-
Having trouble using the site?
Contact support
6.5 mm action in 6mm build?
- Thread starter Oldmauser
- Start date
Yes. Same bolt face. Both short actions. You could simply rebarrel your 6.5cm to 6BR and save a lot of money and hassle.
I like my 6.5cm and 6cm, but reloaders seem to love all the BR-based cartridges. I’m Wanting to build a 6dasher or a 6GT to see what all the fuss is about.
@Newbie2020 is correct. Same bolt face. Just screw in a new barrel. You may need to use a spacer in your magazine, or get a separate mag designed for the shorter 6BR cartridge.You are sure about that? Because that would save me a lot of money.
Yes. From what I've learned on here and talking with a gunsmith it is an easy swap. Actions are usually short or long, some others in between depending on manufacturer. The piece that makes it caliber specific is the size of the bolt face and the bolt itself (?) I asked if I could change my 6.5CM to a 6.5PRC and I can but would need a magnum bolt face instead of a regular.
@Praeger so, it's as simple as that? Just change the barrel and buy a 6BR mag and you are ready to go?
A little more color on my 6 BRA:
- I had a 6 CM before I had my 6 BRA made.
- My 6 CM = 3080 fps with 42.0 gr H4350, 105s
- My 6 BRA = 2940 with 30.6 gr H4895, 105s
For that loss of 140 fps, I get:
- Significantly better barrel life
- Better SDs (~4.5 vs ~6.0)
- Better precision - the BRA just freaking hits everything, and does so in tight groups
The only thing the 6 BRA doesn't do well is shoot the heavier bullets like 115 DTACs.
@Rocketmandb I am building 6BR in order to challenge the 6.5CM guys at 300m and 300m alone. Past 300m I have 6.5CM. You think that makes sense?
Y’all are killing me dogs. I’ve got su much 6.5cm and 6cm brass and projectiles. I had planned to shoot out my 6.5cm barrel in 2021 and rebarrel to a shorty cartridge, but the shortage has prevented that. I’m stuck.
Probably nothing better to 600, definitely good out to 1000 if wind isn't bad.
When wind gets bad past 600, adding speed is usually the fix, thus: 6BR -> Dasher/6GT -> 6XC/6creed - but as speed goes up so does powder consumption and recoil as barrel-life goes down... so 6BR is pretty cool for a lot of guys.
Yep. This is the beauty of the way firearms technology has advanced. Bolt guns are now the equivalent of LEGOS just like the AR platform
This was my load development at 300 yards:
EDIT: I think you'll find that the 6 BR will beat the 6.5 well past 300. How far is dependent on conditions.
EDIT #2: This was before tuning for seating depth.
Here is my 6 BRA testing out my 2x4-topped popper at 500 yards. First shot is a little high, so I adjust. 8 out of the remaining 9 are within about 1.7", with the one that's out being because I reset.
The BR vs the BRA means a little less velocity, but you still get all the accuracy benefits.
In what way? Depending on which condition - wind?
The comparison is the bullet's BC and speed. Maybe mass if terminal energy matters to you.
6.5/6 Creedmoor are just as accurate as a 6 BR/BR-variant. You're not leaving anything on the table. Recoil differential is not huge and you'll have the advantage when your stage spotter isn't experienced and the little 6 (or 223) doesn't rock the plate.
I’ve learned so much this year: I moved to a lighter load of StaBall and 130s at 2,808 fps and recoil in my 6.5cm isn’t much different from Hornady factory match 6cm loads.
Really just wind - though at the extremes, DA starts to matter too.
With that said, I wish I had video of a trip I made with a friend out to BLM hills where he was shooting his 338 at a 30" target at 1500 yards. I decided to try my 6 BRA (gusting 15-20 mph winds). I didn't quite keep up with him at that range, but I hit more than I missed. The target was backed by very dry dirt, though, so spotting misses was relatively easy.
OK, the 6 BR is a dandy cartridge for sure, but you just can't say it beats the 6.5 Creedmoor.
Is it more accurate, no. Does it have less recoil, yes. Is it easier to find factory ammo, no. Does it cost less to hand load, yes.
If you are shooting 300 or 600 yards I'd say the 6.5 Creedmoor doesn't give you an advantage, and depending on the game, the lower recoil could improve your game in terms of spotting misses and speed for follow up shots.
If you'll be shooting past 600 to 1000 yards and wind is a variable, then the Creedmoor has the advantage because it can shoot bullets with higher BC's.
Here's a comparison:
6mm Berger 105g Target Hybrid
Speed: 2900 fps
10mph Wind Drift at 1000 yards: 77.2"
Energy at Target (ft-lbs): 478.5
6.5mm Sierra 142g SMK
Speed: 2850 fps
10 mph Wind Drift at 1000 yards: 70.1"
Energy at Target (ft-lbs): 712.8
All that aside, nice job connecting at 1500 yards with your 6BR, and judging from your video, it's a shooter.
This better in wind discussion comes up a lot. The question is, how much better? Is it worth what you are giving up in precision and consistency. A 6BR with 1" of vertical at 600 yards is going to be more forgiving for wind on a diamond or circle target than a bigger, less consistent cartridge that has 3" of vertical at that distance because as you go up and down on the target it gets narrower.
Also, I have posted this before, so I am going to copy and paste it. It is not as simple as saying one has 7" less drift at 1000 yards. We don't call wind in inches. We call it in mph. What that means downrange isn't as obvious as it might seem at first glance. Here is what I posted in a thread weighing the pros and cons of slowing the bullet down to see trace better:
I have a 115 DTAC going 3050 fps at 37 F and 28.7"HG pressure (typical for me 243AI load). At 1000 yds with a 10 mph crosswind (it includes spin drift, but we'll do all the calls in the same direction so they are comparable) I have 1.64 mils of wind drift. At 9 mph I have 1.46 mils and at 8 mph I have 1.28 mils of wind drift.
