Sticky bolt lift not due to pressure

[js2013]

Norma brass is soft? Chuckle chuckle,.

From your little "chuckle chuckle" comment I'm guessing you think Norma brass is not soft. Good to know. I've also read its soft that's why I wrote "POSSIBLY" since I never tested it. Mostly I've read it's good, but it's expensive and I don't want to buy a bunch if it's soft or I might get a soft batch. Never heard of certain other brass manufacturers releasing soft brass. So if you or anyone else can, through experience, tell me they never had a problem with Norma brass, I would appreciate it.

 

[BoydAllen]

I found the opposite as many, but with qualifiers.
I built a 6.5wssm Imp with a chamber of my own that I fitted to new brass. That is, no more than 1thou total clearance, at any dimension, over new brass. I then ran pressure testing to find MyMax load(which is a point of needing FL sizing, I don't FL size). I was able to run pressures way beyond SAAMI max before hitting the beginning of body sizing requirement. I had hit MyMax at ~3290fps.
My accuracy node, which is within the 26cal mid node, is 3025fps with 139Laps. By QL this is 65Kpsi(right at SAAMI max).
With this & 35+ reloads later, I still have no need to size the bodies at all (and never have).

I know others had tried the 6.5wssm without success, but a difference I notice is that they did not run a magnum diameter action/tenon. So they did not have enough barrel steel around the chamber. Some did not run with a coned breech, which extends threading to better support breech expansion. Nearly all used high clearances at the web area..

If your clearances and pressure cause the brass to yield, it will, and it will not spring back with prior recovery.
Mitigate yielding all together, and the brass will spring back recover, full amount, --> forever.
Where it appears this doesn't work, there is something here they missed in their design.

Notions here in the shooting mob remind me of past shade tree/hot rod mechanics, swearing that where things break you need even more clearances.. Eventually I (and pretty much everyone else) learned (from Smokey Yunick) that this was never true, there was never credible basis in it, and in fact the truth was just opposite.
Now modern engines, including the highest performance among them, run tighter clearances than ever.

Two questions: How did you arrive at your pressures? What action did you build on?
Finally a comment, I find your reference to shade tree mechanics to be unnecessarily condescending toward the many posters who have honestly related their personal experiences in this thread. Since you are of the opinion that the rest of us are such ignorant hicks, would you mind giving us a rundown of your qualifications as they relate to this specific subject?

 

[Northridge]

Did the brass in question start it's life in this chamber or a previous chamber?

Shawn Williams

 

[noload]

Very interesting topic....It sure beats the nonsense BS topics I've been seeing lately.

 

[GrocMax]

In this particular case (6XC) y'all are missing the point entirely- the original reamer spec was set up for 22-250 brass which has a base diameter at the datum line considerably smaller than 308/243 dimensions, Norma made their 6XC brass to the 308 base dimension.
Using 22-250 6XC brass in the Norma 6XC chamber caused issues. Norma brass wouldn't chamber, or chambered very tight at the base in the original 22-250 base dimension reamer 6XC.

 

[chuckshooter]

I don't mean to be rude to the OP, but isn't a sticky bolt caused by pressure of some sort. if there was no pressure wouldn't the bolt open the same as it closed. maybe he means excessive pressure or more pressure the brass can handle, or more pressure than ???? do we have a way to measure the pressure? ok it's late and I may have had a adult beverage or two but I still think a sticky bolt is caused by pressure. I'm just saying

 

[jds holler]

I don't mean to be rude to the OP, but isn't a sticky bolt caused by pressure of some sort. if there was no pressure wouldn't the bolt open the same as it closed. maybe he means excessive pressure or more pressure the brass can handle, or more pressure than ???? do we have a way to measure the pressure? ok it's late and I may have had a adult beverage or two but I still think a sticky bolt is caused by pressure. I'm just saying

You should never discuss reloading while under the influence. jd

 

[Milo 2.0]

Norma brass is soft? Chuckle chuckle, Mentioned above I think, a tight chamber and fat dies do not go hand in hand. I don't have that problem because I spec a die reamer .003 at the web and .002 at the shoulder tighter than my chamber reamer.
You can't size a small piece of brass with a fat die.

This answers the question ^^^^ right here.
I just went through the same crap with a 6x47 and an oversized die and a tighter chamber due to reamer wear, and with the smith I use will never chamber another gun without doing 2 barrels at a time.

 

[tclaunch]

At http://www.6mmar.com/6XC_II.php I read that sticky bolt lift (in this instance) was due to using Norma brass in a tight chamber.

Due to a tighter chamber I would expect pressure to go up a little but not a huge amount, and the sticky bolt after firing would be caused mainly by the lack of clearance in the chamber and possibly brass on the soft side. Would you agree?

