30-30 Ackley Improved

Thread starter #1

Mtank

Senior Member
Anyone have an idea of how much it would cost me to convert my Marlin 336 to this chambering? Also, am I correct in that you fire standard 30-30 rounds in the chamber, and the case expands to the new AI dimensions? Thanks for the help!
 
Thread starter #4

Mtank

Senior Member
apparently, and please feel free to correct me if Im wrong, because I dont know if I quite understand it, but the A I case increases powder capacity, therefore giving you about 3-400 more fps out of your 30-30, without increasing chamber pressures." You can shoot standard 30-30 win rounds and upon firing the brass will "blow out" to the new A I dimensions and you have a whole different animal. To the gurus out there, is there another reason why the A I case increases velocity, or is this stricty because you can pack more powder into the case?
 
30-30 Hornady LEVERevolution 150 gr = 2400 fps MV
30-30 Ackley Improved 150 gr = 2600 fps MV

30-30 Federal Power Shok 125 gr = 2570 fps MV
30-30 Ackley Improved 130 gr = 2385 fps MV

Seems like a lot of trouble for a very small improvement, if any. I understand that the 30-30 is pretty thin walled to begin with, and that lever actions by nature can't support the case well with hot loads.

This is how I understand the equation: faster bullet=more powder=more pressure=ruined lever action, so the Ackley answer is marginally larger chamber+marginal addition of powder=marginal difference in pressure=marginal increase in performance.

But let me say that I am no expert and the Ackley data is just from a Google search. Just doesn't seem like a great idea to me, the 30-30 is a 150 yd maybe 200 yd gun. An average 170 gr 30-30 with a MV of 2200 fps drops 3 ft at 300yds when using a 100 yd zero. Ackley cartridge is about 6 % faster, ( I'm pretty sure ballistics don't exactly work like this) but lets say that meant it dropped 6% less at 300 yds. That's only a difference of 2.5 inches, which is about the same distance that a 5mph crosswind would push it at 300 yds.

That said, I don't own an Ackely Improved anything, I've just done a little reading. Someone on here may own one and prove that it does offer a noticeable improvement.
 
Thread starter #6

Mtank

Senior Member
Well the draw to it for me was that almost 100 percent of the info Ive found regarding this cartridge is saying that it does not increase chamber pressures. I'm still trying to figure this one out. Also the data there for the 130 gr AI cant be correct, lighter bullet with more powder should always have higher velocity by nature. Also, for the reloader, you're gonna be hard pressed to get a standard 150-170 grain 30-30 round to reach 2400 fps. Hornady's factory LR stuff, to my knowledge, uses components unavailable to the public. I dunno, downside is you cant go pick the AI stuff up at walmart, but for someone who reloads it doesnt sound like a bad deal, as your still able to shoot the factory stuff, and your gun is ejecting potentially more accurate, more powerful cases. Gonna look around more and see what I find on the chamber pressure thing, just doesnt seem right that the pressures can stay the same. Maybe the gases have more room to expand since the case has more room to the neck?
 
QUOTE=Mtank;4539786]Well the draw to it for me was that almost 100 percent of the info Ive found regarding this cartridge is saying that it does not increase chamber pressures. I'm still trying to figure this one out. Also the data there for the 130 gr AI cant be correct, lighter bullet with more powder should always have higher velocity by nature. Also, for the reloader, you're gonna be hard pressed to get a standard 150-170 grain 30-30 round to reach 2400 fps. Hornady's factory LR stuff, to my knowledge, uses components unavailable to the public. I dunno, downside is you cant go pick the AI stuff up at walmart, but for someone who reloads it doesnt sound like a bad deal, as your still able to shoot the factory stuff, and your gun is ejecting potentially more accurate, more powerful cases. Gonna look around more and see what I find on the chamber pressure thing, just doesnt seem right that the pressures can stay the same. Maybe the gases have more room to expand since the case has more room to the neck?[/QUOTE]

i think you got it figured right here.
 
