Anyone here gauging .22 LR rim thickness?

[uscra112]

I always got better results by measuring bullet diameter and choosing the batches having fatter bullets.

Dittos.

Using a rim gage to "upgrade" bulk ammo I think is nearly fruitless. If they're shipping badly upset cases, there's gonna be a lot of other, more important quality factors that will also have high variance.

The second-worst of these is bullet weight.

Five years or so ago I weighed many hundreds of rounds of bulk ammo to see what I could do about improving the accuracy of a plain-Ed Ruger 10-22. Tedious goes without saying.

The worst weight variance was Thunderduds, (no surprise), but what proved interesting with them was that the weight distribution had multiple peaks. I pulled a lot of bullets and came to the conclusion that they had multiple swaging machines in operation which weren't all adjusted alike, and they were mixing them all together at some point before the assembly process. Bullet weight variance seemed to be about 80-90% of the cartridge weight variance.

Did sorting to minimize weight variance help? Some.

What helped most was swaging all the bullets up to a common .2250 diameter. Paco Kelly makes a tool, and there is another by someone named Waltz. I made my own, which is much like the Waltz, although I hadn't seen his at the time. The process also straightens the cartridge, which ought to have some effect.

Older 10-22s are well known to have cavernous chambers. With weight sorting and swaging, I cut the groups from this one from 5 MOA down to 2-3 MOA, using ammo selected for +/- 0.1 grain weight variance AND swaged.

I ran the same process with several other kinds of ammo. Federal Auto Match, CCI Standard Velocity, Federal 711, CCI MiniMags, my notes say. All were better than Thunderduds, both before and after, but none were magical. Had I kept the 10-22, my go-to ammo would have been the MiniMags. They came in at just under 2 MOA after treatment.

So many factors we can do nothing about: Powder charge variance, primer fill, brass temper, crimp consistency, roundness and runout, and on and on. There can never be a magic sorting process that will yield a useful subset of high grade ammo from the run-of-the-bog bulk stuff. At best, to get a batch of Auto Match with weight variance +/- 0.1 grain, I culled over half of each box.

[arcticap]

A direct replacement 10/22 sporter barrel by ER Shaw for $99 is a really good value and is easy to install.
A lot of reviewers report it shooting really good groups with bulk ammo due to its Bentz chamber.--->>> https://www.midwayusa.com/product/10...-twist-18-blue

[Bigslug]

Somewhat anecdotal, but for what it's worth. . .

Our department sniper team used a number of middle of the road match .22's for low-cost maintenance of skills, and was using one of Federal's lower rung Gold Medal loads for the purpose. Good enough for feedback on target, but not perhaps the stuff you'd actively go searching for Fortune and Glory with.

When a number of the guys decided to go play in a big international match, this was the ammo we had, so I stepped in to help and sorted a case of the stuff by both rim thickness and overall cartridge weight and parceled it out so each of the guys had a brick or so that was as consistent within itself as we could make it. For what it's worth, they brought back a sizable stack of medal from the smallbore event competing against folks with sexier guns and more expensive ammo. How much of that came from what I did is anyone's guess.

I will say that the act of doing it was a ROYAL P.I.T.A. The reason why Eley, Lapua, etc... cost what they do is that they are using actual SILK rather than re-purposed pig cartilage to make their purses from. You're paying to have that sorting done for you, and it's being sorted component by component during assembly rather than the "best you can do" approach you'll be applying during the home spot-check of a completed cartridge.

My advice: the world is full of perfectly good blasting .22 ammo that is ideal for having fun. Have fun with it by ridding the world of soup cans, empty shotgun shells, golf balls, and clay pigeon fragments - one cheap 500-round brick at a time. If however, you want the high-octane results, buy the high octane gas and run it through a high-octane car. Considering the comparatively smaller amount of rounds shot in that pursuit, the cost is probably not all that greater. Your eyes, back, and sanity will thank you.

[uscra112]

The thread is about the utility of measuring / sorting ammo to gain improved performance. Not about accurizing a particular brand of rifle. O.P. asked about measuring rim thickness. I've never found any improvement at all from that, so far as it is applied to bulk ammo, even though some of it varies by several thousandths. I wrote that post to agree with Outpost 75, that bullet diameter makes the most difference, of the things that we can measure, along with cartridge weight, in rifles with "sporting" chambers.

[uscra112]

High grade competition ammo isn't achieved by sorting. It is done by applying very tight limits to every step of the the manufacturing process, and constantly monitoring. This means much more in-process testing and measurement is done to assure that every step is functioning as precisely as possible. Machines have to be run much more slowly to attain this end. The process has to be halted for corrective action if anything starts to drift away from target (pun intended) values. Dies are replaced much sooner than they would be if cheap ammo was being made. Components have to be handled much more gently between stations. All this adds cost.

BTW ask a serious competitor how much ammo they burn in a year. Lots more than Joe Sixpack blasting targets of opportunity!

n.b. I did high tech process control gaging for GM/Ford/et.al. powertrain plants for many years. If a manufacturing process is fully under control, (and it always is), they never make a bad part. They will halt a machining line if just one characteristic drifts off target by just 30% of the tolerance value.