How do I headspace a 30 degree shoulder Swift?
- Thread starter 1911nut
- Start date
Make a 30 degree headspace gauge.
Why a 30° shoulder on a 220 Swift? If you go to the standard 40° improved swift, there are tons of gauges, reamers, and excellent dies, right off the shelf. But with a 30°Swift, every thing has to be custom, hand made, months of wait, and lotsa money.
It’s for a Shilen pre-thread barrel for a Savage target action.
I want a 30* shoulder Swift and Shilen chambers one. Whidden will make a fl bushing die, my last one came in 4 weeks.
It’s been suggested by those who worked with Ackleys you can use the standard go and no-go gauges. The shoulders blow out and then use a bump gage to set up the FL dies.
I want a 30* shoulder Swift and Shilen chambers one. Whidden will make a fl bushing die, my last one came in 4 weeks.
It’s been suggested by those who worked with Ackleys you can use the standard go and no-go gauges. The shoulders blow out and then use a bump gage to set up the FL dies.
swd
Silver $$ Contributor
I've chambered and worked with lots of Ackleys. A properly set up Ackley will have about a .004" crush fit on a non fire formed case. Set it up to your brass. It will fire form and shoot great that way without any case web stretching.
Standard headapace gauges are used, although only the GO gauge is really utilized. Once the bolt closes on the GO gauge, reaming stops. In a pre-chambered Savage barrel it’s even easier: stick the GO gauge in the chamber, tighten the barrel into the action until it’s snug against the gauge and cinch the barrel nut. Piece ‘o cake.
swd
Silver $$ Contributor
Please don't do this with an Ackley chamber. Your just asking for case head seperation.
"Standard headapace gauges are used, although only the GO gauge is really utilized. Once the bolt closes on the GO gauge, reaming stops. In a pre-chambered Savage barrel it’s even easier: stick the GO gauge in the chamber, tighten the barrel into the action until it’s snug against the gauge and cinch the barrel nut. Piece ‘o cake."
Another faithful follower of the "savagedasher" school of improving cartridges! AKA known as "an accident waiting to happen".
Another faithful follower of the "savagedasher" school of improving cartridges! AKA known as "an accident waiting to happen".
Gents,
I only base my statements upon thorough study of how PO Ackley did it. And, of course, first-hand experience by actually implementing his technique. I’ve personally rechambered several factory chambers to Ackley Improved.
Maybe you mistook the use of a GO gauge with the NO-GO gauge?
I only base my statements upon thorough study of how PO Ackley did it. And, of course, first-hand experience by actually implementing his technique. I’ve personally rechambered several factory chambers to Ackley Improved.
Maybe you mistook the use of a GO gauge with the NO-GO gauge?
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Since WHEN does chambering just deep enough to close on a GO gauge cause excess headspace? The only measurement that matters is the neck/shoulder junction point on cartridges that headspace on the shoulder (datum, whatever). Nobody here is suggesting running an AI reamer into an already chambered barrel without setting it back first. Good Lord, people. Get your facts straight before putting on your Keyboard Commando helmet!
BoydAllen
Gold $$ Contributor
From page 155 of vol. 1 of P.O. Ackley's Handbook for Shooters and Reloaders speaking of chambering a standard .30-06 and then of the improved version,
"For the improved cartridge it is necessary to use the 1.940 gauge,..."(previously discussed as the dimension of a standard GO gauge) "...as the "No Go" gauge, and our "Go" gauge must be approximately .004 shorter. There our "Go" gauge will be 1.936." He goes on to cite another example.
In the past, a friend had a custom, from scratch (not a set back) .22-250 AI built. He took it and a case each of two different brands of factory ammo to fire form cases. One brand worked without misfire, the other had many. Because it is common for new brass to be several thousandths shorter than a minimum headspace chamber, and this amount can vary from brand to brand, at the time we thought that the reason for the difference was probably due to differences in the dimensions of the two brands of ammunition.
