Let's Talk Precision Rifle Brass (Full Length vs. Neck Sizing)

[Member 5605]

I'm working towards making specific brass for my rifle. For my rifle only.

The rifle:
Remington 700 in .308, 20" SPS Tactical
Gun has probably a little less than 80 rounds through it right now after break in and load development.
Brass is trimmed to 2.000" +/- .001, chamfered and deburred.

Here are a couple things I've come across and I want the local NWFA'ers opinions. You know, they are like feet. Sometimes they stink but sometimes people want to lick them.



I purchased some Federal .308 rounds and fired them in my rifle.

Using a Hornady headspace gauge I'm running with a .400" datum line setup.. I'm getting this:

My chamber: 1.6245" +/- .0005



I would resize my brass using a neck sizer which would keep the 1.6245" case length at the .400" line... BUT.. I was using my full length sizer to resize the brass down to: 1.6175" +/- .0005


Now this got me thinking.... and reading. Why am I using a neck sizer only, when I could take my full length brass and since I know exactly what my chamber is.. I could size some brass down to say 1.6220 +/- .0005??

So I tried it. I took a 1.6245" piece of brass, back my full length sizer die out and sized the brass. I figured it would grow a bit but the jump to 1.633" shocked me.

So I kept going down on the die in small increments....


Then I went .002" a little too far than I wanted....



So I'm essentially bumping the shoulder back .002" every time to ensure enough clearance and ease of feeding into the rifle.

The dilemma:

1. Resize full length using only enough to set the shoulder back, not using my neck only sizer..
2. Use neck sizing only if I'm not having feeding issues, when the headspace grows, then bump the shoulder back to .002" below chamber
3. Keep neck sizing and only bump back when brass grows before chambering issues, keep full length die set to run 1.620" or slightly under that to 1.618" so any brass you get can be fire formed and then neck sized after that

I'm really wanting to dial this rifle in. I already have the load and I'm hitting .620" at 200y grouping right now using just neck sized brass.

.620" was taking the overall spread and subtracting the .308", so spread from end to end was .928" outside of hole to outsid of hole.

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[Steve M]

I don't have any neck sizing dies and don't shoot any of my rifles for that kind of accuracy yet, but I do use the gauge like you have shown to bump the shoulder back 1-2 thousands with my FL die for the bolt guns. To do otherwise is brass torture at best and outright brass murder in one gun. I want to say that the competitive shooters are actually using bushing dies to get uniform neck tension.

 

[Greenbug]

Put down the calipers, and step away from the reloading bench.

You are going to drive yourself crazy.....

 

[Member 5605]

Haha. Maybe so. I strive for precision on the mechanical aspects of shooting that I have control over.

When I'm dropping powder, as soon as the granule of powder hits making it my target load that's it. It doesn't get another granule. 44grains is 44grains, not 44.05.

Only error should be me and my ability. Yes, I make precision rounds to the best of my ability... Well I'm trying to anyway.

 

[Velzey]

I've got a little info for you, but later this evening!!

 

[Gun Mechanic]

Well, if option 3 is what you're currently doing and giving you a 0.31" MOA at 200 yards I'd say stick with option 3! Have you tried option 1 or 2? What's the goal of the dilemma, to eliminate a step?

I'm not sure of your reloading history/skill but you're using Federal brass which isn't the most consistent. Are you measuring concentricity? Are you weighting each piece of brass? What dies are you using?

 

[Silver Hand]

You can invest months or years developing a round that not only shoots in in hole at 100 yards but delivers it's energy at the rate desired and with a projectile that passes all the tests for your requirements.

Once you find it load up on brass from that lot, primers, powder and projectiles all with the corresponding lot numbers. As they will never be the same again.


For kicks just weigh every projectile. About 1980 += I found Nosler partitions in .30 caliber 180 grain to weigh low as much as 20 grains. Not one of 200 were over weight but I distinctly remember the separate weight piles, even there best would not shoot straight.
Silver Hand

 

[Certaindeaf]

I think most all precision benchresters just throw their powder, not weigh it.

