6Dasher Machine Testing

[Remington223]

I've been working up loads for my new dasher rifle that will be used for mid range sling matches. It's a trued R700 action in an Elisio R5 stock with a 30" Schneider polygonal 8 twist.

I'm getting the loads narrowed down but they are all stringed vertically, small groups, but vertical.

Being an iron sight sling XTC shooter, I've been working up my loads using a scope with the rifle mounted in a machine rest to eliminate as many variables as possible. All tests have been at 500 yards.

A trusted source told me that this happens when the front bag is too hard or tight. Being in a machine rest, it is very tight and does not move.

Has anyone else seen this when testing with this style of rest?

Ps: everything is tight and the scope tracks perfectly (box tested)

Thanks, Jim A

 

[johara1]

Jim you can out shoot a machine rest, My tube gun had to much movement in the fore end tube to shoot good off the bags.Drilled three more holes in between the others and then it shoot good...........jim

 

[Remington223]

Went out this morning in the dead calm of the Florida sunrise and tried again.

I loosened everything up on the rest and made sure that the front mount (bag) was not rock hard, basically let the whole thing free recoil and just used the machine to realign the cross hairs perfectly for each shot.

Using the best load of my previous tests I shot 3 consecutive groups of 10 shots each again at 500 yards (i cant resist). The SD for each was under 4 with the best string being 2.38.

The good thing is that the groups did appear flatter with the largest being 1.573 tall. So it seems a machine is not always the best thing to test with as designed.

I'm going with this load as it will easily shoot out the X ring of any mid-range target if I do my part.

 

[memilanuk]

Just out of curiosity... which 'machine rest' are you using? Something commercially available, or a custom job?

 

[Remington223]

Just out of curiosity... which 'machine rest' are you using? Something commercially available, or a custom job?

Don't know the name, but it is a commercially made one that I reengineered a bit to make it more solid and repeatable. I bolt it down to the benchrest table at my range. It's rock solid.

I'm sending my bolt off to Greg T to get bushed. When it gets back I think I'm going to mess with my 105 HY load some more. I'm sure the groups can be pulled in further. Got a few months till the season starts down here.

 

[memilanuk]

Is it one of these:

http://hyskore.com/wp/2011/01/14/black-gun-machine-rest/

 

[BoydAllen]

It would be interesting to see what kind of groups a real quarter inch rifle would shoot using that rest, at 100 yards, compared to shooting the same rifle off of a good front rest and rear bag.

 

[memilanuk]

Hello Boyd,

It would, indeed. I'd even go so far as to say vs. off a bipod, given a shooter who knows how to drive one.

My interest stems from a few years back when I was more actively interested in NRA XTC High Power Rifle competition... had an interesting discussion with a fellow who knew a fellow (yes, one of those stories) who was the armorer for the local Guard team... and happened to have access to a full-on machine rest that they used for accuracy testing the team rifles (previously M14s, by then M16s). The topic was that despite most people's claims of their rifle shooting 'quarter minute' - or even half minute - 'all day long', reality showed that surprisingly *few* rifles would really put every round inside a minute over a longer string of fire, say 50-60 consecutive rounds (leaving aside windage for the moment). Supposedly they'd strapped in a few full-meal-deal 'Match' Rifles (think Tubb 2000, etc.) as well, and they didn't do as much better as one might expect.

After that... I've been kind of itching to get ahold of a 'machine rest' of some kind and take a gun & load that is a 'known good' performer... and see how it compared, even just in shorter strings of fire - say 10 or 20 rounds. Someday, when I've run out of other things to spend money on, I suppose

Monte

 

[BigDMT]

I've been told by some of the current 10 shot 1000 yard BR world record holders (Leo Anderson and Tom Mousel) that if a rifle is too heavy in the front, it will vertically string rounds as well. If the vertical stringing re-appears in the future, it might be worth making sure the rifle is properly balanced by adding some weight to the rear of the stock to counteract the weight of the 30" barre in the front.

Looks like the rest was the issue, but if for some reason the stringing comes back it might be worth a try. take care.