Yes and no. I do most of my clearance work with the neck-turner but yes I use a neck bushing also to get the grip I want. dedogs
what size bushings
- Thread starter mudduck
- Start date
This can be somewhat predictable.
With a given loaded neck measure, and reasonable chamber clearance, partial neck sizing with a bushing can be chosen as 2thou under loaded diameter. In this case the neck would spring back(outward) ~1/2thou leaving 1.5 thou under cal for bullet grip. Then it's good to run an expander mandrel through necks (pre-seating) to push thickness variance outward (away from seating bullet bearing) & leaving necks 1thou under cal. Plenty of bullet grip there, as tension with partially sized necks amounts to no more than spring back, which is pretty much maxed at 1thou anyway.
Any amount over springback here, & without expansion, 3thou under cal, or even 10thou under cal, only affects seating force and not actual tension. You would just be oversizing followed by excess expansion using your bullets (which are horrible expanders). This, work hardening necks(increasing tension variance), and increasing seated CBTO variance.
Less predictable with bushing partial neck sizing is the result after firing in chambers with excess neck clearance. Once you're sizing >5thou the high interference angle will roll neck brass inward greater than expected. With this you could wind up reaching for next higher in bushing size to get what you want. Many folks buy at least 2 bushings.
If you are expanding necks prior to seating, then the little variances seen with bushing IDs won't be seen in practice.
With bushings, you don't adjust tension with bushing sizes. You adjust tension with length of sizing using a correct bushing. This is where the gun can show you what it likes -and not force you into constant annealing to manage it. Precision seating goes quicker too, so if your barrel loves your bullets 8thou off the lands, not so much 5thou or 11thou, you'll appreciate this.
The suggested 3thou under cal is the most I would bother with (probably excess), and if I started there I would get -2thou & -1thou bushings with the same order. Especially with either a factory chamber(loose) or custom chamber (tight).
With a given loaded neck measure, and reasonable chamber clearance, partial neck sizing with a bushing can be chosen as 2thou under loaded diameter. In this case the neck would spring back(outward) ~1/2thou leaving 1.5 thou under cal for bullet grip. Then it's good to run an expander mandrel through necks (pre-seating) to push thickness variance outward (away from seating bullet bearing) & leaving necks 1thou under cal. Plenty of bullet grip there, as tension with partially sized necks amounts to no more than spring back, which is pretty much maxed at 1thou anyway.
Any amount over springback here, & without expansion, 3thou under cal, or even 10thou under cal, only affects seating force and not actual tension. You would just be oversizing followed by excess expansion using your bullets (which are horrible expanders). This, work hardening necks(increasing tension variance), and increasing seated CBTO variance.
Less predictable with bushing partial neck sizing is the result after firing in chambers with excess neck clearance. Once you're sizing >5thou the high interference angle will roll neck brass inward greater than expected. With this you could wind up reaching for next higher in bushing size to get what you want. Many folks buy at least 2 bushings.
If you are expanding necks prior to seating, then the little variances seen with bushing IDs won't be seen in practice.
With bushings, you don't adjust tension with bushing sizes. You adjust tension with length of sizing using a correct bushing. This is where the gun can show you what it likes -and not force you into constant annealing to manage it. Precision seating goes quicker too, so if your barrel loves your bullets 8thou off the lands, not so much 5thou or 11thou, you'll appreciate this.
The suggested 3thou under cal is the most I would bother with (probably excess), and if I started there I would get -2thou & -1thou bushings with the same order. Especially with either a factory chamber(loose) or custom chamber (tight).
Dusty Stevens
Shiner
I cant remember the jab so i figure it wasnt too bad. Ive been on an action truing marathon today. I let em stack up too far sometimes.
Anyway- i only use pins for bores and theyre deltronic but for bushings id get some cheaper stuff if i needed to measure em. Zoro was mentioned. Ive got a box in my trash can right now from them for some type of measuring tool and have dealt with them on ebay a lot for cheaper stuff. Good company.
Dusty, Neither can I remember what it was about.
Thank you for the reply I will look into Zoro. dedogs
Here's a direct link but John Whidden also sells them. I got my first from John a couple of years ago with a die I'd ordered from him, like them over Redding's quite a bit.
They also make a superb powder funnel that uses cartridge-specific neck adapters for a best-fit to case mouth when charging. I'd been using Satern funnels for several years, the CRT are a vast improvement. Whidden can supply them too.
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