A new barrel for my Rem 788 in 6mm. 600 yards max.

[Xerothermic]

I want a varmint or Palma, heavier barrel so I can shoot 5-10 shot groups without a 20 minute cool-down. The stock, sporter barrel isn't getting it at three shot and hot. I will be ordering from Pac-Nor and they will be mounting the new barrel to my action. I haven't a clue about "free bore", but everyone is talking about it so I better get me some.

Assuming Pac-Nor uses a factory or Saami spec reamer, how do they enlarge or decrease the FB? I will be using Sierra 75 and 95 gr flat based-hollow points and also the real, pointy bullets like Hornady 105 and others up to around 107. No 115s like Dtac. The 6mm Remington has along case neck so maybe I don't even need more FB.

Second question, is there a definitive answer between 3 groove and 5 groove rifling with regard to accuracy and cleaning?

I shoot pretty good but I'm not a smith by any means, Obviously. I am invested in the 6mm Remington in brass, bullets and LH reproduction stocks. I'll stick with it until I wear this new barrel out and then I'll be looking at a 6mm Norma BR.

I'm bouncing this off you guys so I have something in writing prior to making the phone call. Any help would be appreciated.

 

[10XSHOOTER]

I'd do the 6 BR now! it will shoot better at 600 yds!
Or even better yet a 6 Dasher

 

[boltman13]

Save yourself the time and money. Go with a 6 Dasher now. I wish had. You will end up there anyway.

 

[slm9s]

Sell your 6mmRem brass and dies.
Would the 6br/dasher have feeding issues in a 788? Or are you single loading with a sled? There's the 6creed also that should feed fine right?...
Good luck!

 

[Xerothermic]

Sell your 6mmRem brass and dies.
Would the 6br/dasher have feeding issues in a 788? Or are you single loading with a sled? There's the 6creed also that should feed fine right?...
Good luck!

I do single feed. I'm just, mainly, looking for advise on free-bore (how to determine what I need for the 105 and107 pointy bullets) and the benefit of the 3R vs. 5R. The info on other cartridges is appreciated though.

 

[nakneker]

6mm Remington is a good cartridge even if it is a bit dated with its design, that being said I don’t think there’s anything wrong with sticking with it on your project. I’d consult with whoever is gonna chamber your rifle as far as free bore goes. As far as 3 vs 5 groove that’s an area of opinion, I’ve used them both with good success As far as accuracy and cleaning. Pacnor makes a good barrel.

 

[280ai]

6gt with .120 free bore 107 sie mk or 108 eldm Absolutely hammer at 600!!!!! Win 65 staball and a cci or Fed srmag primer set .020 off touch my 4 groove Brux shoots .200-.300 @ 100 My son's proof 5 groove shoots equaly as well with same load in an AR 10.

 

[Rubberduckie]

Curious... are we talking about 6mm remington or 6br remington?

 

[Adam 6mm build]

I chambered one of my 788 in 6x47 lapua its an absolute hammer I went with a heavy magnum contour brux if I was to do it again I definitely would have went with at least sendero or light varmint contour

 

[Tommie]

Far as I can see, the OP is building a 6mm Remington. Can’t for the life of me find where he asked for other cartridge suggestions.

 

[Bob3700]

For bullets up to 105-107 gr. a freebore of .104 is pretty standard. Make sure you specify at least an 8 twist to accommodate this wt. bullet range.

 

[Kracken McGraw]

I chambered one of my 788 in 6x47 lapua its an absolute hammer I went with a heavy magnum contour brux if I was to do it again I definitely would have went with at least sendero or light varmint contour

Would the Sendero fit in the original wood stock?

 

[Xerothermic]

Curious... are we talking about 6mm remington or 6br remington?

6mm remington

 

[Rubberduckie]

6mm remington

I have a 6mm ai and used a manson reamer. The print on it rotates .103 freebore. Ill paste the print notes from manson. I shoot 85 grain sgk.

Ackley Improved version of 6mm Rem. Base diameter is slightly tightened. Free bore length remains the same as 6 Rem, but leade angle
is changed to 1.5 degree (from 3 deg). Throat will be longer than needed for most 6mm/.243 bullets with the exception of some of the
heavier (105+gr) hunting type bullets. Will shoot any traditionally loaded 6 Rem bullets as well as a standard 6 Rem would

 

[AlNyhus]

I do single feed. I'm just, mainly, looking for advise on free-bore (how to determine what I need for the 105 and107 pointy bullets) and the benefit of the 3R vs. 5R.

