First time reloader...few questions on order of operations

[OmegaRed]

Sorry for the length, but I wanted full background to illuminate my various questions...

I've done plenty of due diligence, read plenty of manuals, watched vids etc. But I still have some questions on my specific process, and wanted to make sure I was doing things to be the most efficient and not be wasting precious components.

I bought a 6br built on a Rem 700 action. with a Hart .270 barrel. The local gentleman I bought it from included a variety of notes and different loads that he had made up for this gun. Unfortunately, he is no longer with us, so I can't ask any of these questions to him. I am however going to be helped by a friend with many of the reloading equipment necessities that I will need, but he's never reloaded for a benchrest gun. So many of the processes he's never had to do (neck turning etc)

I'm not competing, so I wanted a loading that would shoot well, but be the same bullet for having fun shooting all the way out to longer distance shooting. This gun shoots in the .2's with 95 VLD's and Varget off of sand bags, before I bought a rest and rear bag. That being said, Varget is not possible to get locally, but RL15 is.

I went off what seemed like a popular loading, and ordered components for 105 VLD's, RL15, CCI450's.

Q1: So I have freshly shot in this chamber brass. I'm not sure if this brass is Blue or Gold box, or if it was neck turned or not. I've read some varying reviews that sometimes you can get away with not neck turning for a .270 neck, sometimes it's too tight. My question is, if it fits now, will it always fit (in regards to neck diameter) or does the neck expand like the COL? If it does expand, about how often will it need neck turned. I realize this is subjective, just looking for a ballpark answer.

Q2: In regards to load development. I plan to get the case back to spec, then start a ladder test. I've read from Berger to start with .010-.015. The article by Jason Baney (http://www.6mmbr.com/laddertest.html) suggests a well known seating depth is .020 for this exact loading. Any suggestions on where to start here? Will in matter in regards to ladder testing?

More later. Thanks for the help in advance.

 

[tightneck]

First things first. You need to get yourself a micrometer, if you don't already have one. A .270" neck may be very tight for some brass, and not too bad with other brass. Not even the best brass holds the same thickness from lot to lot. With .013" wall thickness, your left with .0005" total clearance if loading a .2435" bullet.That's not enough clearance. The same bullet from the same manufacturer can vary in diameter quite a bit from lot to lot (I've seen 6mm bullets as big as .2439"). Now this is where the mic comes in. You need to be able to measure the neck diameter of the loaded round at a minimum, and a set of calipers just aint accurate enough. You'll need at least .001" clearance, and more is better, within reason. For tight neck chambers, I like at least .0015", and as much as .003" total clearance. You can invest in a neck turning setup, but there are also sevearal sources for pre-prepped brass.

As to the load work up, you'll just have to play with different neck tensions, seating depths, and powder charges to come up with what works. Remember, this is the entire point of reloading. While you can find lots of different recipe's online, they are just references, each rifle/barrel is unique.

 

[OmegaRed]

So I'll def. need a neck turner?

For the load development, I should have been more specific. The seating depth that I referred to above was in reference to the starting point for the ladder test, in order to find a favorable node. I realize that I'll have to start playing around with the other variables after that.

 

[tightneck]

Without knowing what the loaded neck diamter is, I can't say whether turning necks is required. My point is that .270" is not a standard "no turn neck" diameter. At least, it didn't use to be. I haven't bought any 6BR brass recently, so I don't know what the current wall thickness is. There was a time when .272" or even .273" was a no turn neck. Brass varies, so that's why it's imperative to know what your loaded neck diameter is. As for load work up, I don't use a ladder test. I use a pet load, and adjust seating depth until I see what I want, then work on the other stuff. Many ways to skin this cat.

 

[HTSmith]

• A few comments.
• You are likely running very close on neck clearance. I just miked some blue box brass loaded with Berger 105 VLDH's and they were .268".
• Check your twist. Most likely it is 8" which will be fine for 105's, but there could be a reason the previous owner was running 95 Gr. bullets(eg a 9" twist)
• R15 will work fine and will likely get you a bit more velocity than Varget. I think Varget is bit more consistent.
• The 105 VLD Hunting bullets have the highest ballistic coefficient and shoot as well as the targets
• CCI 450's work really well for me--so well I've never even tried others.
• .020" off the lands is a good place to start. Some advocate starting jammed and working back. Whatever you do stay away from just touching. Mine likes .025" off. Small changes in seating depth (like .003") can make a discernable difference in accuracy.
• Sounds like you have yourself a shooter. You'll love the 6BR!

