Posts: 101 | Location: Sweden | Registered: 03 March 2008Reply With Quote
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Yes. It is as you describe. You have exceeded the elasticity of your brass and it has entered the permanent deformation state. Doesn't mean it is not "safe".
All brass is not the same, however.
 
Posts: 17046 | Location: USA | Registered: 02 August 2009Reply With Quote
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DON'T BELIEVE QUICK LOAD without testing!!!!!!!!!!!!!!

I've had QL since it first came out and also Load from a Disk and ALL the Powley computers even before the paste board "slip/slide rule" and I GUARANTEE QL has come up with VERY SPURIOUS results...I DON'T trust if for any thing other than a reference...all the software programs and reloading manuals should be used a REFERENCE ONLY and NOT as "the be all and end all"....some are only software mathematical algorithms, some are actual firing and some use pressure guns with LONG barrels to develop data.

I've been doing this game since the late 50's and can ALSO GUARANTEE that various brands of brass are softer/harder than others and can give varying "sticky bolt" results with the SAME set of load parameters...bullets have varying amounts of "barrel friction" and barrels are notorious for being "fast or slow"

"Start Low and work up SLOW" has been my mantra...the difference between 50 to 100 fs velo doesn't mean squat doodly to a game animal and only gets relative out past say 300 yds as far as drop is concerned regardless of all the online BS hype and mostly with VLD type bullets.

Most of the early "pressure indicators" like "sticky bolts, flattened primers, fired case length increases, high velocity over reloading manual results and so on, and can still be used to in dictate a "hot load". Case life can be a good indicator...a case that lasts 15 firings is getting less pressure than one that dies after 3-4 firings. Once a good load is found you should take ONE case, load and fire it as many times as it will take until the "incipient head separation" bright ring starts to show...THAT will give you a good indication on where the pressure is...absent sending a few loads to a pressure testing lab for a pressure average reading which is the best way or do it yourself with a "pressure testing kit"

Remember also that ALL hunters, fishermen, golfers, bowlers and EVERYONE ELSE are total, abject liers, so what "camp followers" say is not always what is real. Besides chrono'es can "lie" also and give results that are MANY FPS different between each other. I have an Oehler 33 and a Beta Chrony and the Chrony is ALWAYS between 75 and 125 fs higher...that is one set up behind the other and switched just to check. My 33 is usually very close to what several reloading manuals show as long as ALL the parameters a very close, i.e., barrel length, bullet weight and brand, COAL, the same brand/type of primer brisance and brass, trimmed length etc.

Receivers and headspace can be problematic areas...rear locking lugs and/or front locking lugs have varying amounts of seating contact and can cause sticky bolts without getting into the "danger zone". Judicious use of a small amount lapping paste can cure some of those problems.

A "sticky bolt" can mean MANY THINGS besides pressure problems...that is...unless you have to use a hammer to get the bolt loose, and you have to work through many parameters, OR NOT if you want to reach those higher "SAFE working pressure loads"

Good Hunting tu2 beer
 
Posts: 1211 | Registered: 25 January 2014Reply With Quote
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Also, is your brass being fired in more than one gun. I have had brass that was shot exclusively in one barrel, Had the gun rebarreled, and got the same click at the top that you refer to. The brass had taken a "set" in the one chamber that the sizing die could not take out, and the new chamber with slightly tighter tolerances caused the sticking.
 
Posts: 288 | Location: AL | Registered: 11 July 2005Reply With Quote
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You need a chronograph when using Quickload and adjust the burn rate in Quickload until it matches chronograph velocity.

Meaning you need to tweak Quickload to get ball park computer generated guesstimates.
 
Posts: 217 | Registered: 29 July 2009Reply With Quote
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I believe a sticky bolt is a warning sign you should pay attention to. It usually means you are substantially beyond max pressure. Can you post a picture of your brass after firing with the primer still in it? I'm guessing the primer is cratered and there are shiny spots on the head of the case. If so you need to back off your powder, or go to a slower powder and start working your way up again.

I consider myself a safe, but not conservative reloader. I've loaded 150g Partitions to 3000 fps in my 270 Win for many years. It's a BDL with a 22" barrel. I use my cases 10 times then throw them out. I have no cratered primers or hard extraction or shiny spots on the head of the cases. You can get to the advertised velocity, it just may take a different powder.


Regards,

Chuck



"There's a saying in prize fighting, everyone's got a plan until they get hit"

Michael Douglas "The Ghost And The Darkness"
 
Posts: 4712 | Location: Colorado Springs | Registered: 01 January 2008Reply With Quote
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quote:
Originally posted by dpcd:
. . .You have exceeded the elasticity of your brass and it has entered the permanent deformation state. Doesn't mean it is not "safe". All brass is not the same, however.

Exactly. Once the bolt indicates resistance on opening the elasticity of the brass has been exceeded and the load, though not necessarily "unsafe" is not sustainable (the brass will become unusable in only a few firings). A lot of brass with a harder head might not exhibit the same deformation, thus allowing a higher pressure and velocity (although you would have no way of actually knowing that the pressure was higher.)
 
Posts: 13214 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
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The most common brass in Sweden Norma are designed to give tell signs still at safe pressure levels, it a bit softer than some other makers. 72% copper and 28% zink other may use 70% copper and 30% zink.

I once had a Browning 81blr what had sticky lever because of some brass expanded in the ejector hole, the solution was to reduce the load a bit.
 
Posts: 3611 | Location: Sweden | Registered: 02 May 2009Reply With Quote
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I guess that is because Sweden always used the 96 Mauser for everything so the brass is a sort of safety valve.
Nothing wrong with the 96; don't send me any hate mail. I get enough already for stuff I post.
 
Posts: 17046 | Location: USA | Registered: 02 August 2009Reply With Quote
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quote:
Originally posted by dpcd:
I guess that is because Sweden always used the 96 Mauser for everything so the brass is a sort of safety valve.
Nothing wrong with the 96; don't send me any hate mail. I get enough already for stuff I post.

Except for the distraction of cocking on closing, the M96 Mausers aren't really any less strong than the 98 Mausers. The steel used by any particular manufacturer would have more to do with the strength of a given Mauser action than which series it belongs to.

And yes, the Norma brass that I have used is softer in the head than that of most manufacturers. Norma used to advertise this (many years ago) as a "safety" feature so that handloaders would know when they were approaching "unsafe" pressures. This is hogwash, of course, since it is the brass case head that gives up long before the integrity of the action is exceeded. Ergo, if you make the case head weaker (softer) then the "safe" load pressure is lower.
 
Posts: 13214 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
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I suppose most sticky bolts have a case head with a extractor mark and you need to be safe and cut back a grain..cutting back a grain or two is always a good idea under such circumstances..A combination of both is a definite cut back, a ever so lightly sticky bolt doesn't necessarily say cut me back, cut me back, but its time to pay attention. shocker


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
 
Posts: 41763 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
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