Still doubts about shoulder bump...

[LCazador]

Due to brass springback there isn't a perfect bump 100% of the time. And the more you shoot that brass the less spingback you'll get. I prefer to err on the side of more bump. Dave beat me by a few seconds on his post.

 

[Webster]

Due to brass springback there isn't a perfect bump 100% of the time. And the more you shoot that brass the less spingback you'll get. I prefer to err on the side of more bump. Dave beat me by a few seconds on his post.

Some things are not a problem until you get OCD and start measuring everything.

 

[64Rambler]

Very often times there is a mismatch in the radius at the neck shoulder junction causing a touch point. Not variations in shoulder angle.

And, I found the hard way, that if you have a donut building inside, this effect is amplified, giving harder and harder bolt closing.

 

[jackieschmidt]

Some things are not a problem until you get OCD and start measuring everything.

I measure everything.
But then, I know how.
And I also make my own tools to accomplish the task.

 

[Bob3700]

I have found that annealing the brass after each firing helps maintain consistent shoulder set backs. Using a mandrel to uniform ur necks, if u feel an increase in pressure towards the neck base, donuts are forming and need to be reamed to remove.

 

[Bora72]

If you’re full length resizing without the expander ball, then you’re expanding the neck in a separate operation. Simply switch from using the expander ball to a .262” mandrel to avoid distorting neck geometry.

Hi, that's what I do, I use a mandrel to expand the neck. Let me give you an example... rest your elbows on the table, raise your hands and point them toward each other. Does it look like the shoulder of a cartridge case and its neck? Space your hands as if a mandrel or bullet were going in. Does the angle of your forearms change? I hope I've explained myself clearly, otherwise I'll try a drawing when I get home; maybe I can do it better.

 

[Bora72]

Did the honed die work before honing? You might not have tried.

If I understand the above post correctly, you are comparing brass sized with two different dies, in the same chamber. This will not work. It’s no different than expecting brass sized in one die to fit two different chambers.

The only way to do that is to loosen the tolerances. Both dies meet standards, the standards allow .010”, you are only allowing .001”. That is a problem, +/- .0005” will not be possible until you have a custom die made to match brass fired in your chamber.

I bought the honed die directly from Forster; I didn't send mine, I didn't have it. I had an FL bushing that I used before this one. I'm not trying to compare two sizes; I'm just saying that with this type of die, I don't get the same bump as the other die.

 

[rwj]

Hi, that's what I do, I use a mandrel to expand the neck. Let me give you an example... rest your elbows on the table, raise your hands and point them toward each other. Does it look like the shoulder of a cartridge case and its neck? Space your hands as if a mandrel or bullet were going in. Does the angle of your forearms change? I hope I've explained myself clearly, otherwise I'll try a drawing when I get home; maybe I can do it better.

Using a cylindrical mandrel typically does not cause neck/shoulder distortion as it is always in contact with the neck ID surface. A ball type expander can cause distortion when it reengages the neck on the upstroke, especially if there are “donuts” present. Best wishes to you in resolving your issue!

 

[Doom]

There is a lot BS in this thread and some good advice. The first thing to understand is that measuring brass to determine the chamber headspace is not going to work. This is simply due to springback. Any dimension measured is going to be shorter. The Wheeler method is probably the best approach. However that slightly hard bolt close may not be headspace but body taper. Understand that when you bump the shoulder you are also sizing the rest to the tapered portion of the body. It depends on the specific die.

As for actual datum dimension a few thousandths isn't likely to make a difference in precision as long as it is repeatable. Have you tested this? It's affect on case life is debatable, depending on what sets the ultimate life (primer pocket, case head expansion, case thinning, etc).

As for the bolt lug issue, some slight compression is actually considered in the SAAMI specs. The datum dimension of the case can slightly exceed the headspace dimension by about .004". While some manufacturers do not recommend lubricating the active faces of the lugs it makes sense to lubricate it.

 

[Bora72]

Using a cylindrical mandrel typically does not cause neck/shoulder distortion as it is always in contact with the neck ID surface. A ball type expander can cause distortion when it reengages the neck on the upstroke, especially if there are “donuts” present. Best wishes to you in resolving your issue!

