XCB- bullet in the .308 win

Spindrift

Well-Known Member
Had a nice day at the range today!
Fresh winter air, 25 degrees F, snow on the ground, no wind. And a couple of new (to me) bullets, among which is the NOE 310-165-FN, aka XCB. The rifle today was my Howa 1500, bedded into a GRS stock with a Timney trigger and Ultimax 3-12x56 scope in standard Leupold rings. The alloy is 96/2/2, where the «96»- part is nuclear medicine lead; an enigmatic/brilliant alloy of BHN 10-11, high density/ductility. Bullets are water quenched from a 4- cavity mold. Then, they are subjected to malicious visual sorting, but absolutely no weight control. 2 weeks post-casting, BHN is in the region of 24-26.
My plan is to try to develop a «high velocity» load with this bullet. Not that I have any particular need for a high velocity round, but... I´m curious, and want to learn cast bullet stuff. Then you have to try different things... You know how it is.

But before venturing into HV- shooting, I wanted to get a feel for the accuracy potential of this bullet/rifle combination. I chose to start with N110, 17-19grs, since this powder seems very good in the accuracy department (actually, N110 is good in all departments- totally clean burning etc).
I first tried with .3105 bullets, but when I determined max COL with this size, the base of the bullet intruded in the boiler room of the cartridge. When i sized them .309, everything came together... The bullet seemed to have a «vacuum- fit» in the neck, and max COL gave a bullet base flush with the base of the case neck. I had a really good feeling about this bullet.

Bullets were dip- lubed in my home- made «bullet gravy», made from X-lox, beeswax and liquid boat wax (dipped, dried, base- first trhough sizer). Hornady copper GC.

Shooting distance 100m ( about 110y). Prone position, with support on a bag. Target increments 30mm, which is almost exactly 1 MOA at 100m. The most accurate load (19grs) was sub- MOA. Very happy about this start. So, next I will drift down the burn chart, using slower powders /higher load density, to see how far I can go. Thought I could keep track of my (hopefully) progress in this thread.
 

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Spindrift

Well-Known Member
Thank you for the encouraging words!
I am shooting at an electronic target, which show a representation of where the bullet strikes on a screen next to me. The red one is the last shot. This target has a function («ammo testing mode») you can activate if you want, where it moves the center of the group to the middle of the target; this makes it easier to compare groups. This mode was activated in the targets pictured.
I actually obscure the screen with my loading notebook when I shoot, as I can get distracted if i follow the group while I shoot. You know, with 4 shots really toghether, you start to think to much («Oh, hope I don´t mess this up, this will be the best group ever...»).
 

Spindrift

Well-Known Member
Electronic targets are very common at public ranges in Norway. They are practical in a way, no one needs to go in front of the line to check the targets, so you can just fire away all day. But sometimes, I miss the ranges with paper targets where you get to stretch your legs, cool your gun (and head), and can inspect your actual group- and not just an electronic reproduction.
 

Brad

Benevolent Overlord and site owner
Staff member
Nice shooting.
Would be interested to see a few photos of your range. Sounds very different from what most of us are familiar with.
 

Rick

Moderator
Staff member
That is fascinating and mighty fine shooting. Do you have an idea of the velocity, E.S., S.D. in the 308 with N-110? I've burned up a fair amount of N-110 but never in a bottle neck rifle round. It's the powder that shoots the best long range revolver groups I've ever managed in a FA 41 mag. I've got 5-6 pounds of it on hand, the 308 huh? Fascinating indeed.
 

fiver

Well-Known Member
N-110 being the European VV equivalent to our 2400 in the load books for rifle loads I'm not too surprised.
 

Rick

Moderator
Staff member
Quite close to H-110, a stick powder so reduced works well also plus it's a little bulkier. As Spindrift mentioned burns very clean. Easy to ignite. Good stuff it is. I just had never considered it in a bottle neck case. Looking forward to seeing what velocity he got with the 19.0 grains.
 

Spindrift

Well-Known Member
Thank you for your kind words!
My experience so far with N110 is with bullets ranging from 130- 220grs in .308 and -06 (and a little bit with 6,5x55),and alloy strengths from BHN12-25 (approximately). In all combinations I have tried, happiness was found in the range 15-19grs.

I will chrony my loads at some point, and tell you my results. For now, I am focusing on accuracy (I get a little distracted when using my magnetospeed, so I prefer testing speed and accuracy separately). Next, I plan to load N110 19-20 grs, then Vectan tu-3000 (short grained, single base extruded powder, approximately 3031-speed). Then I plan to test with imr-4064 and tu-5000 (quite similar), n150, tu- 7000 (4350-ish) and imr-4831.
I think this will be an educational (and hopefully wildly sucsessful) journey. It might take a while, but I will keep you posted.
 

Spindrift

Well-Known Member
Tried the XCB- bullet with Vectan tubal-3000 today, an extruded single-base powder with burning speed approximately like 3031, I think. Clean burning, floats nicely in funnels. Tried 25, 27 and 29 grs (fishing a little here...). 25 and 27grs gave reasonable accuracy, 1,5- 2MOA. Things opened up at 29grs. Will try IMR 4064 and Tubal-5000 next time (they are quite similar with respect to burn speed). So, I didn`t get the sub- MOA accuracy i got last time (probably was very lucky), but the potential is there.
As a side note, I tried my «new» Rem 700 in .30-06 today, first time with cast bullets. Also tried the XCB- bullet (first time in -06). N110 turned out to be a good option for accuracy, once more- 20grs gave the best group.
A09C812E-AAD1-4B55-B1EC-56D127039C5E.jpeg8BC314C2-759A-4C27-99DC-8A99AE8F32B8.jpeg
 

Ian

Notorious member
The XCB bullet is actually designed to fit a SAAMI-specified .30-'06 throat angle. Size about .0005" smaller than the throat entrance and you should have a good fit.

I have no experience with the tubal powders, but IMR 3031 needs a certain minimum peak pressure to burn consistently and likes at least 80% load density.
 

fiver

Well-Known Member
get the 4064 up in the 38-40gr area.
39.5 is well,,, you can see the groups it shoots in that thread I linked.
also look at the alloy I used.
ww alloy will let you down at some point, the XCB design needs a stout alloy not a high BHN when you start climbing up and out of the 2-K speed zone.
 

Spindrift

Well-Known Member
@Rick ; chronographed the 19grs/n110 today. Started with cold rifle (and the first shot was a bit faster than the others). 10 shot string, magnetospeed (which works well with sensitivity at «hi 1»)
Avg 1752fps
Hi 1778 fps
Lo 1715 fps
Sd 16
Es 62
Nothing to impressive in the chrono data, really. Quite cold day, 19F.

Tried imr4064 in the .308. Since my alloy is not as resilient as Fiver’s alloy, I tried a lower load spectrum than suggested. 32, 34 and 36 grs. 32 and 34 was good (approximately 1moa@100m/5 shots, very good by my standards :)). At 36 grs the group opened up to 3moa. I believe I have reached the tolerance level of my alloy with this powder. Of course, my alloy is not particularily suited to real HV shooting, but neither is it intended to be- it is my standard, do-it-all. I think I will keep using it, and live with the limitations, for now.D9CDA051-A079-49A5-A7BD-AD2A4FDE17AA.jpeg47C2DB6B-DD03-4BF1-B9D3-A8904905EB41.jpeg
I think I will explore the node around 34 grs a bit more. Then, try viht n-150 35-36 grs.