Shoulder bumping issue now stuck case

[vancewalker007]

So, I annealed all my brass and went back to the bench to see if I can get the shoulder bumped. I removed the firing pin for the bolt (M700) and chambered a fired, sized case. Stiff bolt closing. I preceded to size another case with shell holder .010, no change. I grabbed another case and tried shell holder .008, no change. I did this all the way to .002 with no discernible change using different brass with each shell holder.

Recap:
Hornady factory 7x57, fireformed in my rifle with a 40 degree AI chamber. All brass were then loaded again as 7x57AI with RCBS 7x57AI 40 degree die and fired again. That twice fire fired brass was loaded a 3rd time. These are the loads (3rd loading) where I've had 3 that I cannot close the bolt per post #1. If memory serves me right, I've had tight closing bolt with some at after the 2nd firing but nothing near what the 3 were that I had to pull. The remaining 20 loaded rounds I have all chamber nicely with a few that have a little resistance but not bad at all. I started this thread thinking It's a simple shoulder bump issue but I can't seem to figure it out. The rifle has about 100 rounds down it and shoot great. I know I've read where some reamers don't quite match the die and one's 40 degree isn't the others. Thinking the next step is to trim all down to 2.225 which I think is the standard 7x57 trim length. A few I measure last night were at the upper limit of 2.235-2.240. I may have to eat crow from my reply on post #20 of not needing to be trimmed.

Is it possible that my chamber is just too tight? Die is mismatched?

I'd be recording the following on fresh cases, fired cases and fired-sized cases.
- base to mid-shoulder length measurements
- Web diameter
- Over all case length, I'd trim about .001 under suggested trim to length just to be sure

The web area on the case can cause snugness on close, ran into this on my 6.5 PRC. If you don't have your bump set correctly the cases will sometimes not go into the die the correct distance to resize both the shoulder distance and the web area. I found with my setup I needed to bump this 6.5 PRC .004-.005 to get the whole case properly resized. It cured my web area size issue completely. I went through a bunch of fired cases moving the die down and up until I hit the sweet spot.

 

[Shane Lindsey]

Don't trim until after you size. Did you try to adjust the die down or just the shell holders. I had to move the Hornady die down a good bit and it still doesn't cam over.

 

[338weatherby]

I'd be recording the following on fresh cases, fired cases and fired-sized cases.
- base to mid-shoulder length measurements
- Web diameter
- Over all case length, I'd trim about .001 under suggested trim to length just to be sure

The web area on the case can cause snugness on close, ran into this on my 6.5 PRC. If you don't have your bump set correctly the cases will sometimes not go into the die the correct distance to resize both the shoulder distance and the web area. I found with my setup I needed to bump this 6.5 PRC .004-.005 to get the whole case properly resized. It cured my web area size issue completely. I went through a bunch of fired cases moving the die down and up until I hit the sweet spot.

I am going to start with the fresh factory loads and do this ^

Need more cases fire formed anyway and I've got 4 boxes of factory sitting doing nothing.

 

[338weatherby]

Don't trim until after you size. Did you try to adjust the die down or just the shell holders. I had to move the Hornady die down a good bit and it still doesn't cam over.

I tried both. The MEC press cams over pretty good.

 

[nksmfamjp]

The MEC press cams over pretty good.

Are you sure about that? It is not a camover press.

 

[338weatherby]

Are you sure about that? It is not a camover press.

Yes

When it cams is over, I can let go of the handle and it'll stay. Then you can feel it pop back.

 

[sedancowboy]

OK guys Redding does NOT make a set of shellholders that are smaller/shorter than regular shellholders which are .125 nominal. The Redding Competition Shellholders are taller to size Less not more. Each Shellholder in the set of 5 is taller by an increment of .002. In other words the shellholders are in order .127, .129, .131, .133, .135 taller than a standard of .125. They are made to set a hard stop at cam over to size less.
They are a really great tool to fine tune your sizing to fit your chamber plus you can use the same die setting with more than one gun without having to readjust your die.
However they do not allow you to size more only Less. They simply keep you from pushing the case into the die as far as a standard shellholder allows.
The simple fix to the OPs problem is to shave a little off of the top of the shellholder. I have done this very successfully by turning the shellholder upside down onto a flat surface and using fine emory cloth. Go slow and check often to get to the sizing you need.