Yeah, I guess the fact that it will still shoot standard 30-30 cartridges means you aren't really losing anything.
 

seaweaver

Senior Member
There are fellas shooting the Corlock 170 out to 200 w/ no problems.
The FTX bullet hornady uses is available. But the powder is not.
I think the rebore would run $175.

Why the interest? To do/have something different?
Why not find a .32 special?
cw
 

Hammack

Senior Member
I have never done a 30-30, but I think 300-400 fps with ANY ackley variation is going to be optimistic. Unless the 30-30 is different you won't be able to just run the reamer into the standard chamber and it work. The barrel has to be removed, setback and then rechambered. The pressure will not go up. Yes, you are burning more powder, but the area that it burns in is also larger. However, to truly make use of an ackley cartridge you will need a longer barrel to make use of the added powder.
 

Cknerr

Senior Member
It is not the bullet speed or more powder that is intended by going AI. It is consistency of powder burn. For an extreme case of AI, plus a few other mods, are the WSM. The shoulders contain the powder in the cartridge longer and burn it there. When powder is blown down the bore to burn, the burn rates will vary a tiny amount from round to round. This helps eliminate the variations. Consistence is the name of the game for accuracy. AI is one of the first and easiest ways to gain a jump in getting your bullets to be more sociable.

Chris
 

rayjay

Senior Member
When you add up the cost of rechambering the bbl, buy new reloading dies, experimenting with bullets and powder to find the best load, etc you could probably just go out and buy a 308 rifle .
 
Thread starter #13

Mtank

Senior Member
Very true, but that .308 wouldnt be a lever gun that also shot 30-30s :p
 

bowhntr

Senior Member
Most people that rechamber for the 30-30 Akley set back the barrel some to get a past the old chamber area . This way you dont have any lines in your chamber if the new reamer doesnt clean the old chamber deep enough. This is a very good round for Contenders either in pistol or carbine form - single shot .:flag:
 

Hammack

Senior Member
Most people that rechamber for the 30-30 Akley set back the barrel some to get a past the old chamber area . This way you dont have any lines in your chamber if the new reamer doesnt clean the old chamber deep enough. This is a very good round for Contenders either in pistol or carbine form - single shot .:flag:
It's not just set back to keep any lines out of the chamber. Ackley cartridges have a few thousandths shorter headspace than their standard counter parts. This is to get a crush fit on the standard case when fire forming. Most I have ever talked to on the subject recommended taking .004" off of the standard go gauge when dictating chamber depth. I've done two with that method, and they turned out great.
 
Thread starter #16

Mtank

Senior Member
Any gunsmiths out there capable of doing this conversion?
 
30/30 AI...I've built one..

One thing about the rimmed cases is that you DON'T have to 'set back' the barrel. Headspace is controlled by the rim for the first shot of new ammo with rimmed cases. There is no shoulder contact at all with rimmed [30/30 Winchester] cases before fireforming. It is only with the rimless cases you MUST set a factory chambered barrel back to get at least 0.004" less headspace. Rimless cases DO headspace on the shoulder both in the origional factory chamber and even the first fireforming shot of a standard case in a 'new' Ackley Improved chamber. Setback of the barrel is necessary even if the origional chamber was 'tight', but most factory chambers are a bit sloppy. What is needed, is for the only contact point of a standard round in a new AI chamber, to be a tight fit of the area on the standard unfireformed round AT the shoulder/neck junction point. The contact is only here at this point so even a new AI chamber in a barrel set back 0.010" instead of one set back 0.004" will allow a standard round to chamber. The contact point is only a slim ring at the shoulder/neck junction and usually will 'crush' easily in the thin walled area of the case at that point. Standard is at least some 'feel' when closing the bolt on a rimless round for the first firing. I know a few Ackley Improved builders that make their AI chambers a full 0.010" smaller in length! They want even the occasional smaller factory new round to be 'contained' by at least some contact in the AI chamber that it will be fireformed in.

