Wilson case gauge

[JCSC]

I have a few questions, which I was unable to clear up on the previous site I visit.

I have a Wilson Grendel case gauge and it is the first one I have purchased for reloading purposes. My hopes were to establish a good feel for my chamber and use this in properly bumping shoulders when reloading.

Upon opening the CG I checked a new hornady black. The base of the case sat nicely between the .010? cutout on the gauge. Nice consistent ammo, aside from the base to Ogive measurement I have taken.

Secondly, I checked a few PCs of once fired range brass ( not from my gun ) This was a gentlemen blasting away some Hornady American gunner and not reloading. I picked up 184 pcs. This brass when checked on the gauge is .009/.010? longer than the gauge. I am referring to the shoulder to case, not the necks that commonly grow and need trimmed.

My initial thought was that this persons gun has excessive headspace?

Now on to the brass from my first test day of my horrible shooting excuse for a first AR build. ( still diagnosing the cause )

My brass also falls into a similar range of oversized. Roughly .010 past the max on the gauge??? This is a quality barrel, bolt and ammo.

My last quandary with the case gauge is sized brass. I am using the RCBS full length SB lbc 264 die. I know this die doesn?t say Grendel on it, but everything I have read says that the case dimensions are the same. I briefly glanced at the prints to confirm.
The die worked the brass a fair amount at the base and seemed to size a little more than what I have previously experienced. My press was set to cam over and the brass was lubricated properly. On the case gauge, my sized brass is still .005? over the max from shoulder to base. It also grew a bit in the neck area, but for the purpose of these tests, I am measuring from the gauge to the case base, as to exclude any trimming required.

Obviously, I can still push the shoulder back enough to have decent ammunition in my chamber. It?s doubtful the die is capable of producing ammo that would fit in a tight chamber, but I have three precision tools showing me different deviations from sammi. A precision Wilson case gauge, Odin works chamber and RCBS die.

Let me know what you think.

[BCHunter]

My Odin works grendel has a long shoulder also 020" longer then factory black, just bump it back .003 to .005 keep the brass separate and run with it. Mine is more accurate then I need or can utilize, so I can live with the long base to shoulder.

[grayfox]

The RCBS die will work fine, the differences between LBC 264 and Saami Grendel are in the throat, which is beyond anything the case would touch.
Yes it is possible to have an "in spec" chamber that stretches your brass 0.010-0.018 over original, base to shoulder datum. Typical Hornady fresh brass is about 1.209 IIRC, and I once had a chamber that gave me fired brass at 1.226-1.228. Now if you take that brass and keep it separate from other Grendels (if you have more than 1), and only resize/bump the shoulder back 0.004 (I actually like 0.005 but that's another story)-- ie, not all the way back to the original which will place too much stretch/cycle/stretch on your brass and cause it to thin and weaken --, then it will stretch back to your "0.020" after firing but only will have stretched from the resized-bump-back. It can be within spec... but for me I unloaded that chamber and got another 'cause I didn't like it, plus it was much different from my other chambers.

It is also possible that the chamber could be out of spec but I don't think a wilson gage will tell you that. For this you really need a case comparator tool like Hornady's, which will measure case size and growth along with your calipers. Use the "B" insert (? it is the 0.350 insert) because that puts you to the datum point for the Grrr's shoulder. By the way I use a digital calipers so that I can zero the comparator's readout when the insert is used... then go back to original zero after I take it out and it returns to normal, coal-type measuring.

[A5BLASTER]

The RCBS die will work fine, the differences between LBC 264 and Saami Grendel are in the throat, which is beyond anything the case would touch.
Yes it is possible to have an "in spec" chamber that stretches your brass 0.010-0.018 over original, base to shoulder datum. Typical Hornady fresh brass is about 1.209 IIRC, and I once had a chamber that gave me fired brass at 1.226-1.228. Now if you take that brass and keep it separate from other Grendels (if you have more than 1), and only resize/bump the shoulder back 0.004 (I actually like 0.005 but that's another story)-- ie, not all the way back to the original which will place too much stretch/cycle/stretch on your brass and cause it to thin and weaken --, then it will stretch back to your "0.020" after firing but only will have stretched from the resized-bump-back. It can be within spec... but for me I unloaded that chamber and got another 'cause I didn't like it, plus it was much different from my other chambers.

It is also possible that the chamber could be out of spec but I don't think a wilson gage will tell you that. For this you really need a case comparator tool like Hornady's, which will measure case size and growth along with your calipers. Use the "B" insert (? it is the 0.350 insert) because that puts you to the datum point for the Grrr's shoulder. By the way I use a digital calipers so that I can zero the comparator's readout when the insert is used... then go back to original zero after I take it out and it returns to normal, coal-type measuring.

Your correct gray. 350 bushing.

[VASCAR2]

I have a Sheridan case gauge I bought from AA a few years ago so I’m not sure if there are any differences between Sheridan and Wilson. Normally fired brass will not fit in my case gauge. Most reloaders state the shoulder needs to be bumped back .003-.005 but is most dependent on your barrel. An easy way is to size a piece of brass and drop into your barrels chamber. Most forum members report on rarely needing to trim 6.5 Grendel brass. I figure I can get at least five or six reloads before I get close to the maximum brass length. Most new 6.5 Grendel brass is short and shorter than the recommended trim length.

