20 thou of the Lands now what?

[diego-ted]

As most know I have just started reloading and am trying to find the best recipe for my rifle, 308 Tikka Vamint 23.5” barrel. After some trial and error, I have determined my rifle’s best accuracy is about 20 thousands off the lands. This is about 40 thousands longer then my magazine. Now I know I can load one at a time, however, I want to be able to chamber out of the magazine. Now I have been able to shoot .5 moa with Federal Match Gold 168 grain but so far have not developed a recipe that gets me there. So my question is, do I now forget about load development of the lands and just do ladder tests to develop a load that shoots at maximum mag length?

Secondly I tried to do a ladder test utilizing 20 rounds stepped from a Max load I have been shooting; however, the first 5 rounds with the lowest charge were no even on paper at 300 yards? Should I move up to 200 yards and start from there?

Diego

 

[M77Shooter]

Re: 20 thou of the Lands now what?

I think you should have started looking at powder first and then moved to seating depth.

If your first 5 where not on paper they must have been considerably slower than the last 15. I wouldn't worry about loading that slow, but that's just my opinion.

How did the ladder test look as shot?

 

[diego-ted]

Re: 20 thou of the Lands now what?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: M77 Shooter</div><div class="ubbcode-body">I think you should have started looking at powder first and then moved to seating depth.

If your first 5 where not on paper they must have been considerably slower than the last 15. I wouldn't worry about loading that slow, but that's just my opinion.

How did the ladder test look as shot? </div></div>

I know there are so many opinions on wheater to find the best powder first or seating depth. I have a powder that is shooting just a hair over 1/2 moa, so I figured I would try and tune it? As for the ladder test I aborted after the first five misses and decided to come and get some advice.

Diego

 

[Sr-WiNdTeCh]

Re: 20 thou of the Lands now what?

Sounds like Tikka wasn't the route to go?

 

[M77Shooter]

Re: 20 thou of the Lands now what?

I have a Sako A7 300wm with a similar problem (short magazine length with a long throat). I would just add some extra elevation or speed up the start of the ladder test. My 300 varied almost 10" vertical at 300 yards with my ladder test.

Sounds like your T3 is pretty capable.

 

[MALLARD]

Re: 20 thou of the Lands now what?

no stay at 300y , get a bigger target or figure a way to catch those rounds on paper. I would shoot ocw style test , 7-10 shots, instead of a ladder test if your trying to find your ideal seating depth. Have you tried shooting your sweet load seated to your magazine length ? i might back the charge down 1 grain (maybe even 2) and shoot three groups in .3 increments if you reduce the seating depth to fit your mag from your sweet load. The extreme solution is to modify your rifle and magazine to be able to feed the .040 longer rounds, you can do that , though i probably wouldnt.

 

[diego-ted]

Re: 20 thou of the Lands now what?

No I have not. I know my rifle love 20 thou off the lands, so I will work power types and charges to find the "Best overall recipe" the rifle likes. I then want, need to find the recipe that is going to give me FMG like results at 2.112 off the OGIVE, that is my max magazine length. I know it's out there because FGM does it!! Trying to find a like recipe is the challenge. I guess the trick will be to roll a bunch at mim charge then adjust elvation until I am on paper then work the test.

thx for the input

Ted

 

[colt933]

Re: 20 thou of the Lands now what?

Do you have a chronograph?

Take the velocity of your load at .020" jump, and duplicate that velocity with a lesser charge seated at magazine length. It'll probably be a few tenths of a grain lower.

 

[diego-ted]

Re: 20 thou of the Lands now what?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: colt933</div><div class="ubbcode-body">Do you have a chronograph?

Take the velocity of your load at .020" jump, and duplicate that velocity with a lesser charge seated at magazine length. It'll probably be a few tenths of a grain lower. </div></div>

Not yet, it's a sadd thing!! I plan on getting one soon, but in the mean time>>>>>>

diego

 

[kyreloader]

Re: 20 thou of the Lands now what?

If you want to load from magazine, not sure why you did an overall length test.

I would just load at maximum mag length and shoot an OCW test or ladder test to find your powder charge at that overall length. It doesnt matter what length from the lands your rifle shoots best if you want to shoot from a magazine. You can then do an OAL test going shorter in 5 thous increments from max mag length.

What powder, cases, and bullet weights are you using? If you let us know that, we can likely get you in the ballpark to help you not shoot charges that are out of the nodal area.

 

[diego-ted]

Re: 20 thou of the Lands now what?

Why you ask, I don’t really know. I was just following the reloading for long range guide on page one and following along. I do care about both scenarios and would like to find the pet load for each situation. Right now I am only using Sierra Match King 168 gr and 155 gr bullets. I have
H335 Powder, IMR 4064 powder and Varget.

Thx Ted

 

[kyreloader]

Re: 20 thou of the Lands now what?

Which cases? Winchester, Lapua, Fed, etc??

Each case has slightly different capacity.

I think Varget is going to be your powder, how much is likely dependent on which cases you are using.

Let us know.

(Sorry if I came across ashholish, just trying to get more information).

 

[diego-ted]

Re: 20 thou of the Lands now what?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kyreloader</div><div class="ubbcode-body">Which cases? Winchester, Lapua, Fed, etc??

Each case has slightly different capacity.

I think Varget is going to be your powder, how much is likely dependent on which cases you are using.

Let us know.

(Sorry if I came across ashholish, just trying to get more information). </div></div>

You did not, I was just saying!! LOL, I am useing once fired FGM cases and I also have 100 Lapua cases.

 

[kyreloader]

Re: 20 thou of the Lands now what?

Here is a link to some OCW charges with Winchester cases and Varget powder in .308. He recommends that you reduce your load by 0.4% for Lapua cases. (He's not a fan of Federal cases). These are directly from Dan who came up with OCW loading and these are off his webpage.

.308 OCW loads

For your 168s with Varget and Lapua cases, your OCW load should be around 45.8g. I would load up starting at 5% less and work up. I would load up 43.5, 44, 44.5, 45, 45.5, 46g to shoot. I would personally shoot an OCW test at 100 yards, then shoot a couple ladder tests at 300+ and see which load shows itself with both tests. I would be surprised if you dont find you load in that load range.

My understanding is that Federal cases have less capacity, so I am not sure what loads would work for those cases but would assume it would be less.

Just repeat the same math for the 155g loads.

Let us know.