I have started shooting in the monthly service rifle match at a local club and after a first go with my K31, I am going to settle on shooting the Garand. I spent a good portion of the weekend getting a bunch of military brass to the point that I could load it. I want to share the process I used, get any feedback on improvements to the workflow, and ask a couple of final questions before I head to the range to see how my stuff shoots.
My buddy gave me a bag of 30-06 brass. Most of it had the heads tamp TW 54 with the T at 12, W at 3, 4 at 6 and 5 at 9 on the clock face. Not sure what it is.
First the headspace checks:
Cleaned the chamber really good and used Clymer Go and No-Go gauges to make sure the rifle was safe to shoot.
Bolt closed on the Go, but would not on the No-Go. The right side lug was about 1/4 inch off the receiver with the No-Go.
I checked the Clymer Go gauge with a Hornady ogive length kit and got exactly 2.027" so I figured I'd move the shoulders of the brass back to 2.025", if possible.
Then the brass prep:
De-prime
Wet tumble with Dawn and Lemi Shine for 2 hours
Dry
Lube cases with Imperial Sizing Wax
Full length resize (Could only get the die to give me 2.026" so that's what I went with. Most of the brass was 0.030-0.040" out from 2.027" at the ogive.)
Trim to length (2.484")
Chamfer case necks inside and out
Swage primer pockets
Chamfer primer pockets
Clean up bottoms of primer pockets
Wet tumble with Dawn, Lemi Shine and SS pins for 2 hours.
Rinse and dry
Next the bullet seating checks:
I used a Hornady OAL length gauge kit to figure out where the bullet would hit the lands.
Turns out the ogive length at the lands was 2.800" and even after moving the bullet down 0.020" for the jump, the cartridge looked really weird as the bullet was barely in the neck, but definitely past the boat tail. It would have seated. BUT, I didn't want to have longer rounds for single shots so I made the rounds 3.300" OAL which measure 2.721" at the ogive. This was 0.058" shorter than the "short jump" depth I had just figured. These military chambers must be very generous.
Now the load:
Bullet is a Hornady 150 gr FMJ-BT
Primer is a CCI #200 (large rifle)
Power is 45.0 grains of IMR 4895 (I went a little conservative knowing this was military brass and not knowing its volume.)
I hand seated all of the primers and have started dropping powder with an RCBS Chargemaster Combo and seating my bullets to the 2.721" I figured above. I'm only 8 rounds into 120.
So, questions:
What could I improve with my process? Anything out of order?
Once seated, should I crimp these bullets in? I have a Lee factory crimp die.
I would ream the primer pocket for depth and square bottom. Each time you fire a case, the pressure can move the brass. Making sure the primer pocket is full depth to the margins of the pocket, ensures the pocket will hold the primer low enough to avoid slam fire.
I use dawn and lemishine but not the stainless pins. And like to let the brass dry for a week.
Got a bunch of duds, and hangfires, then quit after the first squib, from just drying in the sun for half a day.
No fun pulling all those bullets and throwing away powder and primers.
Crimping is not necessary, Try crimping some, and see if they shoot better than non crimped. If your rifle does not feed well, and some bullets get crammed back into the case. Then crimping is a good idea.
Quote from: HammBone on June 11, 2018, 04:04:13 PM
What could I improve with my process? Anything out of order?
Once seated, should I crimp these bullets in? I have a Lee factory crimp die.
I'd suggest a Neck inside sizing mandrel as the ultimate control on neck tension and to make sure the neck ID is ironed smooth with any irregularities pushed to the outside so they won't affect the bullet.
Neck mandrel body - https://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/generation-ii-expander-dies-prod38807.aspx (https://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/generation-ii-expander-dies-prod38807.aspx)
(https://www.brownells.com/userdocs/products/p_749011715_2.jpg)
Neck Mandrel - https://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/30-caliber-307-stainless-expander-mandrel-sku749001183-33134-65130.aspx?rrec=true (https://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/30-caliber-307-stainless-expander-mandrel-sku749001183-33134-65130.aspx?rrec=true)
(https://www.brownells.com/userdocs/products/p_749001145_3.jpg)
Consistent neck tension is a huge part of accuracy and this is the easiest way to make sure every case is as perfect as possible without neck turning or reaming.
