12 Twist BRA & Bart’s 80’s

[JamesnTN]

This past summer I did a little testing with my 12 Twist BRA and Bart’s 80 BT seeing where my accuracy node fell off. I started at 31.3 grains of 8208 and went up to 31.9 in .2 grain increments. At 31.9 the group opened up just over 2” at 500 yards. Total agg was just over 1.5” this test lead me to think ok my summer load should also be good for the winter where temps would be 50-60* cooler.
This am I decided to test my theory based on shooting in near 90* temps and shoot the same load at 37*.
The results are what I expected and shows me there is no need to tune from summer to winter.
Here’s the test target this am at 500 yards the agg of the 2 groups are 1.302 which is plenty good for me and very impressive for an 80 grain bullet.

 

[DBLNUT]

Are you jamming or jumping? I am at 31.8 of 8208 and using .006 and .012 jam and both are shooting great.......Speed is right at 3250. 32.0 takes it to 3270.......and my groups are still good......
I will be shooting 32.0 and 6 jam at a winter league UBR style shoot this weekend. Temps will be in the 20's.

 

[JamesnTN]

Are you jamming or jumping? I am at 31.8 of 8208 and using .006 and .012 jam and both are shooting great.......Speed is right at 3250. 32.0 takes it to 3270.......and my groups are still good......
I will be shooting 32.0 and 6 jam at a winter league UBR style shoot this weekend. Temps will be in the 20's.

I’m seated .015 in the lands and my velocity at 31.7 is 3250 as well. Today I don’t have a clue what it was as the 3250 is my summer load at 87*

 

[tmwinds]

Leave that gun at home this coming Sat.

 

[boltfluter]

8208 is one of the best powders I have ever found for accuracy and temp insensitivity. One load works great all year for me in my 8 twist .22 BR. Great shooting as usual James!!

Paul

 

[johnnyi]

Can you run the 80’s with a .104 freebore..?

 

[JamesnTN]

Can you run the 80’s with a .104 freebore..?

You can but won’t be much bullet in the case if you’re jamming them.
My FB is .075

 

[sdeal5]

Johnny--- on that new bra barrel w/105 FB, had to jump some 80gr flat bases and some 80 gr boat tails to have enough bullet in neck to feel comfortable about it. Had to jump about .020. Used them to ff and they did okay but not great. Prob need way less fb to give them a fair chance
Scott

 

[DBLNUT]

Can you run the 80’s with a .104 freebore..?

I am using them in a .104 freebore BRA and they are just fine..............There is bullet in over half the neck with a 6-12 jam. Numerous people told me that the .104 was too long. Bart said there would be plenty of bullet in the neck and he was spot on! Don't be afraid it will be fine.


If you want PM and I will send you 5-80 Dominators to test seat in your .104

 

[cdngary]

8208 is one of the best powders I have ever found for accuracy and temp insensitivity. One load works great all year for me in my 8 twist .22 BR. Great shooting as usual James!!

Paul

I also have a 1-8 twist 22br, but haven't tried 8208. What bullets and load are you working with? Thanks

 

[sdeal5]

Johnny, the 80 grainers I tried were not Bart's. Sounds like his work just fine with the 104ish freebore. The ones I was trying definitely needed shorter freebore to be able to jam and still have enough in the neck.
Scott

 

[boltfluter]

I also have a 1-8 twist 22br, but haven't tried 8208. What bullets and load are you working with? Thanks

Century,

I was working with the old 75 A-max for coyote hunting. I was loading 27.0 grains with moly coated bullets. Usual disclaimers apply, start at least 10% below this charge weight. Be cautious and have fun.

Paul