Torque testing
- Thread starter SPACEFORCE
- Start date
This can make a noticeable difference in compressible stocks, i.e. wood or plastic, but it doesn't always. The differences can also be too small to notice. When you're dealing with metal it becomes incredibly difficult to tell if it makes any difference whatsoever. That's why pillar bedding is a thing, and that will also apply to a metal chassis. Before I pillar bedded my rifles I would do this and there would indeed be a sweet spot for my rifles. But once I pillar bedded them it no longer seemed to matter. I just go with 22-inch-lbs. now just for the sake of having a nice, snug value that I'll repeat whenever things are taken apart and put back together. But the actual value doesn't seem to matter much anymore.
TLDR: Don't waste your time.
TLDR: Don't waste your time.
That's what I said, if worded clumsily. Hence "Don't waste your time."
50 yards
50 shots RWS best group was 0.79 MOA
50 shots Eley semi auto benchrest outlaw best group 1 MOA
20 shots CCI SV 20 in-lbs best group 1 MOA
40 shots CCI SV 30 in_lbs best group 0.54 MOA
10 shots CCI SV 35 in-lbs best group 1.5 MOA
10 shots CCI SV 25 in-lb best group 1.2 MOA
My gun prefers SK standard plus typically and gets clover leaf groups at 50 yards but I'm out of it.
Cherry picking one group out of a ton of shots isn't exactly the best way to get any meaningful idea of what's going on. If you're talking about 5-shot groups your confidence window for that is huge. The actual answer can be +/- 40% of that figure for that one group. It is too broad a range to be useful in determining anything. If you took a practice ARA target (which is 25 shots) and shot it for one setting, and did the same with every other setting you tested, you're still looking at an confidence window of about +/- 17% for each setting. Shoot two of them per setting (50 shots) and that'll get you down to about +/- 12%. And you must count every single shot in those 25 or 50 shot batches as a single group in order to do so. Separating them into 5-shot groups and picking the best one of the bunch, ignoring the rest, just makes the water incredibly muddy. It makes it hard to see the answer at all. You have to consider all shots.
That 5-shot group that's 1 MOA could indicate that the actual mean result for that ammo in that rifle is anywhere from 0.6 MOA to 1.4 MOA, and that's the best you can say given that single 5-shot group. And for that 0.54 MOA group the actual mean result could be anywhere from 0.324 MOA to 0.756 MOA. That confidence window overlaps with the 1 MOA group's confidence window, as the low end from one, 0.6 MOA, is less than the high end from the other, 0.756 MOA. That means you cannot really say they differ at all. The confidence in each answer is too low to say they differ. They overlap. Even the 1.2 MOA group's confidence window overlaps with the 0.54 MOA's window. Really, you can only say the 1.5 MOA group likely belongs to a different category because it is the only one where its confidence window doesn't overlap with the 0.54 MOA group's window, as the low end of its window is around 0.9 MOA, which does not overlap with 0.756 MOA.
So what's that all mean? You probably need to at least shoot 50 shots per setting to get confidence windows small enough to begin differentiating, to begin being able to tell if one setting is actually better or worse than another. And you must count every shot, not just the best 5. But even at that, +/- 12% might not be enough to tell, as it might still give you enough overlap to screw the pooch. But it would certainly give you a better chance at differentiation than looking at a single 5-shot group. Depending on how close things actually are at 50 shots, it might work out ok. If things still overlap even with 50 shots it can get pretty expensive to better test pretty quick, as jumping up to 100 shots per setting only brings that confidence window down to around +/- 8%. Burn through a whole brick of 500 for every setting and you're still looking at +/- 3.6%, so, yeah, it takes a LOT of shots in order to really tell what's going on.
Judging by a single 5-shot group is just a shot in the dark, so to speak.
That 5-shot group that's 1 MOA could indicate that the actual mean result for that ammo in that rifle is anywhere from 0.6 MOA to 1.4 MOA, and that's the best you can say given that single 5-shot group. And for that 0.54 MOA group the actual mean result could be anywhere from 0.324 MOA to 0.756 MOA. That confidence window overlaps with the 1 MOA group's confidence window, as the low end from one, 0.6 MOA, is less than the high end from the other, 0.756 MOA. That means you cannot really say they differ at all. The confidence in each answer is too low to say they differ. They overlap. Even the 1.2 MOA group's confidence window overlaps with the 0.54 MOA's window. Really, you can only say the 1.5 MOA group likely belongs to a different category because it is the only one where its confidence window doesn't overlap with the 0.54 MOA group's window, as the low end of its window is around 0.9 MOA, which does not overlap with 0.756 MOA.
So what's that all mean? You probably need to at least shoot 50 shots per setting to get confidence windows small enough to begin differentiating, to begin being able to tell if one setting is actually better or worse than another. And you must count every shot, not just the best 5. But even at that, +/- 12% might not be enough to tell, as it might still give you enough overlap to screw the pooch. But it would certainly give you a better chance at differentiation than looking at a single 5-shot group. Depending on how close things actually are at 50 shots, it might work out ok. If things still overlap even with 50 shots it can get pretty expensive to better test pretty quick, as jumping up to 100 shots per setting only brings that confidence window down to around +/- 8%. Burn through a whole brick of 500 for every setting and you're still looking at +/- 3.6%, so, yeah, it takes a LOT of shots in order to really tell what's going on.
