Horizontal in load development

[Shootin4fun]

Interesting, I did not think about all the energy being transferred to the rifle and scope. I just imagined that's the only way to really stabilize the rifle on a led sled so that every shot is really the same. I've never resorted to all of what I suggested because I just found the sled to be another variable to manage. At the end of the day you have to make everything totally consistent any way you go.

 

[Roninco]

I bought one some years back. I don't use it much for shooting because it divorces you from the shot so much and there are other factors such as getting the same sight picture each time. If you're really going to depend on it for load development, then you must tie the rifle down to it and put as much weight on it as possible and perhapsss a backstop so that it does not move at all when firing. Then get your sight picture perfect, then stand off to the side and pinch the trigger or use some kind of mechanical trigger detonator. That's the only way I can see it being used to zero out the effects of variance in the shooter's actions.

At the very least this will result in a point of impact that is not the same when shooting without the sled. The more you weigh the sled down the more recoil is transferred to the stock through the recoil lug and action screws. These are best used for gun cleaning vises...... or boat anchors.

 

[Patriot007]

I'm hopefully going out to test more with the crony, my best node., it was 5/8 vertical at 300 and around 1-1/2 vertical at 500. Everything else was wide up the powder range. I can't wait to go if the wind would calm !!

If your getting good consistent ED & SD, & Velocity. I would really be looking at the wind. Me, I would take the horizonal stringing over the vertical stringing any day, as far as tuning my loads. just my discipline in tuning a load for set distances.

 

[Pdvdh]

So 308 175mk 41-42 grs of imr 4064, coal 2.800. At 500 yards the vertical is 1-1/4 inch spread, that's the best node, but my horizontal is 3-4 inches. So I'm still doing load development, but I'm wondering will shortening coal help horizontal dispersion? I can't go longer due to mag length. Also what's a good increment to decrease at a time?

The only thing your gun and that load need, is to be shot.

 

[Patriot007]

What rifle did you have and what twist barrel

Thanks, I see I left that out of the spread sheet. 1:8 twist . I bought the barrel and Action from Brownells.
It is a,,, Howa 1500 6.5CM 26" BBL 1:8 twist with a ZERODELTA 4 port muzzle break. The barrel and action came with a factory warranty of SUB-MOA. with factory ammo. Yes, I know, give me a break. lol. I'm glad to say that I do not feed it factory any thing. She's, rather spoiled and gets a healthy diet and never disappoints. I'm the weakest link in our relationship.

 

[swampbug]

I got one of these too, but yet to put it together.

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Video

Sleds are nice for certain purposes but remember that your POI/group size will almost certainly change once you go back to prone or bench off a bipod/bags.

 

[DJ Fergus]

Go in towards the lands to decrease horizontal. Once you go to far in, vertical will increase.

I've saw it happen both ways. At times I've had vertical & getting closer to the lands gave less vertical. More horizontal if I got too close.

 

[Slick8]

I say retest at 300 yards with a very calm to no wind. You can call this your baseline and start adjusting from their.

Imo-at 500 yards and the wind you had was just a little too much to call it a baseline for fine tuning.

When fine tuning i like to do all my work at 300 in as perfectly calm conditions as possible. I shoot at a private range so I can set up in the pre-dawn light and be ready to shoot as soon as visibility allows. This does nothing for my ability to shoot in the wind but is the best way to test and fine tune.

 

[the big greasy]

So went today shooting, I'm kinda mad about it, from 41.2 to 41.8 5 shot groups were around 5-6 spread out all over. 42.0 3 inch vertical, 3 in a line, one 1.1/4 high, and one 3 inch high. 42.2 was 2 tight together, 2 together 2 inches lower, and one shot 2.5 lower yet. So I'm thinking of trying 42.1 and play with seating depth now.

42.0 34 fps extreme spread, average velocity was 2526

42.2 56 extreme spread, average velocity was 2546

I'm going to try shooting prone next time also

 

[Patriot007]

So went today shooting, I'm kinda mad about it, from 41.2 to 41.8 5 shot groups were around 5-6 spread out all over. 42.0 3 inch vertical, 3 in a line, one 1.1/4 high, and one 3 inch high. 42.2 was 2 tight together, 2 together 2 inches lower, and one shot 2.5 lower yet. So I'm thinking of trying 42.1 and play with seating depth now.

42.0 34 fps extreme spread, average velocity was 2526

42.2 56 extreme spread, average velocity was 2546

I'm going to try shooting prone next time also

I would get the extreme spread down a little tighter, say in the teens and single digit SD.
Shall I say, start with a known seating depth that you know the rifle likes, work your powder load up until your
SD & Ed are low.,, " ED-Teens/SD-single digits" with the average as close to max with no sings of pressure, then work on seating to close your group. Do this at 100 or 200yds for load data testing. Preferably 100yds first. When you achieve the smallest group, you can achieve.( With low SD & ED) Then Take it out 200yds and work on the group size by adjusting your seating depth.. Once you do this, you will under stand more about what is happening out at 500yds and beyond. I promise.

 

[the big greasy]

I had my extreme spread Down to 13 fps with 41.6, but my group was terrible.

 

[Patriot007]

I had my extreme spread Down to 13 fps with 41.6, but my group was terrible.

Sir, unless your showing signs of high pressure. That's the load you want to start your seating test at. By moving that bullet in our out will close that group up.,,,,, Extreme spread of 13, your SD had to be single digit. Work this load up at 100yds on paper by adjusting your seating to close that group up. I would work in towards the lands,, And watch your jam measurement. Work in .002 increment's.,, If this fails, go the other direction. If this fails you. Drop me a line and I will reimburse you my Tech fee's.

 

[the big greasy]

Ok, I can only go shorter just because the box mag won't allow longer. I will try that, thanks! I hope it works I hate load developing !

 

[QuietTexan]

You could go longer and single feed just for testing. If you get what you want single feeding, then you know it's the load and not the wind. Better to get a firm answer than miss out because of an arbitrary restriction.

It's not impossible to lengthen a box mag, especially in a Rem footprint.