Depending on the ID you choose you can end up getting .002 or .003 of neck constriction. No idea if the M1 needs .003. Most AR's in High Power are using .002 or less I'm told.
All the reading I've done on High Power says that crimping is not done for competition loads.
Quote from: Mark Davis on June 12, 2018, 02:11:59 AM
I would ream the primer pocket for depth and square bottom. Each time you fire a case, the pressure can move the brass. Making sure the primer pocket is full depth to the margins of the pocket, ensures the pocket will hold the primer low enough to avoid slam fire.
I think I need to spend a bit more time here. I did use a Lyman primer pocket reamer chucked into a cordless drill and visually checked the bottoms for that new brass look. Not all of them would clean up all the way, but I didn't try that hard. I did pay close attention to the primer seating depth as I primed them and all looked below the surface. I had some cases that got "over machined" somehow as the primers just dropped out. I threw those in the recycle box.
Quote from: Mark Davis on June 12, 2018, 02:11:59 AM
Got a bunch of duds, and hangfires, then quit after the first squib, from just drying in the sun for half a day.
No fun pulling all those bullets and throwing away powder and primers.
Crimping is not necessary, Try crimping some, and see if they shoot better than non crimped. If your rifle does not feed well, and some bullets get crammed back into the case. Then crimping is a good idea.
Good feedback. I definitely got in a hurry on the first 8 and will shoot those up to forego any problems with moisture. The next 40 got an extra day to dry. The final 70 have a fan over their open case mouths all day today based on your experiences. Thanks!
Quote from: Lomshek on June 12, 2018, 02:59:46 AM
I'd suggest a Neck inside sizing mandrel as the ultimate control on neck tension and to make sure the neck ID is ironed smooth with any irregularities pushed to the outside so they won't affect the bullet.
Consistent neck tension is a huge part of accuracy and this is the easiest way to make sure every case is as perfect as possible without neck turning or reaming.
Depending on the ID you choose you can end up getting .002 or .003 of neck constriction. No idea if the M1 needs .003. Most AR's in High Power are using .002 or less I'm told.
All the reading I've done on High Power says that crimping is not done for competition loads.
Where does this process fall in the sequence? After full length resizing? And how do you measure to see if you're getting .002 or .003?
I will not crimp these and see how they run in the rifle. Thanks!
The new brass look at the bottom of the primer pocket can lead too primers set low, and duds.
If the reamer goes into the pocket to the stop on the reamer, it's okay to have a black pocket.
It was a sad day last fall when I scrapped 300 pieces of .22-250 Ackley improved brass for primer pockets too deep.
HB,
Try not to overthink the problem.
This is what I would do:
1. Buy, a box of 30-06 ammo (surplus is ok).
2. Shoot it in your rifle, notice that I said your rifle (second hand brass is not ok).
3. Save the brass (this is fire-formed brass and It should equal your rifle's headspace measurement (some folks add 0.001 to this measurement to account for the brass spring-back).
4. Measure the headspace on your fire-formed cases.
5. To measure headspace you'll need a caliper and the tool to measure the headspace. I don't like to recommend specific products, but I use a Forster's Datum Dial kit, but there are more out there.
6. Measure the headspace on a number of your-formed cases (I use 10) and take the average. This is the approx. headspace for your rifle.
7. For gas guns it is recommended that you bump the shoulder back approx. 0.005"-0.007". I do this with a Lyman full length sizing die.
8. As an example, if your rifle's fire-formed cases indicate a headspace of 1.XXX", adjust your die to bump the shoulder back so that your case measurement equals 1.XXX minus 0.005(7).
9. I don't reload 30-06s, so I can't give any specific numbers (anyway your's would be slightly different). All guns are not equal.
10. Go slow, understand the basics before you move to a more advanced technique.
Hope this helps you.
aj
Quote from: Mark Davis on June 12, 2018, 10:27:20 AM
The new brass look at the bottom of the primer pocket can lead too primers set low, and duds.
