Ollin Magnetic Digiscoping System

Need advice on accuracy

nidahunter

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Sep 16, 2010
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North Idaho
I am currently reloading for my Tikka in 7mm08 and my Winchester model 70 .270. I have tried multiple powders and charges, and using accubonds for both. I bench shoot from a lead sled with the barrel strapped to the rest. The best group I can get from either is about 1.5 inches at 100 yards. My question is this: could the use of the lead sled be affecting accuracy, and would I be better off shooting off of sand bags? I cannot believe I can't do better, especially with the Tikka. I even shot factory ammo from the Tikka and had the same results. Any advice?
 
I wouldn't advise strapping the barrel down to the rest. Any un-natural pressures on the barrel can dramatically effect barrel whip and barrel dynamics. If nothing else, pressure on the barrel will effect point of impact.

The best group I've ever shot were off something like a lead sled, but with the forearm simply resting on the front bag. After a fouling shot, I put 3 8mm accubonds into a single hole that was .445" at the widest point. This is from a rifle that will shoot 1/2 groups any day the nut behind the trigger is functioning properly... I no longer shoot off this rest, but that's for other reasons.

Were I in your shoes, I'd start looking at options to shoot off sandbags, or a bipod with a rear support. I do all my range shooting anymore from the prone off a bipod with a rear support, which happens to be the same position I take 90% of my shots at game from.

In my mind, the issue isn't the lead sled; it's the barrel strapped to the rest and the un-natural pressures caused by this.

I would not recommend shooting any rifle with the barrel secured to the rest.
 
1. Remove the strap
2. What is your trigger pull weight? Get it to 3lbs or less if you can, without creep.
3. Have you established ideal seating depth?
4. Have you established ideal charge?
5. Have you checked bullet/case runout?
6. Are you using single headstamp cases from consisten lots?
7. Have you bedded the rifles?

There's always something to improve upon, I'd start with the least intrusive and remove the strap, and adjust trigger pull. From there I'd look to bed the rifle and play with seating depth.
 
Thanks for the advise, I will load up some more and try it from bags. The factory ammo was Fusions and it wouldn't group from the sled either.
 
If it's a factory rifle with no mods, that may be as good as you're going to get.

In addition to the above advice:

1. Make sure you are letting the rifle cool down between shots.
2. Check your bullet seating depth. Your bullet should not be more than .001" off the lands and grooves.
 
2. Check your bullet seating depth. Your bullet should not be more than .001" off the lands and grooves.

Completely disagree, I would start there (assuming you aren't using monos) and work backwards to find the "node". There are general rules, but every rifle is different and you have to experiment.

The image below are Bergers which are recommended to be touching the lands, but actual results tell a different story.

338LMtest001JPG.jpg
 
Those Tikka rifles will generally produce groups of less MOA at 100yds.

As said above, Nothing should be touching the barrel when a round is fired.

How far off the lands are you? Ive been able to always get accubonds to shoot in just about all rifles.. .010 is a good starting point in general.

My favorite rifle will hold 1/2 MOA to 600yds(max for my range) at .100 off the lands. Murphy likes to prove the norm wrong.....

Practice practice practice.
 
Completely disagree, I would start there (assuming you aren't using monos) and work backwards to find the "node". There are general rules, but every rifle is different and you have to experiment.

The image below are Bergers which are recommended to be touching the lands, but actual results tell a different story.

338LMtest001JPG.jpg

I agree with this, Berger used to recommend to shoot off the lands. Right now I am working up a load with 168's out of my 30-06 and Berger actually sent me some recommendations and said when testing to Jump shoot the VLD's, starting from that lands all the way out to .120 off the lands. So far I have had the best results at .080 off the lands and am Sub MOA but still have some fine tuning to go. I am now going to start adjusting by smaller increments until I get the very best group and then try to play with the powder from there.

I appreciate the above pictures, it looks like even .005 adjustment had good results. I started at by making .040 adjustments and Berger says there is a .030 sweet spot where they tend to shoot the best, they suggest even a .002 adjustment is meaningful once you are getting close.

To the OP I would make sure to unstrap the rifle and shoot off of bags, every shot should be fired relaxed IMO and they trigger should be slowly squeezed. I personally like to have a surprise shot each time while bench shooting. If I am anticipating the shot than I am pulling the trigger too fast or too hard. Just lock the cross hairs on the target and slowly pull while concentrating on the cross hairs. Try to have a similar cheek rest each shot and also have consistent shoulder pressure. I think the lead sled should work fine if you un-tie the barrel. You can also pull the action and shim the front up with a thin washer to float the barrel to see if that is causing you grief.
 
This is copied and pasted right from Bergers web site. I am sure this is true for more than just the Berger VLD's, and could be a useful technique for any new load. Defiently worth re-posting and reading.