 

[Member 5605]

Well, if option 3 is what you're currently doing and giving you a 0.31" MOA at 200 yards I'd say stick with option 3! Have you tried option 1 or 2? What's the goal of the dilemma, to eliminate a step?

Thanks a bunch. I'm hoping to remain consistent throughout the process that's all. I'm trying to find that most reliable method, most consistent method without spending time obsessing over .0005" of setback or cutting powder grains in half. After all my RCBS scale only registers to .1 grains.

I'm not sure of your reloading history/skill but you're using Federal brass which isn't the most consistent. Are you measuring concentricity? Are you weighting each piece of brass? What dies are you using?

Reloading experience:
Couple years now. I've had good luck shooting .120"@50 groups in a .223 and loading hole for hole rounds in .243. This is the first time I've went forward with the idea of neck sizing and making brass for one rifle. I used to load rounds (powder and OAL only) for each rifle but it's now getting more precise than that.

That's all good info. The brass I was using was Remington, I was checking headstamp earlier. I did have 8 of 21 were Federal when I did those groups.

Not at the point of measuring concentricity-yet.

Not weighing brass. Goes along with concentric rounds. Not yet.

I did weigh some just as an edit:
Federal on average was 10 grains heavier than Remington. I see the difference.

RCBS dies.

Some of the reasons I don't have a concentric gauge and other stuff is time and monies. Monies being the shortest side if the equation. Im sure slowly I'll build up more precision equipment and stretch those legs when they come.

 

[Member 5605]

You can invest months or years developing a round that not only shoots in in hole at 100 yards but delivers it's energy at the rate desired and with a projectile that passes all the tests for your requirements.

Once you find it load up on brass from that lot, primers, powder and projectiles all with the corresponding lot numbers. As they will never be the same again.


For kicks just weigh every projectile. About 1980 += I found Nosler partitions in .30 caliber 180 grain to weigh low as much as 20 grains. Not one of 200 were over weight but I distinctly remember the separate weight piles, even there best would not shoot straight.
Silver Hand

Thanks.

Once I get ahead a little more I will probably go purchase some new brass. Use that as a starting point and run that brass until it's done.

 

[ron]

Bumping the shoulder of the case to closely fit the chamber as
you describe is beneficial. IMHO My input to you is about
brass. Lapua is the best but too exspensive for me. Winchester
brass is popular among the competitors I shoot with. Federal
has a reputation as being soft and not desirable. I prep my
brass my trimming, uniform primer pocket and flash hole
debur. For long range I will separate the brass in 1 grain lots.
Lapua brass is very consistent. "Bench Rest" primers probably
is a good idea. So many variables to play with.

 

[Silver Hand]

Thanks.

Once I get ahead a little more I will probably go purchase some new brass. Use that as a starting point and run that brass until it's done.

I have had Winchester brass shoot under 5/8 inch using Hornady 140 grain pills in a .364 win mag. @ 100Yards. Just a pinker round!
All things being equal 'except' I purchased 200 pieces of Remington brass, otherwise in the same load worked up exactly, the group opened up to six inches.
The interior web of the cases are totally different and the Remington brass never did shoot well. Winchester had a unique roll in the web, Remington did not.

After doing a chamber cast, I weigh everything even the brass after it is prepared to include sizing, trimming the length, burring the necks and squaring of the case heads.
Silver Hand

 

[v0lcom13sn0w]

you guys are nuts...



all kidding aside, dyjital, i am intrigued by your effort to make the perfect round for your rifle!

sounds like you should be machining your projectiles on a lathe man!

while i cant offer much advice aside from what you probably already know,i can tell you that
theres three types of loads i make for my 308 win:
plinkers, hunting rounds and 'because i can' rounds. ha.

my plinkers are full length sized, powder +\- 0.2-0.3gr out of my powder dispenser with varying bullets. these shoot 1"- 2" groups at 100 and a pie plate out to 500.