 

[dcali]

Necks do not expand. Turn once and you're done. And yes, you should turn for that chamber - even good brass (Lapua, Norma) varies by as much as .001" in neck thickness - sometimes from one side of the case to the other, and your clearance is too tight at .270. People sometimes use .001" of clearance for benchrest, but it's tight - you have to be careful and understand what you're doing. You have to measure and cut carefully and make sure all the cases fit. Turning to +/- .0003" neck thickness is easy. Turning to +/- 0.0001" takes care. For a typical custom chamber, a good rule of thumb is .003-005" of diametrical clearance or so - it's plenty tight to give good brass life and gives a little margin for safety. (Even .007" will help keep you from splitting necks.)

 

[BillPa]

First and foremost before going any further I'd make or have a chamber made so you know exactly what the chamber neck OD is. Armed with that info then you can determine if the brass needs to be turned or used as-is.

Bill

 

[OmegaRed]

I'm learning a lot off of this thread, I appreciate it.

I do have a mic, so that's no problem. I'll have to look at my notes tonight, I recorded a good bit of all the measurements of most of these finished loaded bullets. If memory serves it seems like most were right around .268x

Barrel is a 1:8. He had a bunch of ammo from 88's all the way up to SMK 107's. So from what I've read here, I would assume the brass has already been neck turned. I'll try to get some on a dial indicator and check them. That should be me a better idea. (after re-reading my original post, I should clarify that these are not just brass, they are loaded rounds)

 

[Comrade Terry]

So from what I've read here, I would assume the brass has already been neck turned. I'll try to get some on a dial indicator and check them.

You'll need a tube micrometer to measure the thickness of the brass in the neck. Measure it in three or four places, all equidistant from the mouth of the case. That will tell you if the necks have been turned or not.

 

[gotcha]

Use your Mic. to measure seated bullet neck diameter at two or three different points of the diameter. If necks AREN'T neck turned you will see up to .001" variation in diameter.... Also separate barreled action from stock. Some Smiths will electro etch chamber specs on BBL. just forward of lug at bottom of BBL. ....... If your rifle came with a "gizzie" you might find the chamber specs electro etched on it........ A gizzie is a short piece of barrel 1" to 2.5" long (approx.) that was partially chambered to provide for establishing bullet seating depth or a basis for determining throat erosion. Just another angle here. Good luck & good shootin'

 

[HTSmith]

Just mike the loaded rounds in several places. Diameter of the neck with the bullet seated (at its largest point) compared with your neck diameter is the key. Sounds like what you've shot so far has done really well. If you are getting good groups without any unexplained flyers or any signs of high pressure, this may be a theoretical problem but not a practical one.

For your new brass a light neck could be in order.

 

[OmegaRed]

Sweet. I'll report back with my progress.

 

[barefooter56]

Sorry for the length, but I wanted full background to illuminate my various questions...

I've done plenty of due diligence, read plenty of manuals, watched vids etc. But I still have some questions on my specific process, and wanted to make sure I was doing things to be the most efficient and not be wasting precious components.

I bought a 6br built on a Rem 700 action. with a Hart .270 barrel. The local gentleman I bought it from included a variety of notes and different loads that he had made up for this gun. Unfortunately, he is no longer with us, so I can't ask any of these questions to him. I am however going to be helped by a friend with many of the reloading equipment necessities that I will need, but he's never reloaded for a benchrest gun. So many of the processes he's never had to do (neck turning etc)

I'm not competing, so I wanted a loading that would shoot well, but be the same bullet for having fun shooting all the way out to longer distance shooting. This gun shoots in the .2's with 95 VLD's and Varget off of sand bags, before I bought a rest and rear bag. That being said, Varget is not possible to get locally, but RL15 is.

I went off what seemed like a popular loading, and ordered components for 105 VLD's, RL15, CCI450's.

Q1: So I have freshly shot in this chamber brass. I'm not sure if this brass is Blue or Gold box, or if it was neck turned or not. I've read some varying reviews that sometimes you can get away with not neck turning for a .270 neck, sometimes it's too tight. My question is, if it fits now, will it always fit (in regards to neck diameter) or does the neck expand like the COL? If it does expand, about how often will it need neck turned. I realize this is subjective, just looking for a ballpark answer.

