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I can't remember where I read how to use a caliper to measure the web on brass to determine when there's too much pressure. Boy that was mouth full. Anyway, I know I read it somewhere but can't remember where. The article on 444s on beartooth was helpful but, I want something pertinent (ooh another big word) to 30-30s. Thanks for the help, Rick
 

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Hi Guy`s,

If you start to see presure signs like you mention for the 30-30 you are WAY OVER the safe presure for a rifle like the marlin 336 and a winchester 94.

Your best bet is to stick with reliable reloading data and use a chronograph to chk your loads.If you want more from your 30-30 just get a 30-06.Hot roding a 30-30 isn`t worth beating a gun up and posably hurting yourself.

30-30 brass is thin and the leverguns don`t vent gas very well.i don`t mean to preach but this is your best bet.

Riflemen10x
 

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I forgot to mention this in the last post and it might help you out when you work up a load that you don`t have any info on but use caution this is just like anyother presure sign test its just ballpark but it can help.

1 start low and work your way up with the powder charge in full length sized casses.notice that the primer sticks out when fired.the pressure is pusshing out the primer but it won`t strech the case and re seat the primer.work up the powder charge untill you see the primer get flater and the primer is reseated in the case.then stop you are in the ball park once the pressure is high enough to strech the case.

Remember this is just like looking at other pressure signs its hard to do right and be reliable so many varables like brass and stuff

I hope this helps.
Riflemen10x
 
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I measure my 30/30 cases with a micrometer about 1/2" or less above the base or rim (high spot). If I remember right the F/L sized brass measure around .417" and after firing go up to around .421"-22" on heavy loads. Each rifle is different and like the others say, the lever action is pretty springy to try too hot of a load in. If I use some milder loads that don't expand the pressure ring (Ken Water's term) any more than .419"-20", like with cast bullet loads, I might just neck size the brass before using again.
Luck BM

Bill
 

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Hornady has had a good article on how to do this in their reloading manuals. It is tough to do but with practice it can be learned. The most important part is their recommendation that the case be fired for the very first time. I bought my micrometer from www.midwayusa.com I picked a Starrett Electronic Digital Micrometer for the job. This is # 141-893. Hang on to your wallet. This baby goes for $154.29. However it is easier for the average gun slinger to use. In reality you are measuring the expansion of the case head, near the primer. One of the pressure signs that is used on high presure cartridges like the Magnums is primer pocket expansion. If the primer is loose in the pocket, then the pressure is way on up there. The typical levergun round like a .30-30, the case should expand .0003-.0004 inches. That is not much at all. With the Starrett you can take a measurement before firing, then zero the "mic" and then read the after firing diameter. This way you don't have to do any math. You take the measurement just ahead of the extraction groove. I cheat, though, you should really use a "blade" micrometer to get the best results. Instead of the normal flat cylinder surfaces that most micrometers have, the blade type use a thin blade which measures a smaller area. I have one, but it isn't digital and is a lot harder to use.
I have seen other articles about measuring the case head expansion, but the Hornady method was developed using pressure guns to come up with the expansion values that they give.
 

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Rifleman10x is right at my method. I have seen numerous leverguns show sticky extraction when the load is getting to be more than the rifle likes, especially the 30-30. I just got a new Marlin and decided to use some loading data I worked up years ago with 3031 and 32.5 grains of 3031 under a 150 grain Hornady RN gave slightly sticky extraction, I backed off 1 grain and everything is fine. When I work up my 170 grain load it won't be from old data but up from the minimum listed to where the primer is seated in the case and I'll be happy.
 
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