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The .17 Caliber Rimfires - Choosing What's Right for You

By: Eric Kiesler

You’ve probably heard a lot about the new .17’s over the last few years – we know from the response we’ve had every time we’ve mentioned the new cartridges. A couple of months ago Cleaning Clinic described the care and cleaning of the new .17s. Click here for that article.

So, with all that information out there you may be eying that old .22 in the corner and wanting to convert it to one of the hot, new .17s. The problem is you’re not too sure which cartridge is right for you: the .17HMR, .17 High Standard (or Aguila), and .17M2.

Recently there has been a lot of press regarding the new .17M2, and you may have noticed we have some products for the .17 High Standard/Aguila. Both of these cartridges are designed to be compatible with the .22 long rifle cartridge.

By now you’re probably pretty familiar with the terrifically fun .17 HMR. It’s based on the .22 Magnum Rimfire Cartridge; and we have the reamers, gauges, drop in barrels (10/22), (77/22), and barrel liners for doing a conversion.

Back in early 2003 the ammunition company Aguila, in cooperation with the High Standard Company, began development of a cartridge referred to as the .17 High Standard or .17 Aguila. The .17HS was/is more closely based on the .22 LR case than is the .17M2.

Before I go into the differences I should say that at this time only the .17 HMR has been approved by SAAMI, so the specifications for the .17M2 and .17HS are subject to change.

You’re probably wondering how the .17M2 and the .17HS are different. All of the dimensional comparisons I make are based on the dimensions of the Manson tooling and an M2 dummy round obtained from Hornady. The .17M2 is about .100” longer and .003” larger in diameter than the standard .22 LR or .17HS, the shoulder angel also differs slightly with the M2 being 20° and the .17HS 25°. We obtained samples of the .17HS cartridge in early 2003 and became really excited, High Standard began making barrels for their pistols and the 10/22. Then the ammo supply dried up, I contacted Centurion Ordinance (the US marketer of Aguila ammo) back in April 2003 and they were expecting to receive more in a few weeks. Unfortunately we are all still waiting for that ammo, and any reference to the cartridge is conspicuously absent from the High Standard and Centurion web sights (rumor has it that several million rounds are in the United States and will be available shortly).

Since that time, the Hornady M2 has stolen the lime light, and may be nearer to going into full production. The overall length of the M2 cartridge measures .979”. The case length of the .17HS is .623” and .728" for the .17M2. Either will work in a .22 LR with a .17 barrel or one of our liners #770-000-001 and it would seem a .17 High Standard chamber could be reamed out to the .17M2. The larger case dimensions for the .17M2 also imply a velocity difference estimated to be 200-300 FPS.

Manson Precision is making reamers #513-050-014(M2), #513-050-004(HS) and gauges 513-000-047, 513-000-048(HS), and M2 (coming soon) for both of these cartridges. Whichever direction you decide to go, you’ll know Brownells has what you need in stock (as soon as it’s available) and the technical know-how to help you complete the job – and complete it right!