20 Vartarg problems help wanted

[17VLD]

Berger 40's are very accurate and will shoot in an 11 twist,they work in my 13 twist Pac-Nor 20 Tactical imp. as they are the shortest 40 out there.
Matt

 

[CM21VE]

My best 20 VT load was AA1680 and 32gr BKs...little bitty holes..AA2200 worked well also...

 

[mav007]

Have to agree with the H4198. Use that in my cooper 21, a little lighter that everyone else, only running 17.8 g but it seems to be the sweep spot for the 32 VMax. You might want to play with different seating depths. In mine I found it shoots best at .010 off the lands

 

[Dan Hall]

REL 7, 18.5 grains under 32 grain V-Max touching the rifling if you can. And try not to interfere with the rifle, don't touch the gun,except the trigger, if you can.
The groups just keep getting tighter and tighter. Dakota Predator and 18.5 grains REL 7, 32 grain V-Max. qx

 

[hogpatrol]

BTDT, primers, powder, bullets, brass, scope, ad nauseum, with a .20 Practical. Every combination known to mankind and inconsistency was the rule, not the exception. Problem solved with new barrel. Some just plain don't shoot.

 

[rrwildlife]

This is what I'm afraid of. I have had several people say that it may be the barrel.

BTDT, primers, powder, bullets, brass, scope, ad nauseum, with a .20 Practical. Every combination known to mankind and inconsistency was the rule, not the exception. Problem solved with new barrel. Some just plain don't shoot.

 

[roadkill61]

I also have a 3 groove, 11 twist 20 cal pac-nor barrel that did the same thing until I traded it for an 11 twist 3 groove x-caliber barrel.

 

[Codeman]

Are you shooting over flags?

 

[rrwildlife]

Are you shooting over flags?

All the load testing was done over flags at 100 yards. Not that I'm any good at shooting over flags but I tried to pick similar conditions to shoot in for each 5 shot group

 

[Yote Hunter]

The reason your 1:11 twist barrel does not prefer the 40 gr class bullets is because the bullets are not that stable. If you run the numbers on the Berger twist stability calculator you will see the 40 gr Vmax is in the unstable category at a coefficient of .994 and the 39 gr Blitzking is barely marginally stable at 1.03 and the 40 gr Berger is about midways in the marginally stable category at 1.3. A coefficient of 1.5 is required for full stability and best results. I based these numbers on a speed of 3450 fps which is pretty close to what you can expect out of a 20 Vartarg. I struggled with the same issue as you. The Berger 40 gr bullet is the shortest of all of them and still requires a twist of 1:9.8 for full stability. I switched to the Berger 35 gr bullet and it shoots .3 MOA at 200 yards.

 

[fourpower]

I had the same problem with mine. I was about to give up on gun because it didn't want to shoot anything I put in it! I kept going back to 4198 but same problem and all my brass was real dirty after shooting 4198 no manner what grs I used! as a last try I got some hodgon little gun powder and man problem solved. this gun now shoots 32 &40gr bullets into a very small hole! brass now comes out of gun clean and man the fps increase is out of this world.

 

[L.Sherm]

If you run the numbers on a 32 gr.vmax it shouldn't shoot in a 1-12tw.and there's plenty of them do. I have 3 1-12tw that shoot the 34 gr. V- nitemares just fine. Bottom line some barrels shoot some bullets, some don't.

 

[Yote Hunter]

Yes that's true. If you are in the higher end of marginal stability they may shoot pretty good but the question was about 40 grain bullets in an 11 twist. As as been proven many times that many barrel twist are not exactly what they say. But for optimum stability you need to at least pay attention to the coefficient. The bullets will also get more erratic at longer distances due to marginal stability and you are sacrificing some of your ballistic coefficient.

 

[rrwildlife]

Based on my experience with Lil gun and the 221 fireball I will be avoiding that powder. I had it go from no problem to blowing the extracor out of sako with a modest increase in temperature. The load I was using was not "hot" based on published data and casehead measuremens, extraction, and visual inspection of primers. I know there are a lot of people who have had good luck with Lil Gun in the 221, its just not for me. I will say be careful when using it in variable temperatures

I had the same problem with mine. I was about to give up on gun because it didn't want to shoot anything I put in it! I kept going back to 4198 but same problem and all my brass was real dirty after shooting 4198 no manner what grs I used! as a last try I got some hodgon little gun powder and man problem solved. this gun now shoots 32 &40gr bullets into a very small hole! brass now comes out of gun clean and man the fps increase is out of this world.

