Armory Sponsor
Posted: 1/23/2012 9:56:54 AM EDT
|
I am interested in reducing runout in my reloads on my Dillon and recently saw a post on Sniper's hide that said one could pull the expander ball out of their die and use a Sinclair neck sizing mandrel die. According to this post, the expander ball was the root of runout. I do my initial sizing on a 550 toolhead and have plenty of room for an additional step, since it's a progressive press anyways. I am interested in doing this for an AR15 with a quick detach can. After getting a baffle strike, I had the barrel/threading checked, and am now trying to tighten up my rounds as far as quality is concern. Any thoughts on this? I'm using a RCBS FL die currently. http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1323468
|
|
Quoted:
I am interested in reducing runout in my reloads on my Dillon and recently saw a post on Sniper's hide that said one could pull the expander ball out of their die and use a Sinclair neck sizing mandrel die. According to this post, the expander ball was the root of runout. I do my initial sizing on a 550 toolhead and have plenty of room for an additional step, since it's a progressive press anyways. I am interested in doing this for an AR15 with a quick detach can. After getting a baffle strike, I had the barrel/threading checked, and am now trying to tighten up my rounds as far as quality is concern. Any thoughts on this? I'm using a RCBS FL die currently. http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1323468
Sir, FWIW most would consider me to be a "high volume" reloader, I usually do about 500 rounds at a time. I use a single stage press and a Dillon 550 when I reload for match .223 Rem. I'm not in total disagreement with what the Sinclair tech told you, I've used their mandrels for years. Keep in mind their mandrels come in two sizes, one for neck turning which are .002" under bullet diameter and expander mandrels which are .001" less than bullet diameter. Since the bullet is the center of gravity for runout purposes it makes good sense to me that the shell that holds the bullet needs to be concentric with the bullet axis. From my perspective beside the obvious that is the purpose of the mandrels. The expander ball can the the root of many problems but there are acceptable remedies. One of the problems is that standard FL commercial dies reduce the case neck outside diameter more than is necessary and their design depends of the expander ball to return the inside diameter of the case neck to a dimension more suitable for the diameter of the bullet you're using. When the differences in these dimensions are sufficient significant distortion of the case neck can and generally does occur and neck runout is one of the more obvious symptoms. If you experiment with different relative dimensions the problem has a resolution but you have to have some understanding of exactly what the dimensions are that your dies are producing. I like the Redding type "S" dies because they allow the user to experiment with different diameter bushings to determine exactly what dimension is needed to provide adequate neck tension on the bullet depending on the neck wall thickness of the brass he is using. Given a known reduction of the case neck outside diameter it is relatively easy to determine based on measured wall thickness how much reduction is needed to achieve the desired inside neck diameter. In my experience .002"-.003" less than bullet OD is adequate neck tension and I use the appropriate sized neck bushing to achieve that dimension. I also use a carbide expander ball on the decapping assembly of my type "S" die. I do all my case resizing with the Redding die on a single stage press. All other case prep steps are done with a Giraud trimmer or by hand such that when I insert a prepped and primed case into the first stage of my Dillon 550 the Sinclair "Turning" mandrel which is .002" less than bullet diameter expands the case neck slightly leaving me with an inside neck diameter slightly greater than .002" less than bullet diameter. By doing so it also ensures the concentricity of the case with the bullet and the resultant cartridge runout is generally less than .001" TIR measured with a NECO gage specifically intended for the purpose. HTH, 7zero1. |
|
Got a link to this Sinclair Neck Sizing Mandrel Die?
