The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools
Old June 11, 2014, 08:45 AM   #1
Longshot4
Senior Member
 
Join Date: February 22, 2014
Posts: 226
load tests

I have a bit of a age tremor (shake) to deal with at the bench. This is where my old machine rest comes into play. Yesterday I went to the range and forgot the rest. so I used a couple blankets as rests. My grouping was a real challenge to control. I had lots of fliers out to As much as 2". Although I was testing for 3 different 50 gr. Polymer tip bullets. Nosler, Hornadys and Sierra BlitzKing. I shot 15 rounds each. The Nosler were at aprox. 2", Hornady at about 1.5" and Blitz were at a inch. With two tight clusters. The loads were also with OACL variations off from .010 to full contact on lands. The Blitz had a noticeable higher resistance when closing the bolt. The Hornady and Noslers I didn't feel the high resistance. So I am guessing that I didn't make full contact with lands. I have plans to pickup a pocket uniformed then continue tests with my machine rest. Oh how I missed the good rest. My next loads will be with the Blitz and with contact to lands. I think the rest should shrink the groups down to about 0.5"< Report to continue. I am curious on what you think about my methods of testing these loads?
Longshot4 is offline  
Old June 11, 2014, 03:43 PM   #2
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 10,412
You may want to look at setting up a test of seating depths. Each bullet ogive shape typically likes something a little different.

Writing in The Precision Shooting Reloading Guide, Dan Hackett stated that he was loading Nosler BT's for a .220 Swift, whose best 5-shot groups were about 0.350" with that gun, with most being closer to 0.500". He normally loaded all bullets for this rifle 0.020" off the lands, a number mentioned by many "experts" as best (many other "experts" offer different "best" numbers, but that's the one what Hackett was going by).

Then one day, when switching from loading for this rifle with another bullet, Hackett accidentally turned his micrometer adjustment on his seating die the wrong way. As a result he loaded twenty rounds seated 0.050" off the lands before noticing the error. Well, thats a COL 0.030" shorter than his intention. But, rather than pull the bullets, he decided just to shoot these rounds in practice. To his amazement, the twenty rounds gave him two 5-shot groups that were about 0.250" and two bughole groups in the high ones (a bit 0.200 inches). So, that Nosler bullet in that chamber liked the greater distance off the lands better.

Anyway, I think it's worth a try to take your existing load and also try it at several different depths. Read item 3., near the top, here. Then read Berger's procedure for secant ogive VLD's.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member
Unclenick is offline  
Old June 11, 2014, 06:33 PM   #3
Longshot4
Senior Member
 
Join Date: February 22, 2014
Posts: 226
Wow. Harmonics,time of bullet travel is cool. Load development in increments of charge shows good practice. I have chosen a load from past history in my rifle but was trying different bullets. I will be using the CCI br4 primers, H 4895 and 50 gr. Blitz. My change will be to further tune bullet seething depth. My two small groups were on seated depth increments of .010. I will make a wider range of depths four at .005. Hopefully I will see if it is what I want. I will stay in the range that I had. since I Had no indication of pressure problems on the primers. thanks for passing on your information. Note after reading The Burger information I will be using .002 increments for my test.

Last edited by Longshot4; June 11, 2014 at 06:49 PM.
Longshot4 is offline  
Old June 11, 2014, 07:32 PM   #4
Jim243
Senior Member
 
Join Date: January 5, 2009
Location: Just off Route 66
Posts: 4,618
Longshot, I use a L-N-L OAL gauge for finding the max OAL for any new bullet/rifle that I am loading for. I find the max and back the OAL down by 0.050 inches. Some may say this is too much but it has worked out very well for me.

Two reasons I do this is:

1: I do not have to worry about additional pressure build up do to the bullet sitting on the lands and taking more energy to start the bullet out of the case.

And

2. No worry about concentric run out and that the bullet is perfectly centered in the mouth of the case.

it would seem that the additional 0.030 gives me that luxury.

Jim
__________________
Si vis pacem, para bellum
Jim243 is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:17 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.06717 seconds with 7 queries