Home Forums Reloading Big Game Rifles Sinclair Concentricity Guage or RCBS Case Master?

This?



or this?



Casemaster seems more versatile, but Sinclair concentricity guage seems like a higher quality tool. Your thoughts?

John

This

Sinclair.

Hondo,
Never used the RCBS Casemaster and I am sure it's a fine tool but the Sinclair on my loading bench works real well and is easy to use.

Dave

Both are good tools. The Sinclair is smoother and easier to use. The RCBS is a little less expensive and is more versatile, it will measure neck and wall thickness etc.. The Neco is more versatile yet but more difficult to setup and use. The Bersin is the best because it will also straighten bullets but it's the most expensive. The Holland tool will straighten larger caliber rounds but isn't as easy to use as the Bersin.

So if all you want to do is measure Concentricity buy the Sinclair. If you want a tool thats a little more versatile buy the RCBS..............................DJ

I`d go for the Sinclair. Love the quality.

What is the Accubond Society? Is there a secret handshake?

Since the forum is Reloading - Big Game Rifles, I'd say don't get either one. They're not needed for accuracy on the large critters.

I once purchased the RCBS unit. Took it out of the box, looked at it quizzicly, realized the error buying it, and put it away. Realized I didn't need another tool to drive me crazy.

If you are happy with average accuracy and never shoot past 200yds you might be right.
If you want to improve the accuracy of your loads it's a good idea to buy one and learn what it will teach you......................DJ

I have the RCBS casemaster and it's a decent tool to measure runout of case necks and loaded rounds. But for measuring neck wall thickness I found it far less than satisfactory. It has too much slop so it gives all kinds of false readings. I bought a Sinclair neck wall thickness gauge and have been very satisfied with that.

Don't own the Sinclair concentricity gauge so cannot speak from experience on it but since - 1) the RCBS tool in my experience is only a single use tool anyway and 2) the Sinclair stuff I have owned is very high quality - I would recommend that you get the Sinclair.

You will never be sorry buying the best quality you can.

I disagree with that.

I have rifles that qualify for big game, yet I enjoy shooting them at paper for fun. I derive a lot of satisfaction from seeing improvements in my handloading techniques and processes translating into better and more consistent groups.

Really??? You mean to tell me that a guy with a rifle hobby like yours (and mine for that matter) does NOT own a run-out gauge of any kind?

I find that hard to believe


While we're on the subject, I have the RCBS gauge. I used to own the Sinclair as well, which was leant to a friend and he disappeared with it. I was broke and needed another one, and bought the RCBS gauge. It works just as well. But like others have said, it's pretty much just a run-out gauge. All the rest of the features are crap.

There is a right and wrong way to use a run-out gauge. Especiall the V blocks on the RCBS gauge. If you've got rifles with sloppy chambers that pressure ring brass pretty good, you'll get hellacious readings on those cases if you set up the gauge as in "Example A"

Example A



Example B



In "Example B", the forward most V block is moved up to the case neck, allowing the back end of the case to ride the rearmost V block above the pressure ring (right hand edge of the block in this picture) This allows for the fact that your rifle may have a less than match spec chamber, and/or you partial full length resize cases. The case head doesn't always stay centered behind the rest of the case after its first firing. If you allow the V block to reference off the case head, the whole case can wobble, showing a lot more run-out than is actually present. If you think about it, when the round is chambered it references on the shoulder and the part of the case that has been formed somewhat to the chamber, so 'plan B' you're actually measuring run-out as the rifle sees it. In the real world, there's plenty of room on a .473 bolt face (more like .480") for a slightly out of round case head to find its own center without affecting accuracy.

In the real world, in all my sporters and tactical pattern rifles. Any TIR under .003" won't affect accuracy enough to worry about in any real world environment. Ammo selected that runs under .003 TIR, will produce much tighter groups than ammo that isn't. What do you do with ammo that runs over .003" TIR??? Shoot it offhand at an 8x8" steel plate at 200 yards. It'll still hit it if you do your job and I bet you could use the practice

Dan,

I tried your theory out and my RO was less as in ex. B..measuring as in ex A gave me .003-.004 RO..in ex B, I ran .001-.002 I guess you set your accuracy requirements depending where you measure them. I always measure as in A and consider anything <.003 as pretty good..<.002 as exceptional! If you measure as in B, notice that the case is tipped down and is bearing on the mouth of the case, and the dial indicator is closer to the bearing surface. In A, the distance looks about 2.5X longer, hence, minor deviations of concentricity would result in larger deviations of RO. So, If I were using your method, I would "reject" RO >.0015 in my case. In using method A, I have usually found RO in fired cases to be very concentric, and I can see the increase in RO as I proceed with expanding and seating...and yes, it does make me crazy sometimes. All in all, I think the RCBS tool is good for my use, and a ball micrometer is probably better for neck thickness...just what I think...

Art

Dan, the good news is the "handloading hobby" can be useful/enjoyed at any number of levels... I certainly have the intelligence and ability to take it to the extreme, measuring concentricity, truing primer pockets, case necks, blah, blah... Frankly, I don't enjoy handloading enough to bother. It's a particularly anal pursuit that, for me, isn't worth the trouble at that level.

I live by the 80/20 principle... I get the "80%" out of most pursuits and leave the final 20% unexplored because, in nearly any pursuit, the final 20% is the most difficult to attain... in most things, though not all, the "80%" is good enough for me.

I'm a couple steps above a LEE Loader and pre-measured charges, but not by much. That's my informed choice... I'd rather spend my time elsewhere.

Like most all of us, I would MUCH rather be shooting than reloading. However, I'll still check every few cartridges for runout just to make sure things is square.
It's also a good tool for setting up dies. I had crazy runout on the first .270 Win reloads. Asked a few questions here about sizing and soon got things down to <.005. One less variable I guess.

"Casemaster seems more versatile, but Sinclair concentricity guage seems like a higher quality tool. Your thoughts?"

I think you are correct. The value of versatility tends to get lost in the relitive lack of accuracy tho.

Example "B" above is really more of a measure of the case neck run out than the bullet, as Thumper found.

Of course bullet RO WILL follow the neck RO but the actual bullet to bore alignment will be much greater IF we measure near the tip than at the case mouth. Work to get the RO low, TIR of .002" or less, at the bullet tip and you will have some precision loading. (TIR is Total Indicated Runout, or twice the actual misalignment.)

OK folks, I appreciate the input. I will probably go with the Sinclair unit, then get a sinclair neck thickness guage at a later time. Figure first to sort loaded ammo, then when I get the case neck thickness guage, sort cases, but doubt I will ever turn case necks unless I start shooting benchrest.

Thanks,

John

John,

Very nice results can be had without neck turning. For my "best grade" stuff I sort and select brass for neck thickness variation <= .001" and run with that. For general fun stuff variation <= .0015" will do.

When you're sorting for .001" you'll find that domestic bulk brass gets just as expensive as Lapua when you divide the initial cost by the number of keepers.

mathman

No