my hunting rounds are full length size, hand weigh each one so theyre dead nuts on for the powder charge. and topped with a ballistic tip or accubond. the recipie i have chronos at ~2650fps consistently. not the fastest, but im happy with them. these have proven themselves in the field as a reliable hunting round. made some up for some buddies and they love'm. if i put a number on it i'll shoot 1/2 -1" at 100 or so.

my 'because i can' rounds are fire formed then neck sized. powder is dead on, and FMJ-BT or BTHP is backed off .001-.002 from the lands. believe me, im no bench shooter. ive never been to an actual range but, 'because i can' make awesome super accurate rounds for my HUNTING rifles i will on occasion. 5 shot group touch each other at 100yrd.

i dont do much long range stuff. 2-300yrd mostly in preparation for deer season. 500 on occasion but i dont practice it as much as i would like.

youve got me motivated to start loading more precision stuff!

i guess i gotta build another rifle...

 

[Member 5605]

@v0lcom13sn0w
If I had the proper tools/machine/press, I would make my own. I have the how to in the brain, I just need the stuff to practice it.

A mini lathe and I would be a dangerous thing.... , I'm sure I would have a couple suppressors already.

 

[v0lcom13sn0w]

@v0lcom13sn0w
If I had the proper tools/machine/press, I would make my own. I have the how to in the brain, I just need the stuff to practice it.

A mini lathe and I would be a dangerous thing.... , I'm sure I would have a couple suppressors already.

i liked this post. bad thing is i cant double like it

 

[SinisterSouthpaw]

To clear up a couple of points:

1--BR shooters do at some point weigh their powder if only to compare the new lot to the old lot. You may see shooters who load at the match use a volumetric measure and no scale, but you can be sure that they know what is coming out of it into the case. With today's better battery powered scales you will see some of these folks double checking their measure's accuracy in "clicks" compared to actual weight as the conditions change. More and more BR shooters are loading at home using scales and dispensers, some will load for the entire season, especially after Jim Borden became an advocate of this practice.

2-The effort and expense taken with microforming brass is one small, small part of precision shooting and of questionable value when the rifle in question is a factory off the shelf weapon. Those folks shooting BR (with competitive rifles and rigs) at ranges over 300 yards may consider it more worthwhile. Short range BR folks seemingly abuse their brass, a lot of them using the same hundred or two for an entire season not ever annealing, and then discard them at season's end. I say seemingly because we use FL dies resizing brass over and over never trimming unless something went way wrong, and often hurrying the process between relays.
In truth those cases are probably worked less than cases shot by plinkers and reloaded 3 or 4 times. The reason for this is that serious competitors have their dies custom made to match the chamber in the custom barrel they use. They may own their own reamer for making both. They may actually make them both. Work hardening and stretching of brass does not necessarily become so bad as to require annealing or trimming -- it is the difference between roomy factory chambers and FL dies that leads to quick work hardening. It is almost impossible to prevent the loose fit of the cartridge in the chamber of a factory gun, even using neck dies, due to the tendency of the brass to spring back to its former shape. This is doubly true if the cases have not been properly fire formed or hydo formed.

Anyway the time and treasure spent on trying to improve your groups by brass forming for a factory rifle would be better spent on buying and learning to use wind flags, finding the best bullet/powder combination for your barrel and practicing the art of shooting over and over--with some initial instruction.

 

[jluck]

A good projectile over consistent brass and technique and exact powder charge will shoot better than the person behind the rifle can 99% of the time IMO.

 

[rick benjamin]

The case neck and chamber throat hold the bullet in alignment with the bore.
Cases are imperfect, more brass ends up on one side of the case.
When re-sizing, the case and neck are squeezed into outside uniformity (piston up).
Then (piston down) the inside of the neck is stretched into inside uniformity (expander ball). Resizing won't fix (excess material) in the neck.
Outside neck turning shaves the excess material.
I use the Lyman.

 

[rick benjamin]

Use the shaver AFTER resizing. You will see one side getting shaved

 

[Certaindeaf]

Don't forget that Harry M. Pope would load from the muzzle (using a false muzzle) and or seat them fully into the rifling with a seating device. Used the same piece a brass like what, 100,000 times? lessons