Let's talk about precision reloading

[SWThomas]

I've been posting a lot lately but my brain is a sponge right now and you guys always provide the knowledge. I wanna talk about all the different things folks do when reloading for maximum precision accuracy. What I'm gonna do is list some things I've seen folks do and ask for your input on the topic. What I would like is some sort of proof/data that a certain step has made a measurable difference in accuracy. Right now I'm chasing the accuracy goal with my GAP-10 but I will be having a precision bolt gun built soon. Here goes...

- Turning case necks

- Using bench rest primers VS standard primers

- Using competition seating dies over standard dies

- Crimping and not crimping

- Loading to be just off the lands or kissing the lands

- Uniforming primer pockets

- Deburring flash holes

- Bumping shoulders VS resizing to factory specs

- Checking run out with a concentricity gage

Please provide input on any or all of these steps and if you've personally observed increases in accuracy by performing them. If you would like to add something I didn't list, feel free to do so.

Edited December 11, 2013 by SWThomas

[Tcon260]

I'v spent the last number of years shooting F-Class with custom built rifles including 4 GAP's and have done all of the above and then some. Heres my opinion:

1 - Turning necks - not worth the effort. Maybe some small, incremental improvement if you chamber with a tight neck reamer. I doubt I will ever turn necks again. Are you interested in buying some used neck turning equipment?

2 - Primers - A low standard deviation on velocity is definitely desirable. I use CCI Brenchrest or Wolf primers.

3 - Since a rifles accuracy for a particular load is highly dependent on seating depth, I use competition seating dies to be able to easily and accurately adjust the seating depth during load development

4 - I only load for bolt guns so no crimp. But I do use bushing dies to control the neck tension. Consistent neck tension definitely affects consistent velocity (see 2)

5 - The most accurate load can be anywhere from 0.030"off the lands to 0.030" into the lands…just gotta find the sweet spot

6 - Primer pockets - ya I do it…not sure why

7 - Flash holes - ya I do it…not sure why

8 - Sizing - I usually bump the shoulder and FL every few firings…more for brass life than accuracy

Edited December 10, 2013 by Tcon260

[HighCountryStalker]

What TCon says mirrors my own findings. To add to that: I don't crimp even with semiauto. I don't believe there is a need and I find it easier to control neck tension. Trim to length. I trim as precisely as possible each time. Case volume consistency is huge so both trimming and weight sorting batches of brass and bullets contribute to the overall picture. Believe me I do not carry over the OCD into the pistol or high volume shooting.

This link has been referenced many times before and it has quite a bit of good info http://optimalchargeweight.embarqspace.com/

[SWThomas]

OK I'm sold on the competition seating dies.

If I were to buy a Redding seating micrometer, would it fit in my Dillon seating die?

Also, what's the difference between the VLD micrometer and the Standard?

[Powder Finger]

OK I'm sold on the competition seating dies.

If I were to buy a Redding seating micrometer, would it fit in my Dillon seating die?

Also, what's the difference between the VLD micrometer and the Standard?

it will fit the press but the dies are different.

the difference on stems is the vld is deeper. a vld bullet will most likely bottom out

in the step which means the tip of the bullet is seating it not the ogive.

IOW the bullet gets seated crooked.

[SWThomas]

Ok. I'm pretty sure I don't own any VLD bullets. For my match stuff I use SMK and AMAX.

[Alaskapopo]

Don't crimp even on your standard plinking fodder. Only makes things worse. I have found that match primers make little to no difference. What I have found that matters is finding the optimal powder charge for your rifle with ladder testing or simply starting at the start level and shooting 5 5 shot groups measuring the average group size and moving up in 2/10th of a grain increments until you reach max and then look over where you had the best accuracy. I also trim ever time I fire the cases and I chamfer the case mouth on my match reloads.
Pat

Edited December 13, 2013 by Alaskapopo

[thegunnerd]

Your seating depth will depend on the bullet you choose , the barrel you have, and the chamber that is cut into the barrel. Like Tcon said , could be .03 off the lands or jammed .03"

I think something to consider is headstamp . Which brass you use is nearly as important as how you prep it. When working up loads i'm currently using winchester cartridges and then once i have a consistent load i'm going to buy lapua brass.