Having owned a standard Swift, I can tell you that because of their shoulder angle they are more susceptible to case stretch than cases that have larger shoulder angles, and for that reason I learned to pay strict attention to how I set my FL die. When I set up for a measured bump that worked fine for other calibers I quickly got a bright ring near case heads. What worked the best was setting the die to the same dimension as fired brass. The bolt close was fine and there were no more bright rings. This is why I think that in this case setting up off of the longest case for a little feel on the bolt is a good idea, if you do not have an AI GO gauge for your particular caliber. What matters is the end result, and no matter how "by the book" you are, if the end result is not satisfactory, being "correct" is of no consequence.
Some of us keyboard shooters may actually know a thing or two.
"For the improved cartridge it is necessary to use the 1.940 gauge,..."(previously discussed as the dimension of a standard GO gauge) "...as the "No Go" gauge, and our "Go" gauge must be approximately .004 shorter. There our "Go" gauge will be 1.936." He goes on to cite another example.
In the past, a friend had a custom, from scratch (not a set back) .22-250 AI built. He took it and a case each of two different brands of factory ammo to fire form cases. One brand worked without misfire, the other had many. Because it is common for new brass to be several thousandths shorter than a minimum headspace chamber, and this amount can vary from brand to brand, at the time we thought that the reason for the difference was probably due to differences in the dimensions of the two brands of ammunition.
Having owned a standard Swift, I can tell you that because of their shoulder angle they are more susceptible to case stretch than cases that have larger shoulder angles, and for that reason I learned to pay strict attention to how I set my FL die. When I set up for a measured bump that worked fine for other calibers I quickly got a bright ring near case heads. What worked the best was setting the die to the same dimension as fired brass. The bolt close was fine and there were no more bright rings. This is why I think that in this case setting up off of the longest case for a little feel on the bolt is a good idea, if you do not have an AI GO gauge for your particular caliber. What matters is the end result, and no matter how "by the book" you are, if the end result is not satisfactory, being "correct" is of no consequence.
Some of us keyboard shooters may actually know a thing or two.
I might add that several of my Ackley improved rifles, as chambered by 2 gun smiths, have negative head space with new unfired brass like 6mm Rem, and a former .257 AI. I was forced to grind down shell holder(s) to allow greater set back or "bump" so I could get the unfired round chambered for fire forming - not able to close bolt after running brass though F/L die like 6mm Rem or .257 R using a normal shell holder contacting the F/L die. After that no problems but never use the ground down shell holder for other rifles. I also have noticed variations among brands of brass in the amount of head space for easy chambering. Working with 7X57 PPU brass to make 6mm AI required the most effort.
Redding makes an assortment of shell holders of different thicknesses or heights to achieve the same purpose of attacking a shell holder with a Dremel tool.
Redding makes an assortment of shell holders of different thicknesses or heights to achieve the same purpose of attacking a shell holder with a Dremel tool.
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swd
Silver $$ Contributor
I've seen new virgin brass vary in headspace up to .012" short of a go gage. But apparently that won't induce headspace or web separation according to you. I guess that's not a reason to headspace it your brass. So what the hell do I know. Apparently I'm just a key board commander idiot that knows nothing. But thank you for your expert opinion. Next time something makes perfect sense to me I'll be sure and ask you to set me straight.
BoydAllen
Gold $$ Contributor
It sounds like your smiths may have gone past the recommended .004 shorter. New brass only makes contact at the neck shoulder junction because of the difference in shoulder angle. New brass in a minimum headspace has plenty of room in all directions. The shorter number that Ackley recommended would not given you chambering problems with untouched, untruned factory brass. Do you know exactly how short they made your chambers? On the shell holders, the only ones that I know about are all taller (thicker) than standard, none are shorter. When using a new case the idea is to get some feel when you close the bolt, nothing more. It could happen that you would have to shorten a shell holder but that would be cheaper and less trouble than stretching a bunch of cases...at today's brass prices.
You just need a head space gage for a .220 Wilson Arrow. Basically a .220 Swift with a 30 deg shoulder.
Paul
www.proprecisionrifles.com
Paul
www.proprecisionrifles.com
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