Lapua and Eley - Two different tuner settings?

C

center22

New member
Finished up a new rifle build this week. Shilen Ratchet .900" diameter barrel 25 1/8" long. Action is an X-III , Jewel trigger. Stock is a Stith 250 with aluminum pillars Devcon bedding. Hoehn/Harrel tuner and a nice NightForce 12x42x56 scope. Chamber was hand cut with a PTG Lilja reamer and polished.
Took the rifle to the range twice so far to acquire the best tuner setting, but conditions (windy) were not ideal either day. I was using a very good lot of Lapua Center X ammo to tune with. Tuner settings at "200" and "150" were showing tight round groups, so I shot 13 bulls with a "150" setting and 12 bulls with "200" tuner setting ... score was 242 3X (USBR target). Then shot one full card using a setting of "150" and scored a respectable 245 5X.
Cleaned the bore well and decided to try two different lots of Eley Match 1011 machine 2 - 1060 / machine 6 - 1059. Neither lot would group at a tuner setting of "150". Started turning the tuner out one full turn in increments of .025. Finally when I reached a setting a "300" the Eley Match ammo groups began to tighten up. Shot a card with the 6 machine Eley Match with a tuner setting of "300" score was 240 4X ... this was not the ideal setting of course.
I have always been a "set it and forget it" tuner guy ... but today's range session has me scratching my head. Any one have any similar experiences tuning two difference brands of ammo? John
 
John:

Sounds to me like you need to keep looking for the for the correct setting... I have a 40X built by Gene Davis about 2 years ago, and I have not changed my tuner setting since I got the rifle back from Gene.. I have shot Wolf Target, Lapua Center X, Fiocchi, Eley Team and Match EPS in my rifle, and I might have to move the tuner 1 or 2 clicks from the original setting, to "tweek" it due to different conditions, but my original setting is still the same. Now when I change ammo, I will get a different point of impact, but the group size stays pretty much the same...
When you find the correct setting, you will know it....

JMHO

Dave
 
Dave:
My testing so far has been very prelimary. My gut feeling is that I will find a tuner setting somewhere between 300 and 350 that will be best all around. However, one of our clubs top shooters (Bob M) who tuned his Anschutz 1913 from the start with Lapua Midas +, made a remark that his rifle will not shoot Eley ammo.
I measured the length of both the Center-X and Eley Match brass that were fired from my Lilja chambered rifle yesterday. The Eley brass measured .597" in length and the Center-X .605", which makes the Lapua .008" longer. Also, Eley and Lapua bullet profiles are completely different, not to mention possible differences in speeds or velocity. Various chamber dimensions could also affect how a projectile is released from the case when fired. Now, some of my other rifles shoot various ammo brands pretty good at one tuner setting. I'm just trying to think outside the box on this issue.
Hope to meet you at a match one day. John
 
I think what everyone does is to find the best setting and then find ammo that shoots at that setting. The Hopewell method if finding the best tuner setting works. You can probably find a discription of it in the archives. First one needs a good lot of ammo to work with, which sometimes isn't easy to find. It's not quite a catch 22 but close.
 
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