Another +1 for redding competition bushing dies , that's what i use and have for years.

[SWThomas]

Your seating depth will depend on the bullet you choose , the barrel you have, and the chamber that is cut into the barrel. Like Tcon said , could be .03 off the lands or jammed .03"

I think something to consider is headstamp . Which brass you use is nearly as important as how you prep it. When working up loads i'm currently using winchester cartridges and then once i have a consistent load i'm going to buy lapua brass.

Another +1 for redding competition bushing dies , that's what i use and have for years.

But then when you switch cases you'll have to work up the load again.

[SWThomas]

Don't crimp even on your standard plinking fodder. Only makes things worse. I have found that match primers make little to no difference. What I have found that matters is finding the optimal powder charge for your rifle with ladder testing or simply starting at the start level and shooting 5 5 shot groups measuring the average group size and moving up in 2/10th of a grain increments until you reach max and then look over where you had the best accuracy. I also trim ever time I fire the cases and I chamfer the case mouth on my match reloads.

Pat

Yeah, I'll be doing a ladder test. Right now I have them loaded as long as the magazine will allow. Once I complete the ladder test, find my node, and find my load, then I'll start to play with seating depth.

[thegunnerd]

Not really , the winchester cases have nearly the same case volume as the lapua does. A lot of the older benchrest guys do the same . But hey be my guest if you want to do load workup with lapua cases. Besides minor differences in case volume and possibly case weight , if you do the same procedure in prep to both cases then they'll be the same length have the same resize , same primer , same chamfer and deburr etc .

[fastshooter03]

All the things you mentioned are good.

I buy cases in 1000 rd lots or more.

If you're going to use bushing dies without an expander ball, turn the case necks.

You forgot weighing the cases to get initial batch consistency. Make sure you weigh after all prep work is done.

And once you've decided on a load.....If you have the time...

Every round down range goes through a chrono. A good chrono like an Oehler.

Every case's velocity is kept track of along w environmental conditions.

Don't be afraid to check out benchrest/ long range websites.

Nick

[Tcon260]

Fastshooter03,

I agree that case neck thickness affects neck tension when using bushing dies since the neck ID (i.e. neck tension) is set by sizing the the OD. However, neck turning is not the only solution. And in my opinion not necessarily a good solution. First, you can end up with a lot of neck clearance unless you chamber with a tight neck reamer. Secondly, turning 1000 necks is enough to make any one go crazy. After neck sizing, I run the cases over a mandrel like this http://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/sinclair-expander-mandrel-oversized-prod33134.aspx I have various sized mandrels and this is how I set the neck tension.

[SWThomas]

All the things you mentioned are good.

I buy cases in 1000 rd lots or more.

If you're going to use bushing dies without an expander ball, turn the case necks.

You forgot weighing the cases to get initial batch consistency. Make sure you weigh after all prep work is done.

And once you've decided on a load.....If you have the time...

Every round down range goes through a chrono. A good chrono like an Oehler.

Every case's velocity is kept track of along w environmental conditions.

Don't be afraid to check out benchrest/ long range websites.

Nick

I appreciate the advice. However, I see no compelling reason to justify buying a chrono. What would be some of the benefits.

[Alaskapopo]

Reasons to buy a chrono.

Saves you time and ammo when figuring out your long range dope. If you get your actual muzzle velocity and take the time to enter all the data into a ballistic calculator your dope will be good. Every time I have verified mine it has always been on. You can also make sure your pistol ammo makes major or minor. You can also check to see how accurate your ammo is on the chrono for extreme spread and standard deviation. This will give you an idea of what to expect at longer ranges for accuracy.
Pat

[SWThomas]

Doesn't sound like something I really need right now. But neither is half the stuff I have. I'll look into getting one soon.

