Too much deviation in head space when resizing?

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little_scrapper

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May 31, 2019
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#1
So I resized about a hundred or so M118LR brass. They mostly come out of my chamber at 1.626" give or take. I try to set Redding FL resizing die to head space at 1.623". However, I tend to get outliers. I will get two or three that end up as short as 1.620" and some that still measure 1.626".

These troublesome longer ones I run up and down and measure and they stubbornly stay at 1.626". I can usually handle them by ramming the handle down quickly and slamming a couple thou off them. I can only think of a couple things that would cause this. Its got to be either a burr or imperfection on the unsupported middle of the head or the shoulder angle is.... off as in a dent or curve in it causing it to not set back at the 400 datum line of my Hornady headspace gauge????

So a couple question that I am basically asking as I am fairly new to reloading.

1st ?: once die it set, snugged tightened set, and not adjusted. Is it normal to get outliers ranging from 1.621" to 1.626"?

2nd ?: anything I can do to reduce that variance?

3rd ?: Once FL resized I have case OAL ranging from 2.002" to 2.015" on the ones I have measured so far? What do I do with these shorter ones?

I realize these may be rhetorical ?'s I am just trying to get some edification here. 5 or 6 thou seems wierd.
 
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#3
1) Rock Chucker Supreme.
2) Redding FL sizing die with expander ball.
3) Squirt drops of lube on that rubbery sponge green tray and rolling the rounds then using brush to lube inside the necks. Fingering the shoulders with lubed fingers.
4) The cases vary on Head space a thou up or down but most all come out of the chamber of my AR10 at 1.626". I have not been measuring OAL on cases before resizing. I may have to start. If it matters. So far at this stage I was only looking at head space length.

Some of the older M118LR 2002, 2003, 2004 I have had come out as much as 1.628" The newer stuff, 2016-2019 all seem more consistant at 1.626"

The ones I just resized are all 2016 head stamp. Also, regarding the shorter necks; Should I just trim the long ones to match the shortest ones for consistant necks? Or should I sort & batch them using the longer necks? I am trying to get some level of precision so I guess the basis question is, is 2.002 TOO short?
 
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#4
You may not have a point of comparison, but does the sizing effort feel high into the die or over the expander ball? Do you have ejector marks on the case heads that could be affecting your measurements? Is this the only brass you’ve sized, or have you sized any other brands of brass?
 
#5
Brass is springy and presses deflect under load, so some variation is normal. The exact amount will vary based upon how much work is being done.

I use Redding competition shell holders, which always run in a cammed over arrangement, so press deflection isn’t an issue, and sizing variations are very small. If you have some trashed brass or brass you’re willing to sacrifice, you can adjust the die to cam over on a standard shell holder and cram a few down and check the variation.
 
#6
Did you happen to measure the outliers before you sized them?

I almost wonder if, on the long ones, you arent sizing enough to bump the shoulder, just enough to lengthen the case. First thing I remember being frustrated about was setting up a basic ass FL die wrong and watching my cases get longer at the datum line eith my comparitor.

Also, how many firings on the brass? You might be running into spring back on some of the cases. You may want to look into annealing if you can.

I am in no way a pro at this either, just my own 2 observations.
 
#7
@super I am not sure if I fully understand the 1st question. So I will just say this. My understanding is that it is better to have the expander ball higher up, so that the case is fairly well supported by the die, before the ball hits the neck. Of corse cant be TOO high or will jam in the neck. SO I have attempted to set my ball just below the neck sizer part so that the neck isnt being squeezed on the expander ball.

Some heads have ejector marks I do try to reduce them with a light sanding. LIGHT! Drag the head over some emery to reduce burrs.

Only brass I have ever sized. I get this straight from LC for fortyfive cents a round so I shoot the M118LR then reload the brass.
 
#8
@ryrid I measure pretty much every piece before hand. I have been doing this because the fact that I found a coouple that came out at 1.628" I am toying with the idea of making a few SMALL batches at 1.625" and see if I have any feed issues.

I always start long with several pieces of sacrificial brass and drop my die until I hit my 1.623". Then start cranking out like 5x at a time and measure each one to see if I need to adjust.

This batch is 3F on each case and i have an Annealeze that I use. On the annealer i again use a handful of sacrificial pieces to set the dwell time. I turn off all but one light in my shop and set the dwell so that the neck shoulder just starts to glow in a very dim room.
 
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#9
Having a minor amount of deviation across a batch of fl sized cases is not abnormal. I also sized M118LR brass today (100 cases) and 11 were not 1.628 but the furthest deviation from that target was one piece that sized down to 1.623 for some reason. Those that get sized more than .002 over (e.g. 1.626 or less) get put into a separate bin for later fireformimg to bring them back to spec.

