Question about custom dies

[dkhunt14]

I shoot Bat M actions with the big lugs and big tenon. So the tenon isn't the problem. The problem is when the chamber is smaller then the die. Some gunsmiths order the wrong reamer or get one with a tight at the .200 line reamer to try and keep primer pockets. Then they minimum headspace the gun and now the die won't size the case at the .200 line. The die needs to size this .001 if your going to run near max loads. Sammi dies won't touch them there. And if the die doesn't size them there you end up with the click. A hot load will lift hard from the start of the bolt lift because the whole case is tight in the chamber. The click is only the back of the case is tight. My first WSM was done with a die that was .002 under at the .200 line and after the first firing you would get the click. I had to get a special die to size the case there for those 2 guns. My next reamer was a .001 bigger and it still isn't enough for a factory die. If you spin the barrel in the lathe and remove a hair from the back end of the chamber it will go away. I measure my pressure by how much the extractor groove moves on a firing. Also if the primers are round on the edges you are not overpressure. Matt

 

[calgarycanada]

I shoot Bat M actions with the big lugs and big tenon. So the tenon isn't the problem. The problem is when the chamber is smaller then the die. Some gunsmiths order the wrong reamer or get one with a tight at the .200 line reamer to try and keep primer pockets. Then they minimum headspace the gun and now the die won't size the case at the .200 line. The die needs to size this .001 if your going to run near max loads. Sammi dies won't touch them there. And if the die doesn't size them there you end up with the click. A hot load will lift hard from the start of the bolt lift because the whole case is tight in the chamber. The click is only the back of the case is tight. My first WSM was done with a die that was .002 under at the .200 line and after the first firing you would get the click. I had to get a special die to size the case there for those 2 guns. My next reamer was a .001 bigger and it still isn't enough for a factory die. If you spin the barrel in the lathe and remove a hair from the back end of the chamber it will go away. I measure my pressure by how much the extractor groove moves on a firing. Also if the primers are round on the edges you are not overpressure. Matt

So if die was .002" under and you were still getting bolt click, how much under would you recommend? Or is there something else that can be done to the die to make it better? I'm asking so I can talk to die manufacturer and request that measurement/design.

 

[Mikecr]

He must have meant reamer .002 under SAAMI.

Whenever you go custom, you need to go custom all the way to your plan.
It is YOUR plan, good or bad.

 

[dkhunt14]

Yes it was the reamer and not the die. Matt

 

[dkhunt14]

So if die was .002" under and you were still getting bolt click, how much under would you recommend? Or is there something else that can be done to the die to make it better? I'm asking so I can talk to die manufacturer and request that measurement/design.

That is why you send the custom die people fired cases. So they can measure them and make the die. Matt

 

[AZShooter]

This discussion is something I have been interested in for a while.

I have noticed that the WSMs, RCMs and RUM cases tend to become hard to remove from the chamber after they have been fired a few times. Not the bolt snick at the end of the bolt opening movement but rearward removal.

I think it has to do with the thicker brass and multiple firings making the brass more resistant to any springback so they hang up in the rear of the chamber. I have observed that the area just in front of the web has a shiny area where it is rubbing on the chamber wall as it gets extracted. I know the fl die is not sizing this area. I have tried Redding, RCBS and Hornady FL dies in my 338 RCM. I finally had Whidden make a FL/bushing die which helped some but not completely. I spent almost $200 with all those dies.

I recently began to do my own barreling and chambering and have tried opening the rear of a chamber by light sanding and polishing which helped some. I finally resorted to making my own small base dies. I use a carbide tool bit and cut off the top of a FL die so shoulder and neck are removed. I then machine off some of the bottom of the die so I have a tapered section that can be incrementally lowered to size the web area. I partially FL size the case after reducing the diameter of the web as the brass gets lengthened in this process. I know a custom FL die with the proper dimensions would solve the issue but I am not ready to pay big money for a custom die with a chambering I may abandon in a year or two.


I talked to Dave Kiff and asked if the chamber reamer dimension vs the FL sizer reamer dimensions are different for thicker brass. He said no they have a set difference between the two. Can't remember the dimension.


Would love to hear what you think MikeCR and dkhunt14.

 

[dkhunt14]

Yes you can cut the shoulder off a die and remove from the bottom and get what you need. Some of the problem might be the case on the WSM. It is so thick at the base. Cut one apart and see. It is just about as thick as the 338 Lapua case. After you get what you need then you can run it in your full length bushing die to get your neck tension and shoulder bump. If you are not getting any size on the case at the .200 line you will get what you describe; or bolt click like the match shooters call it. I have a 4 digit Mitutoyo digital friction thimble mike that will repeat measurements. I can tell if my die is moving the brass and where. A lot of people think that necksizing is more accurate. That is not true. I have seen some of the best 10 shot groups fired in 1000 yard BR shot while fireforming cases. That is when the case is at the smallest it is ever going to be. I like my cases to go in and out the gun easily. It doesn't matter if I'm hunting or Target shooting. Matt

 

[Mikecr]

There is no proof that looser fitting cases are more accurate. What exists, is anecdotal evidence that tighter brass does not work as well or shoot as well for some, and with common conditions/causes(like poor cartridge designs, or huge runout, or bag shooting troublesome between conditions, etc).

