Dies for Garand and M1A Recommendation

[Shanghai Jack]

Okay all my reloading prior to now has been bolt action and falling block rifle and pistol. Just branched out into Garand and M1A. Been reading about small base dies for autoloaders. Whats the conventional wisdom? Any die recommendations? Thanks

[M-Tecs]

I don't recommend small base dies until you actually need them due to chambering issues.

[fastdadio]

I've been loading for my M1a and Garand for a good number of years using RCBS plain base dies with no problems. These rifles are hard on brass so when I see the shiney line develop around the base, I toss that lot. 4 to 5 reloads max and I toss the lot also.

[Winger Ed.]

I've been loading for my M1a and Garand for a good number of years using RCBS plain base dies with no problems. These rifles are hard on brass so when I see the shiney line develop around the base, I toss that lot. 4 to 5 reloads max and I toss the lot also.

^^^this^^^
It's exactly what I do, and if I wasn't so lazy, I'd have typed all that myself.

[Larry Gibson]

RCBS X-DIES: A TEST

By Larry M. Gibson


Surprisingly, there was little fanfare with the introduction of RCBS’s X-Dies. All I saw were small blurbs in the trade magazines and mention of them in Rick Jamison’s Shooting Times column. Advertised to reduce or eliminate case stretch the question is; do they? My real interest was: Will they reduce case stretch, i.e. increase case life, of 7.62 NATO (that’s .308 WIN to you non-mil types) cases fired in M14/M1A’s?

The number of reloadings per case for M14/M1A’s is probably the worst of any rifle/cartridge combination short of the .303 Lee Enfield family. Incipient head separation is the reason for case loss. My experience with rack grade M14/M1A’s is five good firings per case with the sixth being a “throwaway”. This only if the brass was fired in a bolt gun or M14/M1A to begin with. A match M14/M1A with a tight “match” chamber may get 1-2 more firings but more often not. If surplus oncefired brass is used the first firing was more than likely done in a machine gun and only 1-2 reloadings/firings are possible before head separation.

Most head separations can be identified as a speckled crack forming around the case just ahead of the web at the expansion ring. This crack is sometimes quite obvious. Then on some cases the head will separate from the case on ejection. Many times both parts of the separated case are ejected. But sometimes only the head is ejected leaving the front half of the case in the chamber. The rifle picks up the next round attempting to chamber it and things get jammed up. Not good! The other question here; is there gas cutting damage to the chamber?

What causes this incipient head separation to happen? Simply put, on firing, the case expands to grip the chamber walls sealing off the gas pressure. When the bullet leaves the barrel pressures are reduced and the case contracts (not to its original dimensions) releasing it’s grip on the chamber walls and allowing extraction. However, it appears that the M14/M1A begins extraction prior to the pressure dropping completely. The cases do not contract as much as they would if fired in a bolt action for instance. Compounding the problem is the mil-specs for military chambers are somewhat generous in their diameter dimension to allow for functional reliability during combat conditions. When full-length resizing (necessary for M14/M1A) case walls are squeezed in first. This pushes the shoulder forward. The shoulder is then set back by the FL die and the brass flows forward into and elongating the neck. This increases the case length on each resizing considerably. Also, since the brass at the expansion ring expanded and was squeezed in and forward during resizing the case gets progressively thinner in that specific area. The result is, eventually, a head separation at that thinning location. Most mil-spec (US) chambers allow for a maximum case length of about 2.045”. I, like most M14/M1A users, have found trimming unnecessary. Incipient case head separation will occur, and cases discarded, before maximum case length is reached and trimming is necessary.

Are these RCBS X-Dies a cure for this? I decided to use my rack grade M1A to put them to the test. The issue GI barrel has quite a generous mil-spec chamber with headspace being within tolerance. This usually results in the fifth firing being the “throwaway” for brass in this rifle. It has untold thousands of rounds through it, many rapid fire. Accuracy capability is 2 1/2-3 MOA with M118 Special Ball or equivalent reload. This would be the best “worst case” test rifle. All rounds would be fired with the rifle loading from the magazine in normal semi-auto function. Slow fire single loading technique would not be used.

For ammunition I selected 10 rounds of LC 92 M118 Special Ball. A check for concentricity revealed a runout of .011” for one round with the others being .004-.007”.