If the reamer goes into the pocket to the stop on the reamer, it's okay to have a black pocket.
It was a sad day last fall when I scrapped 300 pieces of .22-250 Ackley improved brass for primer pockets too deep.
No way! That's good feedback. I just gave them a couple of seconds each so hopefully didn't eat away too much brass. I guess I will see very soon.
Quote from: airplanejoe on June 12, 2018, 10:46:36 AM
3. Save the brass (this is fire-formed brass and It should equal your rifle's headspace measurement (some folks add 0.001 to this measurement to account for the brass spring-back).
4. Measure the headspace on your fire-formed cases.
aj,
This is the procedure I follow with a bolt gun, but from reading (and reading) I was worried that a gas gun like the Garand might not be giving me a true fire formed reading.
This is from an article called "Reloading for the Match M14":
QuoteDon't be fooled into thinking that brass from an M14 "fire formed" to fit the chamber; it may well have "fire deformed". A spent case from an M14 will often have the shoulder blown farther forward than chamber specs should allow, and may also exhibit more case head expansion than it "should".
So, since the M14 was closely derived from the M1 Garand, I figured they would be just as brutal on the brass. Maybe not, but if this is the case, trying to derive head space from "fire deformed" brass could give a case that has not been bumped back enough to be safe.
Mitch
HB,
Headspace is headspace. That is why I mentioned you need to take a sample, not just one case. I've never encountered a "fire deformed" brass, but I would think in a 10 case sample it would stand out like the provervial sore thumb and can thus be eliminated from the sample. Self incriminating myself, I've never heard of "fire-deformed" before and can't see how it could even physically happen. When the firearm fires the cartridge expands in all directions to "fill" the chamber. It just can't physically go any farther (impossible to put ten pounds of potatoes in a 5 pound bag). Weakened cases may rupture, and maybe that can be construed as "fire-deformed".
You measure headspace the same way regardless is a bolt gun or a gas gun. But you bump the shoulder back farther on a gas gun.
An M14 is a .308; a garand is a 30-06. When they fire the case really expands very little. Just enough to fill the chamber and in a properly sized case that is not much at all. I don't understand how can that be brutal on the brass since the walls of the chamber will contain the pressure and the excess pressure will drive the bullet forward. Now, I imagine, if the wrong powder is used, or the safe amount exceeded an overpressure can be created and maybe the shoulder may be pushed forward into the neck or even as far forward into the leade and the receiver would probably also be ruined. That would be a catastrophic failure. I've also never seen that.
Anyway, I stand by my 2 cents. Seems the 30-06 has been around practically forever and has been reloaded many, many times. Don't put much faith in what you read in internet forums. I would recommend a book titled "Handloading for Competition" by Glen D Zediker. Good luck!!
aj
Quote from: airplanejoe on June 12, 2018, 02:52:54 PM
Anyway, I stand by my 2 cents. Seems the 30-06 has been around practically forever and has been reloaded many, many times. Don't put much faith in what you read in internet forums. I would recommend a book titled "Handloading for Competition" by Glen D Zediker. Good luck!!
AJ,
That is actually an excerpt from Zediker's book. ;)
In the previous paragraph, he explains the phenomenon a bit better than just saying "fire deformed":
Quote...the M14 has about the quickest operation of any auto-loading rifle -- so much so that the bolt can unlock before the case has fully retracted from its expanded dimensions. We're talking about milliseconds, but that's all we have devoted to the entire process. The net result is that some amount of expansion frequently occurs in a case fired through an M14. Compounding this condition is that LC (Lake City) brass is liable not to contract as readily as other cases fired in other rifles. It's very, very (comparatively) hot and getting jerked on by an extractor, and most seem to think this is responsible for a lot of the additional measure case growth.
So, plausible I think. And coming from Zediker I take it as near gospel versus something I read on a forum. However, I will take these reloads to the range and get a good sample of the fire formed brass to see what my rifle is doing to them. I know exactly where they are starting. I'll report back.
Mitch
Question 1: What is your goal for accuracy?
