Talk:.17 HMR

From Wikipedia, the free encyclopedia

This article is within the scope of the WikiProject Firearms; If you would like to join us, please visit the project page where you can find a list of open tasks. If you have any questions, please consult the FAQ.
Start This article has been rated as Start-Class on the quality scale

[edit] Just a question

Is it safe to use .17HMR in a .22WMR revolver? —Preceding unsigned comment added by 68.0.149.121 (talk) 08:52, 24 January 2008 (UTC)

No. It would fit, and fire, but the case would fail and possibly lodge the undersized bullet and/or case fragments in the chamber or barrel. This could seize up the cylinder, preventing the gun from working, or block the barrel and cause a very dangerous overpressure situation if a subsequent round is fired. Because of this, .17 HMR and .22 Mag ammunition should be stored separately to prevent accidental mixing. scot (talk) 17:10, 24 January 2008 (UTC)

Maybe we should include such a warning on this page because that's a pretty common misconception at my firing range, and I tried one and it worked —Preceding unsigned comment added by 68.0.149.121 (talk) 01:31, 25 January 2008 (UTC)

"It worked" is a pretty presumptive statement. I'm quite sure the bullet went out the barrel sideways and tumbled off in some random direction, and that you blew out the case mouth and may well have split the case as well, and you probably didn't develop enough pressure to cause the case to seal the rear of the cylinder, which means you could get gas blow-by (a much bigger issue in other action types). Search the web for "excessive headspace" and look at some of the things that can happen, and keep in mind that with the .17 HMR in a .22 WMR chamber the headspace was not just excessive, it was infinite...
The problem with posting a warning here (besides the general issue of Wikipedia disclaimer policy) is that I'm quite certain the firearm manufacturer already tells you quite explicitly to ONLY use ammunition marked as .22 Winchester Magnum Rimfire; even if it was made long before .17 HMR, it is also unsafe to fire straight walled .22 Short, Long, and Long Rifle ammunition out of the tapered .22 WMR chamber, as the case will fail and split lengthwise in the oversized chamber, resulting in gas blow-by past the breach. There are hundreds if not thousands of unsafe combinations of mis-matched ammunition and chambers; see http://saami.org/Unsafe_Combinations.cfm for a very short list (and out of date because it doesn't list the .17 rimfires). There are many more than that however; many wildcat cartridges are made by shortening and/or reducing the bullet diameter of another cartridge, exactly as the .17 HMR was made by necking down a .22 WMR, and the wildcat will often fit in the parent cartridge's chamber and may even be convinced to fire. This is especially true of rimmed cartridges and rimless cartridges chambered in controlled-feed actions, like the Mauser bolt action. There are also exceptions to the SAAMI ruling, for example, 5.56x45mm ammo, which is loaded to a higher pressure than .223 Remington, should in general not be fired in guns marked .223 Remington, but it can be fired in some, such as the Ruger Mini-14, if the manufacturer explicitly allows it. There was an odd revolver some years back (the Medusa, as I recall) that used a deliberately oversized chamber and a flexible extractor, and would fire any .355/.357 straight walled cartridge of .357 Magnum or less length, including rimless cartridges like 9x19mm, .380 Auto (when asked at the Shot Show, the manufacturer dodged the question of "What does it do to the brass?", because, looking at the chamber design, I'm sure the answer is "Mangles it beyond re-use"). And, just to toss some more oddball stuff in the mix, at one point you can buy specially chambered .19 caliber barrels for .22 LR rifles (http://ct-precision.com/ used to make them), and fire standard .22 LR ammo out of them. The throat is cut long, and tapers from .22 down to .19, swaging the bullet into a .19 caliber projectile and upping the chamber pressure for a higher velocity. So for just about every rule there's a special exception, though no one recommends firing a sub-caliber bullet, because the lack of bore seal means no velocity, and no accuracy.
Adding a warning to all ammunition and/or firearms related articles probably isn't practical. If you think it should be done, however, post a comment to WT:GUNS, and let the Wikipedia firearms group discuss it. scot (talk) 15:41, 25 January 2008 (UTC)

[edit] Ideas todo

Ideas on todos: typical usage of this cartridge, mention that it's likely to render .22 mag obsolete (if a source can be found). Friday (talk) 13:45, 2 September 2005 (UTC)

Probably a bad idea, considering that the .22 mag continues to sell. Arthurrh 08:49, 2 September 2007 (UTC)

[edit] WPMILHIST tag

The WPMILHIST tag has been removed due to this caliber not being military related.--Oldwildbill 07:50, 8 July 2006 (UTC)