My M118 equivalent load is:

BRASS: The 10 LC 92 cases from the selected M118 Special Ball
PRIMER: Winchester WLR
POWDWER: H4895 – 41gr
BULLET: M118 174gr
CARTRIDGE OAL: 2.8”

Other than deburring the flash hole, chamfering the case mouth and removing the primer pocket crimp, there was no special “case preparation” done. Cases were measured after each resizing with the minimum to maximum case lengths recorded. Concentricity was checked after each loading. Two cases (marked and tracked) consistently had .004-.005” runout with all others being .0005-.003” throughout the test. Neck thickness (outside diameter) was measured after each loading to check for brass flow into the neck area.

The test would be concluded based on any one of these criteria:

Any sign of incipient head separation.
Case buckled or dimensionally damaged/deformed during resizing.
Split neck or body.
Case length exceeding 2.045”.
Loose primer pockets.
Neck thickening to cause excessive runout (.010”).

Drastic deterioration of accuracy. (6th, 12th and 18th groups will
be fired in Fulton Armory Match M1A to verify accuracy)
Malfunctions caused by damaged (dinged up) cases.

All test firing was conducted at Tacoma Rifle and Revolver range.
The range has solid cement benches, which were used with sandbag rests front and rear. A 100 yard reduced “A” bull target was used. All targets were at 100 yards. I set up the Oehler 35P to chronograph all rounds fired for each 10 shot string. But as the test went on, and on, and on I quit after the 10th string. Chronograph results were consistent and showed no variation other than that normally expected. The LC 92 M118 averaged 2600 FPS and the M118 equivalent reload averaged 2575 FPS for the subsequent 9 ten shot strings chronographed.

The RCBS X-Die was installed in my Pacific single stage press and adjusted as per the instructions. It’s really quite easy. These dies differ from other FL dies in the dimension and design of the decapping rod. The diameter of the rod is larger and appears to act as a mandrill of sorts. There is a shoulder on it, which controls the length as the case. Apparently the case is prevented from stretching by the case mouth butting against this shoulder. Thus the decapping rod must be carefully adjusted as per the instructions. This shoulder is the key to the success of the die.

I found on the second resizing that the expander was really getting hard to pull through the necks. Also, the lengths of the cases were varying more than I thought they should. Case lubing technique was changed to standing the cases in a tray. They were then sprayed lightly with Dillon case lube. With this method the necks (lube gets sprayed lightly into the case mouth) pulled over the expander quite easily and the uniformity of case length dramatically improved. Cases are cleaned again to remove the lube. This should also remove the lube from the inside of the case neck.

Throughout the test case length never exceeded 2.027” and actually remained quite consistent. After the 12th resizing the necks had begun to thicken by about .001” at the shoulder to taper forward about 1/3 of the way to the case mouth. However, this did not adversely effect concentricity or accuracy.

The case rims got a little beat up but there were no malfunctions of any kind. This included the 2 firings in the match chamber M1A. Primer pockets remained tight throughout the test. I thought the case mouths would require rechamfering but they did not. Accuracy remained consistent with the rack grade M1A. The LC 92 M118 ten shot group was 2.8”. The last (15th) ten shot group with the M118 equivalent load was 2.4”. The average of groups 2-15 being 2.7”. Groups 6 and 12 were fired with the match M1A to verify the accuracy and both were 1.6”.

The test was concluded after the 15th firing based on incipient head separation. One case developed that slight speckled circle at the expansion ring. There was no clear-cut crack and probably no gas cutting happened. I may or may not continue the test with the rest of the cases.

Tabulated below are the measurements after each resizing:

RESIZING MINIMUM MAXIMUM INCREASE
CASE CASE IN CASE
LENGTH LENGTH LENGTH

1 2.013 2.019

2 2.021 2.025 .006

3 2.025 2.027 .002

4 2.025 2.027 .000

5 2.022 2.027 .000

6 2.023 2.025 -.002

7 2.023 2.025 .000

8 2.024 2.026 .001

9 2.024 2.027 .001

10 2.025 2.027 .000

11 2.025 2.027 .000

12 2.024 2.026 -.001

13 2.025 2.026 .000

14 2.024 2.027 .001


Case length evened out at the third resizing and remained fairly consistent. Interestingly #’s 6 & 12 that were fired in the match M1A show a decrease in length! At #12 is where I detected a thickening (.001”) of the case necks in the shoulder area which tapered forward. Again this did not effect concentricity or accuracy.