Look, I knew it, did you get offended? Look, I swear, I wasn't trying to make fun of you, I didn't know how to explain it to you. Honestly, if I was at home, I'd be drawing a picture. But I swear, I didn't mean to make fun of you, absolutely not!

 

[rwj]

Look, I knew it, did you get offended? Look, I swear, I wasn't trying to make fun of you, I didn't know how to explain it to you. Honestly, if I was at home, I'd be drawing a picture. But I swear, I didn't mean to make fun of you, absolutely not!

No worries here mate!

 

[jimmymac]

A recurring theme I see in these minutia threads is that we as a group tend to overthink things and want to add steps to our process instead of keeping it simple. Frequently, the fastest way from point A to point B is in a straight line. At least that is how I approach reloading. As long as I figure out what matters and what doesn’t by analyzing my down range results, I can keep my reloading steps to a minimum which I feel benefits me personally. YMMV, but I think that same philosophy would benefit a large swath of this audience based upon all the threads on here where guys are clearly buried in shit that is way down the list of stuff to worry about.

 

[Webster]

A recurring theme I see in these minutia threads is that we as a group tend to overthink things and want to add steps to our process instead of keeping it simple. Frequently, the fastest way from point A to point B is in a straight line. At least that is how I approach reloading. As long as I figure out what matters and what doesn’t by analyzing my down range results, I can keep my reloading steps to a minimum which I feel benefits me personally. YMMV, but I think that same philosophy would benefit a large swath of this audience based upon all the threads on here where guys are clearly buried in shit that is way down the list of stuff to worry about.

I'll bet 80% of the guys on this website worrying about minutia don't shoot competition. They have a factory rifle that shoots about 3/4 to 1"" groups. If you want an accurate rifle buy a caliber that's known to be very accurate and buy a barrel made by one of the top brands used in competition.

 

[dellet]

I bought the honed die directly from Forster; I didn't send mine, I didn't have it. I had an FL bushing that I used before this one. I'm not trying to compare two sizes; I'm just saying that with this type of die, I don't get the same bump as the other die.

And I would say that is perfectly normal. If you have two different types of dies, bushing and normal, possibly made by two different manufacturers, certainly made with different tooling, and the end product they produce is only different by .001” you are a very lucky man.

The problem you are having is more likely diameter since it only happens after sizing the neck with the mandrel. It may Brass thickness at the base of the neck is the most obvious, measure carefully. The angle of the shoulder should not change, but the length will, very slightly. If a bullet is seated deep in the neck, and there is a donut, it could be trouble.

There is another possible problem that can be very dangerous. If your trim length or neck is too long. The transition from case mouth to freebore diameter in the chamber is angled. So a small diameter neck will fit longer into that angle. If the neck is too long, and touches when expanded .002”, it will be worse with a bullet seated and will pinch, if you can even chamber it. If it does chamber and pinch it will raise pressure significantly.

 

[Bora72]

There is a lot BS in this thread and some good advice. The first thing to understand is that measuring brass to determine the chamber headspace is not going to work. This is simply due to springback. Any dimension measured is going to be shorter. The Wheeler method is probably the best approach. However that slightly hard bolt close may not be headspace but body taper. Understand that when you bump the shoulder you are also sizing the rest to the tapered portion of the body. It depends on the specific die.

As for actual datum dimension a few thousandths isn't likely to make a difference in precision as long as it is repeatable. Have you tested this? It's affect on case life is debatable, depending on what sets the ultimate life (primer pocket, case head expansion, case thinning, etc).

As for the bolt lug issue, some slight compression is actually considered in the SAAMI specs. The datum dimension of the case can slightly exceed the headspace dimension by about .004". While some manufacturers do not recommend lubricating the active faces of the lugs it makes sense to lubricate it.