If I recall correctly, you're not getting better than 3-4 MOA out of a good USGI barrel, so your ammo may not be the limiting factor. Load to an acceptable tolerance, and spend time practicing instead of messing with reloading, IMHO. The reloading hobbyists will look down their noses at my setup (Lee turret, Lee FL sizing die, Lee seating die; I do use an RCBS micrometer seating die for .223 Rem 600-yard ammo), but for Service Rifle in general and the M1 in particular, most of the variability is in the shooter's position and firing technique, and you're trying to hit a pretty huge target.
With that in mind, conventional wisdom says "load development" is largely a waste of time, money, and barrel life for Service Rifle, unless you're a High Master looking to improve X count at 600 yards. For the rest of us, full-length size, charge with a Lee Perfect Powder measure (works well with extruded powders like H4895, IMR 4064, and Varget), seat to mag/clip length, and go shoot. For goodness sake, don't trickle powder or weigh cases, because that's not where the 8s and 9s come from. :wb:
Question 2: Are you shooting across-the-course (200, 300, 600), or just reduced course matches?
I didn't have consistent results with the Hornady 150 FMJBT, and I switched to the 168 Sierra Match King and saw immediate improvement. Some of that was me, but I think some was the bullet. If you're only shooting 100-200 yards, you can get away with a lighter bullet, and it will be easier on you and on the rifle (Speer 125TNT is commonly recommended, though I found this advice after buying 168 SMKs). Every time I've cheaped out on bullets, I've regretted it. YMMV.
You've already learned that the M1 extraction cycle will beat the snot out of your brass. Don't get attached to it, and be prepared to pitch it after a few firings. That's just the cost of doing business safely with your rifle. Here are a few additional links that I've found useful.
Sierra on gas gun reloading, with some good specifics on the M1:
http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm (http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm)
A variety of proven Service Rifle loads. Watch for pressure and work up.
http://www.radomski.us/njhp/cart_tech.htm (http://www.radomski.us/njhp/cart_tech.htm)
Neck tension (useful for adjusting expander ball dies like mine; I run 0.002" neck tension on the 223, as Lomshek says.
https://sierrabulletsblog.com/2016/05/26/how-important-is-neck-tension/ (https://sierrabulletsblog.com/2016/05/26/how-important-is-neck-tension/)
The NM forum is pretty good, as forums go, and there are some guys there who still shoot the M1.
http://www.usrifleteams.com/forums/index.php?/forum/92-the-loading-bench/ (http://www.usrifleteams.com/forums/index.php?/forum/92-the-loading-bench/)
Quote from: maxwell on June 12, 2018, 05:18:46 PM
Question 1: What is your goal for accuracy?
Question 2: Are you shooting across-the-course (200, 300, 600), or just reduced course matches?
Good questions!
I would like to win every now and then so to do that based on this year's scores I need to shoot over a 420. I assume these guys get better over the course of the year so let's say a 450.
Answering your second question, we shoot reduced range so (2) SR-1, (1) SR-21 and (2) MR-31 NRA targets.
On the SR-1, 3-4 MOA will score 90, the SR-21 will score 95, and the MR-31 a 75. That gives a 425 total so that's in the hunt. That assumes I do my part, of course. I shot the first match with my K31 and only got a 320. The last second "oh, you can't use a sling while standing" kind of threw me. :)
I have a box of 168 HPBTs (Sierra #2200) so if I don't get decent groups off the bags with this 150 grain stuff, I'll see how those shoot.
I will either shoot this Garand or an M1A NM for my Appleseed KD shoot this Fall. I really have no idea how good the M1 is, but I assume the M1A is decent as it's almost brand new. I'll shoot the most accurate one as the KD looks way hard to score a patch.
Much obliged for all the good information in your links. I will continue reading and learning.
Quote from: HammBone on June 12, 2018, 08:50:47 AM
Quote from: Lomshek on June 12, 2018, 02:59:46 AM
I'd suggest a Neck inside sizing mandrel as the ultimate control on neck tension and to make sure the neck ID is ironed smooth with any irregularities pushed to the outside so they won't affect the bullet.
