Rimfire cartridges with crimp?

[Naphtali]

I have been informed that rimfire ammunition based upon 22 RFM case design have bullets crimped as occurs with centerfire cartirdges. If my information is accurate, is any 22 LR cartridge comparably crimped? Do heeled bullets preclude the possibility of crimping 22 LR bullets within cartridge case?

[tazman]

At least some 22lr bullets are crimped into the cases. I have tried pulling bullets from the cases a few time in the past and the crimp is obvious.
I don't remember the brands involved.

[John Boy]

Take a round and try to push the bullet out of the case with your thumb. If it does, no or light crimp

[uscra112]

Uncrimped .22 ammunition went out about 120 years ago. The round was originally meant for Stevens single shot rifles and pistols, which didn't need a crimp. They even warned in their literature that extracting an unfired round would leave the bullet behind.

With the advent of .22 repeaters, the rounds had to be crimped to prevent them from coming apart in the magazines or while feeding. Someone may know of some obscure type of .22 ammo available today that isn't crimped. but I don't.

[Naphtali]

Following up, is any 22 LR bullet jacketed or partly jacketed or constructed of material that is significantly harder than the lubed lead or copper-zinc (??) wash of ammunition like Lubaloy® that I believe is not comparable with any non-round ball lead/tin/antimony bullet? I think I'm asking whether any 22 LR ammunition is capable of being as tightly crimped as 22 RFM-based ammunition.

[uscra112]

I think the answer is yes. Going back into the '30s one of the .22LR companies advertised with a picture of their machine for measuring bullet pull. Very much like the tensilometers used for testing strength of metals, but smaller. .22LR bullet pull is quite significant, as you will find out by trying to pull a modern round apart. Even money that it's not much different from your .22 Magnum rounds. It's a crucial factor in obtaining consistent powder burn, and I'm sure that all .22 ammo companies still test for it in the same way they did 90 years ago.

[Forrest r]

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[Traffer]

In the book "Ammunition Making" by Frost, the author relates the story of developing 22lr match ammo with the then "new" smokeless powders.
His r&d led to the understanding that smokeless powder, because of the dramatically different burn characteristics, needed to be more deeply crimped and for match ammo, more consistently crimped.
Here is a link to a copy of that book in pdf format. I believe it is Chapter 11 in which he explains the 22LR Match ammo development...https://www.dropbox.com/s/lilb8pmxgn...st%29.pdf?dl=0
And here is a video with an explanation of the development of my modified rimfire dies. (Bernie at Old West Molds sells crimp dies for rim fire...I don't recall if he makes them in 22 caliber)

[uscra112]

What a resource! Thank you.

[303Guy]

I've never heard of any 22 LR having a jacket of any sort. Being a heeled boolit, it needs to be soft enough for the heel to bump up. Although, having said that, I have recovered 22 boolits in which the heel did not bump up. And maybe I am wrong in thinking the heel needs to bump up but generally, they do. Well, all the recovered boolits I've seen have bumped up except for just a few I recently fired into a catch tube, and then it seems only in the one rifle. I did not test to check. I just assumed there was something wrong somewhere. It was old ammo so it could have been that.

Some ammo has less crimp than others. I read somewhere that less crimp is more accurate so I looked through my selection and found some brands do indeed have less crimp but it is still there. I don't know whether that claim is correct though.

[Traffer]

I have experimented with jacketed 22lr bullets as well. Here are some pics.



And here is an example of the hollow/rebated base filling into the rifling in the barrel:

[Traffer]

The depth of crimp is interdependant on the burn rate of the powder. Slower powder needs heavier crimp. Many folks who reload 22lr use "Bullseye" or "Red Dot" which both burn fast enough to NOT require much of a crimp at all.
I use HS-6 which burns slower and if those are not crimped they will burn poorly even to getting click bangs.
I have tested the pull weight on several commercial brands of 22lr ammo.
It appears that the consistency of the crimp is the essential property in consistency in speed and accuracy.
The crimp pull weights DO vary a lot. I have seen from 70lbs of pull to 18lbs of pull. But again the consistency seems to be the determining factor on the target. PS on my previous post, the jacketed 22lr shown was made by starting with a 40gn .223" bullet made for a 22 Remington Jet. I swaged it to create the hollow base (swaging punched out the bottom of the jacket). Swaging bumped it up from .223" to .224" I only fired a few because I didn't want to take the chance that they would mess up my barrel. That being said I have seen on the shelves a 22lr (Cleaner round) which is a copper jacketed 22lr round. The idea is that the copper jacket will scrape out excess leading when shot.
Also on the discussion of the rebated part of the bullet not expanding to the barrel...I worked with several different hardnesses of lead. Only practically dead soft lead with obturate correctly. I made a lot of bullets that were around 10 BHN and they did not obturate. I didn't do enough testing to be able to tell the difference in performance but I did switch to dead soft lead just because the major manufacturers were using it and I assumed they did their howework.

[uscra112]

The O.P. was comparing .22LR to .22 Magnum. The latter is loaded with a jacketed bullet, (at ~2000+ fps).

Anyone who hasn't read Frost's Chapter XII yet should be made to sit down and do so. Nobody who has studied it will ever complain about the price of Tenex again.

[John Boy]

My reloads are charged with 2.1gr Bullseye … 1520fps and 4.5gr of Swiss Null B … 1230fps using the Old West seating/crimp die with a light crimp just enough to keep the heeled bullet from falling out of the case. Accuracy at 50 and 100 yds is very good in either a JM Marlin Ballard or a Stevens 44 or 44 1/2. With a Henry Arms lever, I put a moderate crimp on the rounds … still accurate reloads
Haven’t tried any reloads with a tight crimp

[tazman]

The O.P. was comparing .22LR to .22 Magnum. The latter is loaded with a jacketed bullet, (at ~2000+ fps).

Anyone who hasn't read Frost's Chapter XII yet should be made to sit down and do so. Nobody who has studied it will ever complain about the price of Tenex again.

I would like a bit more information about that reference. I searched but can't find it.

[uscra112]

Dropbox link at post #8. Big file - takes a minute or two to download.

[Mr_Sheesh]

Perhaps this?

https://ia801603.us.archive.org/28/i...29%20_text.pdf

[uscra112]

Yup, another source for the same book.

[tazman]

Thanks. Got it.

[Mr_Sheesh]

I'm pretty good with web searches