6 DASHER pierced primers AND no case expansion

[reloaderron]

Hey gang,

Last year I took the short action out of a 110 Tactical that had bought brand new a couple years earlier in 6 Creedmoor and used it to build a rifle in 6 Dasher using a Shilen barrel from Northland Shooters. The load develpment process went horribly as I kept having primer piecrings all the way from 31.4 of Varget (a very common load) until I got down to 29 grains! And no, I wasn't having any piercings while using the same action in the stock 6 Creedmoor right up until I retired it to build the 6 Dasher. I have re-checked with the go/no go gauges thinking maybe I got something wrong there, but all is fine. A guy at the range I go to who has built many rifles using Savage actions immediately assumed that the bolt probably needed a bushing but upon examining conclued that all looks great. I read somewhere that the problem could be the wrong type of firing pin because the 6 Creedmoor uses large rifle primers but the 6 Dasher uses small rifle primers, but I can't get any confirmation on this. The rifle actually shoots amaingly well even with the reduced load but obviously velocity has been compromised. Furthermore, there's another problem that I just can't comprehend. I bought 200 pieces of Peterson brass which I am now on my fourth reloading of. I use a full length RCBS bushing die and yet to have anything but the necks sized by the die. What I mean is, the cases are not expanding to the point where the full length sizing die actually has to resize the case AT ALL. I also built a 7 SAUM at the same time and it works perfectly so it's not like I'm a complete moron. lol. So any ideas would be greatly appreciated. Thanks in advance.

 

[Yoteski]

Did he check the firing pin protrusion? That would be my first guess if everything else is in spec.

 

[Dai Bando]

 

[reloaderron]

Did he check the firing pin protrusion? That would be my first guess if everything else is in spec.

I believe he did but he was only eye balling things so I don't know if that is good enough. The thing I don't get is why just by changing from 6 Creedmoor to 6 DASHER, using the same action/bolt, would protrusion be an issue unless indeed I need to change the firing pin because I've gone from a cartridge that uses a large rifle primer vs. a cartridge that now uses a small one. The more I checked into this the more I found it didn't matter. I honestly don't know what to think. Thanks for getting back to me so quick.

 

[just browsing]

Sounds to me like you’re sizing your cases too much.

If the case is unsupported by the shoulder, it can move away from the bolt face when the firing pin strikes the primer. Pressure forces material back through the firing pin hole resulting in cratering or in extreme cases, pierced primers. It could also explain why your case is not being completely formed, with the case head absorbing some of the pressure rather than the shoulder.

I’ve seen a lot of Dashers do this and pretty much all of them have had something to do with the shoulders being bumped too much. You’re looking for 2 thou bump max, anything more and you risk this occurring. Re-form with plenty of jam or false shoulder.

 

[reloaderron]

I just checked and he isn't taking any work at this time because he is overwhelmed. The wait listed for such work is 25-50 weeks. Do you have any others that you recommend? Thank You.

 

[FUNCTIONAL]

I just checked and he isn't taking any work at this time because he is overwhelmed. The wait listed for such work is 25-50 weeks. Do you have any others that you recommend? Thank You.

Long rifles inc.

 

[FisherT&C]

Hey gang,

If it's not a sizing issue, it could be the brass itself. See if you can find out what the neck diameter of the chamber is. Most 6 Dasher reamers should be .273" I have two dasher reamers, one is .273" for Alpha brass and fire formed Lapua etc. I also have one which is .275" specifically for Peterson brass. I know it's a pain in the ass but try another brand of brass if you can and eliminate the case as the cause. You may have to switch brass or have the neck opened up to .275". Hopefully that helps.

 

[LV Precision]

Sounds to me like you’re sizing your cases too much.

If the case is unsupported by the shoulder, it can move away from the bolt face when the firing pin strikes the primer. Pressure forces material back through the firing pin hole resulting in cratering or in extreme cases, pierced primers. It could also explain why your case is not being completely formed, with the case head absorbing some of the pressure rather than the shoulder.

I’ve seen a lot of Dashers do this and pretty much all of them have had something to do with the shoulders being bumped too much. You’re looking for 2 thou bump max, anything more and you risk this occurring. Re-form with plenty of jam or false shoulder.

Had the same issue, and this was the exact cause. I was using SAC modular comparators and it was actually giving inconsistent readings because of the inherent design with how it makes contact with the shoulder.

Really knowledgeable buddies who reload told me to switch to Hornady comparators that have a very definite edge, remeasured and reset my die, and the problem went away.

Your problem is a brass sizing issue.

 

[reloaderron]

Sounds to me like you’re sizing your cases too much.