I trim my brass for consistency in trying to get consistent seating depth. I believe my Sheridan gauge is basically machined to minimum spec 6.5 Grendel chamber. So in essence if my brass fits in my gauge it will likely fit in my 6.5 Grendel barrel chambers. So far my reloads have functioned in my various 6.5 Grendel AR-15’s but will not chamber in my Cz 527 American 6.5 Grendel even though the cartridge fit in my Sheridan case gauge. I suspect the gas gun has looser chamber tolerance than a bolt action so I plan on just keeping my brass separate for my Cz.

I bought a set of RCBS 264 LBC Small Base Taper Crimp dies. I thought my 264 LBC sizing die was over working the base of the brass. Some of my brass exhibited a crease near the base of the case so I’m not sure if my sizing dies is out of spec. I read where RCBS had a run of out of spec sizing dies but since I have Hornady dies I haven’t contacted RCBS about this die. The taper crimp die works but I haven’t seen a need for the taper crimp die as my 6.5 Grendel brass have sufficient grip on the bullet.

Most of my dies are RCBS and when I saw the 264 LBC dies on sale for a very good price I bought them. I broke a decapping pin early on in my RCBS die and the 264 LBC die uses a non standard decapping pin. Lapua brass has a smaller flash hole and requires a smaller size decapping pin. My Hornady dies was supplied with a spare decapping pin. I had to call RCBS to get the decapping pin as no one local carried this small DC pin. RCBS did send me a couple decapping pins for free.

Forum members praise the Redding bushing dies in 6.5 Grendel and the Forrester dies get very good reviews. I ordered a Forrester sizing die just to compare to my Hornady sizing die. Unfortunately I haven’t had the time to actually use my new Forrester die.


Not sure I helped any JCSC but some of experience with the 6.5 Grendel.

[VASCAR2]

Double post, internet failed.

[JCSC]

Thank you all for the clarification. I only have one Grendel, so this should be easy.

I will likely buy another die, but this set came up for $6.50 on PSA when I was buying some other things, so I bought it.

I am making some changes to the gun, remounting the barrel and 20 MOA mount, so hopefully get some better results next weekend.

I sprayed hornady black all over the county on my last outing, so something wasn?t right with the gun. If I get similar results after reassembly, both vortex and Odin works will get a call.

[Klem]

JCSC,

It all sounds normal, although I would be cautious about talking in numbers if you are only using a case gauge. I use case gauges, but only as ready-reckoners. It pays to get a Hornady headspace gauge so your measurements are more precise.

I don't know about Wilson but Lyman case gauges are machined with overly generous internal diameters (ID). This is to prevent cases from sloppily machined chambers indexing on the web instead of the shoulder. You can tell if your Wilson has been similarly machined by putting a full-length sized case in it, holding it up and shaking it like a castanet. If you can feel it rattle around then it is likely a wider than spec ID. The internal length of these gauges will be precise however as longitudinal headspace is more important than lateral headspace/ID. Sheridan case gauges will be tighter however as they are machined with a chamber reamer. A gauge with a generous ID will give you the impression your die is squeezing the body too much. But it's not the die, it's the gauge.

You can use an empty 9mm (which is .354") or .357 handgun case with calipers as a poor-man's Hornady headspace gauge. Put it over the neck and it rests roughly near the .350" datum line. It doesn't matter that it is not exactly .350" as it's all about the difference in measurements. The Hornady B350 insert won't be exactly .350" anyway.



Having a sized case still exceeding the Wilson gauge is also not unusual. My cases stretch about 0.016" on their first firing and from there they get bumped back .004". This puts them still outside the gauge but that's perfectly fine. If you squeeze them back inside the gauge then they will unnecessarily stretch again, and again, until they eventually wear out prematurely. Only bump them back inside the gauge if you have multiple guns and don't know which gun the ammo is being loaded for. That way you ensure they work in all guns, but at the expense of short-lived brass. If you only have one gun or you keep the cases and gun together then you may as well only bump the shoulder just enough to guarantee reliable cycling, and that is about .003"-.005"

[Lemonaid]

"You can use an empty 9mm or 357 handgun case with calipers as a poor-man's Hornady headspace gauge. "

Great tip Klem, thanks!

[JCSC]

Thanks klem

The Wilson is definitely oversized on the diameters. The shoulders are accurate though.

I have used a micrometer in conjunction with the gauge, mimicking your hornady gauge. The was after I verified the angular contact on the brass by twisting a painted case in the gauge.

I think I?m on the right track. I appreciate the advice!

[JCSC]

That is a great tip! I have the hornady ogive set and was planning to buy the .350 headspace gauge.

[Popeye212]

This is a good video and notice what he has written on the white board behind him. Hope this helps.

https://www.youtube.com/watch?v=DCxQJZ376gY

[FLshooter]

My Wilson gauge works fine,most of the time.But,a few of my custom AR barrels have tight chambers.I check a few pieces of the resized brass in the chamber of that rifle and adjust my die from there.