Judging by a single 5-shot group is just a shot in the dark, so to speak.Ok so 500 rounds with one specific ammo and one specific torque setting in groups of 20 shots per 25 targets? to get somewhat of an idea,Cherry picking one group out of a ton of shots isn't exactly the best way to get any meaningful idea of what's going on. If you're talking about 5-shot groups your confidence window for that is huge. The actual answer can be +/- 40% of that figure for that one group. It is too broad a range to be useful in determining anything. If you took a practice ARA target (which is 25 shots) and shot it for one setting, and did the same with every other setting you tested, you're still looking at an confidence window of about +/- 17% for each setting. Shoot two of them per setting (50 shots) and that'll get you down to about +/- 12%. And you must count every single shot in those 25 or 50 shot batches as a single group in order to do so. Separating them into 5-shot groups and picking the best one of the bunch, ignoring the rest, just makes the water incredibly muddy. It makes it hard to see the answer at all. You have to consider all shots.
That 5-shot group that's 1 MOA could indicate that the actual mean result for that ammo in that rifle is anywhere from 0.6 MOA to 1.4 MOA, and that's the best you can say given that single 5-shot group. And for that 0.54 MOA group the actual mean result could be anywhere from 0.324 MOA to 0.756 MOA. That confidence window overlaps with the 1 MOA group's confidence window, as the low end from one, 0.6 MOA, is less than the high end from the other, 0.756 MOA. That means you cannot really say they differ at all. The confidence in each answer is too low to say they differ. They overlap. Even the 1.2 MOA group's confidence window overlaps with the 0.54 MOA's window. Really, you can only say the 1.5 MOA group likely belongs to a different category because it is the only one where its confidence window doesn't overlap with the 0.54 MOA group's window, as the low end of its window is around 0.9 MOA, which does not overlap with 0.756 MOA.
So what's that all mean? You probably need to at least shoot 50 shots per setting to get confidence windows small enough to begin differentiating, to begin being able to tell if one setting is actually better or worse than another. And you must count every shot, not just the best 5. But even at that, +/- 12% might not be enough to tell, as it might still give you enough overlap to screw the pooch. But it would certainly give you a better chance at differentiation than looking at a single 5-shot group. Depending on how close things actually are at 50 shots, it might work out ok. If things still overlap even with 50 shots it can get pretty expensive to better test pretty quick, as jumping up to 100 shots per setting only brings that confidence window down to around +/- 8%. Burn through a whole brick of 500 for every setting and you're still looking at +/- 3.6%, so, yeah, it takes a LOT of shots in order to really tell what's going on.
LOL touch crazy
I have the same chassis for my 457. I found no difference in group size at different torque setting. Wasting your time and risk stripping the bolts. Set for 25 -30 ft/lb or CZ recommended torque setting and play with head space instead with either barrel or bolt shims. I have a lilja barrel so I'm able to play with barrel shim for headspace.
Have fun down in the rabbit hole.
I've got bolt shims ordered so thats the next tweak.
I'm going to set to 30lb in-lb only fired a few at 35in-lb and the gun felt too tight in the receiver might actually go 28lb
Just a Q - Are you using a calc program to get these measurements? IMO using MOA is a 'general' measurement at such close ranges. I measure my groups with a caliper and record to 'thousandths'. MOA in inches is 0.5235", 0.79-MOA = 0.4135, etc. I just find 'inches' more definitive, JMO.
BTW, I also found SK+ very accurate in my VMTR in OEM stock, and I'm 'out' too. Now using SL-RM as I have a good supply of a couple Lots. I've been running torque at ca 16-ip and plan to run a 'wider' torque-range test this Summer. On 'good days' (wind permitting), I get groups in the 0.3xx"s.
BTW, I also found SK+ very accurate in my VMTR in OEM stock, and I'm 'out' too. Now using SL-RM as I have a good supply of a couple Lots. I've been running torque at ca 16-ip and plan to run a 'wider' torque-range test this Summer. On 'good days' (wind permitting), I get groups in the 0.3xx"s.
To be honest wasn't sure which measurement was more typical to post but I do both calipers to get inches and threw it into Grok to convert to MOA
The calipers in inches sounds better 5 shot group E 0.24 W 0.5
- Location
- Nova Scotia
Most typical is just the OD of the 2 farthest apart shots, subtracting the bullet diameter for CTC measurement.
Really don't do width and length.
Which ever method you use stay consistent with that method because all you're doing is logging your personal best. If you're going to post online your results than pictures are the way to go and let your audience decide. If your competing in some postal match than use the method in the postal match rules.
For my target practice I use 65 lb card stock paper I got off Amazon. I Measure OD and minus 0.224".
If you use cardboard try to stay with one type. I like to use the boxes from Amazon and I have lots of them.
- Location
- Nova Scotia
Outside diameter
Center to Center.
Subtracting the bullet diameter. Will half the 2 furthest shots, giving you the CTC group size.
Rough sketch. But 0.28 would be the CTC group size.
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As The Roc said, 65# card-stock gives a 'more accurate' hole to measure, regular copy paper tears a lot and makes measurement less accurate if you're looking at thousandths or finer. As for bullet-hole size, I've measured many times on 65# and my VMTR gives me 0.219-.220 holes. Measurements are taken of the "Bullet-smear" around the edge of the hole, and a tiny margin of error likely exists, as well ( 0.0001-0.001 ?). The .224 is the "nominal size" of 22lr in USA-SAAMI calcs for manufacturers. The 'Actual' fired bullet will be less, or it wouldn't go thru the bore (depends on mfr's QC standards). And diff rifles will have diff bores, if only by a few ten-thousandths. Thus, each rifle's "hole size" should be checked, like annually or such. My VMTR has about 2500-3000 rounds (I'm 2nd owner) and so far still 'at or under 0.220. Attached is a pic of my 'most recent' 100-challenge target with the required 'caliper on target' pic, showing the 'outside-to-outside' measurement and my calc of the group size.
PS- Those 2-fliers really f-d my average. That group 'should have been' closer to 1" than 2"
PS- Those 2-fliers really f-d my average. That group 'should have been' closer to 1" than 2"