There is one reason a few will set back a standard chambered barrel that is on a rimmed case [30/30 for example] and that is because many factory barrels are sloppy in the origional headspacing, which is SUPPOSED to be on the rim. The rim is solid and will NOT crush if the rim relief is set too small for the origional barrel and chamber fitting at the factory.
You definately have some interest in the 'improved' theory as do I. I knew I 'had to' have an improved 'something' after all I had read about them. You SHOULD buy the two book set by P.O. Ackley. Ackley explains the ins and outs of well, "Ackley Improving" better than anyone. I think there is a lot of misunderstanding on 'improving' a round, and opinions often BOTH under rate them and OVER rate them! A 30/30 is a fun round to improve and P.O. wrote a lot about this round and it's use in LEVER ACTIONS.
What happens with an improved case is more than just more powder, faster bullet. The non improved factory rounds have more TAPER to the case sidewalls. There is more force upon firing to force the case backwards against the bolt face. Depending on how hot the load is and the case's brass makeup, the case often will expand some at peak pressure and then USUALLY contract at least a few thousanth's back to it's origional dimensions. If it expands a lot and/or the brass tends to retract less because of it's ductiblilty or other traits, being a TAPERED case it tends to hold itself BACK against the bolt face, sometimes making ejection difficult [especially in a lever action which is weaker in it's extraction ability compared to a bolt action]. So, loading the tapered factory, or 'standard' case HOTTER, will only make it more prone to lock up the action. Higher pressure will eventually get you into trouble if you exceed the pressure that the action was designed for.
When you fire an almost 'straight taper' case such as an improved case, there is a bit less force of the expanded case BACK against the bolt face because the almost straight walled case has at least SOME tendacy to 'hold' onto the chamber walls. If the case is oily then the force against the bolt face is the same as the standard round when fired, or close to it. If you keep loading hotter the case can eventually fail in other ways [dangerous] before EXTRACTION shows 'high pressure'. Difficult/sticky extraction is only ONE indicator of a 'too high pressure' in a standard round. With an Ackley Improved round you can USUALLY, by DESIGN [P.O. Ackley's] load to HIGHER PRESSURE and 'usually' higher velocity without sticky extraction. However you THEN need to heed OTHER high pressure signs when determining what is 'safe and practical' when developing a load for your Improved rifle. It usually will NOT be 'sticky extraction' as your improved case will still eject even if you load up to a pressure that is unsafe for your rifle.
What an improved case allows is, for one thing, loading to HIGHER pressure and hence higher velocity [most of the time] and still have easy extraction. Many loads of these 'higher pressure/velocity' loads are still safe. The type of action and diameter of the rounds head indicates how much higher pressure the new round can be safely loaded up to.
There are other reasons many AI rounds are 'better' or assumed by some to be better. One is case life. The sharper shoulder and minimal taper [about 0.007"/inch] of the Improved case seems to minimize case stretching and many times an AI case will not need any resizing of the body, just the neck to hold the new bullet.

I can talk 'improved chambering/barreling/theory longer than most folks care to listen:bounce: but I enjoy them enough to answer any questions you might have. All I can give you is what I believe, and not everyone will agree. Wether or not it's worth 'improving' your rifle depends on several things. I knew I 'had to do it' just to 'find out for myself' what the results would be. I've purchased several rifles that were IMPROPERLY 'chambered' to an improved round for the cheap. I enjoyed setting the barrels back to correct headspace and then testing the rifles at the range. A headspace gauge often shows the barrels on RIMLESS rounds were NOT SET BACK and the barrel is not properly headspaced.
If your lever action was properly headspaced at the factory for the rimmed 30/30 round, it can PROPERLY be chambered for the Ackley Improved and the headspace will be the same as it is held by the same rim. After you fireform a standard round, you then need to headspace on the shoulder or at least rezise the formed case with shoulder contact. My 30/30 rounds were so well behaved that I did not need to full length resize them even after 3 reloads! I also use .308 Winchester FL dies to reload....they will neck size only a 30/30 case, and only part of the neck. I never had an improved case expand to the point where it needed FL sizing, but I did 'toss' the cases after 4 reloads anyway since brass is so common and at least USED TO BE easy to find 'once fired new' at any range before deer season. I never had to buy new 30/30 ammo!
OK, fingers tired....back to bed.
ps. I've built several Ackley improved rifles both on my own lathe and the lathes of friends. It's fun and something some of us just 'have to do' and find out for ourselves.:D
 