You'll want a free bore length around .100" for the bullets you ask about. Remember that as the f.b. length gets longer, the shorter bullets you might shoot will have less of the bullet in the neck (depending on the bullet, of course). Throat angle also plays into this, of course.

PacNor will be able to tell you what free bore length their reamers for the 6MM Remington have. Both the 3 and 5 groove barrels are excellent. Check on the width of the lands between the two and that may help you decide. If the 3 groove lands are appreciably wider, that may be helpful for throat errosion with the bigger case. PacNor is very good with this...let them be your guide.

I'll second the suggestion to do a Remington Sendero profile barrel. The factory stock will accomodate it just fine. Add a quality pillar beddung job by someone that knows what they're doing and you'll have great results.

Good shootin' -Al

P.S: Do yourself a favor and order some BIB 90 gr. flat based bullets.

 

[357Mag]

I want a varmint or Palma, heavier barrel so I can shoot 5-10 shot groups without a 20 minute cool-down. The stock, sporter barrel isn't getting it at three shot and hot. I will be ordering from Pac-Nor and they will be mounting the new barrel to my action. I haven't a clue about "free bore", but everyone is talking about it so I better get me some.

Assuming Pac-Nor uses a factory or Saami spec reamer, how do they enlarge or decrease the FB? I will be using Sierra 75 and 95 gr flat based-hollow points and also the real, pointy bullets like Hornady 105 and others up to around 107. No 115s like Dtac. The 6mm Remington has along case neck so maybe I don't even need more FB.

Second question, is there a definitive answer between 3 groove and 5 groove rifling with regard to accuracy and cleaning?

I shoot pretty good but I'm not a smith by any means, Obviously. I am invested in the 6mm Remington in brass, bullets and LH reproduction stocks. I'll stick with it until I wear this new barrel out and then I'll be looking at a 6mm Norma BR.

I'm bouncing this off you guys so I have something in writing prior to making the phone call. Any help would be appreciated.
View attachment 1605756

Xero

Howdy !

I shoot a wildcat, whose chamber is cut by running a
6mm Remington reamer in " short "; for a .466" base diam.

I use the rifle for anti-groundhog work, and also for target shooting. The barrel is a Broughton 29" SS 5-groove 1-8, in a
" Palma " taper. I shoot 87 - 107gr bullets. I am very happy with the Palma taper.

With regards,
357Mag

 

[Xerothermic]

For bullets up to 105-107 gr. a freebore of .104 is pretty standard. Make sure you specify at least an 8 twist to accommodate this wt. bullet range.

Good info. Do you think a 7.5 twist will be too much for the Sierra 75 gr. HP/FB? It should handle the Sierra 95 gr. HP/BT just fine. I kind of worry about jump with the Seirra 75 gr., but the 6mm Remington has a long neck.



I only have 6mm Hornady 105 gr. BT/HP on hand right now but have never reloaded or shot them. I need to get the barrel on order tomorrow and at least, now, I feel more confident with my questions to Pac-Nor. Thanks, one and all.

 

[gpoldblue]

Good info. Do you think a 7.5 twist will be too much for the Sierra 75 gr. HP/FB? It should handle the Sierra 95 gr. HP/BT just fine. I kind of worry about jump with the Seirra 75 gr., but the 6mm Remington has a long neck.

View attachment 1607355

I only have 6mm Hornady 105 gr. BT/HP on hand right now but have never reloaded or shot them. I need to get the barrel on order tomorrow and at least, now, I feel more confident with my questions to Pac-Nor. Thanks, one and all.

12/twist(in inches) times 60 times the muzzle velocity equals RPM's. You might want to check with the bullet manufacturer to see if they think the bullet in question will withstand the indicated RPM's.
Good luck and stay safe.

 

[Will Henry]

The really great feature the 6mm Remington has is the relatively long neck. If the rifle is chambered to accept the bullet with the longest bearing surface, seated with the corner of the boattail about .020 ahead of the neck/shoulder juncture, then there is plenty of neck available to seat shorter bullets out a ways.
I bought my first 6mm Remington in 1972, and I have always had one ever since. For a long time, it was the number one choice for a coyote cartridge, and I barreled a bunch of them. WH

 

[Fast14riot]

Sell your 6mmRem brass and dies.
Would the 6br/dasher have feeding issues in a 788? Or are you single loading with a sled? There's the 6creed also that should feed fine right?...
Good luck!

My 788 in 6br feeds great, but it is single shot and has a sako style extractor.