Hotburn76

Been trying to understand the term touching lands, and just off the lands and other terms. I have a 204 Handie and this is a 40 grain Vmax loaded at different lengths.

This is loaded at 2.395 like Mitch has is some of his post. These are land marks right? This is way to deep correct?




This is 2.350 and the marks are getting smaller




This is 2.325 really small now




This is where the marks are off now, this is 2.310


So is my load spot for a 40 grain VMax somewhere between 2.310 and 2.325? This is done with RCBS calipers and is to the red tip. Am I seeing this right or doing it all wrong. I though that I had a long throat, but realized that was a bullet with out a ballistic tip and the Berger is more pointy then the VMax I think. Any pointers on if I am looking at this right?

eldeguello

I believe you are looking at it correctly.

Looks to me like that bullet in the first pic is seated way too far out-perhaps by as much as one bullet diameter. Matter of fact, I'm surprised you didn't end up w/the bullet stuck in the chamber throat and an action fulll of dumped powder when you extracted the round!

You need to seat the bullet deeper in the case, to an additional depthequal to where the the top of the land marks will beeven with about where the BOTTOM edge of the land marks are in that top photo.....The bullets should be sdeated to where they are about 1-2mm shy of allowing the lands in the bore to actually touch them when the bolt is closed. SOME rifles shoot better with even more clearance betwen the lands & the bullet when the bolt is closed......

bigcountry

My suggestion over the carbon on the bullet test is to split the case and chamber it. Compare it with your results above. I have always got huge variations using the smoke bullet test you did.

Hotburn76

So the pics one and two are definitely bad and some guys do number three and number four is totally safe right? Also the bullet was empty, can't work up the nerve to hold a flame to a case with powder in it. Also one thing I did not mention was that I originally seated the bullet just enough to get it to stay in the case, that number was 2.450 and then I chambered it and it closed kinda tight or stiff. When I took the bullet it out I could see scratches on it and then bullet was pushed back to 2.415 but was excited and did not get a pic of this. I am going to try and figure out how to split a case since I do not have a dremmel so I can try your method also BC. Thanks guys for your info so far.

Hotburn76

BC, did a bullet like you said and came up with 2.395? So now I am really messing with myself!! I also did the hold a bullet with a pencil thing and set stops on a cleaning rod and came up with a number similar to the last time I did it and it was 2.43 But with your technique the bullet was in case good, but was soft enough I could push it in with just my calipers. so I figured that should be soft enough and I did it four time and three times I had 2.395 and once 2.396 so to me this seems like a good number? just back off .005 maybe and set to 2.390? Thanks again!

bigcountry

Wow, thats huge difference. Was the bullet able to slide in and out with fingers? Sometimes what happens with split case if the bullet is too loose is the lands will grab it on the way out and give you false readings. Looks like your smoke test is working. If it was me, I would load less than 2.310"

Pawildman

If you are not cutting the smoke at 2.310 and you were at 2.325 with the bullet seated in a resized case, you should start somewhere shy of 2.310 like bc said. What he also said about the lands possibly pulling the bullet back out of the case sloghtly using the split-neck method is correct. I think you have a good starting point to work off now.

RustyD02359

Get a bullet comparator to measure from the ogive so you can seat all bullets to the proper OAL at the Ogive (where the bullet actually contacts the lands)

SJAdventures

Amen, the Hornady Comparator is one of the best little tools I've bought. Check this link out too that Ridge Runner posted in another post. I have one of these headed my way too.

http://www.predatormastersforums.com/ubbthreads/showflat.php?Cat=0&Number=52212062&an=0&am p;page=0#52212062

Pawildman

Ageeed----- But firs you have to establish bullet/lands relationship before you can start to use the Comparator. You need a starting point, and I think that was what the man was looking for.