My rifle’s chamber is 1.630 so I am sizing 1.628 to leave a very minor amount of room as a buffer for expansion.

Do your case heads say “LC” and “LR” along with the year on the case head?
 
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#10
@nn are you saying that you resized 100 pcs and managed to get 89 that were basically exactly 1.628? Because thats way better than I am doing. Are you sizing for bolt gun as opposed to me sizing for my gas gun? What press/die?

Of corse! Case heads all say LC, LR and the two digit year of mfg. I get them literally straight from LC as I have insider contacts. Honestly, I would be better off just pulling the bullets because my price per round is less than I can buy 175 SMK's for. Unfortunately that may not be for much longer though.
 
#11
little_scrapper said:
@nn are you saying that you resized 100 pcs and managed to get 89 that were basically exactly 1.628? Because thats way better than I am doing. Are you sizing for bolt gun as opposed to me sizing for my gas gun? What press/die?

Of corse! Case heads all say LC, LR and the two digit year of mfg. I get them literally straight from LC as I have insider contacts. Honestly, I would be better off just pulling the bullets because my price per round is less than I can buy 175 SMK's for. Unfortunately that may not be for much longer though.
Click to expand...

Yep, exactly 1.628 for my M40A5. The others were undersized by .001-.002 except that odd ball case mentioned above. The ones that were initially under sized were ran through the die again after an incremental die adjustment.

I’m using a Forster COAX and RCBS standard full length die in a Forster lock ring. Hornady One Shot case lube; I spray the cases with a light coat.
 
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#12
I thought about getting the Forster but everyone said it wasnt worth the extra money. It sounds to be more consistant than my RCBS. However, Maybe I have better results with a higher end die? Match die with a micrometer? Then again a couple thou may not make any difference in a gas gun.

I have found that 40.5 gr and 41.4 gr of H4895 shot just a hair under 1MOA with 175SMK's with a POI shift down over 40.5 and then back up again at 41.4.

I plan to run a short ladder at these two charges in .1gr inc. and see if I can fine tune and also prove either wasnt a fluke. After that I want to take said fine tuned charge weight and vary the seating depth/ jump and see if I can further fine tune.

I want to see what this LaRue is capable of. Is it a sub MOA gun or not? That is the question. Or do i just suck and no matter what i cant get 5x5 under 1 MOA. LOL. Likely true.
 
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#13
little_scrapper said:
So I resized about a hundred or so M118LR brass. They mostly come out of my chamber at 1.626" give or take. I try to set Redding FL resizing die to head space at 1.623". However, I tend to get outliers. I will get two or three that end up as short as 1.620" and some that still measure 1.626".

These troublesome longer ones I run up and down and measure and they stubbornly stay at 1.626". I can usually handle them by ramming the handle down quickly and slamming a couple thou off them. I can only think of a couple things that would cause this. Its got to be either a burr or imperfection on the unsupported middle of the head or the shoulder angle is.... off as in a dent or curve in it causing it to not set back at the 400 datum line of my Hornady headspace gauge????

So a couple question that I am basically asking as I am fairly new to reloading.

1st ?: once die it set, snugged tightened set, and not adjusted. Is it normal to get outliers ranging from 1.621" to 1.626"?
Click to expand...

You shouldn't be getting that much variation. Though LC brass had rather thick case walls and can expect more spring back that other brands of brass, you really shouldn't get any more than .001-.0015 of spring back AT MOST.

little_scrapper said:
2nd ?: anything I can do to reduce that variance?
Click to expand...

From what you've already said, you're annealing (initially, I thought that might be the issue). With a good annealing job, you shouldn't be getting much spring back or that much variance . . . unless something else isn't right with you die set up.

Over annealing might cause a similar issue depending on how the expander ball is drawn back through as a too soft shoulder can be drawn up if there's too much drag.

The expander ball could still be the issue on properly annealed brass if it's not set up properly. But I wouldn't expect that much deviation for the shoulder.

little_scrapper said:
3rd ?: Once FL resized I have case OAL ranging from 2.002" to 2.015" on the ones I have measured so far? What do I do with these shorter ones?
Click to expand...

That much variation in cases length can contribute some to this issue as the expander ball that's particularly tight being drawn up through a neck that's a lot shorter than a longer one will have a very different force applied to the neck and could contribute to the variation. So, IMHO, it'd be a good idea to trim them down to something like 2.005 so that the shorter one's don't present such a difference. Eventually, it's a GOOD idea to get they all to the same length and you'd probably have to do another trimming after the next firing to get there, or for sure the next.

little_scrapper said:
I realize these may be rhetorical ?'s I am just trying to get some edification here. 5 or 6 thou seems wierd.
Click to expand...

