Hello, Have a #2 Hawk Hill getting done and it is going on a Rem 700 adl with factory mag box. The smith can throat it at .150 throat length so that the 147 eld will touch the lands at 2.808 or so. Thinking the saami throat is around .198. Thinking there would be no downside to going shorter throat if I can. Any thoughts on that would be welcomed. Thank you
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Throat length on 6.5 Creedmoor chamber
- Thread starter 30338
- Start date
Saami is .199”. LRI does a ‘Berger’ chamber with a .169” throat. Works great with the Berger 140 Hybrid @ .010” off lands. The only downside I have found is I can’t use 99.9% of commercial ammo for practice.
I am sure others will have better knowledge on this, but .150” sounds pretty short, ie, more limiting. Is .150” only optimal for mag fed 147 ELD?
I am sure others will have better knowledge on this, but .150” sounds pretty short, ie, more limiting. Is .150” only optimal for mag fed 147 ELD?
My Tikka has a ridiculous throat. 2.940 to the lands with the 143 ELD-X. It shoots just as ridiculously well though, so I struggled with changing things. I opted to a .170 freebore reamer from JGS and a 26” Bartlein tovreplacevthe sliw 20” factory barrel. The thing about freebore is, ifvthey actuayfolliwed saami it probably wouldn’t be so bad... but I’m pretty sure these super long throats aren’t saami either. If I can get down to the 2.870 or shorter my CTR mag should feed better.
I have a Hawk Hill 6.5 cm with the standard .199 free bore. It runs 140 hybrids and 130 ELDM very well. I do have to run the hybrids .050 OTLs to fit my Magpuls but the hybrid doesn’t mind it.
I believe the max length for a BDL is 2.825 so you’ll benefit from the shorter throat. You’ll probabaly need to hand load if want to 147 eld.
I believe the max length for a BDL is 2.825 so you’ll benefit from the shorter throat. You’ll probabaly need to hand load if want to 147 eld.
Thanks for the feedback guys. Was hoping to have the best of both worlds, reloading and factory. Sounds like a .150 throat takes factory ammo out of the picture. Now thinking I may just use my 6.5x47 lapua reamer and build another lapua lol. Its either that or go with the saami throat length for the creedmoor. Got a few weeks to decide yet.
I wouldn't go that short. I have a .169 freebore and it works great with the 147 and factory ammo. It sets the factory 147s about .030" off the lands which is a good place for them. All my other Creedmoors are and have been SAAMI .199 and it works as well with factory ammo and I can load the 147 .030" off and still fit in mags.
So my idea was to get this chambered in a cartridge that my daughter can easily find factory ammo for. She is a good shot and enjoys hunting but I don't think she will want to reload in the future. So maybe I need to stay with the slightly longer throat for the 6.5 Creedmoor.
Rob, Which factory ammo will work with the .169 freebore in your experience? Like hunting with any of the Berger hunting bullets and thinking the 147 would do great as well. Big plus if those would work in the .169 throat.
Rob, Which factory ammo will work with the .169 freebore in your experience? Like hunting with any of the Berger hunting bullets and thinking the 147 would do great as well. Big plus if those would work in the .169 throat.
I had all the parts handy so I made a dummy. With my saami reamer, touching comes in at 2.895. That’s about .005 long for my AICS mags(unmodified). So with some jump they’d work, but you’d only have .025 to chase. These mags vary a bit as well. 2.895 fits easily in an AW magazine, which is what I use.
AWmag
AICS mag
Edit: Is there a reason you want to run the 147? Unless you’re handloading, I don’t think the factory ammo really makes those worth it IMO. They end up being pretty much identical to the 140 downrange.
AWmag
AICS mag
Edit: Is there a reason you want to run the 147? Unless you’re handloading, I don’t think the factory ammo really makes those worth it IMO. They end up being pretty much identical to the 140 downrange.
Not hung up on the 147. For the last 8 years or so have killed about everything with 140 Berger VLD hunting bullets and that is the preferred bullet. I don’t shoot any other bullets than Berger or Hornady. Number one concern is being able to shoot factory ammo and handloads a secondary concern.
I found approx .020” of seating depth variance in the lot of Prime 130 that I have. About 4 out of every box of 20 was touching the lands in a .169” freebore chamber that LRI cut. True, most were ~.010 off, and some were ~.020 off, but it being factory ammo, enough were in the lands with my lot to give me pause.
