cahunter805
Well-Known Member
- Joined
- Jun 18, 2010
- Messages
- 608
If I'm not mistaken GAP isn't running 8.7 twist anymore. I'm running an 8 twist on mine.
6.5 saum barrel help
- Thread starter JD250
- Start date
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Shooter264
Well-Known Member
I believe you are correct, switched to 8.2 I believe
6point5x284
Well-Known Member
Appreciate the correction gents. OP, sorry for the outdated info.
BucksAndBulls
Well-Known Member
I just checked and George's post in the 6.5 saum 4s page on FB on nov. 27 says that the new standard for gap will be 1 in 8... new standard reamer also. If you are not part of the group there is a lot of info over there.
Mike
Mike
BucksAndBulls
Well-Known Member
Straight from the man...
"I've made a few changes to what I have been historically been recommending. These are from new bullet designs causing issues with what was available a couple years ago.
GAP will be using the .296nk/ .120 free bore reamer from now on and will be adding a .145 FB reamer as well to our reamer selection. The .120 will work well on most match and hunting bullets . The .145 FB will be strictly for the new 143-155 class Bullets coming out with long bearing surfaces. And will be used by request only.
The old. 081 FB reamer will be by request only and only recommended if all you plan on ever shooting is 130-140 JLK and Berger Hybrids.
I believe this may help with guys getting pressure problems with the longer Bearing surface bullets in the .081 Freebore chamber. Especially initially prior to rifle breaking in.
Further information from lots of talks on here. There are about 10-12 different reamers that various smiths are using. There are all kinds of differences in body size, freebore length, freebore size (dia) and neck size. This all affects things. I cannot speak to advantages/disadvantages but I can say that some of these chambers will not yield the same results as Myself and others that did all the initial testing. Also bore size and bore dimensions will also change these results
.256x.264 is SAMMI bore/groove. A lot of barrel makers make .255x.264 and other variations. These will increase pressure. The land to groove ratio will also increase pressure . Barrels should have more groove than land. But some barrel manufactures use up to a 50/50 ratio which also increases pressure.
What's this all mean?? It means that you should always work up a load for your individual rifle and not just drop someone else's recommended charges
61 gr H1000 on a 140gr
63 gr H1000 on a 130gr
Is a max charge rule of thumb. It's not an absolute. Start at 59 on a 140 and 61 gr on a 130.
Also 1-8 is going to be our standard twist. As the trend is that the bullets will get longer. This won't be adverse at all so an easy change from 1-8.7.
Hope this helps some. Any questions ask."
"I've made a few changes to what I have been historically been recommending. These are from new bullet designs causing issues with what was available a couple years ago.
GAP will be using the .296nk/ .120 free bore reamer from now on and will be adding a .145 FB reamer as well to our reamer selection. The .120 will work well on most match and hunting bullets . The .145 FB will be strictly for the new 143-155 class Bullets coming out with long bearing surfaces. And will be used by request only.
The old. 081 FB reamer will be by request only and only recommended if all you plan on ever shooting is 130-140 JLK and Berger Hybrids.
I believe this may help with guys getting pressure problems with the longer Bearing surface bullets in the .081 Freebore chamber. Especially initially prior to rifle breaking in.
Further information from lots of talks on here. There are about 10-12 different reamers that various smiths are using. There are all kinds of differences in body size, freebore length, freebore size (dia) and neck size. This all affects things. I cannot speak to advantages/disadvantages but I can say that some of these chambers will not yield the same results as Myself and others that did all the initial testing. Also bore size and bore dimensions will also change these results
.256x.264 is SAMMI bore/groove. A lot of barrel makers make .255x.264 and other variations. These will increase pressure. The land to groove ratio will also increase pressure . Barrels should have more groove than land. But some barrel manufactures use up to a 50/50 ratio which also increases pressure.
What's this all mean?? It means that you should always work up a load for your individual rifle and not just drop someone else's recommended charges
61 gr H1000 on a 140gr
63 gr H1000 on a 130gr
Is a max charge rule of thumb. It's not an absolute. Start at 59 on a 140 and 61 gr on a 130.
Also 1-8 is going to be our standard twist. As the trend is that the bullets will get longer. This won't be adverse at all so an easy change from 1-8.7.
Hope this helps some. Any questions ask."
elkaholic
Well-Known Member
I use 8's on all the Shermans in 6.5. A 24" in a #3 Bart should work well for what you want out of it......Rich
elkaholic
Well-Known Member
Brux will also flute a #3 and it makes it light but still stiff. I have one on my 270SS and it weighs 7 lbs. scope and all