Again, IMHO, 5-6 thou is too much, where .002 would be ideal . . . .003 to the 1.623 from 1.626 you mentioned would be acceptable.

Well . . . it seems a place to really take a close look at is how your expander die is working for you. You may need to lube it. Also, you may need to take a closer look at how you clean your brass. If you're annealing AFTER you clean your brass, that annealing leaves an oxide deposit on the inside of the neck creating a LOT of friction, thereby a need for lubing. This is why I always clean my brass AFTER I anneal.

Hope this all gives you some food for thought and hope it helps in some way.
 
#14
little_scrapper said:
I thought about getting the Forster but everyone said it wasnt worth the extra money. It sounds to be more consistant than my RCBS. However, Maybe I have better results with a higher end die? Match die with a micrometer?
Click to expand...

No, your equipment is fine, assuming nothing is mechanically wrong. I have a different press I use for fl sizing for each rifle I own so I keep the dies installed at all times in that same press, except for the COAX, which is used to size brass for my M40A5 and SR25.

I think the variance you are seeing is probably a combination of slight metallurgical differences in the brass and perhaps something with your specific set up or techniques (I’m going by learning from experience with my own past procedures and techniques that resulted in variance and inconsistencies in my loads).
 
#15
It is all VERY helpful. I have a good bead on my process, I am patient enough to be anal about most every step. It's all the little nuances that I need to fine tune. Like maybe I need to sort my brass pre-sizing and possible trim necks before I resize.

I have been playing with does quick ramming vs slow effect shoulder and neck. Jury is still out but I could see a quick pull having less impact then a slow pull possible pulling the shoulder back out.
 
#17
I would be consistent in your movements/speed with the press, just to eliminate that as a potential source for variance. Speed should be moderate - not overly fast or slow.

Also, keep detailed records and measurements at each step in the process; it’s tracking those little nuances that will make the difference. That helped me narrow down the location in the process where variability was being introduced.
 
#19
I just finished reading about this remove the expander ball. Next time I go out, Not only will I shoot up a bunch of this barss i always make certain to blast off a bunch of new rounds as well to keep my supply of once fired brass well stocked.\

BTW: correction. This is all 2F LC LR brass. Not 3F. I keep a tracking sheet with all my brass. I have been working on getting several batches all worked up to that 3F level so that I have several hundred rounds of 3F LC LR so I can play with variations.

I havent even begun to use different primers yet! Gawd this wont ever end will it?
 
#21
Definitely deprime with a universal die first.

In all honesty, the variances you are working with here are less than the thickness of a dollar bill. I'm sure there is some quantifiable effect on target, but the real question is, can mere mortals hold the difference?
 
#22
little_scrapper said:
I have been playing with does quick ramming vs slow effect shoulder and neck. Jury is still out but I could see a quick pull having less impact then a slow pull possible pulling the shoulder back out.
Click to expand...

Yes. The speed one is ramming effects the forming of metal. The brass needs a little time to fully from to the shame your sizing it to.
Go fast and the brass will have more spring back. Ram it down and leave for a few seconds and the brass will have much less spring back. You can test this by sizing a case,, measure it right afterwards and a few hours or the next day later measure the brass again and you can see how much it's changed. I always let the sit for 4-5 seconds before lifting the die when forming the brass in any way (it does help with consisteny).
 
#24
You are trying to get benchrest results from mass-produced automated production GI brass, fired from an autoloader.

Good luck.

Hints that may or may not help: anneal all cases before sizing. Use an "S" body-size die with a neck bushing specifically for your chamber and leade (no button dragging through on the down-stroke pull).

Neck-turn the case to clean-up 50%. Trim all cases to length, every time. Internal debur the primer flash hole.

Your actual range firing should be done on fore-and-aft bags if you're not locking the weapon into a mechanical, no-movement fixture.

You are culling per your criteria, vice controlling what you can.

1582472049494.png
1582472294543.png
1582472317207.png
 
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#25
@super yes. First thing in my process is to use Lee decapping die.

@918v Good to know. I will look into that.

@ sinister. Working with what I have until I have more disposable coin to buy better brass. But its good to hear so I know to keep that limitation in mind. I dont have a way to turn necks and the flash hole on LR looks good to go. I have looked at several under a microscope. The M80 brass has a burr at the flash hole and I do deburr those.
 
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#26
little_scrapper said:
@super yes. First thing in my process is to use Lee decapping die.

@918v Good to know. I will look into that.