but to answer your question....

but to answer your question....
because it is not necessary to remove and 'set back' your barrel, it can be reamed with an extension [Marlin?]. I would remove the barrel just because I like the precision of a lathe but a very satisfactory job can be done via the extension tool.
The expense of that job is usually well under $100.

I'm not sure you asked this one but I'm sure some are wondering and I'll ask it of myself: Would I do it again...and why?

Yes,,but BECAUSE I like to TINKER with guns and barrelling/chambering/reloading. I just WANTED to do it.

Is is "worthwhile" or "practiacal"? For a hunting rifle I DON'T think I would. You can actually get a few more fps just by loading your own ammo if you have a low intensity round like the 30/30.

Do you NEED a 'few more fps'. Nope. Your 30/30 is a killing machine AS IT IS inspite of what some might say. You do not need anything close to a 7 mag or 300 Ultra mag to kill deer. I had a 336 RC Marlin that would group 5 shots into 1" at 100 yds. It was made in the late 1950s. I used to bring it to the range JUST hoping someone would BRAG on their super duper rifle's accuracy. Oh it was fun to suggest a 'who buys lunch' competition..with me pointing to an old Marlin lever gun lying there to the side:)

Your 30/30 is a great gun. It is fun to SHOOT and I would spend any extra $ on ammo or reloading components. You will NOT get ANY advantage [in my opinion] by reaming it to AI....and that from someone who would spin a barrel tomorrow and run an AI reamer in!

I shoot a .250 Savage Ackley Improved because I want to. I also have two .250 Savage bolt rifles that are NOT reamed. There is no great reason too do so. IF there are a few hundred fps to be gained and longer brass life, fine, but the gain is not enough to 'do the AI'. If you ENJOY tinkering with rifles/gunsmithing then it IS fun and you will get some increase or benefits.....but the rifle is probably fine the way it is.

If you want an improvement, spend your money on a CUSTOM barrel! THAT can be a great addition to your rifle! I'm referring to bolt guns mostly.....you'd have to really love your lever gun to realize any benefit of rebarreling it.

Buy ammo and go shoot your rifles MORE....that's fun...and practical.
But if you want an Ackley, I'll give you all the "tinkering" credit you want...it's a fun way to spend time at a lathe.

.....a few I've owned or built and shot.......

22 K Hornet
223 AI
22-250 Ai
243 Ai
250-3000 AI
257 Robt. AI
30/30 AI
30/06 AI
17 Ackley Hornet [not a 40 degree but 'improved' of sorts]
 
I've heard lots about the .30-30 AI over the last couple of years. Enough so that I will do one as soon as I find a suitable candidate (I love Marlin 336s, hate the safety "C" models).
I talked to a guy at the range that had one, he claimed that the AI will run up there with the .308 Marlin Express. He did his with a reamer and a pair of go/no go gauges.
Here is a recent discussion on the .30-30 AI: http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/3026061/1
 
...even more...

I also used .375 Winchester brass, it's designed for higher pressures, possibly 50,000 cup if I remember right. Necks might need to be turned.
The .375 Win case is identical on the exterior, just thicker case walls and web area. I mostly used whatever once fired 30/30 cases.
 
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