Full Length sizing my 6.5 Grendel once fired casings

[cocowboy]

I find I have an issue that has me at wits end. I have a Redding turret press and two sets of full length dies one being a Forster and one being RCBS. I have a batch of 100 Starline 6.5 brass that I have fired on time. I set the press and using the Forster die set I ran the 100 pieces of brass through the dies and then began to check them for quality. I first dropped each piece of brass into a Wilson cartridge case gauge and they all dropped in just fine. I checked length and trimmed to meet trim length. Primed, then loaded 20 rounds to take to the range and check out a new load I want to try. Here is where it went wonky. I loaded 10 rounds in a 6.5 Grendel magazine and dropped the BCG and readied my position to shoot. I got a click.. WTH... Pulled the charging handle and removed that round. Again closed the bolt and click. Pulled the round out... tried one more time an bang.. next round click.. I stopped there.. went to my bench and began a bit of investigating.. This time I dropped the remaining loaded rounds into a Lyman headspace gage and found that of the 10 rounds I had in the magazine less the one fired, 7 would stop short about 3/8" from dropping all the way into the case gage with 2 dropping all the way in. I pulled the bullets on all loaded rounds (19) dumped the powder - and re-ran them through the RCBS die this time - of the 19 casings 2 then dropped into the lyman case gage. I know that the Wilson gage does not measure diameter but allows the casings to all drop in where the Lyman stops most thus telling me why i am not getting the correct casing dimensions that allow the round to go into battery. Any assistance form the forum would be appreciated.

[Zeneffect]

What was the measured shoulder bump? If you do not know or can't get the answer, that is a big part of your problem.. but it's easily rectified. By having a numerical value to compare unsized and resized brass you can then make a determination if you are actually resizing at all.

[grayfox]

The shoulder bump, for your chamber, is not getting set far enough back.
Best way is to measure it with a hornady head space comparator, using the right insert (I think it is B, the 0.350, but this is from memory), and your calipers. Compare this distance to datum point with Saami, but knowing what it is for your chamber so you can set it back a few 0.001's is the key thing.
Measure a few of your once-fired but unsized brass also, to see what the shoulder measures after it's been fired.
The resizing needs to set that back, oh, 3-6 thousandths depending on whom you talk to.

Then trim as needed, then see if they will chamber in your rifle without any bullet or powder or anything (they should), just the bare case. If it's an AR, guide the case in while pressing it into the boltface (to overcome the ejector), see if you can close the bolt all the way.

One more thing, this IS a saami grendel barrel, right? not some kind of 264lbc or knock-off... just making sure.

[Klem]

C,

Now you have a couple of spent cases this should be an easy fix.

Those spent cases are arguably more useful than your Lyman gauge. Rather than use the Lyman to benchmark your reloads against SAAMI, consider using spent cases to benchmark reloads to the chamber they will be fired out of. Spent cases are fire-formed to the shape of the chamber, so you now know the key dimensions of what your reloads should be.

Measure the length of those spent cases from the base to roughly middle of the shoulder or 'datum line'. This measurement is often called 'headspace'. The Hornady Comparator gauge set does a great job of this, but if you don't have one a 9m or .357 handgun case will do. It's a bit fiddly but works. Screw the full-length sizing die in until cases start to get bumped. Lock the die ring when the bump is about .003"-.004" shorter than the spent case. This is the ideal compromise in a semi-auto to guarantee cycling, but without working the cases too much. Whether the newly bumped .003" cases fit the Lyman gauge is now almost irrelevant. Sure, it will give you an idea of how your reloads and chamber are relative to SAAMI, but ultimately you should load for the chamber, not SAAMI.

As you don't have the Comparator gauge here's doing the same thing with a 9mm case. I recommend getting the Comparator gauge at some stage.

spent - Copy.jpgsized - Copy.jpg

[Rivercityjeff]

Thanks Klem! Now I have another use for 9mm brass.

[Mark611]

https://sheridanengineering.com/prod...unition-gauge/ This is one of the best things I've purchased to aid my reloading, I also use a Redding body die and a Lee collet neck sizing die for loading my AR 6.5GRR, I also use the Hornady tools when needed, PS, the slotted open gage allows you to sse what you are doing!!!

