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 Best 9mm bullet weight to use with 1:10 twist barrel
sititunga  [Member]
1/22/2009 4:36:51 PM EST
What bullet weight would you guys recommend? 115 grs in my Spike's AR are accurate, but I am thinking as 1 in 10 twist seems fast that 147 grs might stabilize quite nicely and be worth looking at for 80 - 120 yds shots. The gun's has a 14.5 inch barrel with pinned comp. Any views?
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badazzar15  [Industry Partner]
1/22/2009 6:36:41 PM EST
It will handle 147's no problem.
sititunga  [Member]
1/22/2009 7:08:52 PM EST
Thanks for that. In your experience what weight bullet produces the best accuracy out of that barrel - the 115s, 124s, or 147s?
badazzar15  [Industry Partner]
1/22/2009 7:11:47 PM EST
Originally Posted By sititunga:
Thanks for that. In your experience what weight bullet produces the best accuracy out of that barrel - the 115s, 124s, or 147s?



Probably 147's maybe 158's. You really gotta shoot it and see what it likes. Quality ammo is the first thing to try.
sititunga  [Member]
1/22/2009 7:24:14 PM EST
Who makes a 158? Still need to have a conversation with you guys about building me a 556.
Brazos_Jack  [Member]
1/22/2009 7:46:10 PM EST
1 in 10 is an insanely fast twist for a 9mm. It would probably stabilize bullets over 200 grains if they existed.

Bullseye shooters going for peak accuracy with 115 gr ammo only have been turning to 1 in 32" twist. This won't do well with the heavier 124 or 147 though.

Something like 1 in 18" would probably handle any existing 9mm ammo, including 147 gr sub sonic.

Brazos Jack

(are you SURE its really 1 in 10")
badazzar15  [Industry Partner]
1/22/2009 8:18:36 PM EST
Originally Posted By Brazos_Jack:
1 in 10 is an insanely fast twist for a 9mm. It would probably stabilize bullets over 200 grains if they existed.

Bullseye shooters going for peak accuracy with 115 gr ammo only have been turning to 1 in 32" twist. This won't do well with the heavier 124 or 147 though.

Something like 1 in 18" would probably handle any existing 9mm ammo, including 147 gr sub sonic.

Brazos Jack

(are you SURE its really 1 in 10")



Yes its 1:10. We do all of our 9mm's 1:10 to stabilize heavier sub-sonic loads.
Brazos_Jack  [Member]
1/23/2009 1:30:09 AM EST
Originally Posted By badazzar15:
Originally Posted By Brazos_Jack:
1 in 10 is an insanely fast twist for a 9mm. It would probably stabilize bullets over 200 grains if they existed.

Bullseye shooters going for peak accuracy with 115 gr ammo only have been turning to 1 in 32" twist. This won't do well with the heavier 124 or 147 though.

Something like 1 in 18" would probably handle any existing 9mm ammo, including 147 gr sub sonic.

Brazos Jack

(are you SURE its really 1 in 10")



Yes its 1:10. We do all of our 9mm's 1:10 to stabilize heavier sub-sonic loads.


Given the intent to stabilize some ultra heavy sub sonic load, I have to agree with your choice.

I just wish you offered a 1 in 18" or 1 in 24" as an option for standard 9mm ammo from 115 gr to 147 gr. 90%+ of 9mm AR carbines will never see a can or this specialized subsonic ammo. Nothing wrong with offering 1 in 10". It would just be nice if there were a slower twist option.

RRA is doing the same thing to the 458 SOCOM. They are using 1 in 14" for capability of using 500gr+ subsonic loads when most of us would be better served by a 1 in 18" for 300gr to 405 gr hunting loads.

Brazos Jack
sititunga  [Member]
1/23/2009 5:14:08 AM EST
Originally Posted By Brazos_Jack:
1 in 10 is an insanely fast twist for a 9mm. It would probably stabilize bullets over 200 grains if they existed.

Bullseye shooters going for peak accuracy with 115 gr ammo only have been turning to 1 in 32" twist. This won't do well with the heavier 124 or 147 though.

Something like 1 in 18" would probably handle any existing 9mm ammo, including 147 gr sub sonic.