I know of Sinclair Neck Expanding Mandrels/dies, but not a Mandrel sizing die. Lee makes an excellent Collet Neck sizing die that squeezes the case neck around a mandrel. The Lee Collet die produces very concentric brass with little runout. Couple the Lee die with the Redding Body die for FL sizing and you have an excellent sizing combo that keeps runout to a minimum. |
|
Quoted: Got a link to this Sinclair Neck Sizing Mandrel Die? I know of Sinclair Neck Expanding Mandrels/dies, but not a Mandrel sizing die. Lee makes an excellent Collet Neck sizing die that squeezes the case neck around a mandrel. The Lee Collet die produces very concentric brass with little runout. Couple the Lee die with the Redding Body die for FL sizing and you have an excellent sizing combo that keeps runout to a minimum. I believe your correct. I think the proper terminology is a Sinclair Neck Expanding Mandrel. Brownells carries them. |
|
Quoted: What kind of shooting are you doing? Are you shooting high power matches at 600 to 1,000 yards? If you are, then go for it, but if you aren't, then don't waste your time on BS like neck runout. All my shooting is < 200 yards. The only reason I am interested in the subject is two fold. Due to my recent baffle strike, and the fact that my expander ball (stem?) is bent, led me to start thinking that perhaps I could still use the .223 sizing die (sans expander ball/pin) and augment with a Sinclair mandrel in the next station (I do know that I can get replacement parts from RCBS). Even when the .223 RCBS die was in working condition, I didn't like how the stem would wobble around and not be in true center. Maybe it's supposed to be that way, I don't know. This is all new territory for me. Overall, I am looking to increase the quality of my .223 rounds, prevent another baffle strike and help me get an edge for this drill that I am trying to conquer before the next Trident Concepts class:  |
|
First of all, you need to either buy, or borrow, a good concentricity gage, like the Sinclair, Bersin or Neco gages.
You're just guessing, if you can't say for sure. A baffle strike could be a lopsidedly made bullet, for all you know? Since some runout is caused in the seating step, Redding, Forster and Hornady (to a lessor extent) have sleeves that support the entire case upon sizing, thereby reducing T.I.R.. These sleeves helps keep things in line as the bullet gets pushed into the case.. Concentricity gages are kind of a double edged sword...since once you 'know' your runout is acceptable and low, throughout your reloading process, you really don't need to mess with them any longer, apart from occasionally spot checking things. Chris |
|
Quoted: One of these:http://www.sinclairintl.com/.aspx/pid=38807/avs|Manufacturer_1=SINCLAIR%20INTERNATIONAL/Product/Sinclair-Generation-II-Expander-DiesGot a link to this Sinclair Neck Sizing Mandrel Die? I know of Sinclair Neck Expanding Mandrels/dies, but not a Mandrel sizing die. Lee makes an excellent Collet Neck sizing die that squeezes the case neck around a mandrel. The Lee Collet die produces very concentric brass with little runout. Couple the Lee die with the Redding Body die for FL sizing and you have an excellent sizing combo that keeps runout to a minimum.  And one of these caliber specific. http://www.sinclairintl.com/.aspx/pid=33134/avs|Manufacturer_1=SINCLAIR%20INTERNATIONAL/Product/Sinclair-Expander-Mandrel-oversized  |
|
Quoted: Quoted: What kind of shooting are you doing? Are you shooting high power matches at 600 to 1,000 yards? If you are, then go for it, but if you aren't, then don't waste your time on BS like neck runout. All my shooting is < 200 yards. The only reason I am interested in the subject is two fold. Due to my recent baffle strike, and the fact that my expander ball (stem?) is bent, led me to start thinking that perhaps I could still use the .223 sizing die (sans expander ball/pin) and augment with a Sinclair mandrel in the next station (I do know that I can get replacement parts from RCBS). Even when the .223 RCBS die was in working condition, I didn't like how the stem would wobble around and not be in true center. Maybe it's supposed to be that way, I don't know. This is all new territory for me. Overall, I am looking to increase the quality of my .223 rounds, prevent another baffle strike and help me get an edge for this drill that I am trying to conquer before the next Trident Concepts class: I can't believe there is any way your expander ball could cause that, if you got a strike in your suppressor there's almost certainly a problem with the rifle or the suppressor, there is the slight possibility you had a wonky bullet that caused it. |
|
Quoted:
Quoted:
One of these:http://www.sinclairintl.com/.aspx/pid=38807/avs|Manufacturer_1=SINCLAIR%20INTERNATIONAL/Product/Sinclair-Generation-II-Expander-Dies
