question about short action custom sizing die

[Max_The_Phoenix]

Hi Everyone
I have been Using Short Action Custom 6.5 Creedmoor+ Solo-Loc Die Ring after changing from Forester FL Sizing Die.
now I have the same Setup for my 300 PRC AW chamber.
I am having issues getting consistent shoulder bump, now I am on the Third Firing, I anneal after every firing.
When I stroke the ram on my Forster Co-AX For First Time, on some cases I get 0.0015-0.002 shoulder bump that I am l looking for and get some about 0.003-0.00035.
If I turn the brass and Stroke the Ram for the second time I will get 0.0005-6 shoulder bump but its not like that with the Forster Die, no matter how many time I Stroke the ram, I wont get excessive shoulder bump. The reason I switched to SAC was that every Forster Die I buy leaving lots of scratches on the brass.
need to mention I am using hornady One Shot Lube.
Do you guys have any similar Experience? how to resolve it?

 

[straightshooter1]

Hi Everyone
I have been Using Short Action Custom 6.5 Creedmoor+ Solo-Loc Die Ring after changing from Forester FL Sizing Die.
now I have the same Setup for my 300 PRC AW chamber.
I am having issues getting consistent shoulder bump, now I am on the Third Firing, I anneal after every firing.
When I stroke the ram on my Forster Co-AX For First Time, on some cases I get 0.0015-0.002 shoulder bump that I am l looking for and get some about 0.003-0.00035.
If I turn the brass and Stroke the Ram for the second time I will get 0.0005-6 shoulder bump but its not like that with the Forster Die, no matter how many time I Stroke the ram, I wont get excessive shoulder bump. The reason I switched to SAC was that every Forster Die I buy leaving lots of scratches on the brass.
need to mention I am using hornady One Shot Lube.
Do you guys have any similar Experience? how to resolve it?

When you anneal your brass, are you sure you're getting the brass properly annealed?

If you are using the expander ball with your sizing die, there could be an issue where that ball is pulling up on the neck enough to change the shoulder bump measurement. You may need to make adjustments to the expander ball. . .or, running an expander mandrel afterwards as a separate operation from sizing tends to produce more consistent results.

Assuming your brass is properly annealed, one of the things that will help is "dwell time" (the amount of time you let the sized case sit in the die before removing it). Like, I'll let my cases sit in my Forster FL sizing die for 4-5 seconds while I'm lubing the next case with Imperial Sizing Die Wax. By having such dwell time, you get much less spring back and more consistent results. . . especially when using an expander mandrel as a separate operation.

 

[Max_The_Phoenix]

When you anneal your brass, are you sure you're getting the brass properly annealed?

If you are using the expander ball with your sizing die, there could be an issue where that ball is pulling up on the neck enough to change the shoulder bump measurement. Running an expander mandrel afterwards as a separate operation from sizing tends to produce more consistent results.

Assuming your brass is properly annealed, one of the things that will help is "dwell time" (the amount of time you let the sized case sit in the die before removing it). Like, I'll let my cases sit in the die for 4-5 seconds while I'm lubing the next case with Imperial Sizing Die Wax. By having such dwell time, you get much less spring back and more consistent results. . . especially when using an expander mandrel as a separate operation.

I am using Amp annealer mark2
Genrated Aztec code is 00166
I use expander mandrel after full length sizing. I have to practice dwell time but don’t have any unsized brass left. How is your shoulder bump consistency after 3-4 firing?

 

[straightshooter1]

I am using Amp annealer mark2
Genrated Aztec code is 00166
I use expander mandrel after full length sizing. I have to practice dwell time but don’t have any unsized brass left. How is your shoulder bump consistency after 3-4 firing?

After fire forming, I get pretty good consistency where the variation is rarely more than .001. Fire forming is pretty much compete after the 2nd firing with both my .308 and 6.5 PRC. I anneal after every firing using my Annealeez machine and using the "glow method" for deterring the amount of annealing that works. Today I just process a batch of .308 Lapua brass with 10X firings and they were at .001 of bump (+/- a hair . . .like something <.0005), right were I like them.

PS: I do use a Forster FL sizing die that's been reamed to my spec and don't have any problem with scratching the brass, but I do use Imperial Sizing Die Wax.

 

[Max_The_Phoenix]

After fire forming, I get pretty good consistency where the variation is rarely more than .001. Fire forming is pretty much compete after the 2nd firing with both my .308 and 6.5 PRC. I anneal after every firing using my Annealeez machine and using the "glow method" for deterring the amount of annealing that works. Today I just process a batch of .308 Lapua brass with 10X firings and they were at .001 of bump (+/- a hair . . .like something <.0005), right were I like them.

thanks for the info

 

[CK1.0]

It's probably not the die's fault.

The anti-ergonomic design of the Co-Ax press's lever bothers my minor OCD on an unnecessarily profound level lol. I have a buddy with one and have used it enough to know that it wasn't designed with human arms in mind. I don't think it's a coincidence that many Co-Ax owners end up going to another press (like an arbor press with in-line seating die) for seating bullets when chasing seating consistency.