Consistent neck tension is a huge part of accuracy and this is the easiest way to make sure every case is as perfect as possible without neck turning or reaming.
Depending on the ID you choose you can end up getting .002 or .003 of neck constriction. No idea if the M1 needs .003. Most AR's in High Power are using .002 or less I'm told.
All the reading I've done on High Power says that crimping is not done for competition loads.
Where does this process fall in the sequence? After full length resizing? And how do you measure to see if you're getting .002 or .003?
I will not crimp these and see how they run in the rifle. Thanks!
My reloading sequence for my AR (I don't have an M1 unfortunately). I use a Redding T7 turret press.
1- Tumble in ground walnut media (Lizard Litter). Lizard Litter is ground to almost as small as table sugar.
2- Lube with Dillon case lube
3- Full length re-size (Redding die) to .003 under fired case dimension (using Hornady headspace comparator tool & Mitutoyo calipers).
I turned down the sizing button so my neck ID after initial sizing is .220. That means either neck mandrel just gently kisses and final sizes the neck ID to my target ID.
4- Neck ID size with Mandrel. I use a neck tension of .003 under bullet diameter for blasting ammo and .002 under neck tension for hyper accurate single loaded rounds.*
5- Trim cases with a Trim It 2 three way trimmer that trims, deburs and chamfers in one step.
6- Tumble cases in Lizard Litter walnut media to remove lube.
7- Hand prime with RCBS hand primer (not to happy with its quality but it does a good job).
8- Charge cases with Redding Competition BR30 powder measure that I've polished internally and waxed for slick operation.
9- Seat bullets with Redding Competition Bullet seating die.
*Neck tension" is really just the measurement of how much smaller the sized neck ID is than bullet diameter. Sinclair sells a carbide mandrel that measures .222 and a steel one that measures .223. Factoring a spring back factor of .001 (based on Zediker's books) that gives me a neck ID of either .221 or .222. Minus the bullet diameter that gives me a "tension" of either .002 or .003.
I decided to use the neck mandrels after reading a couple of Glen Zediker's books including "Handloading for Competition" that Airplane Joe suggested. I would absolutely second that as a great book!
Here's what that process gave me using single loaded Sierra 80 grainers at 685 yards fired prone slung up.(https://www.ar15.com/media/mediaFiles/84345/target_3_700_yards_12_Nov_for_forum-388544.JPG)
Here's the range. The target above is the left one of the circled targets.(https://www.ar15.com/media/mediaFiles/84345/Roger_at_Robs_with_targets_highlighted_for_forum-388477.JPG)
I'm just beginning to fiddle with squaring and uniforming primer pockets but not sure if that's going to be worth the effort. Sinclair's tool cuts to the SAAMI maximum depth which concerns me for good ignition unless the firing pin protrusion is at or close to max length too. Others either don't cut so well or are adjustable for depth which I don't trust.
HB,
From your postings I gather that one of your speed bumps is what you called "fire-deformed brass) and your concern that such a round won't give you accurate measurements. My last two suggestions, and they are not what I do are:
1. Adjust your sizing die to size to SAAMI specs (an out of the box full length die should do this). If you don't like this, do #2.
2. Get one round from a factory ammo box, and reverse engineer it.
a. Measure COAL (overall round length).
b. Measure the CBTO.
c. Measure the headspace.
d. Pull the bullet.
e. Measure the COAL (trim to measurement).
d. Weigh the powder.
e. Unknowns are the type of powder and primer, but you can find those in any reloading manual.
Those suggestions are not what most folks recommend, but they should result in a safe round that can be fired in any 30-06 rifle.
The postings by Maxwell and Lomshek are very accurate. Follow their suggestions and your handloads will be safe and accurate.
But don't forget that "the indian is more important than the arrow". i.e., don't neglect your trigger time.
Happy shooting!
aj
Quote from: Lomshek on June 13, 2018, 02:22:25 AM
My reloading sequence for my AR (I don't have an M1 unfortunately). I use a Redding T7 turret press.
1- Tumble in ground walnut media (Lizard Litter). Lizard Litter is ground to almost as small as table sugar.
