• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

1:8 twist 204 barrel manufacturers

texote

The only two manufacturers I found that offered 1:8 twist in a 20 Cal was PAC-nor and Douglas. Have never used either one but would like to know all my options.

Plan on building a 20-250

Anyone know of any other companies?

Thanks
 
My 20-250 is a Pacnor 9 twist so is my 20br they make great 20 cal barrels. What bullet do you plan on shooting both my 20-250 and 20br shoot the 55 Berger great are you planning on shooting some heavier bullets
 
I spoke on the phone today with don unmussig and asked him about his bullets, He said for his 62 and 57gr i needed an 8 twist. What a great guy, answered all my questiions and i had plenty lol. I plan on shooting them and may try out the 55 gr bergers. I guess Ill either go with the pacnor or douglas, lead off time will be the determining factor.

Thanks
 
I have a 20BR built with a Douglas barrel, 9 twist. I can shoot 55's but the 50s work best.

Douglas is top notch. Mine shoots waaaaay better than I can. I've shot a number of groups on good days for me in the .2's, usually its right around or just under .4

This is built on a lightweight gun for coyote hunting.
 
texote said:
Yes please let me know what your results are. What are the bc of those 62gr bullets?
Click to expand...



Posts: 294

20-250
« Reply #10 on: 09:45 PM, 07/18/12 »QuoteThe g1 bc on the 62 vld is over.500. I have yet to shoot the 62's cause an 8tw Barrel is on order.

The 57 g1 bc is around a .450. The bullets look great. I will be shooting the 57's this weekend.

This is copied from a post of kjcpoint yesterday! Hope it helps?

Mike
 
62 unmussig:
OAL is 1.057
Base to ogive is .563

55 berger
OAL is .910
Base to ogive is .438

I went with a 9tw, Greg Tannel told me an 8tw is hard on 55 Berger's at moderate velocities.
I have built a few 20 cals with 9tw barrels and they shoot the 55 bergers great.

If anyone wants to give the 62 unmussig a try, I will gladly send them for free. Maybe a 20br or 20-250.

Not the best shooting conditions here.
 
I would like to try a few in my 20br and 20-250 if your interested I have some 50gr Unmussigs to trade
 
I went with a 9tw, Greg Tannel told me an 8tw is hard on 55 Berger's at moderate velocities.
I have built a few 20 cals with 9tw barrels and they shoot the 55 bergers great. [kjcpoint]
Click to expand...


What sort of velocities Kyle? I'm planning a .20 Tactical and had assumed I'd need a 1-8" twist with the Berger 55, but if 1-9" works, so much the better. Millers Twist Rule spreadsheet gives an Sg of ~1.10 in a 9-inch twist at 3,000 fps, a level which usually puts the combination into the 'might work' rather than 'no worries here' category. So, hearing of what does and does not actually work is very useful.
 
Good accuracy at 3700-3850 fps with the 55 bergers.
The 20tac may need an 8tw. Thats a great round with 39/40gr bullets?

What would the millers twist rule number be on the 62 unmussig going 3600fps or a little more in a 9tw?

Kyle
 
Can you guys give any contact info for the purchase and pricing of the Unmussig bullets please?

I just picked up my 9 twist 20x47L a few days ago, yahooo ;D
 
What would the millers twist rule number be on the 62 unmussig going 3600fps or a little more in a 9tw?
Click to expand...

According to Miller, it won't stabilise under standard conditions - 0.85 Sg. That's using the 1.057-inch OAL you quoted earlier. If you're several thousand feet ASL in 100-deg air temps, it might just.

Don Miller's Twist Rule


Caliber 0.204 Inches
Bullet Weight 62 Grains
Bullet Length 1.057 Inches
Barrel Twist 9 Inches/turn
muzzle velocity 3600 fps
Temperature 59 degrees Fahrenheit (59 is standard)
Pressure 29.92 inches of mercury (29.92 is standard)

Sg = 0.85

Sg shouldn't be less than 1.4. If Sg is greater than about 2.0, you may
gain some accuracy by going to a slower twist barrel.


Here's a link to download the formula in EXcel from elsewhere on this site


http://accurateshooter.net/Blog/millerformula.xls

Hmm 1-8" it seems to be for me.

We have a 'legal issue' in the UK post the Dunblane massacre. Because Thomas Hamilton used JSPs in some of his ammo to murder the teachers and schoolkids, all expanding bullets and bulleted ammunition were moved into the 'Prohibited Weapons and Ammunition' category in the ensuing legislative changes that banned most pistols here. A limited derogation allows those who hold firearms certificates for deerstalking and vermin control to buy and use expanding bullets and ammunition, but they're not allowed in target shooting which is what I'll be using the Tactical for. A UK gunsmith and Berger dealer, Norman Clark persuaded Berger Bullets to make up some 0.204s in 'Match' format in 40, 50, and 55gn weights. I've got a few 40s left over from this order, but mainly plan to use 50s and 55s that I bought up when they were still available. Crazy ... but that's the law here.
 
Hey kyle do you have a 20-250? If so what are the details on it? How do you like it? How does it compare to the other big 20 wildcats if you've had any experience with them?
Thanks
Tex
 
Varget and H4831sc get me to 3700 fps with the 55's in the 20/250, I can get them over 3800 with 4350 but the accuracy isn't as good and RL15 gets me 3500 in the 20br with the 55's Varget works well in the 20br also
 
You must log in or register to reply here.

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Classified Ads

Forum statistics

Threads
165,841
Messages
2,204,674
Members
79,160
Latest member
Zardek

Share This Page

Back
Top