6.5 Grendel Brass problems

[bdsss]

I'm having problems with my new 6.5 Grendel brass streaching. See pictures attached.
When I resize the brass full length, it seems to streach the brass down creating a rim like a belted magnum cartridge.
I'm using Lyman dies with a Lyman cartridge checker and the resized brass or a loaded round will not fit it. I also have a Wilson brass checker and all of it will fit perfectly.

I'm shooting it in an AR platform. And I'm having problems getting it to load also.

I'm using new Star Line brass. I know it's cheap but this is not a target or bench gun so I don't want to us Alpha or Lapua unless I have to.

Any help would be greatly appreciated.

Bill

 

[Bat Rastard]

I had similar issues with 6grendel.
Long story short, back off on your powder.

 

[Sniper338]

Yeah thats an issue.... does it do this to new brass when you size up new brass to shoot it?

You need to figure out whats causing it first... if the new brass getting sized is fine then the issue is occurring after firing.

If new brass does this then your die is bad.

If its not doing it upon initial sizing, then only doing it after fired, you got too hot of load going on.


Personally I use lapua brass for mine. But I have a very ExPeNsIvE built AR that shoots STUPIDLY good. Closer to the .25moa consistently than half moa. Cost as much as a bolt rifle to build kinda deal.

By all means though I can attest lapua brass is the best grendel brass. I've got over 25 firings and still going on some. Trashing a few ever reload session at this point tho

 

[Rat Rifle]

I had trouble with My 6.5 Grendel Brass when I was sizing with a die that had an expander ball. It was stretching the brass to where it wouldn’t chamber. I removed the expander ball and used the die as a body die. I then neck sized with a LEE Collet Die. Problem solved.

 

[603Country]

I had problems with Hornady brass in the Grendel. Second loading, every neck split. After some diligent measuring, it was apparent that the dies were working the brass far too much. I switched to a Redding Bushing Die and all is well - since I’m now working the brass as little as possible. I suggest new dies for the OP.

 

[358WCF]

Hard to tell without any measurements, but maybe either a very large chamber or a very small die without much bevel on the lower end. Or a combination of the 2?

Odd that they fit in the Wilson gauge but not the Lyman though.

 

[msalm]

W/ the Grendel in an AR, if the maker of the barrel has too large of radius/chamfer at the chamber mouth, in conjunction w/ a type II chamber (.135-7” depth bolt face vs .125”), the case will have more than the solid case head protruding out of the chamber and be unsupported. Can exhibit the swelled case ahead of the solid head portion because of this. I like to build my Grendel AR barrels w/ the .125” 7.62x39 bolt and reduce the chamfer in angle and depth to minimize this possible issue.

 

[joshb]

I agree. You have a gun problem giving you a brass problem.

 

[Spacegunr]

I have seen this kind of thing with a 6mm Grendel based cartridge in an AR. Compare the case diameter at the web of a new unfired case with one that you've fired from the rifle. My guess is the fired case is several thousandths wider. In my case the chamber was cut too big, brass expands to fit...

 

[Coyotefurharvester]

So the op has type 11 chamber and 7.62 bolt? Brass is unsupported and not able to size after firing?

 

[Lone Hunter]

Agree with Spacegunr and Joshb…. Chamber too big…giving you a brass problem..

 

[Gray420]

I am with coyote, you May have the wrong bolt head with the wrong chamber.

 

[RegionRat]

Time to inspect everything that you can.

If you have the tools, inspect the brass in virgin, fired, and sized conditions.

If those dimensions don't make sense, it would be time to also inspect the chamber and maybe even the dies.

You can find the prints on the web from the SAAMI web site, but here ya go.



For starters, what is the diameter of the brass at a line 0.200" above the base?
Virgin, fired, sized?

 

[searcher]

You might want to elaborate on whether your new brass exhibited this problem BEFORE or AFTER you fired it. If before, you need to look at the brass, dies or die adjustment. I have (and have had) a few 6.5 Grendel A/R's and I've never run into anything like that, regardless of brass maker. And I have used some pretty inexpensive brass back when one couldn't get the stuff. Bad lots of brass happen, but best to take things one step at a time.

If you are experiencing this on unfired, new brass, I'd first look at your die and check it over, being sure to clean the heck out of the inside body to remove the anti-rust stuff they put on new dies. Look inside carefully to see if there are any brass "smears" on the inside of the die. If there are, they must be removed. Take the expander/de-prime rod out of the die and try sizing a round. If it still does this, I'd change lubes, especially if you are using as spray product. I'd try some regular RCBS or whatever other lube you have locally - or better, buy some imperial lube. If it still has that problem, you need to try a few pieces of another make of brass (and no - it doesn't need to be Lapua). If it still does it with different make brass (without the de-cap rod)- you have a bad die.

If the new brass originally sized well and you didn't run into this until after firing it - it is almost certainly your rifle. It is a bummer to question your brass and have to buy more just to see what the problem is. I'd be happy to send you a few pieces of brass on my dime if you want to try some good brass in it to see if your brass is the problem - assuming you might not have any, being a new rifle. Just send me a PM with your address. Hope you get that sorted out.

 

[dellet]

I'm having problems with my new 6.5 Grendel brass streaching. See pictures attached.
When I resize the brass full length, it seems to streach the brass down creating a rim like a belted magnum cartridge.
I'm using Lyman dies with a Lyman cartridge checker and the resized brass or a loaded round will not fit it. I also have a Wilson brass checker and all of it will fit perfectly.

