Using 180-grain bullets versus op rod stress.

Discussion in 'M1 Garand' started by Laufer, Sep 25, 2010.

  1. Laufer

    Laufer G&G Enthusiast

    Will go buy 30-06 dies soon. A friend offered to give me about 500 .309 match bullets.

    Many people state that the heavier bullets can create too much gas pressure for the op rod.
    Is this also the case if you reload with the minimum recommended powder, such as IMR 4895, very similar to original spec. GI powder?

    My only reloading so far is for the Enfield #4 and #5s, began last February.
    Last edited: Sep 25, 2010
  2. Garand Handloading

    Anything's possible, I suppose, but why take unneeded risks? I'd suggest that you get a copy of the 7th Edition Hornady Handbook of Cartridge Reloading; there is a section of Garand-specific loads. The heaviest bullet listed, however, is 178 grains. Close enough? Dunno...your call. Looks like a good place to start, though.

    You can find the manual at Midway --MidwayUSA - Advanced Search There are doubtless other sources.


    Ben Hartley

  3. rl69

    rl69 G&G Evangelist

    Recommended .30 caliber M1 loadings from the NRA

    147 - 155 grain FMJ or HPBT bullets

    IMR 3031 - 48.0 grains
    IMR 4895 - 49.0 grains
    IMR 4064 - 50.0 grains
    W748 - 48.0 grains
    AA2460 - 49.0 grains
    AA2520 - 51.0 grains
    AA2495 - 50.5 grains
    H4895 - 49.0 grains
    BLC-2 - 49.0 grains
    H335 - 49.0 grains
    RL-12 - 48.0 grains
    165/168 grain FMJ, HP or SP bullets

    IMR 4895 - 47.0 grains
    IMR 4094 - 48.0 grains
    AA2520 - 47.5 grains
    AA2495 - 47.0 grains
    H4895 - 47.5 grains
    BLC-2 - 49.0 grains
    H335 - 47.0 grains
    RL-12 - 44.5 grains
    173/175 grain FMJ or HPBT bullets

    IMR 4895 - 46.0 grains
    IMR 4064 - 47.0 grains
    AA2460 - 46.0 grains
    AA2495 - 46.0 grains
    H4895 - 47.0 grains
    BLC-2 - 48.0 grains

    180 grain FMJ, SP or HPBT bullets

    IMR 4895 - 43.0 grains
    AA2460 - 46.5 grains
    AA2495 - 45.5 grains
    H4895 - 44.0 grains
    BLC-2 - 47.5 grains
    RL-12 - 41.5 grains

    Master Po's comments

    These loads only duplicate military spec. velocities for the given bullet weight, using commercial cases and powders. If you are using military cases, drop all charges by 2 grains.
    If you are looking for accuracy, drop all charges by 1 grain and work up .2 grains at a time.
    Master Po's Ancient M1 load secret

    This is my personal M1 load I use in my CMP M1. It will shoot better than Master Po can. I worked this load up, as you should for your own rifle.
    Remington .30/06 cases, flash holes deburred and weighed within 1 grain.
    Federal GM210M Primers (Master Po has heard the horror stories of Federal match primers in the M1/M1A rifles. If you're squeamish or new to reloading, use Winchester Large Rifle)
    47.0 grains IMR 4064
    Sierra 175 grain MatchKing
    Overall length 3.340 inches This load, in my M1, duplicates almost perfectly the M72 match load specification with a very low standard deviation. Groups off the bench run 1 - 1.5 inches with the original 1945 barrel on the rifle. Of course, Grasshopper YMMV.

    thees loads or at the top end of the hornady specs i use a 180 gr bullet for hunting and 147 gr for just plinking
  4. Laufer

    Laufer G&G Enthusiast

    Thanks very much for the time spent on the detailed info.
    Have it bookmarked, and will chat more with local experienced Garand reloaders for a while, then decide.
    Last edited: Sep 26, 2010
  5. Orlando

    Orlando G&G Evangelist

    No offense meant to anyone but get a reloading manual that has Garand loads and follow it. Taking info copied off the internet can be dangerous
  6. texnmidwest

    texnmidwest Sir Loin of Beef Forum Contributor a matter of fact, I would advise getting several manuals and comparing the Garand loads. Even different editions of manuals can list different loads for Garands.

  7. Is there a particular reloading manual, or manuals, that you can suggest or recommend? Or do they all have loads for Garands? To be honest, I've been focusing on handgun loads and haven't even looked. Maybe I should check my books and see if they have anything? But if there's any specific ones you suggest or can recommend, it would be appreciated.

