SmallCaliberCentral

Hi, all –

I've just completed an AR-15 bench gun in .204 Ruger. I chose a Shilen barrel, which has a 1-9" twist rate. I specifically went with Shilen for the faster twist rate after a poor experience in a Ruger #1 with a 1-12" rate and heavier bullets.

Anyone have any loads to share that are oriented toward faster twists, or any advice on how I might go about finding a good load for this gun?

Thanks.

mz

Same barrel as both my son and I have. Sad part is both our guns shoot different so have to compromise a bit on loads.

I'm currently working up loads for a .204 Ruger built with a 24" Savage Varmint contour 1:8.5" twist Pac-Nor 3 groove barrel on a Savage Dual Port Precision Target Action. This barrel is an experimental project for longer lead free boat tail designs, and the Berger 50 and 55 grain HPBT bullets. Most of my varmint hunting is in California's lead free area.

First test loads with new unfired Winchester cases produced a seven of ten shot .341" group using the Berger 50 grain HPBT over 25.0 grains of Varget. Velocity 3,147 fps with a SD of 24. Cartridge OAL was 2.300". The three flyers out the group were equally tight, but landed out of the main group due to very heavy mirage and wind conditions, producing a group of .576" C. to C. overall. Charges of Varget used were from 24.0 to 26.0 Grains (Hodgdon data) and Remington 7-1/2BR primers. Velocity with 26.0 grains of Varget was 3,278 fps average for a SD of 27, about maximum velocity for this bullet.

Results with the 30 grain Hornady NTX offering are mixed, possibly due to the barrel being broken-in during preliminary testing. Several adjustments to the newly assembled rifle itself, such as bedding and action screw torque, being made during the process made definitive results inconclusive. Also, I reduced firing pin protrusion from .058" as set at the factory, to .044" which nearly eliminated the "primer cratering" artifact common to .204 Rugers. This ridge of primer cup metal seems to be related to the depth of the firing pin displacement and subsequent reforming around the firing pin during the firing cycle, and not high chamber pressure.

Best accuracy with the 30 grain NTX bullet was a .626" 10 shot group with 25.5 grains of Rl-10x powder. Seating depth adjustments will be made as it seems to be critical with this bullet, and additional powders tried.

The surprise was that I used my standard load for another rifle as a fouling load between groups after cleaning. That load is a Barnes 26 grain Varmint Grenade over 25.2 grains of Rl-10x with a Federal 205 Match Primer COAL is 2.260". The fouling group measured .356" for well over 10 shots, as a matrix out of a freshly cleaned bore! Fired through the screens, velocity was around 4,110 fps. It hit dead on the same aiming point as the other bullets. My entire theory about fast twist barrels for longer lead free bullets, or heavy lead core bullets, may be cockeyed as the short little Varmint Grenade may prove to be the most accurate choice for both fast and slow twists.

The Berger 50 grain bullet is recommended for a 1:9" twist, and they are very consistent dimensionally. Main thing is to select one or two bullets based on your needs, I'm also looking at the new 45 grain Hornady bullet, then try some common powders for testing. I prefer powders that flow through a measure consistently and have a track record for a given cartridge. In the .204 Ruger my choices are Rl-10x, Varget and Benchmark. If Varget almost works, then try some H4895. I plan to add IMR 8202 XBR in the future. In the AR platform I'd use the Remington 7-1/2BR primer for its robust cup designed for that application. After finding which loads show potential, refine them by varying seating depth, you will be limited by constraints of the magazine, but many bullets seem to prefer recommended factory seating depth around 2.260", defying loading mythology. I use Winchester or Remington cases, never having been able to justify the cost of premium cases on the target. I also deburr flash holes and uniform primer pockets for consistent primer seating depth.

Thanks for the detailed response, John. I don't have any Varget, but I do have H322, H335, IMR 8208 and Benchmark. My next pass will probably be the H335 or the 8208.

Wrangler John wrote:The Berger 50 grain bullet is recommended for a 1:9" twist, and they are very consistent dimensionally ... I plan to add IMR 8202 XBR in the future.

I rebarreled my Remington 700 VLS with a 1 in 10 twist Pac-Nor Super Match, with a custom spec chamber, following some good advice (and assistance!) obtained here. I have no trouble shooting the 50 gr Berger, and in fact, it has become my favorite bullet choice for this rifle. Right now I am using the tried and true H4895, but I am looking forward to trying the IMR 8208 XBR. Hearing some good things about it and the small caliber centerfires.

mzimmers wrote:Hi, all –

I've just completed an AR-15 bench gun in .204 Ruger. I chose a Shilen barrel, which has a 1-9" twist rate. I specifically went with Shilen for the faster twist rate after a poor experience in a Ruger #1 with a 1-12" rate and heavier bullets.

Anyone have any loads to share that are oriented toward faster twists, or any advice on how I might go about finding a good load for this gun?

Thanks.

mz

Which bullet do you want to use? I have a 1/9 twist Shilen and I shoot the 40 and the 50 grain Berger. I use 26 grains of Varget for the 50 and 25.2 grains of Rl10x with the 40. Work your way up and see what works for your rifle. Good luck.

Jimmy

CV32 wrote:

Wrangler John wrote:The Berger 50 grain bullet is recommended for a 1:9" twist, and they are very consistent dimensionally ... I plan to add IMR 8202 XBR in the future.

I rebarreled my Remington 700 VLS with a 1 in 10 twist Pac-Nor Super Match, with a custom spec chamber, following some good advice (and assistance!) obtained here. I have no trouble shooting the 50 gr Berger, and in fact, it has become my favorite bullet choice for this rifle. Right now I am using the tried and true H4895, but I am looking forward to trying the IMR 8208 XBR. Hearing some good things about it and the small caliber centerfires.

That's good to know, there just isn't enough time (or money) to test every twist rate. Berger seems concerned about the twist rate their bullets will be used in, because when I emailed for loading data, they wouldn't send me any until I acknowledged that I was using a fast twist barrel. After my reply that it was an experiment with an 8.5 twist Walt Berger sent the data sheets. Berger is a company that makes a superior product and wants the customer to be satisfied. I like that.

I have same barrel on my ar. Look up load data and start at lowest charge. with dog town bullets it worked best in my barrel. load three to five rounds in half grain increments up to max load. See what shoots the best. I can give you my best loads for 4 bullets, but it is pointless as all barrels shoot a little different. Most important follow proper barrel break in steps. I used midway 34 grain dog town bullets for this. Cheap! Guess what they shoot as well as hornadys with the right charge. Best advice i can give is do proper load workup and work off best load , dont let your ego tell you the hottest fastest load is best. In some guns it may be but they are all different.
You Are Gonna Love The 1 In 9 Shilen! I had my doubts, but it is the most accurate gun I own! Good Luck
Oh and try 10x powder and imr 4895!