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Discussion: HV

in: kensr; kensr > 2020-04-25

Apr 26, 2020 12:29 AM # 
fossil:
Not that it matters in training but I don't think you can use HV in competition. (At least that's what I was told by someone with far more experience.)

Were you having trouble with jamming? Curious what ammo that was and what was going wrong.
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Apr 26, 2020 1:08 AM # 
arthurd:
Yes, standard velocity ammunition only. And I think generally you can't/shouldn't use high velocity with metal targets even if it isn't a race.
Apr 26, 2020 1:43 PM # 
fossil:
But on the plus side, it sounds like you were successful at flattening the curve!
Apr 26, 2020 4:52 PM # 
kensr:
The jamming was with CCI Standard Velocity Target (see day before). Shells seem to fit a little tight and the ejector won't pull them out. Switched to the CCI High Velocity and they were fine without even cleaning the bolt and ejector. However, doesn't look like I can use it in competition. Just as good as the sight adjustment was totally different from all else I've been using. Been trying different ammo guided by results of rimfire ammo comparison test. As you might expect, Eley and Lapua come out on top. A bit pricier
Apr 27, 2020 1:39 AM # 
fossil:
Well that's interesting. I have a brick of CCI, maybe the same one, but I've never opened it. Will have to give it a try when I get a chance to see if I get the same results. Might be a long time before I get a chance for some target practice now though.

On rethinking your sight observation though, I'm not understanding why the HV ammo would cause you to take clicks up and not down. If it's a flatter trajectory and dropping less, then I would expect if you're already zeroed with SV then your HV shots would hit high and you'd have to take clicks down to compensate.
Apr 27, 2020 2:36 AM # 
garymm:
Apr 27, 2020 2:58 AM # 
garymm:
It's odd that the STD velocity cci was a problem and the high veloity chambeered and extracted normally. Are both 40 grain bullets? A lot of the ammo manufacturer use lighter bullets (36 grain?) and a different profile bullet in the high veloity load. That could affect the bullet surface area and the way it chambers. I would not think it would affect the way an empty ejects. In high powered rifles stuck or hard to eject empties are an indication of excessive pressures. I can't see how that could be your problem. If you have a micrometer or a set of digital calipers you could measure the cartridge length and bullet diameter to see if they are different. The cheaper the ammo the more variability between rounds there is likely to be.
Apr 27, 2020 6:20 PM # 
kensr:
@Mitch - I shot 1000 rounds of CCI standard velocity which came in a box bricks of 500 in 50's. The latest were in plastic cases of 100 and immediately caused a problem. Same bullet, different packaging. The first 1000 shot okay.

Semantics: I clicked up the sight which lowered the barrel, but you're correct, I clicked towards H.

@Gary - Yes, both are 40 grain bullets. I measured the SK Biathlon, Eley Target, Lapua Biath Extreme and the two CCI's. The unfired shells are all between 5.65 and 5.69 mm, with the CCI's on the lower end. I do notice a trace ring of black around the outside of the lip of the CCI Standards that are giving me a problem. Hence my thought they may be firing "dirty" and the deposit is sticking the shell. When stuck, I have to pull the rim out with a knife tip.

Have 4 more boxes of the CCI Standard. Maybe I'll try a different box and see how those run. It was pretty cheap at $8 / box of 100.
Apr 27, 2020 7:38 PM # 
fossil:
Well if 1000 of the cardboard-boxed ones shot flawlessly and then the plastic-cased ones immediately caused a problem, I would propose a theory that they aren't in reality the same bullets.

I'm pretty sure my 500 brick of CCI Standard was about $75 when I bought it a year or two ago. The $8 per 100 for the plastic boxes works out to $40 for the same quantity. I've been paying $45 / 500 locally for Federal Gold Medal Target, which is the same thing Craftsbury was handing to their novice shooters when we went up for their fall weekend last fall. It's been working fine for me in non-frigid temps. Your rifle action is the same as mine so you might want to give it a try.
Apr 27, 2020 9:26 PM # 
kensr:
The original 500 bricks cost $36 each -- a pretty good bargain, since they did work okay. Trying different (and more expensive brands) to see if they will work better for me. What do you use for cold weather?
Apr 27, 2020 10:12 PM # 
fossil:
Yeah the real questions I think are "what is better?" and "would you know it if you saw it?" Biathlon shooting isn't about hitting the center of the circle like some shooting sports. It's about hit or miss, and secondarily how fast. In my mostly self-informed opinion, when I miss it isn't usually the equipment or the ammo's fault.

It's still an open question in my mind of whether or not a Savage barrel is good in cold weather. I read something not too long ago that seemed to imply that the stainless steel version is. That's the one us lefties typically end up with but not usually so for righties. Unfortunately when it's cold enough outside to do cold weather testing and try to gather some useful data, both the availability of daylight hours and my interest in laying down in the snow for an extended period are at a minimum.

But to answer your question I've used Lapua Polar Biathlon the last couple years in cold races. Is it better? I'm sure it is. But if the problem in cold is the barrel then I doubt using expensive ammo is going to fix it. Kind of like ski flex, grind, and fluoro wax.

I felt like I saw the cold weather problem for real a couple of years ago when I borrowed the same Izhmash rifle several times through the season and was unable to get it to zero on a really cold windless day. I haven't yet had that much of a contrasting example I could point at with my Savage. I've had days when I couldn't get a good zero but there have always been confounding circumstances... usually related to my technique.
Apr 28, 2020 10:36 AM # 
kensr:
Technique and solid rifle handling sure is the overriding issue for me. No doubt about that, however, I'd like to know how much the ammo contributes to the challenge. Checking by resting the barrel on a bench rest would be one way to explore the zero problem and inconsistent grouping. As Gary pointed out to me, in very cold weather the combustion products of some ammo will condense inside the barrel and cause interference. The better ammo like Lapua is formulated not to do this.

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