If Your Seating Die is Leaving Rings on Your Bullets...

[IndianaRem5r]

Ok, I had this issue when reloading for my .223 fun rifle and I decided to finally take action. My load is 25 grains Varget, 69 gr. Sierra TMK's, Lapua brass, CCI 450 magnum small rifle primers. The load is slightly compressed and this doesn't help any. My full length die was from a standard RCBS FL Die Set #11101. So, I researched the issue and found that you can grind your bullet seating stem to fit your bullet. I did this and it helped somewhat but still some ring impressions. I did notice that it seemed like I had excessive neck tension when seating bullets. I use a Redding Type S full length bushing die for my 6.5 x 47 Lapua reloading. You buy the bushing size that is 0.001 less than the neck diameter of a finished cartridge. This gives you precision control of your neck tension. I ordered a Redding Type S in .223 and a .247 bushing. Long story short...problem solved. Who knows how much neck tension I was putting in using the standard RCBS sizer, but it was excessive. I still use the same .223 RCBS seating die but the RCBS full length sizing die will gather dust. Hope this helps someone. I'm a fan of the Redding Type S bushing-style sizing die for everything going forward.

 

[AIAW]

No doubt the bushing dies are the way to go hands down. I own very, very few non-bushing dies. I have polished seating cups to help alleviate the rings.

 

[Trappnp]

I've seen several video's on You Tube on how to polish the seating stem, but what do you all recommend?

 

[XLR308]

A titanium nitride coated turning mandrel and die is a cheaper alternative to having to buy a new bushing die but is also an excellent addition to be used with the bushing dies.

 

[XLR308]

I've seen several video's on You Tube on how to polish the seating stem, but what do you all recommend?

I have always used valve lapping compound and a few sacrificial bullets, don't know if it's the best method but it has worked for me.

 

[Caveman0101]

I had the same problem with VLD bullets and RCBS dies, I tried several things that were supposed to help, none of it totally eliminated the problem. So I'm trying Horn. new dimension dies so far so good. But I do keep hearing that the bushing dies are the way to go.

 

[Jayhawkhuntclub]

Is this more than a cosmetic issue? Rings would be minor compared to a cannelure.

 

[Lynn Jr]

You can epoxy bed the hollow stem on your seating die to eliminate the rings.
If your running alot of neck tension like on a custom flatbase bullet the hollow seating stem will dig into the bullets jacket.
Years ago guys were cracking the stems on there Redding seating dies using heavy bullets and compressed loads in the 223. Redding replaced alot of stems at first but then they said it voided the warranty.

 

[IndianaRem5r]

A titanium nitride coated turning mandrel and die is a cheaper alternative to having to buy a new bushing die but is also an excellent addition to be used with the bushing dies.

An expander mandrel would make good sense for new brass to obtain proper neck tension. However, I'm certainly not going to add a step to my .223 reloading when using the Redding S Bushing full length sizing die which delivers perfect neck tension to fired brass AND bumps the shoulder back.

 

[Lynn Jr]

IndianaRem5r
The ring is caused by the inside edge of the seating stem. If you can, picture the seating stem as a piece of pipe or tubing. The end of that pipe is flat so it has an inner edge and a outer edge and the inner edge is what is against the jacket on the bullet.
If you use lapping compound on the bullet that inner edge now looks chamfered and is no longer flat or squared up but rather funnel shaped.
The epoxy does the same thing just over a wider area.
With an expander mandrel your not fixing that inside edge of the pipe your just reducing the seating force until you can't see its effects on the bullet.

 

[IndianaRem5r]

IndianaRem5r
The ring is caused by the inside edge of the seating stem. If you can, picture the seating stem as a piece of pipe or tubing. The end of that pipe is flat so it has an inner edge and a outer edge and the inner edge is what is against the jacket on the bullet.
If you use lapping compound on the bullet that inner edge now looks chamfered and is no longer flat or squared up but rather funnel shaped.
The epoxy does the same thing just over a wider area.
With an expander mandrel your not fixing that inside edge of the pipe your just reducing the seating force until you can't see its effects on the bullet.

Yes, I totally agree. But, by reducing the neck tension I finally got the result I was after. I had already performed the lapping compound operation. That helped but did not eliminate the issue.

