Ive been reloading for around three years mostly for bolt guns. Recently I puchased a M1a NM and have read in the owners manual no reloads-of course. But they also threw in a write up on slam fires and the consequences. So my question is what do I have to do to insure that I dont blow up my rifle and or my face. Read on another site that I need a headspace gauge and need to make sure that cases are full lenth resized. I have Lee full lenth resizing dies but will I need small base dies? Any expierecned remarks and what equipment will I NEED? Will standard primers work or should I bye the CCI no 34's. Plan on using 147-155 gr bullets and Imr 4895 by the way. Thank you.

You definatly want to use those "hard" CCI primers

Anything is too soft.

IMR-4895 would have been my first suggestion.

Extracting the chambered (but unfired) rounds from many different AR's has made me real nervous about using soft primers in military type rifles.

AD

I can only tell you what works in my M1A, and that of everyone else I shoot with...
Win. primers,165 or 168 gn. bullets,40-41.5 gn IMR 4895, full length resized using a small base die. Brass trimmed to 2.010 or so. Out of literally thousands of rounds fired, I don't think my rifle has ever seen a factory load other than some U.S. National match rounds.
Your experience may vary...
Cheers

Thanks guys. I was under the assumption that bullets around 150gr were easier on the rifle. Is there any truth to that or is the burn rate more important? So I will invest in some some small base dies and #34 primers. Any thoughts on headspace gauges or do you just make sure to full length resize each time? Also I have used stony point oal gauge with my bolt guns, is that applicable to the M1a or do you recommend correct Oal out of the manuals. Don you mention 2.010 trim lenth which is right in the middle of the book trim to and the max case lenth. For what reason have you done this? One would think if trying to minimize the chance of a slamfire you would want the case on the short side. Thanks again guys!

i duno i just use the same loads as i do in a bolt gun. but then again i've only been loading for one for 40 years

I have a SA M1A. I shoot Black Hills and Lake City Match ammo without a hitch. I have a bunch of Federal silver box ammo but my rifle does some serious slam firing with that particular ammo. Because of the slam fire issue, I use CCI #34 primers in my reloads and haven't had a problem. Powder Valley is selling the CCI 34s for $75/5,000.

I have loaded and fired thousands of rounds through M1 Garands,the M1A and AR's without incident and have never found it necessary to use a small base die (but I never used brass salvaged from machinegun ranges either). SB dies are probably necessary if your GI brass has been fired in machineguns in order to bring the base of the case back into spec to fit the tighter match chambers. Having said that, IMO, SB dies will over work your brass and can contribute to premature case head separation.

Other than a dirty chamber, a broken firing pin or a pin that is no longer free floating for whatever reason, ammo is probably the number one cause of slam fires in the Garands & M14's. Anything that can cause the round to "stop short" of full chambering can result in the firing pin hitting the primer with sufficient force to set it off. If this occurs before the bolt is in battery, it can be disastrous!

Soft primers can contribute to a slam fire. The CCI #34 & #41 military primers have a hard cup to duplicate GI ammo, most of which is loaded with a hard primer. Handloaders must be aware of two other factors that can result in slam fires.

First, make it a practice to run your thumb over the primer as each round is removed from the press to be sure that the primer is fully seated.

Secondly, each cartridge must be sized sufficiently to fit your rifle's chamber giving proper headspace clearance. I would not load for any "gas gun" without using a cartridge case headspace gauge. Best practice is to run each case through the case gauge at the time the loaded round comes off the press after determining the actual headspace required for your rifle; remember, all rifle chambers are not created equally. At the very least, spot check every few rounds in a given lot of reloads (for this to be acceptable, one must keep all brass in lots that have been fired the same number of times).

I had a friend who is a very experienced highpower competitor and reloader; he wrecked his match grade M1 Garand using the same handloads he has used for years when the rifle slam fired out of battery. Bent his op-rod, blew extractor/ejector out of bolt and rounded the receiver locking lug recess about 1/8" showing the bolt lug (thankfully) had barely entered the recess and was not in battery at the time the slamfire occured. He received a cut on the forehead and had somewhat of a problem with his trigger control for a while thereafter. Fortunately, the rifle, and his shooting ability have since been restored.

Upon examination of the remaining lot of ammo, we found that the rounds did not have sufficient headspace (clearance) in his snug match chamber. He had loaded this batch of ammo using the same (full length)die setting as always. Remember, all previous lots had measured OK. The problem stemmed from the fact that this particular lot of brass had been fired at least 8 times and had work hardened; his dies had been set to give proper headspace with once fired brass and he failed to check headspace on this lot after loading. The harder brass springs back more than softer brass after sizing which resulted in oversized (for his chamber)rounds.