2- Lube with Dillon case lube
I do similar. Tried all of the case cleaning methods: dry media, ultrasonic and wet SS pins. I thought dry media was much too messy and ultrasonic was just not as effective. Both paled in comparison to wet tumbling with the SS pins.
My case lube is Imperial Die Sizing Wax.
Quote
3- Full length re-size (Redding die) to .003 under fired case dimension (using Hornady headspace comparator tool & Mitutoyo calipers).
I turned down the sizing button so my neck ID after initial sizing is .220. That means either neck mandrel just gently kisses and final sizes the neck ID to my target ID.
4- Neck ID size with Mandrel. I use a neck tension of .003 under bullet diameter for blasting ammo and .002 under neck tension for hyper accurate single loaded rounds.*
5- Trim cases with a Trim It 2 three way trimmer that trims, deburs and chamfers in one step.
Thanks for the explanation and sequencing on this. I will definitely look into it keeping aj's Indian/arrow comment firmly in mind.
Have not heard of the Trim It 2. Will investigate. The Precision Rifle folks crow about the Giraud trimmer and at nearly $500 it should be good. I just have a Lyman trimmer and hand chamfering/reaming tools that I power with a cordless drill.
Quote
7- Hand prime with RCBS hand primer (not to happy with its quality but it does a good job).
Same, but as you say the results are very good.
Quote
8- Charge cases with Redding Competition BR30 powder measure that I've polished internally and waxed for slick operation.
I use a slightly modified RCBS Chargemaster Combo. I charge a case, return the pan to the scale and while it is dispensing the next one I seat my bullet on my single stage RCBS.
Quote
Here's what that process gave me using single loaded Sierra 80 grainers at 685 yards fired prone slung up.
Here's the range. The target above is the left one of the circled targets.
That's good shooting right there. Nicely done.
Quote from: airplanejoe on June 13, 2018, 08:28:05 AM
From your postings I gather that one of your speed bumps is what you called "fire-deformed brass) and your concern that such a round won't give you accurate measurements.
Correct. That is my concern. But, on your suggestion I am going to get a good sampling of fired brass and see what is happening with this particular rifle.
Quote
1. Adjust your sizing die to size to SAAMI specs (an out of the box full length die should do this). If you don't like this, do #2.
This is essentially what I have done. The Clymer gauges are supposedly the best match for the military reamers and I have sized to 0.001" under their Go gauge which my rifle's bolt easily closes on. I am not worried so much about safety, but am wondering if I am moving the brass too much. I understand this point is mostly moot with a gas gun as they are so hard on brass.
Quote
2. Get one round from a factory ammo box, and reverse engineer it.
I think factory ammo is very conservative in that it has to work in every 30-06 ever made without hurting the gun or the shooter. Matching that would be negating some of the accuracy improvements you can get by careful handloading.
And yes, I totally agree that trigger time is very important and I will put it in. BUT, I would like to have a rifle and ammo that is performing consistently well so that my performance inadequacies can be flagged as such and not have any insecurity about whether is was the Indian or the arrow.
HB,
You really don't need headspace gauges. Go to the SAAMI web page and look up the specs for the round you need. I don't handload 30-06, but for the .308 max headspace is 1.640, min headspace is 1.630 (the "GO" gauge is 1.640). You need a set of calipers and a headspace comparator kit. Size, measure, adjust,..., repeat until you get the results you want.
Factory ammo can be very accurate. Self incrimination again, I reversed engineered Federal Premium (Gold Medal Match) .308 WIN, 168 grain, HPBT. The results are my recipe for handloading my .308, which is as accurate as the factory load and more accurate than me (I always blame poor scores on the indian and not the arrow).
There are thousands of handloading recipes out there (for every caliber made). They are available. Why reinvent the wheel with load development?
aj
Quote from: HammBone on June 13, 2018, 08:53:20 AM
Have not heard of the Trim It 2. Will investigate. The Precision Rifle folks crow about the Giraud trimmer and at nearly $500 it should be good. I just have a Lyman trimmer and hand chamfering/reaming tools that I power with a cordless drill.
Quote
The Giraud everyone loves sounds awesome but the price was just too much for me.