 

[GAnderson]

rrwildlife, I have the 20VT that was the first chamber cut on the reamer by your/my gunsmith and I think if you play with seating depth you might just get rid of the flyer that sometimes occurs. Having said that, it has always seemed to me(my opinion only) that the 20cals are notorious for the one "flyer"...and on most occasions I can attribute that flyer to being me...if I am shooting 3 or 5 shot groups and the first 2 or 4 shots are ragging the hole out, the last shot flyer is usually me "choking"...trying to "will" the last one in with the rest of them. I maintain that a person forgets proper gun techniques on that last shot...grips the gun like they are making love to it or just cannot get the trigger to go and then "slap" the trigger and ruin the otherwise great group. Anyhow, I run my 20VT around .020 off the lands and seem to be getting the results that you are wanting. With 32gr bullets I have used AA2200, RL7 and 8208 with extremely good groups. My barrel is however a Lilja 12 twist but I see no reason that your PacNor 11 won't do just as well...all of my 20cal variations have grouped the best with running them off the lands by a substantial amount...and sometimes WAY off the lands. PM me if you want some of my loads since we have the same chamber and smith.

Gene

 

[Holson]

rrwildlife, I have the following: Kelbly Atlas SS action, Krieger 11 twist #2 Sporter Barrel cut to 20”, Jewel 1 oz. trigger at 1.5 lbs., action screws at 35 inch pounds front, 25 rear. New Lapua cases formed from .221 Fireball cases with case necks turned to .230”. Jam length for 39 gr. BlitzKings = 2.557”, 32 gr. BlitzKings = 2.553”, both over case gauge. All loads at .010 jump. That said, here are the best loads for this rifle but I have recorded others with better groups. All groups at 100 yards.

32 gr. Sierra BlitzKing = 18.4 Reloader 7 = .485 @ 3585 shows powder ½ up neck = Current Dillon load.
32 gr. Sierra BlitzKing = 19.0 Reloader 7 = .593 @ 3700 cannot use Dillon press as case is too full.
32 gr. Sierra BlitzKing = 19.3 H-4198 = .455 @ 3875 cannot use Dillon press as case is too full..
39 gr. Sierra BlitzKing = 18.2 H-4198 = .343 @ 3500

I use a Dillon 550 press for this rifle. I load for both speed and accuracy. If I have a choice of speed over a small improvement in group size, I'll go for speed. Contact me if I can be of any help. Harry

 

[Kermit in Va.]

All,

I have been fighting with my Vartarg for several months trying to run down a accuracy problem. The rifle is a Sako AI Varmint with the target trigger (16 ounces) and rebarreled with a 1/11 twist Pacnor (.235 neck with .035 freebore). I was hoping to shoot 40 grain bullets but it shows a preference for the 32 grain bullets. The problem I'm having is it shoots 3-4 bullets in one hole and the other one or two floating around like a satellite. I have shot some really small groups with it but most of the time it shoots two separate holes. The following targets are pretty typical.

I have tried 3 different scopes, a different stock, different firing pin, and a different trigger. I have experimented with the following powders and bullets: H-4198, H-322, LT-30, N-130, N-133, 40 gr V-max, 32 V-max, 32 Z-max, 32 Sierra, and 39 sierras. I have tried cci 400 primers, cci br-4 primers, and fed 205m. Cases are Laupa or Norma and all loads were tested from the jam to off .040 and seated with a Redding S-match seater and sized with a bushing neck die either .001 or .002 smaller than the bullet diameter.

I'm at a loss. Any suggestions on what to try next would be appreciated.

Thanks,

Ryan

 

[Kermit in Va.]

Did I misread that you a bushing 1-2 thousands smaller than bullet size? Or was it under Your loaded round. Kermit

 

[L.Sherm]

Did I misread that you a bushing 1-2 thousands smaller than bullet size? Or was it under Your loaded round. Kermit

Good catch Kermit, I hope he also meant loaded round.

 

[rrwildlife]

Did I misread that you a bushing 1-2 thousands smaller than bullet size? Or was it under Your loaded round. Kermit

Under my loaded round. Sorry for any confusion. I edited the post