My best guess: the wonky Co-Ax handle, which is known to be difficult to run smoothly combined with the SAC die, may have more leverage and/or influence on the brass when sizing (with its proprietary neck-and-shoulder bushings) as compared to a traditional die.

Maybe try to size a handful of cases more slowly and deliberately instead of just running the lever up and down and see what you get..?

 

[Xumm]

I got similar situation with my 6.5cr SAC die too, but I’m not sure if it apply to your case. For certain rifle, especially AR10s, the chamber is relatively loose, so the brass got expanded a little bit more. I always had hard time get the consistent shoulder bump, even with M-die from Area419. The solution I found is use a redding body die to size the brass first, without shoulder bump, and then use the FL sizing die(sac or another) to size the neck and shoulder bump. All my 6.5cr sizing dies are all happened to claim work more toward the base so that might be the reason it got a lot of resistance during sizing.

 

[Max_The_Phoenix]

I got similar situation with my 6.5cr SAC die too, but I’m not sure if it apply to your case. For certain rifle, especially AR10s, the chamber is relatively loose, so the brass got expanded a little bit more. I always had hard time get the consistent shoulder bump, even with M-die from Area419. The solution I found is use a redding body die to size the brass first, without shoulder bump, and then use the FL sizing die(sac or another) to size the neck and shoulder bump. All my 6.5cr sizing dies are all happened to claim work more toward the base so that might be the reason it got a lot of resistance during sizing.

It's probably not the die's fault.

The anti-ergonomic design of the Co-Ax press's lever bothers my minor OCD on an unnecessarily profound level lol. I have a buddy with one and have used it enough to know that it wasn't designed with human arms in mind. I don't think it's a coincidence that many Co-Ax owners end up going to another press (like an arbor press with in-line seating die) for seating bullets when chasing seating consistency.

My best guess: the wonky Co-Ax handle, which is known to be difficult to run smoothly combined with the SAC die, may have more leverage and/or influence on the brass when sizing (with its proprietary neck-and-shoulder bushings) as compared to a traditional die.

Maybe try to size a handful of cases more slowly and deliberately instead of just running the lever up and down and see what you get..?

It’s been a while that I am shooting only 6.5CM
I tried only lubing the case body and not the neck soulder, oh man I got much more consistent shoulder bump now, I also wait 5 seconds at the bottom of the stroke.
But here is the thing: I always have about 20 pieces of brass from the batch of 100 that will size 1thou more or they size only 0.0005 which doesn’t allow the bolt to drop freely with only half a thou.
I don’t know is it the brass that is thicker or thinner or something else
I anneal after each firing with
I appreciate any input.

 

[prebancolt]

I've noticed the same thing with RCBS Matchmaster 6GT dies using Imperial Wax on a Coax press. For ME, I noticed that the amount of wax and where I put it determined how much movement the neck experienced. A little around the neck and more around the middle body of the case helped me get more consistent results.

I also dwell at least a few seconds.

 

[Max_The_Phoenix]

I am getting much more consistent bump (0.0015-0.0020)with only lubing the body nothing on the neck shoulders.
Last night I noticed if I apply more lube on the body(visibly) the lube will be gunked around and on top of the bushing causing 1 thou more shoulder bump after aizing 30 pieces of brass.
The bushing is not floating in the die by design and I think that’s the reason it there is anything behind the bushing will cause the inconsistent shoulder bump.

Next time I will try to clean the bushing after every 20 pieces to see the results. But I am to the point to give up on this $300 sizing die and go back to non-bushing Forster die since I expand the neck with mandrel anyways.

 

[straightshooter1]

I am getting much more consistent bump (0.0015-0.0020)with only lubing the body nothing on the neck shoulders.
Last night I noticed if I apply more lube on the body(visibly) the lube will be gunked around and on top of the bushing causing 1 thou more shoulder bump after aizing 30 pieces of brass.
The bushing is not floating in the die by design and I think that’s the reason it there is anything behind the bushing will cause the inconsistent shoulder bump.

Next time I will try to clean the bushing after every 20 pieces to see the results. But I am to the point to give up on this $300 sizing die and go back to non-bushing Forster die since I expand the neck with mandrel anyways.

I've tried various bushing dies and find I get my best results with my Forster non-bushing FL sizing die that's been reamed and followed with a mandrel. My bumps are +/- .0005 of my target.

 

[Rio Precision Gunworks]

Yea, you shouldn't be lubing the neck or shoulder anyway (unless inside of neck). The body is where the sticking in the die happens and where the lubrication is needed (specifically the case head is where lube matters the most). Hence why lubrication pads and rolling your brass is an acceptable way to lubricate. You can lubricate the outside of the neck, but dry graphite is better for that as it won't cause issues like other lubricants will in the shoulder/neck area.

Too much lube and/or lube working its way up onto the shoulders or in bushings is the cause of most sizing inconsistency issues loaders have.

Also, you don't need much lube. Especially when using wax type lubricants...it should barely be visible. If you see a lot of wax type on the case, that's too much and it's going to gunk things up over time.