Velocity and recoil and their effects on accuracy. Please educate me.

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keithherrington

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Ignoring for the moment the shooter's sensitivity to recoil what are the effects of velocity and therefore recoil on accuracy? Asked differently, do two guns with the same mechanical accuracy, shoot differently if one recoils substantially more than the other?

Taking it one step further, do you ignore velocity entirely and look for the very best load, or does a higher velocity that limits the effects of wind on the bullet play into your thinking?

Do these considerations impact 100/200 group shooting differently from score shooting at 600? Intuitively, I think it should but would like your opinions on these questions.

What prompted my question was a brief comparison of 30BR to 308. The bullet weight/design in each (e.g., 125 flat base vs 168 Match King) was the first to jump out at me as was the barrel twist for each.

Keith
 
keithherrington said:
Taking it one step further, do you ignore velocity entirely and look for the very best load, or does a higher velocity that limits the effects of wind on the bullet play into your thinking?



Keith
Click to expand...

Velocity is only one consideration for a accurate load and here's why.

Benchrest shooters in the 600/1000 yard game generally try to stay in the 2900-2975 fps range BECAUSE that is where they generally find best stability for VLD (long) bullets fired from fast twist (8-10:1) barrels.

Benchrest shooters in the short range game who shoot bullets made in .750-.825" length jackets and shoot them in slower twist barrels (13-14.5:1)
have over billions of firings normally look to be in the 3100-3400 fps range. Mostly 13.5-14:1 barrels.

Nothing magic here just from tons of effort to get to the ZERO group.

As to wind effect, theoretically, the quicker the bullet gets to the target the less the wind will bias it. In actuality bullet stability has significant effect. i.e. Longtime benchrest shooter and bullet maker Walt Berger says that the sooner a bullet becomes stabilized (goes to sleep) the less the wind will effect it. Makes sense to me. I have been in situations where a bullet in the 3150 fps range "seemed" to have less wind drift than my traditional 3350 fps load. At this recent Shamrock, sometimes I was at about 3460 fps to try to beat the wind. I shot some great 4 shot groups at 200 only to have one jump out. Did it jump out because it was overspun (about 220,000 rpm) or did I miss a flag? Couldn't really test this though since that dastardly wind never stayed the same.

You, being a new benchrest shooter, keep in mind, there is no magic plug-and-play solution to maximum accuracy.

.
 
I would say that in and of itself, recoil is a factor, not just because of shooter sensitivity, but because, at a given weight, the more violent the recoil, the greater chance that the rifle will duplicate its motion from shot to shot. This can be partially compensated for by shooting style, but I think that at a given level of recoil, that it will always be true that heavier guns are easier to manage consistently than lighter ones. I think that rifle class weight limits have been established in recognition of this, and that caliber choice within those weight limits is also influenced by it. For a given caliber and bullet weight, heavier rifles are easier to shoot than lighter ones, and holding weight constant the same can be said of larger calibers and heavier bullets vs. smaller ones with lighter bullets. As distances get longer, wind drift complicates the choices and tradeoffs are commonly made in recognition of the fact that matches are shot in real world conditions that usually involve wind, and that while a given combination may have superior no wind accuracy, that as a practical matter this is entirely lost in the conditions between the the shooter and target, while an advantage in wind drift is not.
 
Recoil is one of the important parameters

We know that what the rifle does under recoil while the bullet is still in the barrel is important. Not to put too fine a point on it, while the bullet is in the barrel, the muzzle is changing its position as well as the direction it is pointing, ever so slightly. The position and direction are influenced by how the wood/plastic stock moves in the leather/fabric surface of the bags for the HV/LV rifles. There is likely some shot to shot variation in spite of good bench technique, and that variation is amplified when the movement of the rifle is increased. The .20 VT moves about half what the 6ppc does, and 1/3 as much as the 30 BR does.

Harold
 
speed

I don't see velocity as being a true indicator. Recoil makes it harder to shoot a gun consistently, and in a compeition where many shots are required chances for a mistake from recoil are increased as fatigue takes over. But a small caliber bullet in a very light bullet weight can go very fast and not hinder the shooter. But the ability to overcome wind is lost on the smaller bullet. There is no free lunch. Many years ago I thought that copper bullets would be the free lunch, but they are not in their form today, maybe some day.
 
Thanks for the offer

dalewoolumjr said:
Keith, Looks like your pretty close I'm over in Charlottesville. If you want to try a 30br or 6ppc you can shoot mine. I'm a member out at Piedmont and Rivanna we could meet at either club. My email dale@woolumsaccuracy.com

Dale Woolum Jr.
Click to expand...


Dale,
I'm a member of Rivanna and would prefer to meet there if that is OK with you. I'm retired and can meet you almost any time except Thursdays. Monday, Weds or Friday work best. Thanks for the offer and look forward to getting together with you.
Keith
keith.herrington@aol.com
 
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