[fastshooter03]

Fastshooter03,

I agree that case neck thickness affects neck tension when using bushing dies since the neck ID (i.e. neck tension) is set by sizing the the OD. However, neck turning is not the only solution. And in my opinion not necessarily a good solution. First, you can end up with a lot of neck clearance unless you chamber with a tight neck reamer. Secondly, turning 1000 necks is enough to make any one go crazy. After neck sizing, I run the cases over a mandrel like this http://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/sinclair-expander-mandrel-oversized-prod33134.aspx I have various sized mandrels and this is how I set the neck tension.

You betcha neck turning sucks big time.

Do you check runout after the mandrel?

Even though the bushings float to align I was worried more about the different neck thickness pushing the concentricity of the case off whack without an expander ball to try and realign it.

I've heard of reaming the neck as well but never looked into it.

One of the biggest mistakes I see reloaders doing is not knowing exactly what headspace their cases are coming out of the rifle before getting resized.

Most people just use a go guage after sizing and if it drops in flush or past it's GTG. You REALLY NEED to know what your brass is before and after you size.

Seen a LOT of stuck cases in AR's due to this which usually comes from Progressive presses and loosened sizing dies.

I don't know any reloaders serious about their accuracy who don't have at least a cheap chrono.

I got fed up with my CED Millenium not working half the time and got the Oehler. Really nice but really expensive.

Some chambers/bores are tighter than others and can cause pressure abnormalties that might be dangerous.

It really helps to know how your loads are doing rather than looking at the primers and feeling how hard it is to open the action.

Nick

[glynnm45]

A lot of good information and I'll add a source of video to increase your library. Go to www.ultimatereloader.com he does an entire project of loading precision ammo for his benchrest .308. Well done videos.

[spikers220]

You forgot to mention one of the most important things - annealing your brass. This is the only way to get consistent neck tension from case to case. It will also add to the lifespan of the brass.

[fastshooter03]

I haven't read about when guys are annealing in a long time so I can't remember how soon it should be done.

I've never done it but I don't shoot much super long precision stuff anymore compared to 3-gun precision stuff.

I also remember reading about neck tension being affected by how much time the bullet has been sitting loaded in the case.

I'm assuming longer time the better for consistency?

I remember finding some 223 reloads that were a couple years old. 5 rds left of some batch of 60 grain hp rbt's made locally.

They went into 1 hole @ 100yds. I was amazed to say the least since nothing else that day was coming close to that.

Might have been luck but there might be something to it.

Nick

[spikers220]

That font is horrible

[SWThomas]

You forgot to mention one of the most important things - annealing your brass. This is the only way to get consistent neck tension from case to case. It will also add to the lifespan of the brass.

How often are you annealing?

[9supercomp]

I anneal after the 6th firing that for my .308 Win and 338 Lapua I don't anneal my 223 brass because it get's lost before that.

[spikers220]

Read this article. I learned a lot from it when it was first published. I actually built an exact replica of this rifle but in a McMillan stock.

http://www.accurateshooter.com/guns-of-week/tennessee-tack-driver/

[Graham Smith]

One of the important things to do is to determine how much precision is necessary. It's really easy to get caught up in the minutia of things, particularly after reading some of the stuff on the interweb. If you dig, you sometimes find that some recommendations are by people shooting "space guns" or bench rest guns (bolted to a platform) or are competing in open 1000yd F-Class where the winner my be determined by a single x-ring shot.

Spending a lot of time developing loads and tweaking things then measuring groups is good, but part of what's being measured is YOU and how you are shooting on a particular day. That's why this can be such a long process and why it's important to compare something new against your standard load on the same day under the same conditions.

As for a chronograph; having a good chronograph is one of your more important tools. You need to know how consistently a load shoots. You may be shooting 1/2" groups at 100yds, but if there's a lot of variation in your velocity then when you get out to 600+ yds that's going to start making a big difference.