CorBon 155 Lapua Scenar, Danmit!

[gugubica]

I originally put this in the Ballistics forum, but no one saw it, so, I am posting it here. I think it might be rifle related, but don't know.

OK, so I was out this weekend doing some ladder testing.

I loaded up some different 175 Sierra MK BTHP loads.

I had re-mounted my scope so I needed to re-zero.

I loaded 6 CorBon Match with 155 gr. scenars in the mag to zero with as well as try them out in my rifle.

Two consecutive groups yielded almost identical horizontal stringing, but fairly good grouping.

I ran a search on "horizontal stringing" and a solid 2/3 of the threads were about the 155's.

Subsiquent groups with the 175's showed no stringing at all, so I am pretty sure this is a projo issue. The ammo was a touch slow, but not to bad at 2860 fps average (about what I would expect to give up from 2900 with a gasser).

This is from a 22" Bartlein barrel on a GAP AR-10.

What gives? I really want to be able to shoot 155's from this, and again, was encouraged by the consitancy, just not the strining.

Has anyone NOT been able to run the Lapua 155's due to this, if so, have you tried Bergers 155.5's?

 

[B.Bates]

Re: CorBon 155 Lapua Scenar, Danmit!

i would personally go shoot them at 300yd and 500yds and see what they do and how they string at distance

 

[USMCj]

Re: CorBon 155 Lapua Scenar, Danmit!

Lapua 155's have always been my pill of choice for .308 and have always printed better groups then I could ever get with 175SMK's.

I agree with shootone, 100 yard groups dont tell you much. Go out to 300 and see what they do.

 

[gugubica]

Re: CorBon 155 Lapua Scenar, Danmit!

Admitedly, I have not done much testing. I am going to run this setup in a 700 yard competition next weekend. I will get the chance to shoot every 100 yards. I mostly am just curious.

It just surprised me that they strung this way in two consecutive groups and the 175 SMK's immediately after that did not.

This leads me to believe that it was not an ID-10-T error (although that is definitely possible)!

There have been quite a few posts about horizontal stringing with the 155's, but I was not able to find any where the issue was solved or not, or why it was an issue in the first place. I was hoping to hear from some guys that had seen this in their loads.

Huh, I am curious more than anything.

 

[Tyler Kemp]

Re: CorBon 155 Lapua Scenar, Danmit!

Those groups are still really good, try them further!

 

[gugubica]

Re: CorBon 155 Lapua Scenar, Danmit!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tyler Kemp</div><div class="ubbcode-body">Those groups are still really good, try them further! </div></div>Yeah, thats why I said Damnit. I am happy with the performance of the ConBon, just not sure what to expect with the stringing. I really would like to run the 155's in this rig, but wanted to try some factory loads before loading a bunch.

I am going to run this setup at Big Piney's match next weekend. I most likely will not be competative, but it will be a good oportunity to test further.

Are you going to be able to make it down for the match?

 

[oneshot976]

Re: CorBon 155 Lapua Scenar, Danmit!

I would have to agree with 100 yard groups not telling you much. I have seen this exact load from Corbon shooting 1/2" to 3/4" groups at 100 yards shoot 1" to 1.5" at 350 yards and 2" to 2.5" at 650 yards. All from the same rifle, obviously. Don't judge it based on the 100 yard performance.

Corbon produces some great shooting ammo at least in my opinion!

Oneshot

 

[gugubica]

Re: CorBon 155 Lapua Scenar, Danmit!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: oneshot976</div><div class="ubbcode-body">

Corbon produces some great shooting ammo at least in my opinion!

Oneshot </div></div>

I agree completely. They are definitely my go to "factory" loads. And you have Lapua brass left over as a bonus!