@ sinister. Working with what I have until I have more disposable coin to buy better brass. But its good to hear so I know to keep that limitation in mind. I dont have a way to turn necks and the flash hole on LR looks good to go. I have looked at several under a microscope. The M80 brass has a burr at the flash hole and I do deburr those.
Click to expand...

I wouldn't say the press is the weak point in your setup man. It's just going to take some effort to get everything dialed in. I noticed that my brass settled into my chamber after a few firings. I notice that my case dimension variances seem to be getting smaller
 
#27
Ryridesmotox said:
Definitely deprime with a universal die first.

In all honesty, the variances you are working with here are less than the thickness of a dollar bill. I'm sure there is some quantifiable effect on target, but the real question is, can mere mortals hold the difference?
Click to expand...

I like the Frankford Arsenal hand de priming tool. Can go through 100 cases every 2-3 minutes while watching TV.

To your other point, largely agree. For a gas gun (which is what he is loading), I prefer to keep at least .003” chamber headspace clearance but no more then .006”. If he can hold to a .003” variance range in his base-shoulder datum say 90% of the time, that should be satisfactory. The cases that fall outside can be ran through the die again after a slight adjustment; if sized too much, put aside.

Won’t notice one bit of difference down range, all other thing equal.
 
#28
@sinister great pic of the flash hole. The M80's look like the one on the right and I hit them with my Lymann hand deburring tool. Wont give me a prefessionally machined chamfer like the one on the left but it does the job. That being said, the LR brass also is NOT chamfered like that. They have some roughness but there is not burr.
 
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#29
little_scrapper said:
@sinister great pic of the flash hole. The M80's look like the one on the right and I hit them with my Lymann hand deburring tool. Wont give me a prefessionally machined chamfer like the one on the left but it does the job. That being said, the LR brass also is NOT chamfered like that. They have some roughness but there is not burr.
Click to expand...

Don’t think this has been covered so will ask:

How do your hand loads perform on the range, say compared to the factory M118LR?

What’s your typical SD/ES over a 10 shot group? Are you seeing inexplicable fliers, excessively high SD or large (above 1.5 MOA) groups / inconsistencies in group sizes with your rounds?

What is vertical dispersion like at 300 and/or 600?
 
#30
I agree with the others that have mentioned the Redding Comp Shellholders. Holds to +-.001 on a bad day, normaly less.

I also ream dies for neck tension without an expander ball so that removes one variable.
 
#31
Here is my last range trip. The circles with center dot are approx half inch. About the size of a AA battery.

I have just recently gotten a chrono to start gathering velocity data.

Also here is a shot of some LR and of a shot of one of my latest load straight from LC. LOL
175gr H4895 38F.jpg
M118LR 2016.jpg
Latest Load - Copy.jpg
 
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#32
@little_scrapper All the obvious things have been covered, but there is one thing that keeps coming to the front of my thoughts on this. You mentioned have different batches of brass that you add in to always have once fired brass available. Even though you are annealing I think it is a spring back issue.

I had two sets of brass from the same manufacture, 6 and 25 Creedmoor. I was swapping out the bushing to use the same FLS Bushing die for both cartridges as i had set up both barrels with the same head space (within 5/10,000). I noticed that my new 25 brass was considerably shorter than 6 brass using the same die and setting. It gave me .001" -.0015" shoulder bump on the 6 and about .006" on the new 25 brass all else equal. I anneal my brass too, but the brass metallurgy is either different or the multi-time fired 6 Creedmoor brass has hardened some in the body and shoulder area and springs back more than the softer new brass. I believe the later to be the case.

I believe this may be what is causing your problems if you are using brass with different amounts of firings on them.
 
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#33
@mil all this brass is '16. Every single one. Just sayin. However, yes. When I started shooting some of the old stock '02, '03 & '04 I started noticing some coming out of the chamber at 1.628" This is what made me start to think my chamber is more like 1.630" and if so, I might be able to use a bit longer headspace on brass.

That being said I plan to start saving the outliers that resize to 1.625". Make a small batch or two and see if I have any feed issues. Finding limits as it were. One of these days I will take rifle and have the headspace actually measured. But that takes effort. LOL
 
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#34
Try segregating by year, as well as annealing and trimming all cases to uniform length. Lake City isn't bad brass, but it's not the best, either. I've got LOTS of Lake City LR and National Match, but also Federal and Winchester. I save Lapua for my hunting loads.

Autoloaders are not necessarily more finicky, but more moving parts, harmonics, and a swinging hammer (vice in-line striker) are all going to contribute to vibration.

I'd be disappointed with the grouping you're getting as well. I don't see a distinctive group pattern with odd flyers, but rather patterns that seem fairly large and random.