 

[Shifty6BR]

I also use the rcbs .223 rem fl die for my gasser accuracy loads. I have found the Forster fl length die decapping stems work with the rcbs fl dies.

The Forster expander button gives me about .002-.0025 perfect, I prefer not to go any less on a semi especially as I do not crimp. It also elimanated the ring during sizing. All this on top of Varget as well. Their expander buttons can be ordered oversized.

The biggest reason I prefer the Forster decapping stems is the o ring that allows the expander button to float and center itself, it has improved runout during the sizing process. I use to stick an o ring under the old rcbs decapping stem but that did not solve anything in the excessive neck tension dept.

Bushing dies really shine if you are turning necks, even to just clean them up.

 

[GBMaryland]

Folks, am I wrong in assuming that his compressed load is just too compressed? ...or am I missing something?

The only time I’ve ever had more than the slightest of marring on a bullets surface is when the case volume couldn’t accommodate the amount of power to be compressed.

 

[XLR308]

Folks, am I wrong in assuming that his compressed load is just too compressed? ...or am I missing something?

The only time I’ve ever had more than the slightest of marring on a bullets surface is when the case volume couldn’t accommodate the amount of power to be compressed.

Excessive neck tension and the interior dimension of the seating stem not being a good match to the profile of the bullet will also cause it.
And of course as you stated a compressed load will only make the previous two even more obvious.

 

[XLR308]

An expander mandrel would make good sense for new brass to obtain proper neck tension. However, I'm certainly not going to add a step to my .223 reloading when using the Redding S Bushing full length sizing die which delivers perfect neck tension to fired brass AND bumps the shoulder back.

I can certainly understand your reasoning if it's for an auto loader although it would be benificial but for a precision bolt gun it has its merits.
You are also assuming all of your brass has identical neck thickness around the circumference and length of the neck which is pretty far fetched unless you neck turn your brass.
That is were the turning mandrel will complement you S-Die or any other type for that matter whether you neck turn or not by returning all brass interior dimensions of the necks as close to each other as possible.

 

[IndianaRem5r]

I can certainly understand your reasoning if it's for an auto loader although it would be benificial but for a precision bolt gun it has its merits.
You are also assuming all of your brass has identical neck thickness around the circumference and length of the neck which is pretty far fetched unless you neck turn your brass.
That is were the turning mandrel will complement you S-Die or any other type for that matter whether you neck turn or not by returning all brass interior dimensions of the necks as close to each other as possible.

Yes, good points if I was running a .223 F-TR rig and wanted to squeeze out all the accuracy I could, no matter the invested time. This is my fun, .223 bolt gun and I'm just not THAT serious about super extreme case prep for this application. I'm running a relatively inexpensive and light bullet in the 69 grain Sierra TMK's.

 

[Milo 2.5]

Folks, am I wrong in assuming that his compressed load is just too compressed? ...or am I missing something?

The only time I’ve ever had more than the slightest of marring on a bullets surface is when the case volume couldn’t accommodate the amount of power to be compressed.

Yes and no, heavily compressed compounds things, need more neck tension to hold the bullet, so most of the time you have 2 strikes up front. A lot of die makers are offering different seating stems to accommodate bullet shapes, which helps, or lapping the stem. I've had a smith chuck a couple up and machine the angle too.
Differing brands of bullets use different jackets also, Hornady jackets are known to be soft, where Sierra's and Berger's seem stouter and less susceptible to deformation.
I used to like compressed loads, I try my best to avoid it today.

 

[TreyMeTrey]

IndianaRem5r
The ring is caused by the inside edge of the seating stem. If you can, picture the seating stem as a piece of pipe or tubing. The end of that pipe is flat so it has an inner edge and a outer edge and the inner edge is what is against the jacket on the bullet.
If you use lapping compound on the bullet that inner edge now looks chamfered and is no longer flat or squared up but rather funnel shaped.
The epoxy does the same thing just over a wider area.
With an expander mandrel your not fixing that inside edge of the pipe your just reducing the seating force until you can't see its effects on the bullet.

You are Absolutely right!

 

[TreyMeTrey]

Lynn Jr You are Absolutely right!