With a 6 Dasher running a 108 Berger at 2843 I get these numbers: 10 mph is 2.01 mils, 9 mph is 1.78 mils, and 8 mph is 1.55 mils.
1 moa is .29 mils. If I miscalculate the wind by 1mph at 1000 yards with either of these 2 setups at on a typical 2 moa target, I get a hit. If I miscalculate by 2 mph in the same scenario, I miss. Even though the difference of 1.64 mils to 2.01 mils in a 10 mph wind looks significant, It doesn't even increase your margin of error for making a wind call by 1 mph on a typical size target for prs. Therefore, if there are advantages to be gained by seeing trace, you are giving up very little between the 2 in terms of wind drift.
The real compromise comes in the form of energy on target as stated by lte82. There is a perceivable difference even between a 105 going 3170fps vs a 115 going 3050fps out of my 243 Ackley. The 115 hits significantly harder and has significantly more splash on misses. Slow the 105 down to 2800 or 2900 and the difference grows.
What you see down range is effected by a whole list of things. Glass quality, recoil management, muzzlebrake effectiveness, your individual ability to keep your eyes open through the brake concussion, TOF, the weight and balance point of the gun, the amount of splash created by the bullet, etc. It is a balancing act to figure out where the sweet spot is. Based on what people are doing that are winning and what I personally see from shooting setups on both ends of the prs spectrum, I would say the sweet spot is between 2750 and 2900 with a 6 br improved variant level of recoil. It allows for seeing trace well without giving up too much on target energy. Also, the exact sweet spot is going to be slightly different for everyone based on individual differences in reaction time, etc.
If you examine my example closely you will see that there is an even larger difference than in Praeger's example above. It still does not make an appreciable difference in the margin of error for missing the wind call and hitting the target. My point is, yes there are differences. They are noticeable on paper. Are they actually noticeable on the range?
Also, I have posted this before, so I am going to copy and paste it. It is not as simple as saying one has 7" less drift at 1000 yards. We don't call wind in inches. We call it in mph. What that means downrange isn't as obvious as it might seem at first glance. Here is what I posted in a thread weighing the pros and cons of slowing the bullet down to see trace better:
I have a 115 DTAC going 3050 fps at 37 F and 28.7"HG pressure (typical for me 243AI load). At 1000 yds with a 10 mph crosswind (it includes spin drift, but we'll do all the calls in the same direction so they are comparable) I have 1.64 mils of wind drift. At 9 mph I have 1.46 mils and at 8 mph I have 1.28 mils of wind drift.
With a 6 Dasher running a 108 Berger at 2843 I get these numbers: 10 mph is 2.01 mils, 9 mph is 1.78 mils, and 8 mph is 1.55 mils.
1 moa is .29 mils. If I miscalculate the wind by 1mph at 1000 yards with either of these 2 setups at on a typical 2 moa target, I get a hit. If I miscalculate by 2 mph in the same scenario, I miss. Even though the difference of 1.64 mils to 2.01 mils in a 10 mph wind looks significant, It doesn't even increase your margin of error for making a wind call by 1 mph on a typical size target for prs. Therefore, if there are advantages to be gained by seeing trace, you are giving up very little between the 2 in terms of wind drift.
The real compromise comes in the form of energy on target as stated by lte82. There is a perceivable difference even between a 105 going 3170fps vs a 115 going 3050fps out of my 243 Ackley. The 115 hits significantly harder and has significantly more splash on misses. Slow the 105 down to 2800 or 2900 and the difference grows.
What you see down range is effected by a whole list of things. Glass quality, recoil management, muzzlebrake effectiveness, your individual ability to keep your eyes open through the brake concussion, TOF, the weight and balance point of the gun, the amount of splash created by the bullet, etc. It is a balancing act to figure out where the sweet spot is. Based on what people are doing that are winning and what I personally see from shooting setups on both ends of the prs spectrum, I would say the sweet spot is between 2750 and 2900 with a 6 br improved variant level of recoil. It allows for seeing trace well without giving up too much on target energy. Also, the exact sweet spot is going to be slightly different for everyone based on individual differences in reaction time, etc.
If you examine my example closely you will see that there is an even larger difference than in Praeger's example above. It still does not make an appreciable difference in the margin of error for missing the wind call and hitting the target. My point is, yes there are differences. They are noticeable on paper. Are they actually noticeable on the range?
What everyone is saying is true to an extent. If you are going to single load it is absolutely true 100%. If you wish to mag feed 6BR it will depend on which action and magazine set-up you have. 6BR is finicky to get to mag feed and some setups will not do it reliably.
You are sure about that? Because that would save me a lot of money
Yes, we are certain
@308pirate For 300m+ applications I will use 6.5 CM. I am looking for consistent 0,5 moa or better 10-shot groups at 300m. I hope it will be easier to deliver this with 6BR than with 6.5CM.
I know, that's why I said what I said. Lot of people in this place don't even pay attention to the OP's questions.
Yes, it will be easier with the 6BR. There's a reason it's hugely popular with benchrest competitors all over the world and with the ISSF 300 meter crowd.
I paid attention. My response is due to the fact that it came up and someone may reference this thread with different aspirations than the OP. Also, the 6.5 Creed doesn't really beat out the 6br significantly until well past 300 yards. If he has it, he might as well use it.