Regards,
hm

Al,
I've never had or seen a slam-fire. I do make sure my primers are seaed properly, and as I mentioned, all my brass is full length re-sized using a small base die. I mentioned 2.010 as a guide...2.005 is indeed the "trim-to" length. Shooting brass that has "grown" a bit out to 2.010 or so won't hurt your rifle, although it my(or may not..) hurt your groups. I've found consistency to be one of the most important things to keep in mind when loading for match shooting in any discipline. One other thing.. the M1A is notoriously hard on brass.
Best Wishes...
Don

RE: Read hm1996's post again.
Much good information here!


Do the above and you will avoid "slam fires"

muck

I reload a good bit for the M1, and have a process that has eleminated misfires, misfeeds, jams, and the potential for slam fires.

I use the #34 primers; I inspect cases; trim if necessary; I full length resize in a regular die; I drop the case into a case gauge and make sure it seats fully; if it doesn't, I take my dremel tool and dress the base which gets damaged by the extractor; when it drops smoothly into the gauge, I prime, charge and seat and re-gauge.

I have seen a couple of M1s ruined from slam fires and the shooters were lucky they were not seriously injured. The steps seem difficult, but it really is pretty straight forward. Kudude

http://www.zediker.com/downloads/m14.html
http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm
These two sites have some good info. I agree totally that a headspace gage is a necessity. I use the RCBS Precision Mic myself. I also use the back of my calipers across the primer and holding each primed case up to a light. You can see easily that there is a high or unsquarely seated primer by the light between the primer and straight edge of the caliper. This only takes seconds and is well worth the effort as you can not always feel that the primer is correctly seated while priming.

Just a couple items to go along with what hm1996 says and that is over the 45 years or more that I have shot the M1Garand, M14/M1A is not to reload the brass more than 3 times. Garands, M14/M1A offer violent action to the brass and stretching can occur and just leads to separation of the case and lots of problems which I am sure you can imagine. "high primers..." are often the culprit that produces those slam fires and needless to say, make sure, whatever primer you are using, it is fully seated and then some. Clean,ream the primer pockets helps. Since we have a floating firing pin, suggest you not "drop" the bolt on a round in the chamber. Feeding from the enbloc mag. or the M14's clip will normally suffeciently slow down the forward motion of the bolt to not permit the pin from flying forward rapidly and producing a "slam fire..."
The Garand and M1A will give lots of good service if maintained and not "hot rodded..." with loads. Good luck in your shooting your "gas gun."

Al James

You will not need small base dies. I suggest the regular RCBS X-Die. I've also been loading for M14/M1As for 35 years. I used to agree with dsiteman about only loading the cases 3 times for matches as on the 4th or 5th firing incipient head seperation becomes apparent. The following article I wrote based on my test should be of help to you.

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 “throwawayâ€. 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 once fired 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 2.045â€. 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-.007â€.

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: 2.8â€

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 2.045â€.
Loose primer pockets.
Neck thickening to cause excessive runout (.010â€).
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 chronographing 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 affect 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 2.8â€. The last (15th) ten shot group with the M118 equivalent load was 2.4â€. The average of groups 2-15 being 2.7â€. Groups 6 and 12 were fired with the match M1A to verify the accuracy and both were 1.6â€.

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 (.001â€) 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!

Good luck, good shooting and good hunting

Addendum: I continued on with the test using the remaining nine cases. On the 16th firing another case showed signs of incipient
Case head separation. The other eight cases have been fired 20 times. I doubt I’ll continue on as 20 firings per case is enough.

Good info from Larry Gibson;however, having switched to the AR15/16 platform for most match style shooting has pretty much eliminated all of the process to maitain case life and as a real plus, increased scores out to and including the 600 yard range. Progress one might say, eh?? Again, been years since I shot the M14/M1A and in those days, LC match brass very common and yes, even free, and just did not take the time to do anything but really trim to 2.005, bevel inside of case neck, ream out primer pocket, seat to 2.800" make sure primer seated well, and shoot. Again, very good data for the M1A shooter as found in Larry Gibson's posting.

The only slamfires I have ever seen with an M-1/M-1A family firearm were at the 1966 Navy Atlantic Fleet matches. We were using standard Match Grade M-1s and a "special" lot of Lake City ammo at the 500 yard line (Annapolis range). I was on the first relay at 500, and popped my first round down range when the bolt slam fired, costing me the match. The range master classed the failure as operator error. After everyone else on the 500 yard line had the same experience as I did, he changed the ruling, but did not allow anyone from the first relay of slamfires to refire a single round!!! Obviously, slamfires are etched in my brain. I've never had another slamfire. I also have used hard CCI primers in all my reloads since I began reloading for matches in 1981, and never seen another slamfire. Of course, you must assure that all primers are seated properly, not allowing any to remain "high" or you do run the risk of slamfire, not to mention failure to chamber the round. I think slamfire is more of a bugaboo today, with good reloading practice, better primers, and good sense saving the day!
LLS

A suggestion, in addition to all of the good info above. Get yourself a primer pocket uniformer. This will make sure all of the primers are seated to a uniform depth and a bit below flush removing any chance of slam fire.
Jim