Can the Redding Instant indicator gauge for .308 be used for either .243 or 7mm-08 in addition to .308 to measure headspace on once fired brass?
Question on Redding Instant Indicator Headspace and Comparator gauge
- Thread starter rdinak
- Start date
I have the .308 gauge and like it. Need one for .243. If the same tool works for both I am happy!
Ok, try it out. Take the indicator apart and rest the sleeve on the shoulder of your 243 and or 7 08 case. If it rests on a datum point on the shoulder, you are good. Btw, as far as I know, not many people on this site use the instant indicator, but I have been using it since 2008, and I think it is the nuts.
I got my handy dandy Hornady gauges and dial calipers. Measured a couple pieces of new lapua brass in .308 and .243. 1/1000's difference between the two.
Yeah, but remember that the instant indicator is just to make measurements relative to the amount of shoulder bump applied. If it fits in the indicator and indexes off the shoulder, then that is all you need to know. No need comparing the actual datum point from one caliber to the next. Measuring a 243 case, sizing it, and then measuring it again is an apples to apples comparison. Remember, the instant indicator doesn't give you an actual measurement; it is not a caliper. The purpose of the tool is to measure variance, which it does quite well, especially in a T7 turret press.
I forgot to mention something that you may already know, but in case you don't, here it is. If you are also interested in measuring the seating depth relative to the ogive/distance to the lands, you need another steel bushing, as the one included with the 308 indicator is .300. Not sure what the bushing is for a 243, but maybe something like a 239? Need to know the diameter of the 6mm bullet ogive.
With Respect to the aforementioned Redding Instant Indicator and Hornaday headspace gauge used to measure base to ogive; I found a difference in the diameter of the bushings (e.g. ogive contact point) between these two instruments.
In 6.5CM the Indicator bushing is .256 and my Hornady 5-26 bushing is .254. this difference, albeit small, was giving me headaches when measuring different bullet shapes and seeing variation in length between the two tools.
To solve this problem I purchased another bushing from Redding identical to my instant indicator bushing and then mounted it in the Hornaday headspace bushing holder. It fit in with no machining and now I get identical readings between the two no matter what shape bullet I measure. I placed a light compression spring behind the bushing (e.g. inside the bushing holder) to make zeroing the caliper and bushing removal easy.
In 6.5CM the Indicator bushing is .256 and my Hornady 5-26 bushing is .254. this difference, albeit small, was giving me headaches when measuring different bullet shapes and seeing variation in length between the two tools.
To solve this problem I purchased another bushing from Redding identical to my instant indicator bushing and then mounted it in the Hornaday headspace bushing holder. It fit in with no machining and now I get identical readings between the two no matter what shape bullet I measure. I placed a light compression spring behind the bushing (e.g. inside the bushing holder) to make zeroing the caliper and bushing removal easy.
