Heavy bolt after resizing

[Hayudog]

Quick background. New 280Ackley Imp and I’m working up my loads. I fire formed the new Winchester brass with 280 Rem loads.

I have a new set of RCBS 280AI dies. Honestly, these are borrowed dies. Friend had them and never used them. I’ve set them up to just move the shoulder about .002 when resizing the once fired (fire formed) brass. The fire formed brass chambers easily. The brass that I have resized has a fairly stiff close to the bolt. No bullets, just the bare case. Case length has stayed the same. It shortened from pre fire forming, but that’s normal, I think.
The resized brass has the shoulder set back, and neck sized for a bullet.
Any ideas?

Recently I’ve been using a Lee collet die with my 22-250. And the feel of pulling the neck sizer back through the neck is way different than I remember RCBS before.

Thanks in advance. Doug

 

[6.5grendel]

What are you using to measure shoulder set back?

My guess on what is happening is the sizing die is sizing the body of the case and causing the base to shoulder length to grow slightly. That can happen if the die isn't ran down far enough. But if you are certain that the die is ran in far enough and the shoulder is getting set back then that isn't the cause.

 

[Ccrider]

Are you getting bolt click at the top when you open the bolt? If so, you are not sizing the base of the case enough.

 

[Hayudog]

What are you using to measure shoulder set back?

My guess on what is happening is the sizing die is sizing the body of the case and causing the base to shoulder length to grow slightly. That can happen if the die isn't ran down far enough. But if you are certain that the die is ran in far enough and the shoulder is getting set back then that isn't the cause.

Hornady headspace gauge. The generic one, C-375, quoted as use the parent cartridge for AI cartilages. Clamped onto my calipers.

I agree. Somethings moving, displacing. Maybe I’ll move the die down a little.

 

[Hayudog]

Set the dies up to the RCBS specs. Die touching the shell holder, then a 1/4 of a turn. They all load fine now. I’ll play with it, but at least I have another starting point.

 

[K22]

1/4 turn is a lot of cam over but it may be necessary if there is a lot of play in the press linkages. The RCBS instructions I have specific 1/8 to 1/4 turn.

How much measured set back are you getting with the die set at 1/4 turn?

It's good that the case chambers without difficulty but you don't want to push the shoulder too far back that will increase case stretch that might lead to an eventual case head separation. You many want to experiment a little by reducing the amount of cam over, i.e. sizing and see if you can get the case to chamber without difficulty with less sizing. Ideally you're looking for about a .001 to .002" set back on a fired case. I like to be closer to .001 provided the case chambers easily.

 

[searcher]

I'm 99% sure your problem lies with your expander ball. Upon extraction, and being tight, it can pull the shoulder out of whack right at the neck/shoulder juncture a few thousandths. That is all it takes to create the hard bolt closure you describe and that might not show up on your Hornady tool as the culprit. You can determine if this is the problem by de-priming with a dedicated de-priming die or size as you have been - then remove the expander and de-cap assembly - re-lube case - then size again. If the problem disappears - you know that is it. To fix it - take the de-cap assembly out and chuck it in a drill. with drill running, apply fine diamond file (or 400-grit silicon carbide sandpaper if you don't tire easily) against the expander ball, slowly taking off material until the diameter has been taken down about .002". Retry in die. Take down in .001" measurements until problem goes away. Be sure you are lubing the inside of your necks prior to sizing with NECO powder or other good neck lube prior to sizing. Good luck. If you have previously run your die all the way down to where it "cams over", made sure your shoulders were set back a few .000 and your trim-to-length measurement was good - and this doesn't fix it - you have a bad die.

 

[Zero333]

After resizing it the second time with the overcam, I would tape 1 layer or masking/painters tape to the head and see if there is any resistance when closing the bolt. If you feel resistance or the bolt won't close all the way, then you're in the clear. If the brass chambers with out any resistance with the masking tape on the head, that means you bumped the shoulder more than 0.004", and that's not optimal for brass life, and definitely not optimal for fireforming.

 

[gman47564]

take a sharpie and paint the entire case except the base and then chamber it... the problem area will show itself then you can address the area thats causing your problem...

 

[Hayudog]

I'm 99% sure your problem lies with your expander ball. Upon extraction, and being tight, it can pull the shoulder out of whack right at the neck/shoulder juncture a few thousandths. That is all it takes to create the hard bolt closure you describe and that might not show up on your Hornady tool as the culprit. You can determine if this is the problem by de-priming with a dedicated de-priming die or size as you have been - then remove the expander and de-cap assembly - re-lube case - then size again. If the problem disappears - you know that is it. To fix it - take the de-cap assembly out and chuck it in a drill. with drill running, apply fine diamond file (or 400-grit silicon carbide sandpaper if you don't tire easily) against the expander ball, slowly taking off material until the diameter has been taken down about .002". Retry in die. Take down in .001" measurements until problem goes away. Be sure you are lubing the inside of your necks prior to sizing with NECO powder or other good neck lube prior to sizing. Good luck. If you have previously run your die all the way down to where it "cams over", made sure your shoulders were set back a few .000 and your trim-to-length measurement was good - and this doesn't fix it - you have a bad die.

It feels like the expander when it’s coming back through is hard. I have a feeling that could be part of the problem— I do have a dedicated de-priming die I’ll work with it to do the check.
The collet dies for my 22-250 have a completely different feel. I’ve been doing so many of those, I’ve lost my feel with the other style.

 

[6.5grendel]

I'm curious too on how much your shoulders are pushed back now, but I doubt it's a crazy amount. You could back the die out a little at a time until you get a little resistance on bolt closure. Then see what your shoulder bump is at that setting, then run the die back in just a little to get your .001-.002 shoulder bump. I'm glad you're getting the issue solved quickly.

 

[6.5grendel]

If the expander is really hard to pull back through, that could be pulling your necks and shoulders out also, or deforming them. Is the expander button adjusted properly. I haven't messed with many rcbs dies but most dies, if the expander is adjusted too high and too close to the neck portion of the die it will cause the expander to be really hard to pull back through. Is the expander adjustable? If so, does the instructions have a part about setting it properly?

 

[Dusty Stevens]

Hows the trim length?

 

[antelopedundee]

I fire formed some 6.5-06AI cases from Nosler .270 Win brass. I resized them FL with no expander ball. I had a couple extra of Winchester brand that I was using to set up a neck turner. When I expanded the necks with a .263 mandrel, it collapsed the shoulder on one of the Nosler cases and both of the Winchester cases. The case body was wider where it meets the shoulder. Even after running them back through the sizer die, the 3 cases would not chamber in my rifle. Out of all of the hundreds of 6.5-06AI cases I've loaded, I've never had that happen before.

 

[Coyotefurharvester]

I quit using the expander/decapping rod on .22 and larger, made die adjustments a lot easier. I use a mandrel and in process of going to gage pins for inside neck sizing. No donuts yet, less case trimming.

 

[Zero333]

It feels like the expander when it’s coming back through is hard. I have a feeling that could be part of the problem— I do have a dedicated de-priming die I’ll work with it to do the check.
The collet dies for my 22-250 have a completely different feel. I’ve been doing so many of those, I’ve lost my feel with the other style.

Sometimes you gotta lube inside the neck if the expander ball is dragging hard.

 

[Hayudog]

I'm 99% sure your problem lies with your expander ball. Upon extraction, and being tight, it can pull the shoulder out of whack right at the neck/shoulder juncture a few thousandths. That is all it takes to create the hard bolt closure you describe and that might not show up on your Hornady tool as the culprit. You can determine if this is the problem by de-priming with a dedicated de-priming die or size as you have been - then remove the expander and de-cap assembly - re-lube case - then size again. If the problem disappears - you know that is it. To fix it - take the de-cap assembly out and chuck it in a drill. with drill running, apply fine diamond file (or 400-grit silicon carbide sandpaper if you don't tire easily) against the expander ball, slowly taking off material until the diameter has been taken down about .002". Retry in die. Take down in .001" measurements until problem goes away. Be sure you are lubing the inside of your necks prior to sizing with NECO powder or other good neck lube prior to sizing. Good luck. If you have previously run your die all the way down to where it "cams over", made sure your shoulders were set back a few .000 and your trim-to-length measurement was good - and this doesn't fix it - you have a bad die.

Set the FL die up with the expanding and depriming insert as when the problem originated. Went through 3 pieces of brass and all chambered correctly. 4 th piece had a hard bolt close. Removed the expander ball and deprimer and progressively lowered the die. Measuring and chambering each time. The first time I saw a shoulder measurement change, the bolt was easier to close. Moved the die to show about .002-.003 total movement and the bolt closes correctly.
Because all brass isn’t equal, I’ll wait to go after the expansion ball to make it smaller. Maybe this Winchester nickel plated brass has thick necks. Poor choice of brass. Only 280 brass I could find local during the plandemic. New brass on order.

After resizing it the second time with the overcam, I would tape 1 layer or masking/painters tape to the head and see if there is any resistance when closing the bolt. If you feel resistance or the bolt won't close all the way, then you're in the clear. If the brass chambers with out any resistance with the masking tape on the head, that means you bumped the shoulder more than 0.004", and that's not optimal for brass life, and definitely not optimal for fireforming.

Thanks. That seems like an easy way to check.

I quit using the expander/decapping rod on .22 and larger, made die adjustments a lot easier. I use a mandrel and in process of going to gage pins for inside neck sizing. No donuts yet, less case trimming.

Similar to a collet resizing?

Hows the trim length?

Trim length is 2.510 and spec says it can go to 2.530. Cases shortened during fire forming.

 

[Ccrider]

Depending on where you measure at, the amount that you move the shoulder back to get free bolt close may be more than .002. Could be .003 or more. Keep moving the shoulder back until you get the bolt feel that you want and then zero your caliper. After each firing you will have to resize each piece of brass to that point.

After you resize your brass, run each piece through your rifle before reloading to make sure it is sized enough. Resize any piece that gives you tight bolt close until it cycles properly. If it is way out of line with the other brass I would chunk it. Otherwise I would use this point as the setting to resize all of my cases.

As the brass hardens, you may have to make slight adjustments in order to maintain proper clearance.

 

[Fast14riot]

I had the exact same issue with an RCBS die for my 6.8spc. Turned out the neck was getting sized down a little too much and the expander was pulling the neck back up as it came back through. I screwed my die down a little at a time to check when it would chamber, then measured against a fired piece of brass, turned out it was sizing close to .005+". I honed the neck out a little and double checked the expander diameter and after that, I could back the die back out and bump shoulders back .0025 and have everything chamber easily.

 

[243winxb]

Set the dies up to the RCBS specs. Die touching the shell holder, then a 1/4 of a turn. They all load fine now. I’ll play with it, but at least I have another starting point.

Nickel brass springs back more after sizing. Its harder.

Keep this die setting.

Case forming dies are usually cut to size the case slightly smaller than the minimum SAAMI (Small Arms Ammunition Manufacturers Institute) dimensions, to account for the brass case's tendency to spring back after sizing.