My 26WSSM uses the same WSM cases. That is, they are WSM cases cut to shorter WSSM length and then formed. WSSM necks are 19-24thou thick(depending on cal), because the neck area was previously WSM body.
Anyway, same base.

I have 40+ reloadings(right at SAAMI max) on my WSSM cases, with no base sizing at all, zero problems, and so I know for sure there is nothing wrong with the WSM cases or design near webs.
I don't FL size, small base size, and I've applied no band aids to the chamber breech.
What I did was measure my NEW brass dimensions at the webline, and set my reamer 1thou over.
With this, I never intended to FL size, as the thickest part of these cases(webs) would just springback, provided they are never taken to yield. This works (fitted webs) just like it works with fitted necks(I don't neck size the cases either).

Where you cause brass yielding, you're accepting that you'll have to do something about that, and the same holds for a lot of sizing & sizing cycles.
They're all choices, it all makes sense, and there is no 'luck' about it one way or another.

 

[dkhunt14]

Mike tighter fitting brass always shoots bigger at 1000 yards with the same loads Bullets and everything the same. This with every gun we tried it in. It seems to throw vertical fliers out of the group and they almost always go up. Sometimes really far up. We have guys that test almost ever day during the summer and they all say the same thing. If you look back at the shortrange benchrest guys. When they went from fitted cases to full length sized cases they immediately starting breaking records and shooting smaller aggs. The aggs tell the story because anybody at any time can shoot a lucky target or two. The aggs dropped a lot and as more did it the field tightened up a lot more. When that smaller reamer is used you have to compensate with the die. Guys say you can't move the base but they are wrong. We even have guys that made tools to tighten up primer pockets. The one guy made a die for the punch press and hit them with about 40,000 pounds of pressure. It tightens them up. His brother which was a tool and die man made a split block tightened by two screws with a plug the size of a primer. You put the plug in the primer pocket and tighten the screws, then you loosen and turn 90 degrees and do it again. Primer pockets now are as tight as new and the bases are back to new. Matt

 

[AZShooter]

MikeCR,

You may have hit upon the problem my friend and I have had with the 300 RUM on 4th firing They might have gotten into what you called the yield area. Bolt opens easily it is just pulling them back that is the issue and it only shows after the 3 firing.

I solved the issue and the hunting rifles still are shooting quite accurately.

 

[Mikecr]

dkhunt14, there is a reason for everything and qualifiers for everything.
When you suggest that YOU couldn't figure out how to get tighter fit cases shooting, I wonder, have you tried to understand why?
Do you understand it?

 

[dkhunt14]

Nobody gets the accuracy needed to win at 1000 with tight cases. You need to be able to shoot 10 shots in 4 inches on a good day. If so it should be easier for the PPC guys to do it because vertical isn't as important for them. They can't do it either. You are welcome to come to Williamsport and show us. You don't even have to join. You can shoot two matches without joining. Matt

 

[dkhunt14]

The guns shoot at there absolute best when you use new brass and fireform. That is when brass is at it's absolute smallest and the loosest fit in the chamber. More relays are won that way then any other way. I welcome you to come here and I will show you. Matt

 

[BountyHunter]

There is no proof that looser fitting cases are more accurate. What exists, is anecdotal evidence that tighter brass does not work as well or shoot as well for some, and with common conditions/causes(like poor cartridge designs, or huge runout, or bag shooting troublesome between conditions, etc).

My 26WSSM uses the same WSM cases. That is, they are WSM cases cut to shorter WSSM length and then formed. WSSM necks are 19-24thou thick(depending on cal), because the neck area was previously WSM body.
Anyway, same base.

I have 40+ reloadings(right at SAAMI max) on my WSSM cases, with no base sizing at all, zero problems, and so I know for sure there is nothing wrong with the WSM cases or design near webs.
I don't FL size, small base size, and I've applied no band aids to the chamber breech.
What I did was measure my NEW brass dimensions at the webline, and set my reamer 1thou over.
With this, I never intended to FL size, as the thickest part of these cases(webs) would just springback, provided they are never taken to yield. This works (fitted webs) just like it works with fitted necks(I don't neck size the cases either).

Where you cause brass yielding, you're accepting that you'll have to do something about that, and the same holds for a lot of sizing & sizing cycles.
They're all choices, it all makes sense, and there is no 'luck' about it one way or another.

Matt, do not let MikeCR BS you.

As usual he is not telling the whole story or just flat out does not understand FL sizing and have come up with his warped world definition.

1. He is taking WSM brass and loading to max of 53 for maybe 55 PSI which is 15-18 percent below max. NO ONE here loads like that!!!!! So his experience is not relative or practical to real world LR hunting/BR loads.

2. He thinks and claims that he is only NS'ing because he uses JLC custom body dies honed to his chamber AND neck sizing because he leave a small ring unsized on the neck. All he has in effect is a custom fit FL bushing die but in two steps. He normally leaves out the part about using custom body dies to "claim he only NS and it is the answer to the world".

I keep waiting for him to write Redding and tell them they are mis-marketing their FL bushing die as "it really not FL" according to his definition.

The answer is you have to have a die matched to the chamber to give it enough sizing all over or you will get the click IF you are loading anywhere near max. Now you can FL size the body in one or two steps.