Questions not addressed in this test:

1. Case life when used in match chambers or bolt guns?

2. Case life of cases already fired several times?

3. Case life of surplus once-fired (in machine guns) cases?

4. Case life of civilian manufactured(Rem,Win,Fed,PMC,et all) cases?

The answers to these questions will probably have results as positive, if not more so, than this test.

My technique for loading M14/M1A ammo now will probably be as follows:

1. Clean cases
2. Stand cases in loading trays and spray lightly with Dillon case lube.
3. Size with RCBS X-Die using Pacific single stage press.
4. Clean cases. Clean primer pockets. (On 1st resizing prep cases by: remove primer crimp, deburr flash hole, turn necks, trim to uniform length and chamfer case mouth). Conduct visual inspection for defects (split necks, head separation, etc.).
5. Load on Dillon 550B. Use a Bonanza neck size die or a Redding bushing die at station 1. This may or may not be necessary. The idea here is to iron out any dents the second cleaning may have caused in the case mouth and maybe uniform neck tension on the bullet.

This limited test revealed that; using the RCBS X-Dies, when reloading for the M14/M1A, one may expect 3 times or more firings per case as when using standard dies. I have been using Bonanza Benchrest FL Dies prior to this. I’ve never found the need for small base dies, as some recommend, for they really shorten case life.

This increase of case life is, in my opinion, truly astounding. Also, it appears case trimming is unnecessary. I would hope RCBS would make them in a wider array of caliber’s than currently available. I will buy more of them. When I think of the thousands of 5-6 times fired brass I have thrown out … Oh well!


I now have X-Dies for 8 different cartridges including the 30-06 for use in all my '06 rifles including a couple M1 that have come my way. I also use the standard 223 Remington X-die for all my 223/5.56s, especially the ARs. Never found a need for small base or "AR" dies either.

[BLAHUT]

Okay all my reloading prior to now has been bolt action and falling block rifle and pistol. Just branched out into Garand and M1A. Been reading about small base dies for autoloaders. Whats the conventional wisdom? Any die recommendations? Thanks

I just use standard dies; I reload about 3 / 4 times; then toss;

[Jack Stanley]

I've got as many as ten loads of 30-06 in a Garand with Redding dies . The way I did it was to adjust the dies to the rifle and not according to the instructions .

First , strip the bolt of all it's parts and take the op rod off the rifle .

Next find a 30-06 case that does not fit the chamber when you ease the stripped bolt forward . If the bolt doesn't lock that's what you want .

With the die installed but not even close to the shell holder and the case lubed . Run the case in until you feel it contacting the die .

Wipe the lube and see if the bolt will lock . The idea is to let the die down a little at a time and try again . When the bolt lug starts to contact the right side of the reciever you can watch progress as you turn the die down .

When the lug finally touches the bottom of the recess freely (and you may hear it bottom as well ) you're there . Get a couple more cases that don't fit , size them and see they all work right . Trim the cases and re-check . This worked for mine , I only used that method for one rifle but it might work for others you have but check the fit before you run live ammo .

Since the M1A is the same system I think it would work there too . There used to be what was called a Mo-gauge that would measure headspace of a case and that may help for checking cases . Should work with any die but the only ones I've used are Redding and Dillon . Cases went to ten loads before a neck crack appeared . If you anneal at five firings case life is good .

Jack

[Larry Gibson]

It's very hard to beat 20+ firings per case and no trimming necessary with the X-die.

[M-Tecs]

. There used to be what was called a Mo-gauge that would measure headspace of a case and that may help for checking cases .
Jack

I don't know if RCBS bought it or copied it, but the current version is the RCBS Precision Case mic. https://www.rcbs.com/case-processing...n-mic/564.html eBay is a good source for used at a good price.

I purchased my first MO's gauge in 1992 at Camp Perry.

Limiting shoulder setback to .002" or 003" max greatly increases case life in the M1A's, Garand's and AR's.

[slim1836]

It's very hard to beat 20+ firings per case and no trimming necessary with the X-die.