Well I decided to go with the 147 eld hitting lands at 2.81. Got some of those loaded as well as some 140 vld. And was happy that the 135 Berger factory ammo fed without issue and did not contact the lands. So we'll see how the Hawk Hill #2 at 22" does here soon hopefully.
Got to range today. The shorter throat sure shoots well. The very first 3 rounds were the Berger 135 Classic Hunter factory loads. Very low ES and very accurate out to 500 yards today. It makes an easy factory choice if I decide to just buy factory. This Hawk Hill 8 twist chambered in a weeks time by shaenrifles.com is sure shooting everything well.
Same as mine - stupidly long throat on the Tikka CTR. But it shoots great and pretty fast for a Tikka (43.2 grains of H-4350 running at 2,780 fps, .030 off the lands), so I just roll with it and move on.
So your 26" Bartlein at .170 freebore is shooting good?
I actually found some Mountain Tactical AI bottom metal and an MDT mag that will allow 2.950 COAL. I’m still waiting on the barrel install, but since I have the extra room in the mag now, I’m going with a SAAMI spec JGS reamer. I’m hoping to have the gun fairly soon and will report back.
So, jumping in on this conversation. I'm having a barrel chambered right now. I only reload, and never shoot factory ammo. To date, all of my rifles have been shot using 140 Hybrids. I am tempted by the 140 and 147 ELDM's. Due to price.
My gunsmith told me to seat dummy rounds with each 30tho from the neck/shoulder. After reading, I realize that the 140 ELD and Hybrid won't fit in the exact same chamber unless it's long. The Berger seated as above was 2.875, but the ELD was shorter. It still had a longer CBTO measurement due the the bullet design.
Hybrid Only = .169-170
ELD Only = ?
Both = ?
I am very reluctant to leave the hybrids as they have been very good out to distance.
What freebore would one need to shoot both?
Help a brother out.
My gunsmith told me to seat dummy rounds with each 30tho from the neck/shoulder. After reading, I realize that the 140 ELD and Hybrid won't fit in the exact same chamber unless it's long. The Berger seated as above was 2.875, but the ELD was shorter. It still had a longer CBTO measurement due the the bullet design.
Hybrid Only = .169-170
ELD Only = ?
Both = ?
I am very reluctant to leave the hybrids as they have been very good out to distance.
What freebore would one need to shoot both?
Help a brother out.
You can shoot both the 140 and 147 ELDs out of a .169 freebore chamber. Seated .020" off the lands the 147 will be about 2.840" and the 140 will be about 2.820" OAL.
To be clear, will this allow you to shoot reloads without seating the bullet deal into the case? in other words. If I seat a bullets beginning bearing surface 30thou from the neck shoulder junction how would the freebore compare?
No idea about the amount of bullet to neck juncture as that is not a real concern as I have shot these bullets from factory 2.800 length to 2.870" and never a problem with accuracy. There is enough of the bullet in the neck so don't worry about exact figures with that. Worry about the ogive to lands.
Reviving an old thread - I'm looking to get into 6.5 - no reloading just going to be shooting Old Prime and New Prime 6.5 that I got from a group buy, and then also the Hornady 140-147.
Will a .170 freebore work across all the ammo?
Thanks Rob.
Yeah you should be fine with a .170" as it's only .029" in from the SAAMI. With the SAAMI and the 147 ELD I am touching at 2.890" and factory is right at about 2.800" so you would be jamming at around 2.860" which is much more than you would see from factory ammo. I don't think you would have an issue with the .170. Thats said the .199 works pretty well across the board as well. No real wrong answer for factory ammo.
I have a .170 from Straight Jacket Armory found that the new Primes with 130 SMK were touching the lands. I've had a round pull apart after timing out on a stage so just be aware. With that said the new prime shot lights out. The ogive on Hornady 140-147 and Berger 140-144 are further back so you should be good. The only advantage to the .170 is that it's easier to run sub .040 jump while maintaining mag length on the 140 + bullets.
Yep or I got batch of prime not seated all the way. I didn't measure as they were shooting but multiple round a had marks when extracting unfired rounds. Only one pulled apart in two cases.
It was seated. I didn't measure them nor talk to prime to see what their BTO measurement was. I just know that batch was touching the lands in a .170 barrel. They shot well so I didn't worry about it.
It would be interesting to get a measurement to ogive and also to tip on those. Very odd for a light bullet to be that close to the lands. Usually they start moving farther away with the lighter bullets.
Wow great info thanks. SJA also recommended .170 freebore and a 1:8 twist. I think I'll give that a go.
Bumping this again...
Everything I've got in inventory is factory of either 130 Berger otm, 140 Hybrid Target Berger, 140 SMK, and whatever Old Prime 130gr is.
Longest COAL is the Berger factory 140 HT at like 2.808 and everything down to 2.760 (old Prime).
It looks to me like 0.199 spec is the right call, yes?
Everything I've got in inventory is factory of either 130 Berger otm, 140 Hybrid Target Berger, 140 SMK, and whatever Old Prime 130gr is.
Longest COAL is the Berger factory 140 HT at like 2.808 and everything down to 2.760 (old Prime).
It looks to me like 0.199 spec is the right call, yes?
Is there a way to reverse engineer what a barrel's freebore was when it was chambered? My rifle has about 3,500 rounds on it so the throat has obviously eroded. But I know what the jump was when close to new.
With Hornady 140gr ELD-M, the jump to the lands at 600 rounds was 0.032". At 1,000 rounds, it was 0.0398". Measured using the same bullet. So an estimated 0.0000195" erosion per shot = 0.3083" jump when new. If you can even do it this way.
Does that correspond to a .199 freebore?
With Hornady 140gr ELD-M, the jump to the lands at 600 rounds was 0.032". At 1,000 rounds, it was 0.0398". Measured using the same bullet. So an estimated 0.0000195" erosion per shot = 0.3083" jump when new. If you can even do it this way.
Does that correspond to a .199 freebore?
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It shoots way better than any other lol. And test data I've seen lately suggests this ammo shoots better with shorter than .199. But who knows.
And when new, speeds were about 100fps higher and slightly flattened primer. But has since simmered down.
I ask because I do not hand load. I only shoot factory 140 ELDM. And This gun shot sooooooo good in the first 1,500 rounds. I want to emulate that when I get a new barrel chambered.
The standard freebore makes for .030 jump with factory hornady 140 ELD. So if you were jumping .032 at 600 rounds, more than likely it was just the standard freebore.
Perfect, thank you. That lines up with my math for an estimated 0.030 jump when new (edited my post above).
A factory loaded bullet is only .032" off lands? That's not a .199 SAAMI chamber then. In a .199 you would have a minimum of .050" if it was loaded at the longer 2.820" as some were but a lot were back at the 2.800" and give a .070" jump in a .199.
Correct. At 600 rounds, the jump was 0.32". Is what Supersubes is saying not accurate?
It's been a while, but I think the way I measured is with the Hornady OAL gauge to press bullet against lands. Did this 20 times, took an average. I then compared that against 20 factory rounds (took average) and calculated the difference for the jump.
Then I did that again at 1,000 rounds.
Not if he is saying .032" is normal jump in a .199 freebore with factory ammo. Never been anywhere near that close in multiple barrels since 2008 with .199 SAAMI freebores including the three I have now. All chambered by custom gunsmiths and not factory rifles so I know they were right.
Well something's not adding up then. But... it can't be a coincidence my math arrived at 0.030" for brand new. And doing a search a lot of people are reporting that's the exact jump that gave them great performance when hand loading.
Here's the data I have recorded base to ogive
600 rounds: 2.2280"
1,000 rounds: 2.2358"
New box ammo: 2.1960"
2.228 - 2.1960 = 0.032" jump
2.2358 - 2.1960 = 0.0398" jump
Working backwards, the math is bang on for a 0.030" jump when new.
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The 140 ELD, like the other ELDs, don't mind a jump. Shooting factory ammo and jumping .070" it shoots great in my rifle. Used a tuner to tune harmonics and got it to 1 hole 5 shot group so the bullet jump is not an issue. Most load to the .030-.010" as they can and like being closer. I load mine at .020" off because I can. So not sure what to say but I would say no your rifle was not a SAAMI .199 freebore chamber. What rifle is it?
