Comparator trick

[Tesoro]

Yesterday I loaded up a bunch of test rounds with varying oal's. I paid more attention to the fine measurement repeatability using the stoney/hornady with anvil and I was spot on. I think that with whatever system you use, the most important part of the process is the tactile process. And no matter whether you measure off the base or the shoulder, the end result will be a specific datum that you will vary off to find the sweet spot.
I cant comprehend how that machinist bar would do anything that mating the two pieces would not.

 

[K9TXS]

View attachment 1331421
This is how I get it flat and reading correctly

Thanks. I see what you mean.

 

[SGK]

For a little different perspectives: https://forum.accurateshooter.com/threads/sac-comparator-what-am-i-doing-wrong.4055801/ I wasn't happy with the customer service at sac and the 30% restock fee is ridiculous for a just out of the box and defective product. From my perspective, the o rings weren't the right size on some of the inserts, and those inserts would literally fall out of the stand if tilted while others stayed in place.
Threat of credit card dispute cured the 30% restock fee.

I'm currently waiting for the AC1 comparator and have been using the hornady system. No small anvil and it works. Problem is that it is rather time consuming and hopefully, the AC1 will remedy that.

I have used the Redding dial comparator for 6.5 CM and it works really well. It served well to confirm what the hornady comparator was showing.

I missed this post and just now bumped into the thread. The 'slop' in the o-ring is exactly my concern.

 

[PJ1]

I missed this post and just now bumped into the thread. The 'slop' in the o-ring is exactly my concern.

I think sac had it right with the first generation of comparators from comments that I read from others. Why they went with the o-ring deal is a mystery to me. A lot of people like the new system from sac. It just didn't work for me.

It will be interesting to see what the AC1 will do as compared to the Redding comparator. Looking forward to that as it takes its' measurement from shoulder to ogive, as opposed to cbto.

 

[AlNyhus]

I have a bunch of case-specific inserts for the Hornady comparator bodies that I made from some Delrin round stock. The pic quality is poor as I had to back door them from Photobucket which is where I had them before it's implosion.

-Turn a piece so it fits into the body:

-Like so:

-Bore a hole in it so the shoulder fits right to the shoulder/neck junction, put some epoxy in the hole and with the setup on a caliper, press a case into the epoxy, tighten the lock screw on the caliper and walk away. Release agent on the case, obviously. You'll end up with a perfect profile of the entire length of the shoulder. In this case, I was doing one for the .30 caliber bullets I was making at the time...but you get the idea:

This is it checking the ogive profile of the bullet but the case ones are same-same in operation:

This will check the contact of the entire shoulder rather than a narrow specific contact point of the comparator inserts, if you feel that's an important issue for setting up your dies for shoulder bump amount. I didn't know if there was anything to be gained by doing it...which is why I made these up.

Good shootin' -Al

 

[justinp61]

IMHO, regardless of what tool you use consistency is the key. I've made several bushings for measuring BTO and shoulder bump. These bushings may or may not measure the same as bought bushings, but I'm not concerned with that. I'm only concerned that I get consistent measurements on my ammo.

 

[snoopy001]

They've been on backorder. Measures off shoulder vs base...waiting on mine. These work with most calibers as well unlike instant indicator.

This is a great tool made by great professionals.
The only measure from shoulder to ogive gives consistency from round to round
in relation to the rifling , Mr. John explaine all clearly on his video.
The bullet seating depth comp shut be a "must have it" for any accurate reloader .

 

[6BRA]

Is the Accuracy One comparator sensitive to the amount of pressure when pushing the case into the comparator?

I just got the unit yesterday, but there is no fluctuation by pressure from what I see so far. Rock solid readings.

 

[AckleymanII]

The issue to contend with is how tolerances compound on themselves with the different gadgets added to the caliper, of which none are precision made to begin with.

Start with a world class dependable set of calipers, Starrett, Swiss made Brown and sharp with .100 travel on the dial. Calibrate the caliper with a gauge bock, inexpensive off of ebay.

If you zero your caliper with the blades closed, each little insert will have a different number when the caliper is set to zero. You have two choices, zero your caliper with each particular insert or inscribe that number on the insert.

I do not use electronic calipers, I prefer Starrett, Mitutoyo, and Brown and Sharp mechanical. By the time you discover that an electronic caliper has an electrical problem, you have made mistakes over a period of time that may have had you chasing your tail over various issues.

If you have vision problems or like the convince of an electronic caliper, get a darn good calipers and NEVER drop it! A Small set of gauge blocks gives confidence(Shars), 1/2"-4" lengths will suffice. It is standard for calipers to have amounts of variations in certain ranges and be dead nuts in other areas, repeatability is another issue.

 

[Alex Wheeler]

I have never had any problems with the Sinclair setup. Different inserts for shoulders and bullets. I have made inserts for them using the chamber reamer that was used on the barrel as well and that is probably my favorite setup. I have made inserts for the bullet that contact closer to the ogive too. But the stuff you can buy serves me well, even though I make the custom ones for customers I just use the generic ones because they do the job.
Buy good calipers. My favorite are a old pair of Starrett's my uncle gave me. I like my Brown and Sharpe and Mititoyos as well. Good calipers are surprisingly accurate.

 

[PJ1]

I just got the unit yesterday, but there is no fluctuation by pressure from what I see so far. Rock solid readings.

Got mine yesterday also. I'm loving this thing. No more rocking around with the calipers to get a solid reading. Faster............What's not to like? It's rock solid and I'm not so sure that I even need the stand. Just wish they would machine another body for 338 LM. It was worth the wait.

 

[Tesoro]

I think that the repeatability of the tolerances you guys are striving to attain would be great in machining gears for a precision scope, or making ammo for an ultimate unlimited class rifle. I just can't see how the variance of a few thou in bullet jump could be isolated to determine if it would affect the poi of a bullet down range. I appreciate the quest to produce consistent ammo but where does one draw the line when we dont shoot in a vacuum?!

 

[tsyarnall]

I had never watched (or read) anything about the Accuracy One tools thinking what I had was as good as I could get for measurements. After watching the YT video by F Class John for the Comparator, I’m really intrigued. To me, it’s not about speed. While I understand the draw in saving time, I’m retired and have plenty of spare time. After all, the time that I would save would only be used for more shooting, more relaxing, more time with the grandchildren, or maybe, more fly fishing…….. Wait, maybe it is worth saving time. Anyway, I am curious to see if it would truly make a difference on target. I am always looking for more accuracy.

 

[6BRA]

Got mine yesterday also. I'm loving this thing. No more rocking around with the calipers to get a solid reading. Faster............What's not to like? It's rock solid and I'm not so sure that I even need the stand. Just wish they would machine another body for 338 LM. It was worth the wait.

Put your hornady /stoney point oal guage in it, and use it to measure bullets as a comparator, yes bullet comparator.....my Jlks never varied a half thousandth. Sierra matchkings ,hornady eldmatch and scenar L, all varied .004 or more...this thing is wicked! And it measures .223/5.56 fine , all much faster than calipers

 

[delv7915]

SELLING - Caliper Bases - $22.00 Shipped

Updated - 12.31.2024 - Current time from purchase to received - 3-4 days. Ensures consistent and repeatable measurements during the bullet seating process. See forum comments, reviews and feedback. PM me for additional information. 6061 Aluminum - Hard Anodized Black. Use in conjunction with...

forum.accurateshooter.com

Guys - As other members have recommended above - Check out the link.

Dan