20 Vartarg help version II seating depth revisited

[rrwildlife]

In my earlier post there were several suggestions to revisit my seating depth. Here are the results of today's range session. The powder was H-4198, cases Lapua, primers Fed 205M, and bullets 32 gr Nosler FBHP. The conditions were 50 degrees and sunny with a ~10 mph wind. The target was shot at 100 yards over wind flags. To my eyes there seems to be no discernible pattern. The last two powder charges at 2.537 (~.008 off the lands) seem to have possibility but the rest pretty much stinks.

Any thoughts other than try a few more tests further away from the lands?

Ryan

 

[LitLBoy]

Work with 18 - 18.5 with the powder and .537 to .542 with the seating, I think you will find it in there.
LitLBoy

 

[SS427]

Ryan, I agree with your assessment of the ones with possibility.

I also like the 2.547 seating depth. If you combine all 9 of those shots, they are all close together except that one with the lightest charge.

I like the 18 grain charge the best. I would load 15 rounds at 2.537 and 15 at 2.547 and see which one shoots the best 3 five round groups.

My test results are not that much different than yours. I shot two remarkable three shot test groups, but my five shot groups have not come close to those but are still good. I went with the 18.1 grain charge and the 2.579 seating depth.

 

[ricksaw]

your using quality brass,weigh out 5 cases that weigh the same,try 32 v-max with 18.5 grs H-4198,fed primer,seat the bullet so it just touchs the lands.When ive had unexplained flyers it came back to the difference in the weight of the brass,good luck!

 

[Ledd Slinger]

I dont see the problem here???

2.537 with 18gr shot awesome, then with a full 1/2gr more (18.5gr) shot with nearly identical accuracy. Your 2.537 seatung depth is obviously very forgiving at 18gr and above.

If you dont accept those groups then I dont think theres anything else we can do to help. Your rifle definitely prefers FB bullets as I suspected because there are a fair amount of good groups in the bunch. It appears that about 8 of the groups are 1/2 MOA or better and of those, a few groups are sub 1/4 MOA. If you are trying to achieve consistent dollar bill groups then you might not have any hair left by the time you find it...or your barrel will be shot out

 

[th82457]

Ryan,
I must be missing something here. Is this a 20 VT ? My Vartarg usually has an OAL of 1.880" to 1.910" depending on the bullet I use. At the stated dimensions bullet would not be in case. Maybe this is a Turbo or some case other than .221 & I missed it ? Anyway, I have had better accuracy using RL-7 and H322 in my Vartarg with 32 gr V-Max.

Regards,
Terry

 

[L.Sherm]

Only go .2 of a grain at a time max maybe even .1 .5 at a time is alot dealing with this small of a charge. I think of it this way if you are dealin with a 55.0 -70.0 in bigger cartridges and are going .5 at a time which I do percentage wise going .5 at a 18.0 -19.0 is like going 3-4 times the charge as you would in a 55.0 - 70.0 charge. If you went from 18.5 to 19.0 you could be in a over pressure situation, anyway hope this was not to confusing.

 

[rrwildlife]

I dont see the problem here???

2.537 with 18gr shot awesome, then with a full 1/2gr more (18.5gr) shot with nearly identical accuracy. Your 2.537 seatung depth is obviously very forgiving at 18gr and above.

If you dont accept those groups then I dont think theres anything else we can do to help. Your rifle definitely prefers FB bullets as I suspected because there are a fair amount of good groups in the bunch. It appears that about 8 of the groups are 1/2 MOA or better and of those, a few groups are sub 1/4 MOA. If you are trying to achieve consistent dollar bill groups then you might not have any hair left by the time you find it...or your barrel will be shot out

I'll certainly experiment more with the 2.537 seating depth.

I would like to see the gun shoot 1/2 MOA sized 5 shot groups. I don't think that is an unreasonable expectation. My factory 223 Sako AI will consistently shoot 1/2 MOA or better so this rifle with a custom barrel and bedding job should be able to duplicate the factory guns accuracy.

Thanks for all the help and input. I appreciate it!

Ryan

 

[rrwildlife]

Ryan,
I must be missing something here. Is this a 20 VT ? My Vartarg usually has an OAL of 1.880" to 1.910" depending on the bullet I use. At the stated dimensions bullet would not be in case. Maybe this is a Turbo or some case other than .221 & I missed it ? Anyway, I have had better accuracy using RL-7 and H322 in my Vartarg with 32 gr V-Max.

Regards,
Terry

Terry,

Sorry I didn't make it clearer. I use a Sinclair "nut" to measure from the cartridge base to ogive. The "nut" adds .960" to the overall length.

Ryan

 

[rrwildlife]

Ryan, I agree with your assessment of the ones with possibility.