Hi,
You're right about the springback, so I'd add that if I measure 1.4710" headspace, it will definitely be 1.4715" or even 1.4720".
At this point, setting a 1.4690" headspace on the die should give me excellent bolt closure, but that's not the case.
So the hypothesis that you support, that it could also depend on the body taper, is plausible...
It seems strange to me, however, that there is a difference in dimensions and proportions between an FL die and an FL Bushing die from the same manufacturer, especially from a specialized company like Forster.
I haven't tested the repeatability of the measurements yet because I'm still trying to find the right die setting and I don't have many fired cases to resize.
Okay, regarding the case life reasons.
To measure headspace, I use the Hornady .375 comparator, which doesn't seem to be CIP-compliant.
The SAAMI or CIP measurements are like a love manual; they're useful as long as you can read them. Once the light goes out, everyone makes do as best they can...
I put a drop of silicone oil on the bolt lugs.

 

[Bora72]

A recurring theme I see in these minutia threads is that we as a group tend to overthink things and want to add steps to our process instead of keeping it simple. Frequently, the fastest way from point A to point B is in a straight line. At least that is how I approach reloading. As long as I figure out what matters and what doesn’t by analyzing my down range results, I can keep my reloading steps to a minimum which I feel benefits me personally. YMMV, but I think that same philosophy would benefit a large swath of this audience based upon all the threads on here where guys are clearly buried in shit that is way down the list of stuff to worry about.

Please can you explain me better?

Thanks

 

[jackieschmidt]

There is a lot BS in this thread and some good advice. The first thing to understand is that measuring brass to determine the chamber headspace is not going to work. This is simply due to springback. Any dimension measured is going to be shorter. The Wheeler method is probably the best approach. However that slightly hard bolt close may not be headspace but body taper. Understand that when you bump the shoulder you are also sizing the rest to the tapered portion of the body. It depends on the specific die.

As for actual datum dimension a few thousandths isn't likely to make a difference in precision as long as it is repeatable. Have you tested this? It's affect on case life is debatable, depending on what sets the ultimate life (primer pocket, case head expansion, case thinning, etc).

As for the bolt lug issue, some slight compression is actually considered in the SAAMI specs. The datum dimension of the case can slightly exceed the headspace dimension by about .004". While some manufacturers do not recommend lubricating the active faces of the lugs it makes sense to lubricate it.

I disagree with your first couple of sentences.
Actually measuring before the case is sized and afterward is the only way to know exactly how much you are sizing the case.
With any other method, you are guessing.

 

[Bora72]

I'll bet 80% of the guys on this website worrying about minutia don't shoot competition. They have a factory rifle that shoots about 3/4 to 1"" groups. If you want an accurate rifle buy a caliber that's known to be very accurate and buy a barrel made by one of the top brands used in competition.

I don't compete in competitions. I've been shooting this "hobby" for about three years. My rifle can do much better than 3/4" or 1" at 100 meters.
It's a factory 6.5x47 Lapua rifle.

 

[Bora72]

And I would say that is perfectly normal. If you have two different types of dies, bushing and normal, possibly made by two different manufacturers, certainly made with different tooling, and the end product they produce is only different by .001” you are a very lucky man.

The problem you are having is more likely diameter since it only happens after sizing the neck with the mandrel. It may Brass thickness at the base of the neck is the most obvious, measure carefully. The angle of the shoulder should not change, but the length will, very slightly. If a bullet is seated deep in the neck, and there is a donut, it could be trouble.

There is another possible problem that can be very dangerous. If your trim length or neck is too long. The transition from case mouth to freebore diameter in the chamber is angled. So a small diameter neck will fit longer into that angle. If the neck is too long, and touches when expanded .002”, it will be worse with a bullet seated and will pinch, if you can even chamber it. If it does chamber and pinch it will raise pressure significantly.

The dies are both Forster.
I think the shoulder angle changes, but I could be wrong.
The neck is resized to .286" at the base of the neck, the measurement is .291".
The case is on its fourth shot; before that, it was resized with a Forster FL Bushing die.
I don't reload with bullets so deep that they hit a possible donut.
The cases are cut to the right size; I also checked with a borescope and by checking the carbon ring formation.

 

[Bora72]

Oh, I forgot, I anneal the necks after every shot.