I’m sure others must have had this happen. 6.5 Grendel Starline brass sized down to 6mm ARC using a Hornady Custom Grade full length sizing die with Imperial sizing die wax and a LE Wilson case gauge. Even though using Imperial wax sparingly, effort needed to size fire formed brass is excessive to the point die will push brass and form a belt at bottom of case body. Do I have a bad die?
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6mm ARC sizing Woes
- Thread starter danr
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Read Hornady die & didn’t even need to look at picture. It seems their 6ARC die is basically an unadvertised small base die.
LE wilson die is also GTG for 6Arc if you want a bushing die. That’s what I’m using.
I agree with Alamo if you want a non bushing die go with Mighty Armory. Have them in 4 other calibers & they’re great die’s.
LE wilson die is also GTG for 6Arc if you want a bushing die. That’s what I’m using.
I agree with Alamo if you want a non bushing die go with Mighty Armory. Have them in 4 other calibers & they’re great die’s.
That’s because the new brass hadn’t expanded to fit your chamber. How much is the die sizing? What is the base diameter before and after?
I had found the Hornady brass or some of it is .003 undersized at the .200 line. Probably matches their FL die.
The Lapua & Starline Grendel I measured was right on saami spec at the .200 line. The LE Wilson FL die is also saami.
I've repeatedly seen reports of the Hornady FL die leaving this step on Lapua & Starline brass.
After 3 firings on the Hornady brass with fairly hot Lever loads it still hasn't blown the Hornady brass out to saami at the bottom. Still has a reverse step where the Wilson die doesn't touch.
Below link shows where I measured it.
https://www.snipershide.com/shootin...e-belted-magnum-problem.7112215/post-10119157
The Lapua & Starline Grendel I measured was right on saami spec at the .200 line. The LE Wilson FL die is also saami.
I've repeatedly seen reports of the Hornady FL die leaving this step on Lapua & Starline brass.
After 3 firings on the Hornady brass with fairly hot Lever loads it still hasn't blown the Hornady brass out to saami at the bottom. Still has a reverse step where the Wilson die doesn't touch.
Below link shows where I measured it.
https://www.snipershide.com/shootin...e-belted-magnum-problem.7112215/post-10119157
Back when you couldn't find any dies anywhere, I had a 264 LBC RCBS small base die that did that to brass. I polished the die with 600 grit until it didn't do it anymore.
Yep I got a hold of a Lee FL sizing die and sizing the Starline brass now is near effortless.
Would you be able to measure and post the ID of the base of your Hornady and Lee FL sizing dies? I might order a Redding FL sizing die (I use for many other calibers), get Lee or machine the Hornady die to alleviate the issue. Seems so odd that Hornady would mis this on their own cartridge.
Couldn’t get the decapping pin out of the way on the Lee die to get a good measurement with the tools I had. The Hornady die measures 0.436Would you be able to measure and post the ID of the base of your Hornady and Lee FL sizing dies? I might order a Redding FL sizing die (I use for many other calibers), get Lee or machine the Hornady die to alleviate the issue. Seems so odd that Hornady would mis this on their own cartridge.
Thanks for the effort! The way the decapping pin is held in on the Lee does leave a little to be desired (I have a couple sets from when I started reloading) so I do understand. As I went a bit further into the rabbit hole, I am (hopefully correctly but I don't think I am) of the mind that this is a hornady brass thing, not a die thing. I don't use Hornady brass (500pc converted Starline 6.5 Grendel) so I'll just keep an eye on this.
Thanks again!
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You have a die cut to improper size. Contact Hornady. This happened to me with my RCBS .264 LBC dies when the 6.5 Grendel first came about. RCBS cut a bunch of them too small, and it caused a “belt” (donut) at the base…Just like pictured. I didn’t reload for it for years after that. Then when RCBS started making actual 6.5 Grendel dies, I bought a set, and haven’t had any issues since.
Okay, this is still a problem even after trying a 3rd die. Hornady, Lee now a Forester FL die. So I’ve read now that if you’re running your loads at max end, sizing will crush cases because the case walls at the base of the Grendel/ARC are thin. Are you’all dealing with this. I have some new Starline ARC brass and will reduce powder charge and start over and see if that eliminates the sizing issues I’m still seeing. A bit disappointing considering the hype was better velocity over the Grendel.
Just saw this. So the solution is to back off on the load and not chase the the published velocities. That’s what I did. Started loading at the higher end and did achieve 2670 fps out of my 22” AR with 105 bthp but accuracy wasn’t acceptable. I pushed pressure enough at that range to find a load with repeatable accuracy and ended up breaking the extractor on my bolt and not knowingly ruining my brass. The reloading dies were never the issue. Once you abuse the brass, it’s not gonna resize back to where it needs to be. I trashed all that original brass I started with and found backing off my load by 1.5 gr, I settled on 2550 fps with my 107s with excellent accuracy, zero gun/reloading issues.
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When I had this problem with a 22 Grendel it was because the chamber was cut poorly. Probably had wobble in the tail stock and wollered the base of the chamber. Or the smith tried to polish a rough chamber and used something too abrasive and took material out. I got a second barrel from him and never had the problem again. 918V was trying to talk you on to it but you ignored him.
I have just a few cases in a batch showing belts. The worst two measure .447 at the base instead of .444 and they will not chamber in my new barrel. The rest of the batch chambers fine. It would not suprise me from what I have seen if the chamber in my previous Rainer ultramatch barrel was all wollered out. So far everything they have sent me and everything I have let them touch. They have turned to shit.