I'm shooting it in an AR platform. And I'm having problems getting it to load also.

I'm using new Star Line brass. I know it's cheap but this is not a target or bench gun so I don't want to us Alpha or Lapua unless I have to.

Any help would be greatly appreciated.

Bill

This is not clear if you are checking a loaded round with new or once fired brass. Same with the rounds that will not chamber.

Most likely, the Wilson gauge is a headspace gauge used to check the case base to shoulder length after firing, before sizing. No surprise that a case with an oversize diameter would fit the Wilson and not the Lyman. The Wilson is designed to allow oversized diameter to fit.

Complete load data would be nice to have, as would be some info on the rifle. You say there is trouble loading. Is this first round chambering off the top of the magazine, or cycling the next round on its own? It’s quite possible the system is over gassed. This could be a rifle problem as well as a load problem.

If you are shooting ammo that has trouble chambering, Thats a huge red flag.

 

[DHD]

As many have already mentioned, not enough information. Specifics please. Gun, ammunition, and how it shoots while you are at it.

Gun: we realize it is an AR because you stated that, but factory gun, or did you put it together? If you put it together, what barrel and bolt? If factory, say which one. I highly doubt anyone wants to trash talk your choices, it just helps diagnose your issues.

Ammunition: we know it is Starline brass because you stated that, but what powder and charge, then what bullet? You stated you use Lyman dies at least.

As you stated you know it is cheap, then that is a good clue. You do not have to spend a ton, but a "cheap" gun (especially an AR) often will make you pull your hair out and QC is going to be either absent or spotty.

Just me throwing something against the wall here, I will echo someone else and suspect you have a generous chamber. Yes, a hot load will add to the issue, but I personally can get pretty warm with my Grendel's and ARC's as I have pretty tight chambers, very good bolts, and I tune the heck out of my .441" casehead AR's as they tend to be primadonnas (one word or two?).

That belted .441" casehead thing you are experiencing is frustrating I know. The one time I watched it happen was due to an early 6mmARC barrel that had too much chamfer (for lack of a better word) at the breech. The manufacturer replaced it with no explanation. That barrel did not allow much beyond middle of the road powder charges before the magnum belt appeared. The new barrel has not shown the magnum belt even with warm loads.

How will you know if that is what is happening to your rifle? IMHO, you will know it if you have a lot of expansion at the .200" line (fresh cases have a belt) with low powder charges. You can throw in different springs, different bolts, change out your gas block to an expensive adjustable one, or try a heavier buffer to try to tune that out as much as possible, but you will still probably have more expansion than the load should show.

Just my honest opinion and I will not mind being wrong. I do not think more expensive brass will cure your issue. It will probably only give you belted expensive brass.

I suppose what I'm trying to say with way to many words is, I don't think you have a "6.5 Grendel Brass Problem", I think you have a 6.5 Grendel barrel problem.

 

[SKWERLZ]

I'm having problems with my new 6.5 Grendel brass streaching. See pictures attached.
When I resize the brass full length, it seems to streach the brass down creating a rim like a belted magnum cartridge.
I'm using Lyman dies with a Lyman cartridge checker and the resized brass or a loaded round will not fit it. I also have a Wilson brass checker and all of it will fit perfectly.

I'm shooting it in an AR platform. And I'm having problems getting it to load also.

I'm using new Star Line brass. I know it's cheap but this is not a target or bench gun so I don't want to us Alpha or Lapua unless I have to.

Any help would be greatly appreciated.

Bill

I had similar issues with 22ARC using starline 6.5 grendle brass.
How much is your headspace growing during firing?
My problem was solved by fixing the entry of my die, rounding the sharp edged bevel and polishing it.

 

[bks22345]

Personally I think it's a die problem. Look how much smaller the brass is just above the "belt." It's a fair amount smaller than the rim diameter and they should be the same at the 200 line with a slight taper to the shoulder. The die box says it's a small base die, maybe too small. Box also says it has a headspace gauge; so, compare the headspace gauge with a piece of fired brass.

And for what it is worth, there is nothing wrong with Starline brass. It's extremely uniform and I have never had a problem with it. I use it in a 6.5 Grendel as well as 6.5CM. I also bought 500 pieces in 270 Win to hydro form to 280AI. Maybe it is not Lapua, ADG or Alpha; but, it's a third of the cost.

 

[msalm]

So the op has type 11 chamber and 7.62 bolt? Brass is unsupported and not able to size after firing?

A type I bolt will not chamber in a type II chamber, headspace will be roughly.010” too small/tight. A type I bolt has a .125” recess. The type II is .135” nominal (I’ve measured some as deep as .140+” deep. So a type II chamber is shallower, w/ more case protruding out the back end.

 

[SKWERLZ]

Personally I think it's a die problem. Look how much smaller the brass is just above the "belt." It's a fair amount smaller than the rim diameter and they should be the same at the 200 line with a slight taper to the shoulder. The die box says it's a small base die, maybe too small. Box also says it has a headspace gauge; so, compare the headspace gauge with a piece of fired brass.

And for what it is worth, there is nothing wrong with Starline brass. It's extremely uniform and I have never had a problem with it. I use it in a 6.5 Grendel as well as 6.5CM. I also bought 500 pieces in 270 Win to hydro form to 280AI. Maybe it is not Lapua, ADG or Alpha; but, it's a third of the cost.

That’s what it was for me.
Cheap die trying to be an extruder.
The finish at the die entrance was terrible.