If the case is unsupported by the shoulder, it can move away from the bolt face when the firing pin strikes the primer. Pressure forces material back through the firing pin hole resulting in cratering or in extreme cases, pierced primers. It could also explain why your case is not being completely formed, with the case head absorbing some of the pressure rather than the shoulder.

I’ve seen a lot of Dashers do this and pretty much all of them have had something to do with the shoulders being bumped too much. You’re looking for 2 thou bump max, anything more and you risk this occurring. Re-form with plenty of jam or false shoulder.

Sounds to me like you’re sizing your cases too much.

If the case is unsupported by the shoulder, it can move away from the bolt face when the firing pin strikes the primer. Pressure forces material back through the firing pin hole resulting in cratering or in extreme cases, pierced primers. It could also explain why your case is not being completely formed, with the case head absorbing some of the pressure rather than the shoulder.

I’ve seen a lot of Dashers do this and pretty much all of them have had something to do with the shoulders being bumped too much. You’re looking for 2 thou bump max, anything more and you risk this occurring. Re-form with plenty of jam or false shoulder.

ok, I'll check that out. I've sized a lot of brass, for many different calibers, including 1000's of 6.5 Grendel which is pretty close in size, and I have never seen a case body not be touched by the sizing die before. Thanks for your help.

 

[short_mag]

You may check the seating depth….

A friend had this issue with a 6x47. Had the firing pin bushed and examined - seating depth fixed it….

Intiatilly, he was trying to stay a couple thousandths of the lands, moved to -.020 and it stopped piercing.

 

[LV Precision]

ok, I'll check that out. I've sized a lot of brass, for many different calibers, including 1000's of 6.5 Grendel which is pretty close in size, and I have never seen a case body not be touched by the sizing die before. Thanks for your help.

It's not that the sizing die isn't touching your brass, it's that you are OVERsizing it and creating excessive headspace between the shoulder and the chamber.

 

[padom]

Had the same issue, and this was the exact cause. I was using SAC modular comparators and it was actually giving inconsistent readings because of the inherent design with how it makes contact with the shoulder.

Really knowledgeable buddies who reload told me to switch to Hornady comparators that have a very definite edge, remeasured and reset my die, and the problem went away.

Your problem is a brass sizing issue.

This is complete horse shit. There is NOTHING wrong with SAC comparators I've used them 1000's of times. You're not "measuring" shit with the comparator...your getting a number to a reference point and pushing back from them... the man himself @Mgordon can respond to this nonsense

 

[LV Precision]

This is complete horse shit. There is NOTHING wrong with SAC comparators I've used them 1000's of times. You're not "measuring" shit with the comparator...your getting a number to a reference point and pushing back from them... the man himself @Mgordon can respond to this nonsense

Calm down Nancy.

I’ve also loaded thousands of rounds across multiple calibers using both SAC comparators and Hornady comparators, and have found Hornady to give more consistent readings. SAC comparators depend on the shoulder to make contact with the comparator insert, but there can be inconsistency where the brass is actually contacting the insert. It could be at the next to the neck shoulder junction, it could be below that, but it is not always the same. Multiple friends have also found the exact same thing and have gone back to the Hornady comparators.

SAC comparators look cool, but they don’t perform better in my experience.

 

[rayvandervort]

ok, I'll check that out. I've sized a lot of brass, for many different calibers, including 1000's of 6.5 Grendel which is pretty close in size, and I have never seen a case body not be touched by the sizing die before. Thanks for your help.

I recently sold a 270 because no matter what I did or what this site gave for Ideas, fireformed cases never got there. Large taper and unidentified multiple issues suspected both in dies and chamber were what I blamed it on. Same procedure on 308, 220 swift, 6.5 Creedmoor had no such issues. The one difference was I could not resize reliably, had 3-4 stuck cases overall, even sent dies back for analysis. I was told the dies were ok but they sent new ones anyway. new cases, old cases annealed cases, 4 different OEM's, heavy bullets and max loads still did not fireform. Neck sizing only, still when shot did not fireform. Absolutely went nuts for over a years and gave up., when adding it was a gun I was using to teach my son reloading. Teaching frustration was not the idea, but I was the only one on that coin, he just kept on learning. In the end, I felt the base diameter of chamber was fat, causing hard FL sizing and somehow preventing fireforming with this or a combination of issues such as a loose neck and back pressure on the shoulder.

 

[wadebrown]

I would get the bolt bushed to reduce the gap between the bolt face and the firing pin. I have seen many Savages pierce small rifle primers, especially the 6.5 x 47 Lapuas, that were fine once the bolt was bushed and the firing pin turned down. GreTan has been the shop to get a bolt fixed up but have been swamped for a while and it not accepting work right now. LRI does bushes bolt and does a great job with good turn around so I would go there. Search the forum on 6mmBR.com if LRI is not an answer as a number of 'smiths who post there do the same work with good quality.