Just checked to support my supposition. I mis spoke. The cases that won't fit in my cmmg barrel with belts measure .446 at the base. They will fit in the 2nd brand new warrenty replacement barrel I got from Rainer arms that I can't shoot because they wanted all my parts to make sure it was put together correct. Then proceeded to take 8 weeks and cometely.botch assembly.
Gas block screw is seized in a gas block which is installed crocked. I heated it with torch but it won't move. I could barley get the handgaurd pinch screws out. They were so tight it took the anodizing off the handgaurd under the bolt head. They also used thread locker on those pinch bolts. First time I have seen it. And it's the second time they assembled this upper.
To surmise. After 8 weeks they sent me a nonfunctional upper. With a shit assembly job I can't correct because they made all fasteners stupid tight and thread locked them.
I am afraid what I will find when I get down to the barrel nut. Initial inspection looks like they rounded the flats on the barrel nut over in the tighten direction.
Gas block screw is seized in a gas block which is installed crocked. I heated it with torch but it won't move. I could barley get the handgaurd pinch screws out. They were so tight it took the anodizing off the handgaurd under the bolt head. They also used thread locker on those pinch bolts. First time I have seen it. And it's the second time they assembled this upper.
To surmise. After 8 weeks they sent me a nonfunctional upper. With a shit assembly job I can't correct because they made all fasteners stupid tight and thread locked them.
I am afraid what I will find when I get down to the barrel nut. Initial inspection looks like they rounded the flats on the barrel nut over in the tighten direction.
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Just checked to support my supposition. I mis spoke. The cases that won't fit in my cmmg barrel with belts measure .446 at the base. They will fit in the 2nd brand new warrenty replacement barrel I got from Rainer arms that I can't shoot because they wanted all my parts to make sure it was put together correct. Then proceeded to take 8 weeks to put my upper together all fucked up.
Gas block screw is seized in a gas block which is installed crocked. I heated it with torch but it won't move. I could barley get the handgaurd pinch screws out. They were so tight it took the anodizing off the handgaurd under the bolt head. They also used thread locker on those pinch bolts. First time I have seen it. And it's the second time they assembled this upper.
To surmise. After 8 weeks they sent me a nonfunctional upper. With a shit assembly job I can't correct because they made all fasteners fuck you tight and thread locked them.
I am afraid what I will find when I get down to the barrel nut. Initial inspection looks like they rounded the flats on the barrel nut over in the tighten direction.
Did you check the gas port hole with a borescope to verify it's off or are you just going off it's relation to the handguard?Just checked to support my supposition. I mis spoke. The cases that won't fit in my cmmg barrel with belts measure .446 at the base. They will fit in the 2nd brand new warrenty replacement barrel I got from Rainer arms that I can't shoot because they wanted all my parts to make sure it was put together correct. Then proceeded to take 8 weeks to put my upper together all fucked up.
Gas block screw is seized in a gas block which is installed crocked. I heated it with torch but it won't move. I could barley get the handgaurd pinch screws out. They were so tight it took the anodizing off the handgaurd under the bolt head. They also used thread locker on those pinch bolts. First time I have seen it. And it's the second time they assembled this upper.
To surmise. After 8 weeks they sent me a nonfunctional upper. With a shit assembly job I can't correct because they made all fasteners fuck you tight and thread locked them.
I am afraid what I will find when I get down to the barrel nut. Initial inspection looks like they rounded the flats on the barrel nut over in the tighten direction.
Sounds pretty fucked up tho...
I am going by more than just its relation to the handguard but that was the first and most obvious clue.
If it's that crooked and hitting the handguard it's even worse if the gas hole is lined up. That would mean the gas hole is in the wrong place. Which is possible because looking where I got o e set screw out. It appears to be lined up with the dimple.
Also looking at the Sami print for wthe chamber. Base diameter should be .442 with max of .002 over that for .444. That means .446 is larger than Sami chamber dimensions also.
So it looks like at least two reasons this 3rd warrenty repacement barrel needs to go back. One thing for sure. They will never touch any of my parts but their barrel again.
If it's that crooked and hitting the handguard it's even worse if the gas hole is lined up. That would mean the gas hole is in the wrong place. Which is possible because looking where I got o e set screw out. It appears to be lined up with the dimple.
Also looking at the Sami print for wthe chamber. Base diameter should be .442 with max of .002 over that for .444. That means .446 is larger than Sami chamber dimensions also.
So it looks like at least two reasons this 3rd warrenty repacement barrel needs to go back. One thing for sure. They will never touch any of my parts but their barrel again.
I use Mighty Armory sizing die and Starline converted 6.5gr as well as their 6ARC brass, no issues through my LaRue, Proof and Christensen Arms rifles. Lots of guys that run extra spicy loads and are blowing the webbing out at the case head OR have a marginal chamber on their rifle use the Sgt. of Arms belt buster to get the webbing back into shape before full length sizing.
Wilson FL bushing die is money for 6 ARC. The case is short avoid small base dies if you don’t want the bottom F’d.
My Lee die is sizing the base down to .438. I need to measure some brass from my other barrel and die. I know I polished my other Lee die to make the belt less pronounced. Shows more on hotter loads of course becuase there is more case and sometimes case head expansion. I know brass from other die and barrel wouldn't fit in my new barrel. I didn't run down if it was headspace or base diameter.
I should add the brass from the first die is 9x fired 6.5 grendel starline and still going. So for the most part it seems to just be a cosmetic issue.
I should add the brass from the first die is 9x fired 6.5 grendel starline and still going. So for the most part it seems to just be a cosmetic issue.
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Place Whidden 6arc die on the GOOD LIST for the 6arc. As it doesn’t over work/ overfuck/ small base/ undersize the base of the die.
