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Rifles, Reloading, Optics, Equipment
Reloading
.280 AI controversy explained ...
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<blockquote data-quote="woods" data-source="post: 834389" data-attributes="member: 6042"><p><a href="http://www.rifleshootermag.com/2012/10/30/new-and-improved-the-280-ackley-improved/" target="_blank">New and Improved: The .280 Ackley Improved - RifleShooter</a></p><p></p><p>For reasons too lengthy to go into here, the headspace dimension for the .280 Ackley Improved cartridge approved by SAAMI and introduced by Nosler turned out to be shorter than headspace gauge manufacturers had established for the original Ackley version. Some reloading die makers have responded by offering different die sets for the two.</p><p></p><p>Dies made by Redding for the Ackley version prior to 2011 were marked "280 Rem Imp 40 Degrees." They are still available. Dies for the Nosler version are marked "280 Ackley Imp," which is the SAAMI-approved abbreviation. In the past, RCBS dies for the Ackley cartridge were marked "280 Imp 40 Degrees," and they will continue to be so while dies for the SAAMI/Nosler version will be marked "280 Ackley Imp."</p><p></p><p>The important difference between the two die sets is in their full-length resizers. Since headspace dimension of the SAAMI cartridge is shorter, the shoulder in a die reamed for the Ackley cartridge won't make contact with the shoulder of the case.</p><p></p><p>If a die reamed for the SAAMI version is screwed into the press far enough to make contact with the shellholder and used to resize a case fired in a rifle chambered for Ackley's version, the shoulder will be set back for an increase in headspace. But it can be used by screwing the die in just far enough to lightly bump back the shoulder enough for trouble-free chambering of the cartridge. So when purchasing reloading dies for a rifle it is important to know which version of the .280 AI it is chambered for.</p><p></p><p>If other companies introduce rifles in .280 Ackley Improved, they will likely be chambered for the SAAMI version, and Nosler cases and ammunition will surely work fine in them. But since the original .280 Ackley Improved is a wildcat, gunsmiths who have chambered rifles for it over the past 65 years or so have not always agreed on precisely how deeply the chamber should be reamed.</p><p></p><p>So to be on the safe side, it is not a bad idea to have the headspace of a rifle chambered for Ackley's version checked by a gunsmith to determine its suitability with Nosler cases and ammunition. Kenny Jarrett, who has chambered more than 1,000 rifles for the original Ackley version, agrees with my opinion. So does Dave Kiff of Pacific Tool & Gauge, which makes chamber reamers and headspace gauges for both versions. </p><p></p><p></p><p></p><p>Personally I don't use go-no go-field gauges as used by gunsmiths and IMO they have little use for us as reloaders. To say that no problem was created or does not exist is again</p><p></p><p>DONKEYDUNG!</p></blockquote><p></p>
[QUOTE="woods, post: 834389, member: 6042"] [url=http://www.rifleshootermag.com/2012/10/30/new-and-improved-the-280-ackley-improved/]New and Improved: The .280 Ackley Improved - RifleShooter[/url] For reasons too lengthy to go into here, the headspace dimension for the .280 Ackley Improved cartridge approved by SAAMI and introduced by Nosler turned out to be shorter than headspace gauge manufacturers had established for the original Ackley version. Some reloading die makers have responded by offering different die sets for the two. Dies made by Redding for the Ackley version prior to 2011 were marked “280 Rem Imp 40 Degrees.” They are still available. Dies for the Nosler version are marked “280 Ackley Imp,” which is the SAAMI-approved abbreviation. In the past, RCBS dies for the Ackley cartridge were marked “280 Imp 40 Degrees,” and they will continue to be so while dies for the SAAMI/Nosler version will be marked “280 Ackley Imp.” The important difference between the two die sets is in their full-length resizers. Since headspace dimension of the SAAMI cartridge is shorter, the shoulder in a die reamed for the Ackley cartridge won’t make contact with the shoulder of the case. If a die reamed for the SAAMI version is screwed into the press far enough to make contact with the shellholder and used to resize a case fired in a rifle chambered for Ackley’s version, the shoulder will be set back for an increase in headspace. But it can be used by screwing the die in just far enough to lightly bump back the shoulder enough for trouble-free chambering of the cartridge. So when purchasing reloading dies for a rifle it is important to know which version of the .280 AI it is chambered for. If other companies introduce rifles in .280 Ackley Improved, they will likely be chambered for the SAAMI version, and Nosler cases and ammunition will surely work fine in them. But since the original .280 Ackley Improved is a wildcat, gunsmiths who have chambered rifles for it over the past 65 years or so have not always agreed on precisely how deeply the chamber should be reamed. So to be on the safe side, it is not a bad idea to have the headspace of a rifle chambered for Ackley’s version checked by a gunsmith to determine its suitability with Nosler cases and ammunition. Kenny Jarrett, who has chambered more than 1,000 rifles for the original Ackley version, agrees with my opinion. So does Dave Kiff of Pacific Tool & Gauge, which makes chamber reamers and headspace gauges for both versions. Personally I don't use go-no go-field gauges as used by gunsmiths and IMO they have little use for us as reloaders. To say that no problem was created or does not exist is again DONKEYDUNG! [/QUOTE]
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.280 AI controversy explained ...
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