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What is Your Opinion for a "crush" fit on the Acklies?

centershot

Silver $$ Contributor
My gunsmith did two barrels with Ackley type cartridges. One a .223 and the other a 6 TCU. He did them both with a "crush fit." I am finding out before going on a prairie dog hunt, that it is impossible to get rounds that chamber with ease. I want to slightly set back the head space but can not. The cartridge bottoms out on the shell holder and I need more setback. The only solution to me is to buy the Redding Competition shell holder set that gives you extra heads pace reduction. Thoughts?
 
Try different she'll holders with a trimmed feeler gauge under the case and above the shell holder . They're cheap and available at most auto and tool stores . I'd start with a .003 and see if it chambers better . Your basically pushing the shoulder back that amount .
 
I set them up with .003”-.004” crush. They definitely drag but aren’t hard to close. If it’s really hard to close it’s too much. I always asked clients to supply some of their brass so I could set it up for them and not run into these problems.
 
It's not about opinion.. All ackley's other than the saami 280 ai(long story) are designed to have .004 crush fit on a parent case go gage. Yes this does, by design, give some bolt closure effort. Brass varies to some degree so it can be from free to tight. But as said, it's intended to have some degree of crush and should be expected.
I wouldn't recommend doing away with all of it but you could do as others have suggested and machine the die or shell holder a bit shorter to allow you to uniform for a light crush between brass.

This subject has been covered in more depth on here many times. Use the search function for more detailed info on the subject.
 
gunsandgunsmithing said:
It's not about opinion.. All ackley's other than the saami 280 ai(long story) are designed to have .004 crush fit on a parent case go gage. Yes this does, by design, give some bolt closure effort..........
Click to expand...

Ding, Ding....winner, winner, chicken dinner!!!! It should have crush fit with the parent cartridge, it wont have any {if it is chambered correctly and the cases are sized right} on the AI version cases. They should size to .004" less than the parent case length, just like the gauge that is used to set the chamber to begin with. Now, that said, while I haven't fired a factory round in many moons, a lot of guys are telling me horror stories about the case or shoulder length being way off in both directions of factory ammo, so it could be the ammo and not the rifle. But, the OP is saying his size die wont properly size the shoulder back far enough....does this mean far enough as measured by a shoulder length case gauge or simply not far enough to easily chamber in the rifle???? Could be a big difference. One means you need better ammo, the other means you need a better gunsmith!!!
You can always grind off the bottom of your resize die so it will allow the case to go further in and hit the shoulder more, but that is really not the answer unless you have a bad chamber or a bad die to start with. Fix the problem. Well, find it first, then fix it.

Edit: I guess I should throw in a disclaimer...yes, you can simply match the case shoulder length with whatever the chamber is and if both are within a few thousandths it will shoot fine and be safe. But as gunsandgunsmithing has said, it's not properly done that way. There is a measurement and a tolerance and you should be within those specs. I would never run any rifle out of spec, but that is just me personally.
 
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I am by no means an authority, but "The Ackleys" is casting an awfully wide net.

I had a look at my 6BRAI print (Wheeler #1 design) and vs standard 6BR Norma and there is .003" nominal crush at the shoulder/neck junction. I realize PO Ackley didn't design that one but it may be the most popular one here.

I certainly believe that other "AI" cartridges will have different amounts of crush.
 
centershot said:
My gunsmith did two barrels with Ackley type cartridges. One a .223 and the other a 6 TCU. He did them both with a "crush fit." I am finding out before going on a prairie dog hunt, that it is impossible to get rounds that chamber with ease. I want to slightly set back the head space but can not. The cartridge bottoms out on the shell holder and I need more setback. The only solution to me is to buy the Redding Competition shell holder set that gives you extra heads pace reduction. Thoughts?
Click to expand...


Are chambering parent cartridges or previously fireformed cases from this chamber?
 
centershot said:
My gunsmith did two barrels with Ackley type cartridges. One a .223 and the other a 6 TCU. He did them both with a "crush fit." I am finding out before going on a prairie dog hunt, that it is impossible to get rounds that chamber with ease. I want to slightly set back the head space but can not. The cartridge bottoms out on the shell holder and I need more setback. The only solution to me is to buy the Redding Competition shell holder set that gives you extra heads pace reduction. Thoughts?
Click to expand...
The “crush fit” is only needed/used for fire forming the parent case to the improved case. Once it is fired the first time, the shoulder blows out and the “crush fit” disappears.
 
oldduc said:
The “crush fit” is only needed/used for fire forming the parent case to the improved case. Once it is fired the first time, the shoulder blows out and the “crush fit” disappears.
Click to expand...

But the reloading die does not if it is a crush if you use someone elses brass.
 
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I don't see any reason for a crush fit on an ackley case. You can set one up with a standard set of go/no-go gauges and it will work just fine, and you can resize brass that will chamber with normal resizing processes. Over the years 'smiths screwed up the rechambering because they used an Ackley reamer and standard go gauge on a regular chamber converting it to Ackley. This is nearly impossible to do because you can't tell when you're approaching the full length of the chamber, so they went oversize a little bit and this resulted in the rounds misfiring when using standard brass (excess headspace). So, I see no need for crushing the brass in a chamber to get it to fire, otherwise you may end up with the same issue as the OP.
 
I find it simply amazing how many knowledgeable builders haven't bothered to read P.O. Ackleys' books, and seem to "make it up on their own". I set back the barrels on 2 pre-64 Winchesters that had been rechambered by Red Cornelson ' back in the day', to .220 Swift Ackley Improved. The owner knew how to deal with these long chambers, but wanted them set-up with the crush fit, so his kids and grandkids could safely fire .220 Swift ammo in them.
 
You didn’t say what action this was on, but if it was a stock Remington I’d send it out to have the bolt face bushed and fp turned down. In the process I’d request .002” to be faced off the bolt face.
 
I don’t do many Akley chambers, but find a crush fit just too tight for any chamber in any application. Might work for Benchrest, ? My $0.02.
 
the other thing about a hard to close bolt to be concerned about is lug galling. IMO, firm to close OK, hard to close watch out. bring ,oil, grease, lubricant of some sort.
It's already been said you can take a little off the top of the shell holder to achieve to crush or clearances you want.
 
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