Trajectory validation off bench or prone ?

[Tyler Holderby]

Hey fellas, two times now I have shot my 500 yd validation. My first cold bore shot/group had been shot on paper with one low then a group above, off the bench, I have also shot groups after this in the prone position at a gong. I get great groups at the gong. So my question is, is the low shot cold bore? Or Is it because the rifle is in rest and it constricts the rifle jump as I let it free recoil. Gun is 300 rum sendero these are hand loads well under .5 moa..or can there be that much difference between hot/ cold bore shots. I guess Next time I can try the cold bore prone off the gong for a group validation. Thanks for advice in advance!

 

[royinidaho]

It shouldn't make any difference between bench and prone IF everything is solid. Do your cold/hot bore test and see what happens.

 

[SBruce]

+1,

Check the cold bore long distance zero from prone first.

2nd, I've personally noticed very very little difference between bench drops and prone drops with my VSSF at 500 yds (short action version of the Sendaro) but it's in a 22-250, not a 300RUM. Major recoil difference.

On the other hand, I do see a difference in my lightweight sporter 25-06 drops between bench and prone; but again, different initial recoil.

 

[C.O. Shooter]

In the most recent episode of long range pursuits, Aaron Davidson, was doing this same thing. However on a bench, he was using a bench rest in the front and a rear bag. When shooting prone, he was using an atlas bipod with rear bag. I'm not certain if this is what you are doing, but his shots were about a .25 moa difference.

 

[Tyler Holderby]

In the most recent episode of long range pursuits, Aaron Davidson, was doing this same thing. However on a bench, he was using a bench rest in the front and a rear bag. When shooting prone, he was using an atlas bipod with rear bag. I'm not certain if this is what you are doing, but his shots were about a .25 moa difference.

I'm shooting mine off the bench in a lead sled - I would think even more drastic changes than how u described Aaron Davidson shooting. Thanks fellas I'm hoping to shoot tonight cold bore prone and report back!

 

[TannerGun]

I'm thinking you'd be crazy to do drop checks from any position other than the one you use most often hunting.

 

[COBrad]

I'm with Tanner on this one. I do all my range validation off a bipod with a small, light bag under the butt of the gun, and then I use this same set-up for long range hunting. I would definitely expect different results from a lead sled. It does not recoil the same as my body does. I have done quite a bit of longer range shooting off a pack with my left fist under the butt in place of the bag. This has worked great on small varmints out to 700 plus, and is what I usually have available when I'm hunting big game.

 

[Tyler Holderby]

I'm with Tanner on this one. I do all my range validation off a bipod with a small, light bag under the butt of the gun, and then I use this same set-up for long range hunting. I would definitely expect different results from a lead sled. It does not recoil the same as my body does. I have done quite a bit of longer range shooting off a pack with my left fist under the butt in place of the bag. This has worked great on small varmints out to 700 plus, and is what I usually have available when I'm hunting big game.

Thanks fellas, did some shooting last night 500 yd first shot in the 3 inch circle, second shot 3 in high of the first. I then backed up did a little more shooting they all seemed to be high, so tonight I'm going to try at 650yd cold bore in relation to the hot barrel shot last night at that distance to see the affect.

 

[kidcoltoutlaw]

Lead sled you can't hunt with it can you ? Maybe you can if it's in a field in your back yard. Be a robot and do everything the same for every shot as far as how you hold the gun . On some scopes all powers do not have the same POI,

Thanks,Keith

 

[Tyler Holderby]

I'm no longer shooting off a lead sled, the only time I have is at 500 and was asking for advice for my 500 yd validation thinking it would possibly be more precise for an input starting on my drop chart. I have found that's not the best to do. Last night my shots at 500 prone were great, now I'm going to start to back up the distance for my cold bore chart. Thanks again fellas

 

[COBrad]

Sounds like you are making great progress. 3" off your first shot is basically 1/2 MOA at 500. As was also stated, become a shooting robot. At long ranges, especially when you double the distance again out toward 1000, having correct body postion, head position on the stock, tension against the bipod, trigger pull, follow through, you get the picture, become critical. The more correct and consistent these things are, the better and more consistent you will shoot.