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Case sizing problems?
- Thread starter ropeNshoot
- Start date
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two thoughts.
You said this was a new lot of powder right?
do you have a chronograph and have you chronographed your old loads. If so check the velocity of these new loads and see if the velocity is up.
How are you measuring your powder charge? could be you need to check your scale.
SidecarFlip
Well-Known Member
That only applies if the die won't bump because the base is too long and 0.015-0.018 is way too much material removal. I like to grind off 0.003 maximum on the surface grinder with a die chucked inverted on a right angle fixture. Thats plenty because 0.002 setback should always be enough and you want to retain as much of the tapered base lead in as possible...
0.015-0.018 will compromise the lead in.
SidecarFlip
Well-Known Member
It is possible to grind off the base by hand (measuring the overall die length with calipers and carefully grinding off the base), however, you must keep the base square to the body because of the possible interference fit against the shellholder if the die is used in the what I consider the 'old style' cam over scenario, which is why I prefer to jig a die and grind the base on a surface grinder, that way the base is parallel to the body.
Any competent machine shop with a surface grinder can do it in short order at minimal cost.
Any competent machine shop with a surface grinder can do it in short order at minimal cost.
dok7mm
Well-Known Member
Just a wild guess, as I don't have one of your fired cases to measure. It is a belted mag and it's likely that your die isn't sizing that portion of the case right above the belt. Measure that area on several fired cases and compare to your new cases. If that's the problem, you will need a Larry Willis collet die to properly size to belt. This is a common problem on belted mag cases.
SidecarFlip
Well-Known Member
Interesting observation.. I own a 300 WM which is a belted magnum and I've had no issues (even after repeated loadings) with the belt or a bulge above the belt causing issues post firing.
And I load 'em hot too, Just a tad under 3000 fps with 185 Bergers.
And I load 'em hot too, Just a tad under 3000 fps with 185 Bergers.
dok7mm
Well-Known Member
Don't know for positive, the exact cause. Used to believe it was because of a sloppy chamber or way-hot loads, but now am inclined to think more likely it's tied to improper die set-up. I had a 7STW and several 7mags that drove me crazy, trying to figure it out. Larry's collet die solved the problem for me. I like the case gauge on the end of die and use it to check all my belted mag brass now. I don't think the problem is as bad in 300 WM, but thought I'd throw the idea out there, based on problem the OP described.
bigedp51
Well-Known Member
- Joined
- Dec 10, 2010
- Messages
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You have several problems.
1. Remington brass is softer than Winchester brass and it expanded more when fired.
2. You are using once fired brass from another chamber and after sizing it wants to spring back to its fired size. This brass spring back can be greatly reduced by pausing at the top of the ram stroke for 3 to 4 seconds. This lets the brass know who is the boss and to stay put after sizing.
3. Because the brass is softer you may need the Larry A. Willis Belted Magnum Collet Resizing Die Innovative Technologies - Reloading Equipment to get rid of the case bulge just above the cases belt.
I'm sorry to say this but when Remington lost the contract to produce ammunition at Lake City Army Ammunition Plant the company fell on hard times. And started using cost saving methods that effected the quality of their ammunition and firearms.
Brass hardness example below, Remington and Federal have the softest brass and military Lake City brass is the hardest.
How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests
http://bulletin.accurateshooter.com...r-brass-5-56-and-223-rem-base-hardness-tests/
1. Remington brass is softer than Winchester brass and it expanded more when fired.
2. You are using once fired brass from another chamber and after sizing it wants to spring back to its fired size. This brass spring back can be greatly reduced by pausing at the top of the ram stroke for 3 to 4 seconds. This lets the brass know who is the boss and to stay put after sizing.
3. Because the brass is softer you may need the Larry A. Willis Belted Magnum Collet Resizing Die Innovative Technologies - Reloading Equipment to get rid of the case bulge just above the cases belt.
I'm sorry to say this but when Remington lost the contract to produce ammunition at Lake City Army Ammunition Plant the company fell on hard times. And started using cost saving methods that effected the quality of their ammunition and firearms.
Brass hardness example below, Remington and Federal have the softest brass and military Lake City brass is the hardest.