The biggest thing I see from your photo is vertical spread rather than horizontal. How do you charge your cases? Dropped and trickled? Thrown? Chargemaster? Your charges also seem a little light.

Need to know a little about your scope and shooting technique.
 
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#35
@sinister So far Im all over the place. I have now purchased an Atlas Cal bipod. Havent used it yet. Will use a rear squeeze bag as well. I shoot seated off a concrete bench. Those previous shots were off a small bag on a chunk of railroad tie. I need the height.

I have a chargemaster light and trickle up to 0.2gr under then use a small pick to drop pieces, one or two at a time out of the tube until the scale rolls over to my desired weight.

My scope is a Vortex Crossfire II 8-18x in a AeroPrecision Ultralight mount.
LaRue UU 18 PredatAR.jpg
 
#36
little_scrapper said:
Here is my last range trip. The circles with center dot are approx half inch. About the size of a AA battery.

I have just recently gotten a chrono to start gathering velocity data.
Click to expand...

I wouldn’t shoot any more handloads unless your chrono is with you, otherwise you’re loading and testing in the dark...I also see lots of vertical spread, which could be a combination of you and your loads. The chrono data will bring a lot of clarity, however and help you fine tune.

Technique-wise, id watch for sympathetic squeezing of the rear bag. In fact, I would go with a proper rear rest of shooting off of a bench (or prone for that matter). It’s more stable...Made a big difference for me vs a regular bag...The scope is on the cheap side, would upgrade for sure but it’s prob not the primary driver of your group patterns. Just check (if you haven’t already) to make sure all fasteners are torqued to spec.
 
#37
I am hoping the bipod will help with consistency vs a bag on a random chunk of wood. The scope and mount screws are all patch-locked and tightened to spec using a FatWrench that was checked in the cal lab at work.

The barrel is a PredatAR 18" which is on the thin side. I am also hanging that big suppressor out there. I have been considering a rebarrel with a Kreiger or Proof stainless. Obviously a higher end barrel wony hurt.
 
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#39
@little_scrapper

Although all your brass is from the same year my point was that some may have 10 firings and some may have 1 firing on them when you go to resize them (I just threw those numbers out there). Also, I don't think a year stamp means all brass is from the same lot of brass, just year of manufacture, so there can be slight differences to the brass itself.
 
#40
I took my chrono out on that last outting and it took me only a handful of shots to find the upright on the visor. LOL Its a pain in the d|ck to set that up by yourself. Got any tips?
 
#41
MilSpecOkie said:
@little_scrapper

Although all your brass is from the same year my point was that some may have 10 firings and some may have 1 firing on them when you go to resize them (I just threw those numbers out there). Also, I don't think a year stamp means all brass is from the same lot of brass, just year of manufacture, so there can be slight differences to the brass itself.
Click to expand...
Point taken. I get all my brass directly from lake city in cases of 500. They (M118LR) come loaded with 175gr SMKs and I shoot them myself. I do keep my brass in lots by year and or number of firings.

I recently got in a batch of old stock that were all headstamped 02, 03 and 04's. LC has a habbit of "misplacing" large batches of ammo in outter storage areas and then finding them a decade later. LOL I got these old stock LR's for twenty cents a round. $100 for case of 500 rounds. They shoot fine and quite honestly the powder weights are not that consistent. I might be better off just tearing them all apart and reloading them myself. 175gr SMK's cost twice that much alone.
 
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#44
nn8734 said:
Lol, you’re hilarious. Buy a LabRadar. Otherwise just be more careful.
Click to expand...
Does my equipment set indicate I have $$$ for a lab radar. I can barely afford the midrange equipment I have.

I get full up LR for less then I can buy SMK for so i just shoot those and reuse the brass because for me thats the cheapest option I have. PM me if you want to loan me your Labradar. Otherwise I live in MN. There is a range up in princeton that you dont have to be a member and only cost $10 to go shoot. However, its mostly just a 100 yrd range and you have to be a member of the long range group to shoot ouot to 500 yards. Thats all i have avail for ranges here.

Now if I can talk grandpa into pushing up a berm with his dozer I could be shooting out to past 1K in his heyfield. But thats a 2 hour drive and the hayfield isnt "kept" therefore not a good shooting spot trying to shoot in 3' - 4' high grass.
 
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#48
Inconsistent case sizing lube will result in inconsistent shoulder bump. Another thing I do is raise the press ram slowly into the F/L die, pause a second or two when you bottom out the ram, then a back out the case a little before hitting the neck and run the case a second time through the F/L die. I have done my own tests and a have found this technique works well for getting consistent shoulder bumps.
 
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