Brazos Jack

(are you SURE its really 1 in 10")



Here's a group my gun shot at 25 yds with 115 grainers. If I can improve on this I will be extremely happy




Brazos_Jack  [Member]
1/23/2009 7:20:41 AM EST
Originally Posted By sititunga:
Originally Posted By Brazos_Jack:
1 in 10 is an insanely fast twist for a 9mm. It would probably stabilize bullets over 200 grains if they existed.

Bullseye shooters going for peak accuracy with 115 gr ammo only have been turning to 1 in 32" twist. This won't do well with the heavier 124 or 147 though.

Something like 1 in 18" would probably handle any existing 9mm ammo, including 147 gr sub sonic.

Brazos Jack

(are you SURE its really 1 in 10")



Here's a group my gun shot at 25 yds with 115 grainers. If I can improve on this I will be extremely happy


http://i216.photobucket.com/albums/cc6/Jess10x/DSC03242-1.jpg



If that's offhand - good shooting. If that's from a rest, try something much heavier - like 147gr. It should do better.

Brazos Jack
sititunga  [Member]
1/23/2009 9:04:14 AM EST
It was off hand. I suppose you don't know who makes a 158 grain .355 dia. bullet?

BTW it looks like both Colt's, Rock River's and Bushmaster's 9mm carbines come with 1:10 twist barrels. Oly seem to be only company that offer a slower twist 1:16 barrel. I wonder how Oly's compares?
ctnsupra1  [Team Member]
1/23/2009 11:12:40 AM EST
Originally Posted By sititunga:
It was off hand. I suppose you don't know who makes a 158 grain .355 dia. bullet?

BTW it looks like both Colt's and Bushmaster's 9mm carbines come with 1:10 twist barrels.


You'd almost need to looking into cast loads for 158 grain bullet. I know Fiocchi and Prvi make 158 grain ball ammo but I can't find just the bullets themselves.
Brazos_Jack  [Member]
1/25/2009 7:45:15 AM EST
Originally Posted By sititunga:
It was off hand. I suppose you don't know who makes a 158 grain .355 dia. bullet?

BTW it looks like both Colt's and Bushmaster's 9mm carbines come with 1:10 twist barrels.


If you want jacketed bullets, see if Corbin makes a die to swage .357 bullets to .355.

I have an old German drilling with an 8x57J barrel (.318 bullet diameter). When I first got it, all the available 8mm bullets were for the more modern "S" bore (.323). Corbin sold me a die to swage S bore bullets to J bore.

Brazos Jack
sititunga  [Member]
1/26/2009 7:23:10 PM EST
I spoke to Grafs and Sons the other day and they suggested the same thing. I am going to order some 147 grainers to handload and see what they are like to shoot at distance.

The groups I am getting at 25 yds with the 115 grainers I am more than happy with, I just don't know how stable they will be at 100 yds. Anyway the 147s will have more ummph!!
sititunga  [Member]
1/26/2009 7:26:57 PM EST
Originally Posted By ctnsupra1:
Originally Posted By sititunga:
It was off hand. I suppose you don't know who makes a 158 grain .355 dia. bullet?

BTW it looks like both Colt's and Bushmaster's 9mm carbines come with 1:10 twist barrels.


You'd almost need to looking into cast loads for 158 grain bullet. I know Fiocchi and Prvi make 158 grain ball ammo but I can't find just the bullets themselves.


I've seen those, it's a shame the bullet manufacturers aren't making them for handloaders.

1LTfptg  [Member]
1/26/2009 7:52:05 PM EST
I have a box of IMI "UZI" lable 158 rounds FMJ.

I also have some Fiocchi 158's.

they will not stabilize out of my glock 19 and I got a baffle strike in my gemtec can.

sort of scared to try it out of my 7.5" carbine with my can on it.

147's are as heavy as I want to go as I know those work.

supressors are to expensive to just go shooting willy nilly rounds out of.
sititunga  [Member]
1/26/2009 7:56:44 PM EST
You've only tried them out of your Glock which runs a 1:16 or 18 twist - so the bullets not stablizing makes sense. Do you know what twist rate your carbine is? It looks like most manufacturers (apart from Oly) offer 1:10 twist barrels for their 9s. Take the can off and give the 158s a try. Just noticed your country of origin, where abouts in Thailand are you?
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