Getting The Best Precision And Accuracy From VLD Bullets In Your Rifle
Posted April 8, 2009
Background
VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle. It can be difficult to get the VLD to group well (poor accuracy).
For years we encouraged shooters to use a base of cartridge to end of bearing surface OAL (I will use the term COAL to represent this dimension) which allows the VLD to touch the rifling or to be jammed in the rifling. This provided excellent results for many shooters but there were others who did not achieve top performance with the VLD jammed in their rifling. These shooters were left with the belief that the VLD bullets just won’t shoot in their rifle.
Other groups of shooters were discouraged by our recommendation to touch the rifling. Some of these shooters knew that at some point during a target competition they will be asked to remove a live round. With the bullet jammed in the rifling there was a good chance the bullet will stick in the barrel which could result in an action full of powder. This is hard on a shooter during a match.
Yet another group of shooters who were discouraged by our recommendation to touch the rifling are those who feed through magazines or have long throats. Magazine length rounds loaded with VLDs could not touch the lands in most rifles (this is the specific reason that for years we said VLD bullets do not work well in a magazine). When a rifle could be single fed but was chambered with a long throat a loaded round that was as long as possible still would not touch the rifling.
Until recently, shooters who suffered from these realities were believed to be unable to achieve success with VLD bullets. Admittedly, we would receive the occasional report that a rifle shot very well when jumping the VLD bullets but we discounted these reports as anomalies. It was not until the VLD became very popular as a game hunting bullet that we were then able to learn the truth about getting the VLD bullets to shoot well in a large majority of rifles.
After we proved that the Berger VLD bullets are consistently and exceptionally capable of putting game down quickly we started promoting the VLD to hunters. We were nervous at first as we believe the VLD needed to be in the rifling to shoot well and we also knew that most hunters use a magazine and SAMMI chambers. Our ears were wide open as the feedback was received. It was surprising to hear that most shooters described precision results by saying “this is the best my rifle has ever shot.”
We scratched our heads about this for awhile until we started getting feedback from hunters who were competition shooters as well. Many were the same guys who were telling us for years that the VLDs shoot great when jumped. Since a much larger number of shooters were using the VLD bullets with a jump we started comparing all the feedback and have discovered the common characteristics in successful reports which gave us the information needed to get VLD working in your rifle. We were able to relay these characteristics to several shooters who were struggling with VLD bullets. Each shooter reported success after applying our recommendation.

Solution
The following has been verified by numerous shooters in many rifles using bullets of different calibers and weights. It is consistent for all VLD bullets. What has been discovered is that VLD bullets shoot best when loaded to a COAL that puts the bullet in a “sweet spot”. This sweet spot is a band .030 to .040 wide and is located anywhere between jamming the bullets into the lands and .150 jump off the lands.
Note: When discussing jam and jump I am referring to the distance from the area of the bearing surface that engages the rifling and the rifling itself. There are many products that allow you to measure these critical dimensions. Some are better than others. I won’t be going into the methods of measuring jam and jump. If you are not familiar with this aspect of reloading it is critically important that you understand this concept before you attempt this test.
Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).
Trying to find the COAL that puts you in the sweet spot by moving .002 to .010 will take so long the barrel may be worn out by the time you sort it out if you don’t give up first. Since the sweet spot is .030 to .040 wide we recommend that you conduct the following test to find your rifles VLD sweet spot.
Load 24 rounds at the following COAL if you are a target competition shooter who does not worry about jamming a bullet:
1. .010 into (touching) the lands (jam) 6 rounds
2. .040 off the lands (jump) 6 rounds
3. .080 off the lands (jump) 6 rounds
4. .120 off the lands (jump) 6 rounds
Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:
1. .010 off the lands (jump) 6 rounds
2. .050 off the lands (jump) 6 rounds
3. .090 off the lands (jump) 6 rounds
4. .130 off the lands (jump) 6 rounds
Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well (even at 100 yards).
Regards,
Eric Stecker
Master Bulletsmith
 
This is copied and pasted right from Bergers web site. I am sure this is true for more than just the Berger VLD's, and could be a useful technique for any new load. Defiently worth re-posting and reading.

