Homemade rim thickness gauge

22 Long Rifle ammo is finicky. Tell us all about it here.
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ShooterP14
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Re: Homemade rim thickness gauge

Post by ShooterP14 »

Trent wrote:"it is all about the happy ending"! :D :D :D
I couldn't agree more!
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Re: Homemade rim thickness gauge

Post by lone ringer »

As one that likes to experiment I appreciate your efforts and wish you the best of luck in what you are doing.
I just hope you know Eley Sport is made in Mexico by Aguila and not in the UK by Eley. In the past I bought a couple of bricks to try it out and after shooting several groups with it at 100 meters I let somebody else buy the rest really cheap from me. Maybe I got a bad or not good enough lot number but I just did not think Eley Sport was good enough to mess with at long range.
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Re: Homemade rim thickness gauge

Post by BCloninger »

Eley Sport is dirty relative to UK Eley or even Federal Automatch. There are better choices.
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Re: Homemade rim thickness gauge

Post by ShooterP14 »

I realize that Sport isn't the greatest ammo, however, I already have a full case that I'll have to shoot up before I can justify buying anything else. The groups I get are not spectacural but acceptable. As for cleaning, I have to clean my rifle twice a year instead of once. :lol:

And if I sit at home evenings measuring ammo, my wife is happy that it keeps me out of trouble.
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Re: Homemade rim thickness gauge

Post by BCloninger »

ShooterP14 wrote:I realize that Sport isn't the greatest ammo, however, I already have a full case that I'll have to shoot up before I can justify buying anything else. The groups I get are not spectacural but acceptable. As for cleaning, I have to clean my rifle twice a year instead of once. :lol:

And if I sit at home evenings measuring ammo, my wife is happy that it keeps me out of trouble.
A shooting buddy that likes inexpensive ammunition has to Flitz the chamber regularly to extract casings. Sure, I'm of the "clean every time" school, but better ammunition is just more fun - and less work when it is time to clean.
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Re: Homemade rim thickness gauge

Post by steve b. »

I have been reading this post with a passing interest, and for the most part I think it's groovy to test and experiment with rimfire ammunition. I did the same thing for many years and I did learn alot from testing.

Now, keep in mind there are quite a few more variables in terms of ignition and mechanics of the rifle's chamber, action, and barrel that are being overlooked. This, as well as how different manufacturers apply priming material in the case, and the difference in brass case alloys from one manufacturer to the next.

To further muddy the waters, there is also the speed in which primer material combusts (explodes), the different designs of powder kernels between ammunition types, the crimp strength / uniformity ( an extremely complicated and important aspect to rimfire ammunition), and the bullet's actual external dimensions in relation to the next round.

In short, measuring thickness addressess about one of 50 or so interrelated variables in terms of rimfire ammunition ignition. The value of this variable is directly related to the uniformity of all other related variables, and then compounded by the external variables of the shooter, system, and environment. As uniformity is lost, values decrease accordingly.

Isn't this all so much fun!
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Re: Homemade rim thickness gauge

Post by RBriscoe »

Spudgun wrote:
Jerry G wrote:I guess you all realize that rim thickness isn't the same. You can get many different numbers for the same rim depending how you turn the thing when you measure.
Really...why? shouldnt it just be meauring at the highest point, no matter what? assuming the .243 rim is flat and level.....
If you are going to measure rim thickness, make sure that the trademark on the case is oriented the same way for all of them because it has been observed that some lots of ammo have a different thickness ad different points around the circumference. You might try measuring at four different points around the rim to see if this is the case for a particular lot of ammo. If it is uneven, there is not much to be gained with this time consuming exercise because each round will be oriented differently when chambered. (One of the gauges I have used supposedly has sufficiently tight tolerances that it is measuring the high point on the rim no matter where it might be located. Yes, everyone goes through the stage of measuring things.)

The only thing I can say that is probably worthwhile is to make sure that the bullet is not loose as you are loading the magazines for your smallbore rifle (or loading it in a single shot). Though I have not done testing to prove this, I am prepared to assume that a round which does not have the bullet crimped the way the rest are is probably not a good choice to shoot when it counts.

The general rule is that you have a better chance of getting more consistent ammo by spending a bit more on higher grade ammo for big matches. When you figure in the cost of gas, meals, motels and such to go to a big match, the additional cost of buying a brick or two of higher grade ammo is not that much compared to the rest of your expenses...not to mention your time.
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