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Distance to lands

Posted: Wed Jul 30, 2008 2:27 pm
by fisherman
I am new to reloading and am trying to find an accurate load for my savage 12, 204. I have read that most rifels shoot there best group when the bullet is loaded to a lenth that just touches the lands. After measuring and doing the math (wich I am Better at than spelling) I find that I can not get there. A factory load, Hornaday 32. gr. total lenth. 2.245 would have to be increased in lenth to 2.450 to touch the lands. All the bullets I have tried Nosler 40 gr. , sierra 39gr., berger 40 gr., hornaday 32, & 40 gr.,are not long enough . it seams that i need a longer neck or a longer bullet, or it could be that my inexperiance is shining brightly!!! . so far i have achived 1/2 " at 100 . not good enough. any advice? thanks. fisherman.

Re: Distance to lands

Posted: Wed Jul 30, 2008 4:36 pm
by skipper
You're just experiencing the outrageously long factory .204 chambers. Most everyone has the same problem. You have one of a couple of choices here. If you use a magazine you can only load as long as the magazine will allow, that is, if you intend to use it, or you can test varying lengths to find out what your rifle likes the best. Start with 2.250 and shoot a group of five. Then load .5 longer each group of five all the way until you just have about a half of a calibers diameter left in the case, for safety. That's about .102 seated in the neck. You may just find that your rifle likes them seated with a bit of a jump. My old XR-100 preferred to have them seated right at book length. Go figure.

The last option is to get an aftermarket barrel and have it reamed to your specifications. (zero freebore) Then you can jamm those little pills into the lands. My custom Lilja barrel loves them like that.

Re: Distance to lands

Posted: Wed Jul 30, 2008 4:50 pm
by Hotshot
skipper,

When you jamm 'em to the lands do you experience higher pressure? I always back off about .010 because I load close to max and someone suggested to me that I could have pressure problems if I touched the lands.

Re: Distance to lands

Posted: Wed Jul 30, 2008 6:23 pm
by OldTurtle
Most factory chamberings tend to be a little on the long side.

I have a Savage 16 that I haven't found a bullet in .204 that will touch the lands and still seat in the case....The rifle shoots some really excellent groups when loaded to the magazine length, or actually just a hair shorter....

I have a custom barreled AR that the gunsmith custom chambered to allow for a .030" jump to the lands using a 40gr V-Max and the 39gr SBKs will run just a little more distance and shoot the best in that rifle..

Re: Distance to lands

Posted: Thu Jul 31, 2008 2:55 am
by skipper
I haven't had any pressure related problems while jamming my bullets into the lands. You would think that there would be a pressure increase since the bullets are starting their flight while being held in place. The velocity of my bullets loaded into the lands and those that make the jump seem to be on par. The only thing I watch for is not to seat my bullets so they just touch the lands. If so, some might end up seated so that they are just shy of the lands and others might end up into the lands. That would surely cause varying pressures and kill accuracy. Since I don't have a way to measure actual chamber pressure, I don't know the exact pressure differences. I'm sure there are some differences. I use a chronograph so I can watch for the signs of pressure related problems.

I know that I can push the 35 gr. Bergers well over 4200 fps. with no problems while jammed .020 into the lands. Mind you, this is with a custom Stolle Panda action with no ejector pin in the face of the bolt matched to a custom Lilja three groove, hald lapped barrel. This action was designed for hot rodding. The tolerances on this rifle were held to .0005 by a master gunsmith who builds competition benchrest rifles daily. I wouldn't even try it with my factory XR 100.

Re: Distance to lands

Posted: Wed Aug 06, 2008 9:54 am
by JD11
After measuring and doing the math (wich I am Better at than spelling) I find that I can not get there
Right, with my Savage LPV 204, marking a bullet, seating it lightly in an empty case then chambering, when it finally touches the lands the bullet is not seated into the case anywhere near enough. It's generally agreed that a bullet should be seated at least as deep as it's diameter. With that said, seating equal to diameter is right at 2.355 overall length which is the measurement I'm using so far with 39 gr. Blitz Kings. The way this summer's been, I haven't had time to work up an ideal powder load for my new 204, let alone dink around with seating depths. I have about 20 cases loaded with varying amounts of Varget in a plastic MTM ammo box divided in marked rows and one of my cats (I think it was my 19 pounder) was laying on my reloading table, knocked the box over on the floor and the shells are now a mixed up mess----I can't win.