Getting The Best Precision And Accuracy From VLD Bullets In Your Rifle
Posted April 8, 2009
Background
VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle. It can be difficult to get the VLD to group well (poor accuracy).
For years we encouraged shooters to use a base of cartridge to end of bearing surface OAL (I will use the term COAL to represent this dimension) which allows the VLD to touch the rifling or to be jammed in the rifling. This provided excellent results for many shooters but there were others who did not achieve top performance with the VLD jammed in their rifling. These shooters were left with the belief that the VLD bullets just won’t shoot in their rifle.
Other groups of shooters were discouraged by our recommendation to touch the rifling. Some of these shooters knew that at some point during a target competition they will be asked to remove a live round. With the bullet jammed in the rifling there was a good chance the bullet will stick in the barrel which could result in an action full of powder. This is hard on a shooter during a match.
Yet another group of shooters who were discouraged by our recommendation to touch the rifling are those who feed through magazines or have long throats. Magazine length rounds loaded with VLDs could not touch the lands in most rifles (this is the specific reason that for years we said VLD bullets do not work well in a magazine). When a rifle could be single fed but was chambered with a long throat a loaded round that was as long as possible still would not touch the rifling.
Until recently, shooters who suffered from these realities were believed to be unable to achieve success with VLD bullets. Admittedly, we would receive the occasional report that a rifle shot very well when jumping the VLD bullets but we discounted these reports as anomalies. It was not until the VLD became very popular as a game hunting bullet that we were then able to learn the truth about getting the VLD bullets to shoot well in a large majority of rifles.
After we proved that the Berger VLD bullets are consistently and exceptionally capable of putting game down quickly we started promoting the VLD to hunters. We were nervous at first as we believe the VLD needed to be in the rifling to shoot well and we also knew that most hunters use a magazine and SAMMI chambers. Our ears were wide open as the feedback was received. It was surprising to hear that most shooters described precision results by saying “this is the best my rifle has ever shot.”
We scratched our heads about this for awhile until we started getting feedback from hunters who were competition shooters as well. Many were the same guys who were telling us for years that the VLDs shoot great when jumped. Since a much larger number of shooters were using the VLD bullets with a jump we started comparing all the feedback and have discovered the common characteristics in successful reports which gave us the information needed to get VLD working in your rifle. We were able to relay these characteristics to several shooters who were struggling with VLD bullets. Each shooter reported success after applying our recommendation.

Solution
The following has been verified by numerous shooters in many rifles using bullets of different calibers and weights. It is consistent for all VLD bullets. What has been discovered is that VLD bullets shoot best when loaded to a COAL that puts the bullet in a “sweet spot”. This sweet spot is a band .030 to .040 wide and is located anywhere between jamming the bullets into the lands and .150 jump off the lands.
Note: When discussing jam and jump I am referring to the distance from the area of the bearing surface that engages the rifling and the rifling itself. There are many products that allow you to measure these critical dimensions. Some are better than others. I won’t be going into the methods of measuring jam and jump. If you are not familiar with this aspect of reloading it is critically important that you understand this concept before you attempt this test.
Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).
Trying to find the COAL that puts you in the sweet spot by moving .002 to .010 will take so long the barrel may be worn out by the time you sort it out if you don’t give up first. Since the sweet spot is .030 to .040 wide we recommend that you conduct the following test to find your rifles VLD sweet spot.
Load 24 rounds at the following COAL if you are a target competition shooter who does not worry about jamming a bullet:
1. .010 into (touching) the lands (jam) 6 rounds
2. .040 off the lands (jump) 6 rounds
3. .080 off the lands (jump) 6 rounds
4. .120 off the lands (jump) 6 rounds
Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:
1. .010 off the lands (jump) 6 rounds
2. .050 off the lands (jump) 6 rounds
3. .090 off the lands (jump) 6 rounds
4. .130 off the lands (jump) 6 rounds
Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well (even at 100 yards).
Regards,
Eric Stecker
Master Bulletsmith

For those that may not know, This is called Ladder testing for future reference.

Never straight up used this method, but i guess in most my load development I have in a round about way.
 
I think the rifle rests that reduce recoil promote poor shooting form. mtmuley
 
or just call it good. elk and deer are pretty big targets. in the real world 1.5 inch @ 100 yards is good 'nuff. (Yeah, I just wrote that to make trouble.)
 
I doubt you will get close to the lands if you are loading rounds to clip length in the Tikka. I am 120 off in my 7 mag and the hunter classics shoot just fine!! You can swap the bolt stop out or alter it and switch to a 3006 mag and have the room to seat your bullets long in your clip. This should get you close. Run some ladders and find the node. Good luck and keep us posted!!
 
or just call it good. elk and deer are pretty big targets. in the real world 1.5 inch @ 100 yards is good 'nuff. (Yeah, I just wrote that to make trouble.)
I'm not trying to make trouble and I whole heartedly agree! Unless you are shooting way past MPBR 1.5" is more than sufficient for big game. That said, a 1.5" group while strapped to a lead slead may or may not, and I'd bet on the latter, shoot the same as from a typical field position in either group size or point of impact...
 
I think the rifle rests that reduce recoil promote poor shooting form. mtmuley

...and un-bruised shoulders, which aids in accuracy.

I get good accuracy from ABs at factory COAL. I believe that your problem is the barrel being strapped down. Try to concentrate on holding the rifle in the same manner as you would in the field. Anything touching the barrel is a no-no. Your groups are not all that bad considering the barrel was strapped down.

I love my lead sled. I am not recoil sensitive, but it allows me to shoot as many rounds as needed through my 7 mags without starting to flinch and getting a sore shoulder. I shoot sub-half-minute groups off mine with regularity. They are a solid rest even if recoil is not an issue. If anything, they promote good field accuracy, because it allows you to use good trigger control etc. and develop confidence without getting pounded. Recoil is not an issue in the field anyway.
 
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