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6mm or 6.5mm?

Posted: Sat Mar 28, 2020 8:32 am
by DavidABQ
If a person is considering rebarreling a rifle from .308 to another caliber for the sole purpose of shooting High Power Silhouette which caliber would be the best compromise between knock down power and recoil reduction.

They reload too if that makes a difference.

I am asking for a friend.

Re: 6mm or 6.5mm?

Posted: Sat Mar 28, 2020 9:34 am
by Merlin
Somebody told me its like bullriding. If you are a wimp you shouldn't be here in the first place. If you have a "here, hold my beer" mentality stay with the .308. If not get a wimpy cartridge and accept the failures at the ram line as part of the penalty of less recoil.

If you are a traditionalist by all means stay with the heavy recoiling rifles. That is the way it has always been done and that is damn sure good enough!

:ympeace:

Re: 6mm or 6.5mm?

Posted: Sun Mar 29, 2020 8:12 am
by dustinflint
Merlin wrote:
Sat Mar 28, 2020 9:34 am
Somebody told me its like bullriding. If you are a wimp you shouldn't be here in the first place.
That person doesn't even shoot HP silhouette! Shooting is not about whether you're a "wimp" or not. It's about having fun, competing and enjoying yourself, your friends, outside, etc. The caliber choice should be made based upon which brings the shooter the most enjoyment. The choice can also be made based upon which caliber produces the best scores for that shooter, but that takes MUCH longer and MUCH more shooting.

Both have their pros and cons - HP silhouette caliber choice is a tradeoff. Bigger calibers will generally knock down more rams when hit, but the shooter will generally hit fewer total targets. Smaller calibers will generally leave more rams standing, but the shooter will generally hit more total targets.

My suggestion is this: if you go with a 6mm, take all the recoil you can out of it and shoot a 6mmBR. There is no sense taking the ram penalty of the 6mm bullet if you are also going to take the recoil penalty by shooting a 6mm bullet in a big case. (The 6mm dasher and XC are good too but I only shoot calibers that Lapua makes brass for and that I don't have to manipulate that brass)

There are lots of good 6.5 calibers out there now - from 6.5BR to 6.5x47L and 6.5 Creedmoor and others - that make great silhouette rifles. If you go with 6.5 choose one and find some good loads that don't hit the shooter too hard.

Don't try to convince yourself that you are getting the same recoil reduction with a 6.5 as you are with a 6mmBR and dont try to convince yourself that you've found a 6mm load that will take rams as well as a 6.5 - that's not the way this tradeoff works. Choose what matters most to you and go with one.

Dustin

P.S. - There are lots of threads on here discussing testing of 6mm and 6.5mm rifles for use in silhouette. I'd suggest checking those out.

P.S.S. - It never hurts to look at what the best in the world are using when choosing equipment for any competitive sport. There is a definite caliber trend in amongst the top shooters in HP silhouette. If your friend is looking to get the best scores possible, it would make sense to check out this trend.

Re: 6mm or 6.5mm?

Posted: Sun Mar 29, 2020 8:39 am
by Merlin
I don't know what your friend should shoot but for me..... - the top Mark Pharr rifle, just received back, has no shots yet on the 6BR re-barrel (from 7-08 to 6BR). The bottom is a 6BR just built by Evelio McDonald. 32 rounds through it and, using 107 SMKs it has about 50% of the apparent recoil as the 7-08. The first 3 shots with no sight in went into ~.5 at 100 yards.

I am a little wimpy shrimp at 6'2 260# so I need a lesser recoiling rifle and am well pleased to admit it... :D

Image

Re: 6mm or 6.5mm?

Posted: Sun Mar 29, 2020 2:48 pm
by DavidABQ
Thank you gentlemen. Currently he is shooting a .308 and has never shot in a high power silhouette match be he does compete in SB Silhouette. I will pass this thread on to him.

Thank you again.

Re: 6mm or 6.5mm?

Posted: Mon Mar 30, 2020 2:36 pm
by kevinbear
Fast twist 6mm {1-8"} so you can shoot 115gr. bullets.