Got a link to this Sinclair Neck Sizing Mandrel Die? I know of Sinclair Neck Expanding Mandrels/dies, but not a Mandrel sizing die. Lee makes an excellent Collet Neck sizing die that squeezes the case neck around a mandrel. The Lee Collet die produces very concentric brass with little runout. Couple the Lee die with the Redding Body die for FL sizing and you have an excellent sizing combo that keeps runout to a minimum. http://spinstage.http.internapcdn.net/Spinstage/userdocs/products/p_749011715_1.jpg And one of these caliber specific. http://www.sinclairintl.com/.aspx/pid=33134/avs|Manufacturer_1=SINCLAIR%20INTERNATIONAL/Product/Sinclair-Expander-Mandrel-oversized http://spinstage.http.internapcdn.net/Spinstage/userdocs/products/p_749001145_1.jpg Ah, their "expander" die. These are not sizing dies but neck expanders. They take the place of the expander button on your RCBS die. Remove the expander button on your RCBS die, lube and size then expand the neck with this die. I do this with several different cartridges using the Lyman "M" die, same principle. Works well. |
| Do you know what really causes the runout problem? There could be many reasons and only one of them is the expander button. What you need is a good dial indicator to measure the cases in different phases of the loading cycle. The reason for runout problems is quite often the gun itself. |
|
Quoted:
Do you know what really causes the runout problem? There could be many reasons and only one of them is the expander button. What you need is a good dial indicator to measure the cases in different phases of the loading cycle. The reason for runout problems is quite often the gun itself. Bingo. And don't forget that it's also a brass related issue, as well. Chris |
|
Quoted:
Concentricity gages are kind of a double edged sword...since once you 'know' your runout is acceptable and low, throughout your reloading process, you really don't need to mess with them any longer, apart from occasionally spot checking things. Chris And when you know, that your arrows are straight, that removes one more thing to put the blaim on before the indian. So when the gun is ok, the dies are gtg and even the ammo is kosher... Well, there's always the weather and/or lighting 
|
|
Yeah I know the gun, flash hider and can are all GTG. I suspect the runout (if any that is significant) MAY not be the issue, just trying to eliminate variables and learn some new reloading techniques as well. Thanks to all who commented. I am going to have do some further research and see what I can come up with.
|
|
Quoted: And that may be where my problem is, as I am using mixed commercial brass. Haven't gotten into the good LC stuff yet, though may have to do rounds for the can using only LC.Quoted: Do you know what really causes the runout problem? There could be many reasons and only one of them is the expander button. What you need is a good dial indicator to measure the cases in different phases of the loading cycle. The reason for runout problems is quite often the gun itself. Bingo. And don't forget that it's also a brass related issue, as well. Chris |
|
Quoted:
Do you know what really causes the runout problem? There could be many reasons and only one of them is the expander button. What you need is a good dial indicator to measure the cases in different phases of the loading cycle. The reason for runout problems is quite often the gun itself. I have my share of rifles, well maybe more than my share and I have checked concentricity/run-out of fired cases on each and every one of them. The run-out of fired brass in all of my rifles is almost non-existent. Maybe I am just lucky, but if I had excessive(.001+) run-out in a fired unsized case I would send the gun back to the manufacturer or have it re-chambered. |
|
Quoted:
Quoted:
Do you know what really causes the runout problem? There could be many reasons and only one of them is the expander button. What you need is a good dial indicator to measure the cases in different phases of the loading cycle. The reason for runout problems is quite often the gun itself. I have my share of rifles, well maybe more than my share and I have checked concentricity/run-out of fired cases on each and every one of them. The run-out of fired brass in all of my rifles is almost non-existent. Maybe I am just lucky, but if I had excessive(.001+) run-out in a fired unsized case I would send the gun back to the manufacturer or have it re-chambered. Well, I doubt you'd be getting a rechamber with a variance of only .001", but you'd have to make a chamber cast to confirm that. As I said above, brass can be a major factor in runout and cheaper, less uniform brass is near the apex for T.I.R.. Since there are various thicknesses in the walls comprising the body of the case, when the case expands, the thicker portions will contract at a different rate than the thinner sections and this can bow the case, somewhat like a banana. It's not the only cause, but it is a cause. Anyhow, you have a gage and that was my other point above...in order to know what's what, you have to measure things like you so vigilantly do and in order to do that, you need a decent concentricity gage. Chris |
Armory Sponsor