How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests
http://bulletin.accurateshooter.com...r-brass-5-56-and-223-rem-base-hardness-tests/
ropeNshoot
Well-Known Member
So after lots of measuring and a research I believe that the rifle's headspace may be too great and/or the chamber was cut long. I'll be taking it to a gunsmith next week to have him look at it and discuss what needs to be done.
It's a great shooting rifle but it is hard on brass.
I appreciate everyone's replies and advice and I'll let you know what I find out from the gunsmith.
It's a great shooting rifle but it is hard on brass.
I appreciate everyone's replies and advice and I'll let you know what I find out from the gunsmith.
ropeNshoot
Well-Known Member
The gunsmith took one look at my fired brass next to virgin brass and said "you got a problem".
The shoulder is moving .020" forward upon firing. He's going to cast the chamber to measure the dimensions proper and we'll go from there.
Anybody else seen this before?
The shoulder is moving .020" forward upon firing. He's going to cast the chamber to measure the dimensions proper and we'll go from there.
Anybody else seen this before?
bigedp51
Well-Known Member
- Joined
- Dec 10, 2010
- Messages
- 1,022
You can not stand a new rimed or belted case next to a fired case and tell if you have a headspace problem. This is for the simple reason the rim and belt controls the headspace and not the shoulder location.
Example below is a new unfired British .303 case in a Wilson gauge and the rim is keeping the case from dropping even further into the case. And why the shoulder location means nothing on a rimmed or belted case. The British use cordite powder that looked like spaghetti and the powder was placed into the case and then the shoulder and the neck of the case was formed. And this holds true of the British designed belted cases and dates from a older time when manufacturing tolerances were much more sloppy than today's standards.
Below the case shoulder was over a 1/4 of an inch shorter than the shoulder of the chamber. And has nothing to do with headspace measured off the rim.
The only thing that matters with a rimmed, belted, or rimless case is head clearance if you want the cases to last when reloading.
And if you have excess head clearance the case will stretch in the base web area.
Bottom line if your "gunsmith" only looked at your cases and said you had a headspace problem and didn't use a headspace gauge I would start looking for a new gunsmith.
At home you can take a new or fully resized case and a fired spent primer to find you head clearance. And the amount the primer is protruding from the rear of the case is your head clearance using the bolt face to fully seat the primer.
Below only rim thickness and the height of the belt controls headspace and the upper shoulder area of the case when fired will fireform to the shape of the chamber.
Example below is a new unfired British .303 case in a Wilson gauge and the rim is keeping the case from dropping even further into the case. And why the shoulder location means nothing on a rimmed or belted case. The British use cordite powder that looked like spaghetti and the powder was placed into the case and then the shoulder and the neck of the case was formed. And this holds true of the British designed belted cases and dates from a older time when manufacturing tolerances were much more sloppy than today's standards.
Below the case shoulder was over a 1/4 of an inch shorter than the shoulder of the chamber. And has nothing to do with headspace measured off the rim.
The only thing that matters with a rimmed, belted, or rimless case is head clearance if you want the cases to last when reloading.
And if you have excess head clearance the case will stretch in the base web area.
Bottom line if your "gunsmith" only looked at your cases and said you had a headspace problem and didn't use a headspace gauge I would start looking for a new gunsmith.
At home you can take a new or fully resized case and a fired spent primer to find you head clearance. And the amount the primer is protruding from the rear of the case is your head clearance using the bolt face to fully seat the primer.
Below only rim thickness and the height of the belt controls headspace and the upper shoulder area of the case when fired will fireform to the shape of the chamber.
ropeNshoot
Well-Known Member
Not a headspace problem. A chamber problem. The shoulder is moving forward a full .020" upon firing and it is visible to the naked eye next to a piece of properly sized brass.
ropeNshoot
Well-Known Member
That was a slick presentation tho
bigedp51
Well-Known Member
- Joined
- Dec 10, 2010
- Messages
- 1,022
Sorry but you did not understand what I was trying to get across.
Below a new rimmed case that was manufactured with the case shoulder a 1/4 of an inch "SHORT" of chamber length'
Below a fired case in the Wilson case gauge and sticking well above the top of the gauge.
You do not have a chamber problem and you just have a reloading die that pushes the case shoulder back so the shoulder does not interfere with the the belt setting the cases headspace .
So one more time, on a rimmed or belted cartridge the case does not headspace on the shoulder. Therefore the shoulder location is pushed back farther than a rimless cases.