Q2: In regards to load development. I plan to get the case back to spec, then start a ladder test. I've read from Berger to start with .010-.015. The article by Jason Baney (http://www.6mmbr.com/laddertest.html) suggests a well known seating depth is .020 for this exact loading. Any suggestions on where to start here? Will in matter in regards to ladder testing?

More later. Thanks for the help in advance.

OmegaRed,
With the .270 neck chamber you will probabaly have to do at lease a "skim" cut on the gold box LAPUA brass if it isn't turned already by the former owner. The blue box brass is thinner and lighter so it MAY not need to be turned . A good formula for figuring just what you need for neckwall thickness for your .270 neck chamber is : .270 - .001 = .269. .269 - .243 (bullet diameter) = .026 . .026 divided by 2 = .013 neck wall thickness . .013 x 2 = .026 . .243 + .026 = .269 measurement across the neck of a loaded round. You may want to turn your necks to .012 neckwall thickness to give you a little more clearance for neck expansion to make sure the neck opens enough to release the bullet just for safety. See our VLD seating depth testing instructions here :
http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/ also read these two articles by Bryan Litz :
http://www.bergerbullets.com/effect...coal-and-cartridge-base-to-ogive-cbto-part-1/
and
http://www.bergerbullets.com/effect...coal-and-cartridge-base-to-ogive-cbto-part-2/

Do your bullet seating depth testing at the lowest powder charge listed for the bullet/powder/cartridge combination you are testing. Once the seating depth accuracy is found. Work the load back up slowly checking for pressure signs and accuracy as you increase the powder charge until your highest velocity accuracy node is found. You have to test to find what YOUR rifle likes in terms of bullet seating depth and velocity . .020 off may work for Jason's rifle . Don't assume it will work for yours.

You are going to need a good "ball end" or tubing micrometer to accurately measure you neck wall thickness. A good cartridge Over All Length (OAL) tool to find your seating depth to the lands , a bullet comparator and a good set of calipers ( digital if you are not familiar with machinist measuring tools STARRET does offer a good booklet on how to read the scales on micrometers that you can find on their website. Great bench source!) PMA on the net is a great source for quality neck turning and measuring tools. http://www.pmatool.com/
Hope this helps get you started. I am sure that there is enough expertise here to help you decipher the former owners notes.
Take care,

 

[HTSmith]

http://forum.accurateshooter.com/threads/norma-6dasher-brass.3898959/page-21#post-36784298

Worth a look regarding neck clearance.

 

[OmegaRed]

Lots of good info to read up on. Again, thank you. I got out to shoot some last night. Even got to register my first groundhog with this gun. Reminded me of my high school days, I wasn't set up yet and still driving through a field to get to the bench. Had to use my driver side mirror as a rest.

Here's 105 A Max / Varget / Rem 7.5 three shot group at 600. Best group of the night, and oddly enough this bullet is the least accurate of any of the ammo that I've shot so far at 100yds (about 3/4 moa).

 

[Larryh128]

As weird as that sounds to shoot a good group at 600 when it shoots 3/4" at 100, it happens. The bullet isn't fully stabilized yet at 100. I have a rifle that shoots 3/4" groups at 100 & 3/4" groups at 300. Where I have seen this is mainly from long for caliber bullets.

 

[HTSmith]

Hmmm....thinking I should be asking your advice instead of the reverse. Good shootin!

 

[OmegaRed]

Looks like I should be good to go. Loaded brass consistently measures .2685


So I am ready to start trimming. Is 1.555 still a good length to trim brass to? Is there a +/- on brass length that is an acceptable deviation, or do you trim back to your shortest piece in the lot?

Same question on a finished round once we get there, whats an acceptable deviation on OAL?

 

[CJ6]

First and foremost before going any further I'd make or have a chamber made so you know exactly what the chamber neck OD is. Armed with that info then you can determine if the brass needs to be turned or used as-is.

Bill

This ^^^^^ before you start anything else IMHO.

 

[rardoin]

Can you elaborate? I'm not sure what is meant by getting a chamber made. Thanks!

I think there was a typo...I assume he meant a chamber casting...like a cerrosafe casting...so you can measure the actual neck diameter. If you are not familiar with the process, basically you are pouring a low melting temp alloy into the chamber (with a plug just ahead of the throat in the barrel) that forms a cast of the chamber. Cerrosafe will shrink a few thou' to allow removal of the cast and after 30 minutes it assumes the original cast dimensions for a period of time allowing you to measure the internal dimensions of the chamber indirectly.