    Thanks in advance.
  8. rl69

    rl69 G&G Evangelist

    hornady 7th edition has garand loads
  9. rl69

    rl69 G&G Evangelist

    Last edited: Sep 26, 2010
  10. rl69

    rl69 G&G Evangelist

  11. twtalbot

    twtalbot G&G Newbie

    +1. The latest edition Hornady manual has the data you're looking for. Also, proper lubrication, with grease in the prescribed locations goes a long way toward protecting the op rod.
  12. Ninja Piper

    Ninja Piper G&G Evangelist

    Nope, don't use them. Send them to me!:tongue2: Seriously, You interested in selling them? I have a hungry Remington 700!
  13. K, thanks, I do indeed have that one and will look. Like I said. ALL, ALL MY FOCUS has been on handgun loads.

    And to be honest, there are probably Garand loads in the others I have as well. lol
  14. M14man

    M14man I don't take prisoners... Forum Contributor

    The .309 diameter is a little larger than normal (.308) and will create more pressure.
    Coupled with the heavy weight. I would drop your first test loads by 4 grains and see how it functions.
  15. Laufer

    Laufer G&G Enthusiast

    "Roger that", I'm also skeptical about my Guru's comment about the ".309" bullets.

    He retired from the Navy Reserves with the Marks. Team (AR), and though he has not reloaded for the Garand, has done other calibers for a long time. Will ask him about the higher pressures, which occurred to me.

    The gun's grease points are on one of the helpful "Surplusrifle" videos.
    It will be a few weeks before I even begin to reload for the M-1. The small CMP booklet describes slam-fires also, and well aware of the SKS issues.
    Last edited: Sep 27, 2010
  16. Bart B.

    Bart B. G&G Addict

    There were never any military spec loads for 180-gr. bullets. If someone knows of one, what's its round designator?

    Two tenths of a grain will be overshadowed in pressure and velocity variables caused by primers and powder weighed to exact charges. Half-grain increments is good enough.

    And you'll still have to shoot 30-shot test groups with each to have at least 80% confidence the load will always produce groups the size it shoots.

    No load shoots better than any person does. If one's rifle and ammo shoots zero MOA all day long, the group it shoots will be no smaller than the area on the target the shooter holds while aiming. Should the best one can hold be 1/4 MOA and that rifle plus its ammo will shoot 1/4 MOA. If the rifle and ammo shoots 1/4 MOA, the group will be 1/2 MOA. Real masters of the shooting sports know this.

    How did you measure peak pressure, mean radius of the shot group at 600 yards (M72 match ammo test range specification) as well as muzzle velocity average and maximum spread?

    A Garand shooting 1 MOA at 100 yards with the very best lots of National Match M72 ammo will shoot well over 2 MOA at 600 yards. M72 accuracy specs are a mean radius of 3.5 inches at 600 yards which equates to about 1.5 MOA.

    There are folks who've pulled the 172-gr. bullet from M72 match ammo and replaced it with a Sierra 180-gr. boattail match bullet. Shot very accurate but only from commercial barrels with a .3075" groove diameter barrel. Arsenal barrels with their .3083" average groove diameter needed the .3086" diameter 172-gr. match bullet to shoot accurately. Which is why Winchester and Western made their 30 caliber match bullets for the Garand as well as Winchester Model 70 Nat'l. Match rifles about .3087" to .3088". Bullets whose diameter is smaller than the barrel's groove diameter won't shoot very accurate.

    You should full length size all fired cases from a Garand before reloading them. Just be sure the sized case shoulder to head measurement (case headspace) is no shorter than a new case. Otherwise, head separation will soon happen and accuracy will not be good.

    Don't expect great accuracy from reloaded cases. New ones have always shot the best in Garands as well as the M14NM and M1A's. Nobody ever squared up those rifle's bolt face which made fired cases have their heads out of square with the bolt face when rechambered.

    Slug the barrel then measure the slug with a good micrometer. Use bullets at least 3/10,000ths inch larger than the groove diameter for best accuracy.

    Bullets as heavy as 190 grains have been used in max loads without hurting the op rod. There's only a few folks in the USA (5 or less I think) who can properly bend and fit a Garand op rod so it will not get bent from heavy loads. Note the USN used heavy charges of IMR4320 under Sierra 190's in their 7.62 NATO Garands without a hitch. And it was (and may still be) the most accurate long range load in any garand; either .308 or .30-06.
    Last edited: Oct 2, 2010
  17. Laufer

    Laufer G&G Enthusiast

    Bart B.:
    I've still not bought the dies for 30-06, and will in a few weeks, but only after more reading and chatting. My main "gun guru" has several reloading manuals.

