SAC comparitor question/problem
- Thread starter TommyD11730
- Start date
Yup ... my 338-LM bullet comparator hits the case and not the bullet ogive. Used my 30-cal bullet comparator and it works fine on my 338 bullets. BTW ... my 300-BLK, 6.5-CM, 300-WM and 300-PRC bullet comparators all work just fine.
Measure the bore diameter of the insert. It should be at least -.002” from bullet diameter. Did you seat your bullets too deep in the case ?
No . These are as deep as I can go before the tool hits the case. Just 2 examples.
TMK 77g. 2.283
Berger 77g OTM 2.262
Referring back to your original post.........
I have the SAC body and inserts for .223, 6x47L and .308W. The bore ID for the .223 insert is 0.221". So, if you are contacting the mouth of the brass, I would surmise "that you don't have enough bullet Ogive sticking out of the case mouth" to properly engage the comparator insert the way that it should. In other words, your bullets are seated too deep.
Again, measure the bullet diameter/OD and the ID of the comparator insert. The ID of the insert should be at least -0.002" below bullet diameter. As I said above, I measured mine and it is 0.221". If the comparator measures 0.221" or thereabouts, there is nothing wrong with the insert/comparator.
I'll check it with a pin gauge when I get home.
However as is If you look at my measurements I'm "not seated too deep". Rather both bullets are longer then SAAMI spec (2.260).
OK, So, how does "SAAMI spec" (of OAL) have any relationship whatsoever to various bullets of different tapers/profiles ? SAAMI does not take into account different bullets with various different tapers/profiles.
Just measure the ID of the comparator with your calipers and compare that against the OD (also measured with your very same calipers) of the bullet. Is that so difficult to understand ?
Hint; Different bullet profiles will have different physical locations of where the comparator bore will hit/interference fit with the Ogive. A very small difference in the taper of the bullet will have a huge difference as to where the comparator contacts/interferes with the "ogive" of any given bullet.
BTW, throw your "pin gauges" in the garbage. You're WAY overcomplicating this. SAC sells comparators/inserts. They bore the 0.223" inserts to 0.221", or 0.002" under (actually 0.003" under when you consider that the bullet diameter is actually 0.224").
Hornady and others bore them to about 0.003" to 0.005" under bullet diameter. Not hard to understand. Which one is better ? Neither/both. It doesn't make any difference because the comparator measurements are RELATIVE, they are NOT ABSOLUTE.
Last edited:
Trust me I get what your saying. I just find it odd if I load either of the two bullets to 2.260 (what most manuals quote as COAL) the gauge insert bottoms out.
I have been using the 224 and 30 Cal inserts and loading long in the past so I never ran into this.
The ogive is almost certainly inside the case neck. The SAAMI spec was not written with 77gr projectiles in mind.
A cartridge with maximum case length and maximum COAL as per the specification will have the bullet protruding from the case by 0.500".
I don't know what bullet you're using but, as an example, all of Berger's 22 caliber projectiles heavier than 70gr have a nose length longer than 0.500". They would all have the ogive inside the case neck when loaded to SAAMI max COAL.
A cartridge with maximum case length and maximum COAL as per the specification will have the bullet protruding from the case by 0.500".
I don't know what bullet you're using but, as an example, all of Berger's 22 caliber projectiles heavier than 70gr have a nose length longer than 0.500". They would all have the ogive inside the case neck when loaded to SAAMI max COAL.
Last edited:
SAC got back to me. They make more then 1 22 insert. I need a 22 "straight" insert to measure these bullets at mag length. They offered to exchange if I would like.
If I knew previously, I've forgotten......
If you are primarily concerned about COAL (Cartridge Overall Length) (which is understandable, given magazine length restrictions), why are you measuring CBTO (Cartridge Base to Ogive) ?
"They offered to exchange if I would like".
SAC seems to be a pretty good outfit. I've been very happy with their products. High quality and not unreasonably priced.
If you are primarily concerned about COAL (Cartridge Overall Length) (which is understandable, given magazine length restrictions), why are you measuring CBTO (Cartridge Base to Ogive) ?
"They offered to exchange if I would like".
SAC seems to be a pretty good outfit. I've been very happy with their products. High quality and not unreasonably priced.
Last edited:
