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View Full Version : distance to lands in my 111 trophy hunter in 6.5 284 Norma



thermaler
02-23-2014, 09:12 PM
After laying this rifle aside for the season I am once again in the hunt for a good load and have settled on 140 berger VLDs powered by RL22.

however I'm continuously stumped by the CBTO measurements I'm coming up with; even with an exceedingly long high BC bullet like the berger 6.5 VLD it is nearly falling out of the case mouth by the time it engages the lands. Even at berger's recommended max COL of 3.228 (and I've seen go up to 3.3 or so in other manuals) it appears that part of the boat-tail is still in the case neck rather down past the top of the shoulder.

This seems like a very long throat and I was wondering if this is par for the course for this rifle?

1.618
02-23-2014, 11:28 PM
Hmmm...once when I contacted Savage about something else regarding my 12 F-Class in 6.5/284 I asked what reamer they used and the guy said it had a short freebore / leade, which pleased me since the throats on guns chambered for this cartridge reportedly wash out fast...

How many rounds on the clock on yours? Do you load it hot?

GatewayShepherd
02-23-2014, 11:29 PM
I have a 116 that is set up the same as the LRH but with the regular Accustock. In loading 140gr. Amax I end up with a COAL of 3.209”. However that is not what I use as a measurement. I measure to the ogive of the bullet with a gauge. My chamber is 2.473” from base to ogive…that’s my Zero measurement….meaning that is the exact point the bullet touches the lands.
Hope that helps.

stomp442
02-23-2014, 11:48 PM
Sounds like you have a throat issue if in fact the bullet needs to be seated out so far to touch the lands. How many rounds down range? could be that it needs to be set back or sent back to savage to fix. I see you mention CBTO and COAL which are you using and how are you measuring? I use this tool from Sinclair and it is well worth the money. Makes finding the CBTO measurement a snap.

My 6.5-284 with a 140 Berger VLD has a CBTO measurement of 2.495" this is .025" from the lands in my rifle. The barrel I'm currently using has roughly 1200 rounds through it and this puts the bottom of the boat tail right at the neck shoulder junction.

http://www.brownells.com/reloading/measuring-tools/bullet-comparators/sinclair-hex-style-bullet-comparators-prod34262.aspx

GatewayShepherd
02-24-2014, 12:38 AM
Stomp442…i thought mine was on the long side…but given your measurements…mines shorter by .047” I know the Amax’s are a little shorter then the Berger’s. Where is the base of the bullet at in the neck?

thermaler
02-24-2014, 04:21 AM
I've got less than 100 rounds down the tube. They have been mostly factory loads (for brass collection) with COLs much shorter than the SAAMI specs I've seen.
Yes, I'm measuring CBTO (I'm using the Hornady LnL OAL gauge, which I believe is the same as the sinclair tool) with the berger 140 vld I get about 2.6615, at which point the bullet is barely in the case.
I mentioned the berger max COL 3.228 (Nosler's is 3.310 for SAAMI spec) cause even at that measurement the boattail base portion of the bullet (where it "slants" back) is partially in the neck--meaning there is not a whole lot of the neck gripping the bullet. It doesn't look possible for me to get a bullet close to the lands (in the .01 to .03 range) and have enough of the bullet in the case for the neck to grip.

stomp442
02-24-2014, 09:11 AM
It puts the bottom of the boat tail right at the neck shoulder junction. I know mines long and im probably getting close to the point of needing a set back but it still shoots amazingly well so im not messing with it until things go south.

thermaler
02-24-2014, 10:07 AM
It puts the bottom of the boat tail right at the neck shoulder junction. I know mines long and im probably getting close to the point of needing a set back but it still shoots amazingly well so im not messing with it until things go south.that's about how I've seated mine--but according to my CBTO measurements that's a very long jump to lands. I can't help but think that's gotta hurt accuracy--and I'm wondering about the implications on throat/barrel wear as well, especially since the 6.5 284 has a rep for being a barrel-burner.

I didn't buy the gun to be a 1000 yd match gun--especially since it's only a 24" barrel--but I do expect to get some longer range accuracy and perhaps at least have the capability for a 600-800 field shot at a deer. How is your gun performing at longer ranges?

Brent
02-24-2014, 11:34 AM
Couple of things, what makes you think the accuracy is hurt because of jump? Also, are you sure that jump is going to kill the barrel?

I have 2 Savage 6.5-284's. 1 shoots Matrix and Bergers at .100 off the lands and consistently shot .3 MOA. The 2nd rifle, I just got it a few weeks ago, shoots .2-.25 MOA at .125 off the lands. At 630 yards on Saturday I had a string going and then yanked one. The first rounds measured 1" center to center. The yanked round, 4th shot was 3" from center of furthest impact. So a 3" 4 shot group at 630 yards. Sunday, yesterday, I was wolf hunting and found some clay's laying on the ground. I found 3 good clays. At 873 yards I layed them on the hill in a triangle. I needed to do 2 things: 1st verifiy drop as I don't trust my chrono and 2. hit the clays. I adjusted for 2950 fps (0 windage, and .5 MOA L for spin) and the 1st and 2nd round hit the same hole in the dirt, low and right. I expected this. Made a vertical adjustment for 2920 fps, Left wind 1 MOA. 3rd was dead on but left about .5. Wind correct made, 4th round hit center clay, aimed for right clay and hit it.

My other rifle did put a couple of 4 shot groups at 1000 just under 4". I don't do a lot of group shooting once a I know a rifle shoots well and have solid DOPE. I shoot for 1st round cold bore hits and work on my windage calls.

Last thing I want to mention. I have 2 savage 204's. Both like .100 min jump. 1, likes factory hornday ammo with .175 jump. I worked up a couple of loads though that are 150 fps faster and shoot .25 MOA. So, in my opinion don't get too hung up on the jump. Make sure your ammo is straight, find a seating depth YOUR rifle likes, and have fun.

thermaler
02-24-2014, 11:59 AM
Couple of things, what makes you think the accuracy is hurt because of jump? Also, are you sure that jump is going to kill the barrel?

I have 2 Savage 6.5-284's. 1 shoots Matrix and Bergers at .100 off the lands and consistently shot .3 MOA. The 2nd rifle, I just got it a few weeks ago, shoots .2-.25 MOA at .125 off the lands. At 630 yards on Saturday I had a string going and then yanked one. The first rounds measured 1" center to center. The yanked round, 4th shot was 3" from center of furthest impact. So a 3" 4 shot group at 630 yards. Sunday, yesterday, I was wolf hunting and found some clay's laying on the ground. I found 3 good clays. At 873 yards I layed them on the hill in a triangle. I needed to do 2 things: 1st verifiy drop as I don't trust my chrono and 2. hit the clays. I adjusted for 2950 fps (0 windage, and .5 MOA L for spin) and the 1st and 2nd round hit the same hole in the dirt, low and right. I expected this. Made a vertical adjustment for 2920 fps, Left wind 1 MOA. 3rd was dead on but left about .5. Wind correct made, 4th round hit center clay, aimed for right clay and hit it.

My other rifle did put a couple of 4 shot groups at 1000 just under 4". I don't do a lot of group shooting once a I know a rifle shoots well and have solid DOPE. I shoot for 1st round cold bore hits and work on my windage calls.

Last thing I want to mention. I have 2 savage 204's. Both like .100 min jump. 1, likes factory hornday ammo with .175 jump. I worked up a couple of loads though that are 150 fps faster and shoot .25 MOA. So, in my opinion don't get too hung up on the jump. Make sure your ammo is straight, find a seating depth YOUR rifle likes, and have fun. I'm NOT sure it affects accuracy or longevity--I'm fishing mostly for responses to whether or not this is outside the norm. The 6.5 284 Norma is a fairly recent "wildcat to SAAMI standardized" caliber and as you can see there is still some variations even within the loading manuals as to what the specs really are. I think this may be because of the parent lineage of the 284--the die I use still says 6.5 - 284 Win and I suspect there is a difference in the chamber evolution of rifles to today's "true" 6.5 284 Norma.

Brent
02-24-2014, 12:22 PM
Gotcha, mis-read.

My dies say the same thing. The diffference is mainly in the throat. I agree that the differences are not understood well. I have issues with my 204 and 6.5's not being the same. I would love to be able to set my seating dies the same but I can't. On my latest rifle the throat is much shorter and the bullet seats much deeper. I can seat to the lands if I want, bullet depth in the neck is still a little marginal though, but the rifle likes the deeper depth with bergers. My older rifle throat is too long for seating to the lands. I want to test Amax's to see if holds true for them as well but have not gotten around to it yet.

To the lands numbers using Hornady guage.
Old 6.5-284 OAL, base of case to ogive of Berger 140 VLD hunting= 2.582 (160 Matrix OAL is 2.608)
New 6.5-284 = 2.537

stomp442
02-24-2014, 12:26 PM
My rifle shoots great I have no complaints with it at all. It still holds under half moa five shot groups at 600. I should have taken a pic last weekend but the range was really busy. I had the first three touching on the steel and then the last two broke about 2" to the left due to a wind change I'm sure.

I say pick a seating depth and work up a load and see how it does. I have found .025" from the lands to be the sweet spot for most of my rifles.

thermaler
02-24-2014, 12:43 PM
My rifle shoots great I have no complaints with it at all. It still holds under half moa five shot groups at 600. I should have taken a pic last weekend but the range was really busy. I had the first three touching on the steel and then the last two broke about 2" to the left due to a wind change I'm sure.

I say pick a seating depth and work up a load and see how it does. I have found .025" from the lands to be the sweet spot for most of my rifles.That's great shootin. I don't think those jumps are possible in my chamber/throat.

FW Conch
02-24-2014, 12:50 PM
I have a 30/06 that gets it's best accuracy with Nosler BT's that take a .160" jump to the lands. I would seat the top of the boat tail .264" into the case neck, work on load development, and see how it shoots. A long jump doesn't increase throat wear, heat does. Book COAL is a "suggested" length to insure loads will fit into the average magazine.

Good Luck-Good Shooting ;-))......Jim

Brent
02-24-2014, 01:12 PM
I have a 30/06 that gets it's best accuracy with Nosler BT's that take a .160" jump to the lands. I would seat the top of the boat tail .264" into the case neck, work on load development, and see how it shoots. A long jump doesn't increase throat wear, heat does. Book COAL is a "suggested" length to insure loads will fit into the average magazine.

Good Luck-Good Shooting ;-))......Jim


Yep. I never pay attention those numbers. Just like velocity in a book is meaningless. You have to take into account the tested barrel length, seating depth, barrel design etc. Just not possible to use anything in there other than for reference and starting points.

thermaler
02-24-2014, 01:28 PM
I just compared the VLD to all my other 6.5 bullets--the VLD has a significantly sharper secant ogive angle (the boattail looks longer too) than any other bullet I have which I'm guessing accounts for the longish COL. The sharp angle may possibly be a factor in how it seats long in the chamber throat??

FW Conch
02-24-2014, 01:37 PM
+1 On That !

CharlieNC
02-24-2014, 01:41 PM
Like some others noted I found my 6BR likes a long jump with Bergers; .050" jump clearly gave the best groups when compared to jambing to even longer per Bergers recommendation to try. Have you tried jumping a bit?

thermaler
02-24-2014, 02:24 PM
Like some others noted I found my 6BR likes a long jump with Bergers; .050" jump clearly gave the best groups when compared to jambing to even longer per Bergers recommendation to try. Have you tried jumping a bit?My jump with the 140 vld at their max COL of 3.228 is at .05 as far as I can tell.