    The reloads would only be for practice and improving modest, novice skills (very late-bloomer with guns): have only been shooting out to 100 yards for about three months.
    If skills were to somehow improve enough for basic competition, the fresh LC ammo would be used.

    Just read all of this topic for the third time and really appreciate all of the advice.
  18. Bart B.

    Bart B. G&G Addict

    Regarding the talk about slam fires in this thread, I've seen a few dozen ejected cases from slam fired Garands; both 30 caliber and 7.62 NATO ones. Every one had it's primer normally dimpled exactly like normally fired ones.

    Which proves to me the hammer struck the firing pin and fired the round when the bolt was fully closed and locked in battery. Two things are the common cause of such slamfires.

    1. The sear engagement with the hammer has been reduced too much by the person who did this. Folks who don't hold their trigger finger back hard against the stop until the rifle's quit moving from recoil can unknowingly flip their trigger finger forward releasing the trigger enough that the sear won't hold the trigger as the shock of the bolt transferrs to it.

    2. Same as above, but with even less sear-hammer engagement. When the bolt slams home chambering a round, the shock of this disengages the hair-line engagement and releases the firing pin.

    I've never seen a slam fired case with a shallow dimpled primer. Every one's had full firing pin impact. And this can only happen after the bolt's closed and the pin's received full, normal hammer impact. Note that the firing pin's leg can't go forward enough for it to even touch the primer until the bolt's about 80% closed; that is unless the firing pin or receiver is worn too much where they align, but even with this condition, there' not enough force of the firing pin on the primer to fire it.
    Last edited: Oct 17, 2010
  19. personally,

    I advise shooting only the loads for which the gun was developed.
  20. M14man

    M14man I don't take prisoners... Forum Contributor

    Bart this happened to me, last year with an M1A Super Match from Springfield Armory and should alert everyone that a slam fire can occur at any time. I had reloaded some rounds that passed all inspections but somehow turned out not to be sized quite small enough. They were sized down, but just not enough to easily close on this minimum headspaced rifle. Since I have 3 rifles chambered for the .308 I wanted to see the lots (boxes) of ammo that would not pass muster in this rifle which had the tightest headspace. I set the safety, the primer was properly set below the head. The rifle was on the ground, muzzle slightly elevated due to the Harris bipod. I was kneeling over it from behind. I placed the cartridge three quarters of the way into the chamber and brought the bolt foward most of the way feeling there was still enough energy left for the extractor to jump the rim. There was no box magazine in the rifle.I let the bolt go and all hell broke lose. I was hit by a blast, and minute shards of brass hit me in the arm and chest. Luckily this was a scoped rifle so there was a limited area of escape for the brass shards. I was OK, small pock marks on my chest and right arm that drew blood in little dots. All fingers were accounted for, no shards in the eye. I was not wearing eye protection since I was not at the range, nor was I wearing a shirt I was in my den.... Luckily my face exposure was above and blocked by the scope. When I regained my composure, I carefully started to check what went wrong since I thought this slam fire was impossible. Especially since the bolt was most of the way home and was not getting slammed as hard as it could have been. The trigger housing was still locked. The case had not ejected and as I opened the bolt, just the head extracted. The primer looked like a normal fired primer. Not lightly dimpled, but fully indented. The front part of the case was still in the chamber and had to be pulled out with a ruptured case extractor. There was about 3/8" of an inch of case missing. Evaporated, or shrapnel. It would appear that the case detonated before it was fully in the chamber as evidenced by the section missing. There was no ridge on the case to indicate how far it got in. It obviously had not generated enough gas to throw the bolt back or the head of the case would have been ejected. I can't conceive of the firing pin hitting the primer hard enough to detonate it, especially since the bolt was not fully slammed and let go from it's rearward position. Testing of rounds that the rifle cycles but does not fire shows the slight dimple as normal in most semi's. It has me stumped as to why, I just know it did, when it shouldn't have. One thing I did learn is not to use cartridges that don't fully pass the Wilson test gauge in that rifle. There was no damage to the rifle, or the scope, no blast marks from the gas that would have hit the rug thru the mag well. Oh it did cost me $350 for a glass sliding door. The bullet landing somewhere on the 1200 acre preserve in my back yard.