The fastest way to get a sticky bolt is to have a chamber so close to resize die dimensions that the case does not have enough clearance for smooth extraction. If you like to order custom dies then run the base numbers of your reamer on the tight end of the spectrum. I have used Redding S-Type FL dies many years now, and have ordered a dozen or so variants of reamers and have learned to simply go with .4714" at the .200" on the 308 based chambers. I ordered the 6 XC-II reamer and the Redding FL S-Type die Mr. Whitley sells. It is the perfect combination for use with Norma brass. I went with different freebore length and diameter.

 

[js2013]

The fastest way to get a sticky bolt is to have a chamber so close to resize die dimensions that the case does not have enough clearance for smooth extraction. If you like to order custom dies then run the base numbers of your reamer on the tight end of the spectrum. I have used Redding S-Type FL dies many years now, and have ordered a dozen or so variants of reamers and have learned to simply go with .4714" at the .200" on the 308 based chambers. I ordered the 6 XC-II reamer and the Redding FL S-Type die Mr. Whitley sells. It is the perfect combination for use with Norma brass. I went with different freebore length and diameter.

Exactly. As Mr Whitley wrote if you use Norma brass use the II reamer at .4714. If you use the Norma brass with the Type I reamer designed around the 22/250 brass with the smaller diameter you'll get sticky bolt lift even at moderate pressure due to lack of clearance.

 

[DJB]

I had a rough time for a while with a sticky bolt, and pierced primers. I watched Alex's video on how to set up your dies with the firing pin, and spring removed from your bolt. I set up my die using his method, and ALL my problems of heavy bolt lift and pierced primers went away. When you set up a wildcat cartridge it is very important to get you resize die set up properly. FWIW. Doug

 

[js2013]

In this particular case (6XC) y'all are missing the point entirely- the original reamer spec was set up for 22-250 brass which has a base diameter at the datum line considerably smaller than 308/243 dimensions, Norma made their 6XC brass to the 308 base dimension.
Using 22-250 6XC brass in the Norma 6XC chamber caused issues. Norma brass wouldn't chamber, or chambered very tight at the base in the original 22-250 base dimension reamer 6XC.

Good post.
Correct me if I'm wrong but I think you meant to write "Using Norma 6XC brass in the 22-250 chamber caused issues." Not the other way around.

 

[GrocMax]

Yeah I could have used better wording. I had problems both ways.

 

[varget204]

Sticky bolt lift can be caused by headspace,if a case has been fired multiple times and shoulder has not been bumped back,ya get stiff /sticky bolt lift.Doesn't have to be High Pressure,Hot loads etc.Normal expansion of case.I'd check headspace of case.

 

[KenOath]

Sounds like your Die doesn’t work with your reamer/chamber.. Either have a FL Die made to match your reamer/fired brass or change reamer spec to suit how much your Die sizes at the neck shoulder/.200” line.. Heavy bolt lift at top of open stroke can be caused by not enough sizing by Die at .200” line.

 

[Willie]

Congratulations Gentlemen! This is the type of discussion that we can learn from. Thanks to those that share their knowledge.

 

[rhovee]

I recently experienced this same issue. A friend had a 300 RUM built for him with a min spec reamer and also neck diameter on Nosler Brass. He tried ADG brass and the necks were thicker than Nosler and caused bolt lift on all charges, even min book.

 

[ratbuster]

Many owners of 20 Vartarg's that use Lapua 221 Fire Ball brass suffer from this malady. Todd Kindler originally designed this cartridge around Remington brass. Years later when Lapua began producing Fireball brass many shooters using it had problems with "clickers" on bolt lift even though pressures were not excessive. Turns out Lapua brass is a few thousandths larger diameter at the base than the early Remington brass. Anyone getting a new Vartarg needs to make sure the reamer is designed with a larger base diameter than Kindler's design to accommodate the new thicker at the base Lapua brass.

 

[KMart]

In this particular case (6XC) y'all are missing the point entirely- the original reamer spec was set up for 22-250 brass which has a base diameter at the datum line considerably smaller than 308/243 dimensions, Norma made their 6XC brass to the 308 base dimension.
Using 22-250 6XC brass in the Norma 6XC chamber caused issues. Norma brass wouldn't chamber, or chambered very tight at the base in the original 22-250 base dimension reamer 6XC.

I suffered through this scenario with my first 6xc. The reamer was made to shoot fireformed brass from 22-250 cases, about .468 at the base. As long as you used the 22-250 brass, everything worked as planned, with easy bolt lift until you got ejector marks and flattened primers.
I bought the Norma Tubb brass and I had a hell of a time opening the bolt no matter how light the powder charge was.