I also like the 2.547 seating depth. If you combine all 9 of those shots, they are all close together except that one with the lightest charge.

I like the 18 grain charge the best. I would load 15 rounds at 2.537 and 15 at 2.547 and see which one shoots the best 3 five round groups.

My test results are not that much different than yours. I shot two remarkable three shot test groups, but my five shot groups have not come close to those but are still good. I went with the 18.1 grain charge and the 2.579 seating depth.

Thanks for posting the pic. It helps to know what I'm seeing is not "odd". I have tuned several other rifles before and just seem to be struggling to get this one to do what I think it's capable of. If I could get 1/2 MOA groups consistently I would be happy. We shall see what happens when I move up to 5 round groups.

Thanks,

Ryan

 

[rrwildlife]

Only go .2 of a grain at a time max maybe even .1 .5 at a time is alot dealing with this small of a charge. I think of it this way if you are dealin with a 55.0 -70.0 in bigger cartridges and are going .5 at a time which I do percentage wise going .5 at a 18.0 -19.0 is like going 3-4 times the charge as you would in a 55.0 - 70.0 charge. If you went from 18.5 to 19.0 you could be in a over pressure situation, anyway hope this was not to confusing.

Nope, not confusing. I was hoping the 3 different powder charges would give me a "road map" of where I should be looking to further test. I can now test the load between 18.0-18.5 moving smaller increments at the 2.537 seating depth.

Thanks,

Ryan

 

[rrwildlife]

your using quality brass,weigh out 5 cases that weigh the same,try 32 v-max with 18.5 grs H-4198,fed primer,seat the bullet so it just touchs the lands.When ive had unexplained flyers it came back to the difference in the weight of the brass,good luck!

I'll give weighing the brass a shot. I have not done that yet.

Thanks for the suggestion.

Ryan

 

[North Fork]

Try RL7 with the 32gr bullits my 20 vartarg loves them

 

[Ledd Slinger]

I dont see the problem here???

2.537 with 18gr shot awesome, then with a full 1/2gr more (18.5gr) shot with nearly identical accuracy. Your 2.537 seatung depth is obviously very forgiving at 18gr and above.

If you dont accept those groups then I dont think theres anything else we can do to help. Your rifle definitely prefers FB bullets as I suspected because there are a fair amount of good groups in the bunch. It appears that about 8 of the groups are 1/2 MOA or better and of those, a few groups are sub 1/4 MOA. If you are trying to achieve consistent dollar bill groups then you might not have any hair left by the time you find it...or your barrel will be shot out

I'll certainly experiment more with the 2.537 seating depth.

I would like to see the gun shoot 1/2 MOA sized 5 shot groups. I don't think that is an unreasonable expectation. My factory 223 Sako AI will consistently shoot 1/2 MOA or better so this rifle with a custom barrel and bedding job should be able to duplicate the factory guns accuracy.

Thanks for all the help and input. I appreciate it!

Ryan

No problem. Ill bet that will shoot 5 shot groups just fine. Like L.Sherm stated, very small amounts of powder charge changes can change the chamber pressure dramatically in the small varmint rounds.

Using that 2.537 depth, I'd load up 5 rounds at:
18gr
18.2gr
18.4gr
18.6gr (as long as there was no pressure signs at 18.5gr)

Whichever 5 shot group makes the smallest ragged hole is your load.

 

[ab_bentley]

My last 20vt loved the bullets .070" off the lands. Yes you read that correct.

Adam

 

[Terry O]

As others have mentioned a different bullet. The Nolser 32 gr. HPFB has produced the worst groups in my five 20 cal guns. Pick up a box of Hornady 32 gr VMAX and go from there. I would expect you will be presently surprised.

 

[Ledd Slinger]

As others have mentioned a different bullet. The Nolser 32 gr. HPFB has produced the worst groups in my five 20 cal guns. Pick up a box of Hornady 32 gr VMAX and go from there. I would expect you will be presently surprised.

Did you see his target on the first page? He's right on track with the Nosler FBHP. Theres some excellent 3 shot groups that should do just fine when tried with 5 shot groups.

There was another thread the OP started before this one where the trouble started and one of the bullets he couldn't get to shoot was the Hornady VMax. Kind of a pain when info is spread over multiple threads on the same topic by the OP. Not your fault, just catching you up.

 

[Dan Hall]

rrwildlife you may be pulling your hair out by now trying to get your Vartarg to shoot as well as you KNOW it should. You may have already tried this but it looks like 32 grain bullets are what your twist may want and Reloder 7 is what my Vartarg likes best. 18.5 grains with the bullets well into the the rifling. Maybe not jam but with a square mark from the rifling. PacNor makes great barrels so I would be surprised if that's the problem. Good luck.