 

[338 dude]

I think I may need to ditch the quick change bushing set up. The press itself does not flex. It's a MEC Marksman. The die is what is moving. Direct threaded won't.

Hornady lock and load bushings have been known to strip out over time

 

[338weatherby]

OK guys Redding does NOT make a set of shellholders that are smaller/shorter than regular shellholders which are .125 nominal. The Redding Competition Shellholders are taller to size Less not more. Each Shellholder in the set of 5 is taller by an increment of .002. In other words the shellholders are in order .127, .129, .131, .133, .135 taller than a standard of .125. They are made to set a hard stop at cam over to size less.
They are a really great tool to fine tune your sizing to fit your chamber plus you can use the same die setting with more than one gun without having to readjust your die.
However they do not allow you to size more only Less. They simply keep you from pushing the case into the die as far as a standard shellholder allows.
The simple fix to the OPs problem is to shave a little off of the top of the shellholder. I have done this very successfully by turning the shellholder upside down onto a flat surface and using fine emory cloth. Go slow and check often to get to the sizing you need.

Isn't that pushing the case .002 into the die further, thus bumping shoulder? The space from the top of the shell holder to the base that supports the case decreases .002 with each shell holder. I measured all of them. This is the method I tried.

 

[sedancowboy]

If you start with the +.010 shell holder that is .135 tall and then use a +.008 then yes it is .002 more sizing than the +.010 but is is .008 less than a standard shell holder. If you look at then they clearly state on the shellholder +.010 all the way down to +.002 the Plus sign is to indicate that they are taller than a standard shellholder. Measure them for your self and it might help you to understand.

 

[DUSTY NOGGIN]

Isn't that pushing the case .002 into the die further, thus bumping shoulder? The space from the top of the shell holder to the base that supports the case decreases .002 with each shell holder. I measured all of them. This is the method

no,
consider the cartrige you have, has a minimum sammi headspace .. the full length die when bottomed out on a standard shell holder is supposed to size the shoulder to the minimum sammi height to fit in any gun of same cartridge chamber..

lets call that zero

most chambers (except yours ) will chamber and fire a minimum sammi cartrige .. but the once fired brass will swell to match the actual chamber size of each and every gun .. that once fired measurement will be somewhere beteeen the zero we stated earlier and +.010 longer than sammi minimum (zero) .. sammi headspace tolerance

once you have measured your once twice or 3 times fired brass you will know how much it will swell to fit your chamber

the objective is to be .002 shorter than the swollen once fired chamber measurement

in your case the Redding comp holders will not help you

is your shell holder the same brand as your die set ???

that is why people are suggesting taking your easily replaceable cheaper shell holder and sanding down the top the .002 more that you say you need to get em all to fit

but before you do that you will want to soot or ink the brass and see that it is in fact hitting on the shoulder when chambering , and not contacting at the case mouth due to carbon ring or lack of trim clearance or

you may need to remove your ejector plunger from your bolt when checking the fitting.. to feel if it may be wedging in the side wall

i find it odd when this happens.....because it adds so many more possibilties

in a perfect world all once fired brass should be in bewteen the headspace tolerances for the cartridge.. its weird when yours is shorter . that means that some factory brass wont fit your gun

 

[DUSTY NOGGIN]

New & Revised Cartridge & Chamber Drawings - SAAMI

saami.org

 

[DUSTY NOGGIN]

if you used a comparator to check length using a .375 opening to hit in the middle of the shoulder


you should end up with a fired case that measures between 1.794 and 1.804 ( notice that is .010 variation ... that is why Redding makes them only in +.010 ..


what i believe you are saying is ( with a .375 comparator bushing per sammi drawing)

you need to size down to 1.790 to 1.792


is your comparator bushing a .375 ???

 

[338weatherby]

Thanks for a good info Dusty. You explained well. I'll be gone for the next 5 days and will be hitting this again when I get back. Instead of using the comparator gauges, I just tried chambering (with firing pin removed) and shouldn't used the gauges.