Giraud also makes a hand held version like the Trim It 2 that you mount in a drill. It might fix the issue I mention below on the Trim It 2 but I've never tried one so can't say.
After using it for a while the Trim It 2 needs a little tweaking to get the best results. The cutting length adjustment can come out of spec because of the design. To lock that down I added some spacers and a locking collar on the shaft.
I love the Trim It 2's tic marks on the length adjuster which are accurate .001" adjustment marks.
Before I used a Redding 2400 hand trimmer and an RCBS power station to chamfer & debur. I can do many times more cases more accurately now.
Quote from: HammBone on June 13, 2018, 09:03:43 AM
Quote from: airplanejoe on June 13, 2018, 08:28:05 AM
From your postings I gather that one of your speed bumps is what you called "fire-deformed brass) and your concern that such a round won't give you accurate measurements.
Correct. That is my concern. But, on your suggestion I am going to get a good sampling of fired brass and see what is happening with this particular rifle.
Quote
Joe is correct that measuring brass that was fired in your chamber will give you a very accurate picture of your rifle's headspace.
He's also correct that using the headspace guages to adjust your sizing is the wrong way to go about it. You're almost certainly oversizing your brass well beyond what is needed for reliable function and will shorten brass life.
To double check my sizing I sorted all my sized cases until I had the collection in the picture below. Essentially a set of graduated headspace gauges.
I stripped my bolt (no ejector or extractor) then hand chamber the cases by pressing the BCG with my fingers. That allows me to see which headspace dimension actually chambers without rsistance as I can feel when the bolt lugs are being pressed against the barrel extension lugs and when they're too tight.
For the M1 you'd still strip the bolt and slow feed the round in instead of letting the op spring slam the bolt home. When a round extracts a smidge harder than an empty chamber you know the lugs are engaged. Any longer than that and you're jamming an overly long case in the chamber. I'd go .002 or .003 smaller than the largest case that extracts without resistance.
Quote from: Lomshek on June 14, 2018, 12:19:19 AM
Giraud also makes a hand held version like the Trim It 2 that you mount in a drill. It might fix the issue I mention below on the Trim It 2 but I've never tried one so can't say.
After using it for a while the Trim It 2 needs a little tweaking to get the best results. The cutting length adjustment can come out of spec because of the design. To lock that down I added some spacers and a locking collar on the shaft.
I watched some videos on the Trim It 2 and it looks pretty nice. Maybe a bit futzy in setup like you say. I'll look up the Giraud drill chuck version and see how much more expensive it is. I want one or the other at some point.
Quote from: Lomshek on June 14, 2018, 12:47:04 AM
For the M1 you'd still strip the bolt and slow feed the round in instead of letting the op spring slam the bolt home. When a round extracts a smidge harder than an empty chamber you know the lugs are engaged. Any longer than that and you're jamming an overly long case in the chamber. I'd go .002 or .003 smaller than the largest case that extracts without resistance.
I like this approach! I finished loading 120 rounds last night. I have 100 with the 150 gr bullet and did 20 with the 168, both over 45 grains of IMR 4895. I'll put together a fired case collection like you did, strip the bolt and see how they feel. Very helpful. Thanks!
Quote from: HammBone on June 14, 2018, 09:10:59 AM
Quote from: Lomshek on June 14, 2018, 12:47:04 AM
For the M1 you'd still strip the bolt and slow feed the round in instead of letting the op spring slam the bolt home. When a round extracts a smidge harder than an empty chamber you know the lugs are engaged. Any longer than that and you're jamming an overly long case in the chamber. I'd go .002 or .003 smaller than the largest case that extracts without resistance.
I like this approach! I finished loading 120 rounds last night. I have 100 with the 150 gr bullet and did 20 with the 168, both over 45 grains of IMR 4895. I'll put together a fired case collection like you did, strip the bolt and see how they feel. Very helpful. Thanks!
Glad to help!
Just to be clear the cases I have dimensions marked on are fired in my chamber then full length resized to the different headspace dimensions written on the cases. If they were just fired and not sized they would likely get stuck in the chamber.