Re: Distance to lands

Posted: Thu Aug 07, 2008 11:39 am
by futuretrades
skipper wrote:I have about 20 cases loaded with varying amounts of Varget in a plastic MTM ammo box divided in marked rows and one of my cats (I think it was my 19 pounder) was laying on my reloading table, knocked the box over on the floor and the shells are now a mixed up mess----I can't win.
one suggestion to avoid such problems: all loads with the same powder, bullet, etc should be marked in some way and notes put in your ammo box. so you can avoid these kinds of problems. i use a sharpie to mark the base of the shell casing, such as a half line, next a full line, next maybe a t and so on. when you put the ammo in your ammo box, put it in so the base of the shells are facing you. also make notes to tell which mark corresponds with each of the different loads. may take just a little extra time, but is well worth the effort, to avoid problems like you just experienced.
Live and learn!

Re: Distance to lands

Posted: Thu Aug 07, 2008 11:50 am
by futuretrades
[quote="JD11"][quote]
I have about 20 cases loaded with varying amounts of Varget in a plastic MTM ammo box divided in marked rows and one of my cats (I think it was my 19 pounder) was laying on my reloading table, knocked the box over on the floor and the shells are now a mixed up mess----I can't win.

one suggestion to avoid such problems: all loads with the same powder, bullet, etc should be marked in some way and notes put in your ammo box. so you can avoid these kinds of problems. i use a sharpie to mark the base of the shell casing, such as a half line, next a full line, next maybe a t and so on. when you put the ammo in your ammo box, put it in so the base of the shells are facing you. also make notes to tell which mark corresponds with each of the different loads. may take just a little extra time, but is well worth the effort, to avoid problems like you just experienced.
Live and learn!

Re: Distance to lands

Posted: Fri Aug 08, 2008 1:19 pm
by JD11
one suggestion to avoid such problems: all loads with the same powder, bullet, etc should be marked in some way and notes put in your ammo box. so you can avoid these kinds of problems.
That's exactly what I did as always, but when Fatso knocked the closed box on the floor upside down all shells fell out of the holder holes so I don't have a clue which went in which marked row. If I shoot the tightest groups I've ever shot with the mixed up mess I'll really be confused! :)

Re: Distance to lands

Posted: Fri Aug 08, 2008 2:56 pm
by skipper
If all the cases were loaded with the same bullets, brass and primers, you should be able to weigh them to determine which is what powder charge. Then just put them back in the ammo box by weight.

Re: Distance to lands

Posted: Sat Aug 09, 2008 7:11 am
by JD11
Holy Crap, stupid me! Thanks Skipper! They're the same everything except powder weight. My wife has a scaled postage meter (platform type) that would be perfect for that.

Re: Distance to lands

Posted: Sat Aug 09, 2008 7:31 am
by Glen
JD11 wrote:Holy Crap, stupid me! Thanks Skipper! They're the same everything except powder weight. My wife has a scaled postage meter (platform type) that would be perfect for that.


:hand: You aint stupid JD!! Skipper is just "more experienced". :wink:


:lmao: :lmao: :lmao:

Soory Skip!! Couldn't let that one slide by under the radar buddy!! :wink:

Re: Distance to lands

Posted: Sat Aug 09, 2008 8:24 am
by skipper
:D

Re: Distance to lands

Posted: Mon Oct 06, 2008 11:10 am
by OldTurtle
I not longer have my cat on which to blame that type of incident,,,, I can do it on my own , which I did at the range one day while working up some loads and, at that time the range was 45 mi from home.

I started taking a black Sharpie and marking each test cartridge with a Roman Numeral that corresponds to my load book record for the day and it allows me to keep them straight in the case of a mishap.. :chin:

I used to write the whole powder charge/primer on the case, but then it became a hassle to clean it off with alcohol after firing. :wall:

Re: Distance to lands

Posted: Fri Oct 17, 2008 5:26 pm
by josebd2006
i measured my savage 12 today with 32vmax it was 2.292