[ocharry]

i use a case gauge from www.whiddengunworks.com

they dont list one for the grendel but i would bet he would make one for you

i have one for the 6.5 CM so i looked at the load manual and the neck and shoulder are the same..only differeance is the length and the rim dia....yep i figured what the difference was and fired up the lathe and tured up the spacer to sit the grendel case on..so now i can use it for both

these gauges work really good...they give you a easy and precise reading so you know exactly where you are and how much you move the shoulder

the other ways mentioned before work too... just passing this on to you guys to check out.....there are always different ways to get what you need or want to know....

my .02

ocharry

[Harpoon1]

i use a case gauge from www.whiddengunworks.com

they dont list one for the grendel but i would bet he would make one for you

i have one for the 6.5 CM so i looked at the load manual and the neck and shoulder are the same..only differeance is the length and the rim dia....yep i figured what the difference was and fired up the lathe and tured up the spacer to sit the grendel case on..so now i can use it for both

these gauges work really good...they give you a easy and precise reading so you know exactly where you are and how much you move the shoulder

the other ways mentioned before work too... just passing this on to you guys to check out.....there are always different ways to get what you need or want to know....

my .02

ocharry

I prefer the Whidden gauges too. Seem like an upgrade from the Hornady stuff I have. Both work fine though. Just wish the Whidden gauges used a thumb screw also instead of an allen screw. The Whidden gauges just seem to be more stable, have better contact on the shoulder, when measuring.

[Old Bob]

i use a case gauge from www.whiddengunworks.com

they dont list one for the grendel but i would bet he would make one for you

i have one for the 6.5 CM so i looked at the load manual and the neck and shoulder are the same..only differeance is the length and the rim dia....yep i figured what the difference was and fired up the lathe and tured up the spacer to sit the grendel case on..so now i can use it for both

these gauges work really good...they give you a easy and precise reading so you know exactly where you are and how much you move the shoulder

the other ways mentioned before work too... just passing this on to you guys to check out.....there are always different ways to get what you need or want to know....

my .02

ocharry

Whidden Gunworks will make a 6.5 Grendel case gauge for you. They made one for me. Per their instructions on their website, you have to send them a 6.5 Grendel GO-gauge for them to use for precise headspace machining. They do return the GO-gauge to you.

[LRRPF52]

I really prefer the Stoney Point (bought by Hornady) headspace comparator kit.






When setting up my sizing die, I use a stripped bolt to check that my sizing operation is producing cases that will actually fit the chamber.

I size the brass down minimally until I get it to fit in the chamber and allow the bolt to rotate into a locked position in the barrel extension.

You will find that fired cases do not fit in or allow the bolt to rotate into a locked position in battery.

Even partially-sized cases will not allow the bolt to rotate into a locked position, as you have learned the hard way.

The main factor in this is shoulder position. The shoulder must be moved back sufficiently to allow chambering and bolt lock-up.

You also have to factor variations in the brass and processes.

You might make your first few pieces of brass fit fine, but others in the batch will not chamber due to these variances.

Account for that when setting up your headspace.

I do a lot of testing initially with sized cases when dialing in the sizing die, and I also check with completed rounds of ammunition from that batch to ensure consistent chambering and lock-up for the batch.

[Mark611]

I can see where the Whidden gage would be useful but using the Hornady headspace gage and a Sheridan gage seeing's how I have them and the fact I can see what's going on inside with the Sheridan gage with everything you need to see makes more since to me, especially in a gas gun where you really need to size your cases back to SAAMI spec IMO for proper and reliable function, I can see where the Whidden gage would be well suited for a bolt action set up JMO,

[montana]

I also use the Sheridan gauge and found it to be a reliable resource for visually inspecting my case sizing..

[Klem]

+1 on the Sheridan rifle gauge.

[Mark611]

I replaced all my Wilson Case gages with the Sheridan slotted case gages, Klem and montana I'm glad you agree with the type of case gage!