Did you anneal at any point?

Slim

[Larry Gibson]

Did you anneal at any point?

Slim

No, and still don't with 5.56, 7.62 NATO or 30-06.

[ShooterAZ]

I use the RCBS X-Dies in the 3 calibers that Larry mentions. 223/5.56, 308/7.62x51 and the 30-06. Beyond the initial trim, I never had to trim them again. The only problem I've had is that with the M1 Garand and M1A the case rims get torn up pretty good after a good many firings. After that, they go in the scrap bucket. I have not had that problem with 223 in the AR though.

[fastdadio]

OK, you guys or this thread just jinxed me. I had my first ever case head separation today. Shooting my SAI Loaded M1a chambered in .308 Win.
The case ejected whole and was cracked about 3/4 around just above the web. 4th or 5th loading on a lot of about 35 cases. They were mixed head stamped, once fired, commercial cases from Diamond K Brass. Loaded with Hornady 150gr fmjbt blems over 43.2 grs Varget and CCI#34 primers. Nothing fishy with the load data. So there ya go, I guess maybe it's time to look into those RCBS X dies that Larry says are the schnizzle for our gas guns.

[NuJudge]

With .308/7.62x51, the only brass I have needed small base dies for is that which had been fired in machine-guns. The problem was the adjustable headspace on these arms being set loose to improve reliability. Unfortunately, virtually all the surplus military brass you are likely to find today was fired in machine-guns.

I have been loading for .30-06 since 1972, and until recently, I have never needed small base dies, even with that fired in machine-guns. One of the lots of Greek HXP I got from the Civilian Marksmanship Program did not size down enough in ordinary dies to fit my Garands.

Use your chamber(s) as your headspace gauge.

[Winger Ed.]

Probably so.
Back when GI once fired 7.62 were $40. a thousand shipped, and even GI .30-06 pull downs wasn't much more,
throwing them away fairly early was no big deal.
Now, they've gotten higher than giraffe lips, and a X die becomes worth its price and pays for itself pretty quickly.

[JWT]

I use RCBS competition dies for my M1 and M1A rifles. Based on Larry's study I will be ordering x dies tomorrow

[nicholst55]

I don't know if RCBS bought it or copied it, but the current version is the RCBS Precision Case mic. https://www.rcbs.com/case-processing...n-mic/564.html eBay is a good source for used at a good price.

I purchased my first MO's gauge in 1992 at Camp Perry.

Limiting shoulder setback to .002" or 003" max greatly increases case life in the M1A's, Garand's and AR's.

Fulton Armory carries Mo's case headspace gauges for .223, .308, and .30-06.

[garandsrus]

With .308/7.62x51, the only brass I have needed small base dies for is that which had been fired in machine-guns. The problem was the adjustable headspace on these arms being set loose to improve reliability. Unfortunately, virtually all the surplus military brass you are likely to find today was fired in machine-guns.

I have been loading for .30-06 since 1972, and until recently, I have never needed small base dies, even with that fired in machine-guns. One of the lots of Greek HXP I got from the Civilian Marksmanship Program did not size down enough in ordinary dies to fit my Garands.

Use your chamber(s) as your headspace gauge.

I have had to grind a little off the bottom of a couple .308 sizing dies to get the case to size to where the case gauge would read zero. I thought it was because the Dillon shell plate may be thicker than a standard shell plate, but it could have been the lot of brass. Either way, a shorter sizing die fixed the problem since I could screw it down more.

[beltfed]

I set up my Garand and M1A like Jack Stanley- with stripped rifle and only the bolt.
I use std die for Garand- but chose the Forster Bonanza "308 National Match" full length die set according to the above technique
for my MiA match rifle.
The 308 National Match die is sized to "fit" the M852 match ammo without oversizing the brass.

OH, and Larry Gibson-- very good testing protocol .
beltfed/arnie

[Adam Helmer]

I reloaded for 3 Match M14s when on my state high power rifle team and several Garands and never needed a small base die. I have used RCBS dies since 1967 and let the rifles tell me when a case is resized enough. Many people over work brass needlessly. I back off the resizing die a turn or two, lube a case, resize and try it in the gun. If no go, I tweek the die down and try again. I label all reloads to a specific arm. It works for me.

Adam