Re: 6mm or 6.5mm?

Posted: Mon Mar 30, 2020 4:02 pm
by Merlin
If you are going with 115s you might consider 7 twist. 8 is marginal so I understand.....

Re: 6mm or 6.5mm?

Posted: Fri Apr 03, 2020 4:57 pm
by Dee
Something to keep in mind other than raw knock down power is the BC of the bullets you're using in whichever caliber chosen. IIRC The .308 at 500+ meters in the wind has twice the drift of a 6.5 with a high BC bullet. Lowers the margin of error on wind read/correction. Which should theoretically mean more hits in the wind if you do your part.

Oh and the guy shooting nextdoor will appreciate not having a cannon going off next to him all match. Someone I forget who was using a 30.06 in St Louis one year and damn!!

Re: 6mm or 6.5mm?

Posted: Fri Apr 03, 2020 5:21 pm
by DavidABQ
Dee wrote:
Fri Apr 03, 2020 4:57 pm
Oh and the guy shooting nextdoor will appreciate not having a cannon going off next to him all match. Someone I forget who was using a 30.06 in St Louis one year and damn!!
I had not thought of that. I kind of like the idea of firing a booming sort of rifle.

Re: 6mm or 6.5mm?

Posted: Mon Jun 08, 2020 11:23 am
by Jerry G
Go with the 6.5. 107 all the way up to 142

Re: 6mm or 6.5mm?

Posted: Sun Jun 14, 2020 6:04 am
by jeff59
Dee wrote:
Fri Apr 03, 2020 4:57 pm
Oh and the guy shooting nextdoor will appreciate not having a cannon going off next to him all match. Someone I forget who was using a 30.06 in St Louis one year and damn!!
I spotted for the guy shooting the 30.06 in St. Louis some years ago. The noise and muzzle blast were brutal.

Jeff

Re: 6mm or 6.5mm?

Posted: Mon Jun 15, 2020 5:11 pm
by RBriscoe
The answer is a definite "it depends".

The major factor IMO is where he will be shooting. On some ranges the rams are tougher than others. On such ranges I think the 6mm BR, even with 115gr bullets, would be a marginal choices. Perhaps Dustin Flint will comment on his experience with the 6mm BR on a variety of ranges.

There are other "lower recoil" out there. Mark Pharr is shooting a 6.5mm BR with good success. Others are shooting a variety of smaller 7mm cartridges and there are a great many people shooting 7-08s, .260 Rem, 6.5 Creedmoor or 6.5x47 Lapua to name a few. Virtually anything will be more pleasant than a .308 Win in my experience.

I would suggest taking your friend to whatever range you shoot at and let him look over equipment and, perhaps, ask people if he could fire a shot or two of various calibers and loads to help him make a better informed choice.

Re: 6mm or 6.5mm?

Posted: Fri Jun 26, 2020 7:10 am
by DavidABQ
RBriscoe wrote:
Mon Jun 15, 2020 5:11 pm
The answer is a definite "it depends".

The major factor IMO is where he will be shooting. On some ranges the rams are tougher than others. On such ranges I think the 6mm BR, even with 115gr bullets, would be a marginal choices. Perhaps Dustin Flint will comment on his experience with the 6mm BR on a variety of ranges.

There are other "lower recoil" out there. Mark Pharr is shooting a 6.5mm BR with good success. Others are shooting a variety of smaller 7mm cartridges and there are a great many people shooting 7-08s, .260 Rem, 6.5 Creedmoor or 6.5x47 Lapua to name a few. Virtually anything will be more pleasant than a .308 Win in my experience.

I would suggest taking your friend to whatever range you shoot at and let him look over equipment and, perhaps, ask people if he could fire a shot or two of various calibers and loads to help him make a better informed choice.

Thank you very much. The only high power match we are likely to attend is the Nationals at the Whittington center. The other time it will be for banging away at the steel plates at out gun club. It is a modest sized range but we do have steel hung out to 600 or so yards that last time I heard. They may have put some new stuff out farther out by now.

Thank you very much.