My HRA Garand "doubles"!
The first time that happened I thought it was a fluke so I replaced the two broken difusers on my Oehler chronograph screens and moved on. It happened again today. No high primers--CMP military stuff. What parts do I need to replace to make it quit that?
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First off, remove the trigger/hammer group and clean any and all lube from the sear area/hammer hooks and perform a function check.
1. Check rifle unloaded (many folks reading these forums)
2. With trigger held to the rear*, cycle the bolt. Release the trigger, and trip the hammer. Perform this function several times.
3. Notice if the hammer follows the bolt back into battery. If it does, that's the problem (the sear angles are off either on the sear, or the hammer hook).
4. The sear problem may be that the trigger/sear/hammer is loose in the trigger housing, either due to damage to the parts, or the pins, or the holes in the housing itself. Wiggle the hammer/trigger. There should be very little side-play.
Now, perform a firing pin check. Break the rifle down into the three main sub-categories, and notice if the firing pin tang will slide freely fore-and-aft by reaching into the receiver, and moving the pin. If movement is binding, that's the problem.
If the firing pin moves free, you can lock the bolt back, and check the face around the firing pin hole for burrs.
Note: if you have a small jeweller's vise, you can place the trigger/hammer group in the vise, and perform the same function check as in paragraph one.
Result: You may find nothing. However, the sear angle is what's giving me pause..and unless you don't know what the correct angles should be, then you have to 1. take it to a G/S, 2. Buy a rebuilt trigger group assembly, or 3. Shotgun the problem by buying a new hammer/sear/trigger and the associated pins (assuming the trigger housing holes are not worked oversize-see the problems building here?) I'm inclined to go with item 1, and maybe item 2.
Item 1 and 2 (in blue, above) directly answers your question. The rest of my post is 'background'..again, many may see this post.
I'll try and locate an on-line video that shows how an improper, and a correct sear 'breakaway' should be. Stand-by for that. Joe
EDIT
Below is a two-part video on the basic function of a healthy M1 rifle. Take a look, to get a 'feel' for the parts' interaction. Good luck! Joe
http://www.youtube.com/watch?v=1YsJwQJx5kA&NR=1http://www.youtube.com/watch?v=eu0wWHGV7aY&feature=fvwrel
*You may wish to have a 2nd party hold the trigger back to do the test.0 -
Thanks, givette. You've given me a real good basis for trouble-shooting.
EDIT: I should probably mention here that there's a possibility of "operator overload". I have had three single-trigger double barreled shotguns double for me in hunting situations; two 20 ga. Ithaca SKB's and a 16 ga. Marlin model 90. They will not malfunction for anyone else. With the SKB's, they (I) did it so often that I retired them. A third SKB works fine for me. Also, I have hunted often with self-loading shotguns, both recoil and gas-operated guns without this problem. This is the first firearm of this type that gave me this trouble. Near as I can figure, with the type or amount of pressure I put on the trigger, the gun recoils, backing away from my trigger finger momentarily, and then bounces back forward against my finger, tripping the trigger again. As improbable as that sounds, I can come up with no other explanation for the shotguns that have no wear or broken parts and work fine in other hands. I wonder if I have the same problem with this HRA. The SA and Winchester fired at the same range session gave me no trouble.
I will follow your trouble-shooting guide lines and replace anything that looks suspicious and if that will change the timing of the rifle/operator, the problem should go away.
EDIT #2: Took the Garands apart last evening (it's too hot and humid here to play outside!). There was, in fact, a lot of grease in that trigger group. I cleaned that up and checked the firing pin movement and for bolt face burrs as well as excessive side play and all OK. I removed the trigger groups from the Winchester and the Springfield for comparison. The first thing I noticed was that the SA and Win. parts still had a lot of finish on them while the finish on the HRA parts was very thin. However, there did not seem to be any noticeable wear on hammer or trigger bearing surfaces. I then started taking measurements. No appreciable differences between SA, HRA, and Win. Then I noticed that there seemed to be somewhat less foreward trigger movement between where the trigger interrupter (sear?) releases the hammer and the trigger catches it so I took some measurements of that. The SA's trigger moves .120", the Win.; .100", but the HRA only .060". I don't know what the specs. are for that or even if there are any but, given my propensity for "bounce-firing", it certainly might be a factor. I am going to try a different trigger assembly. In order for that thing to double, everything must be just right (or just wrong!) so if I can break up the timing, that should take care of it. However, I fired 91 shots between malfunctions so it may take a while to prove that it's fixed! Incidently, this is a CMP rifle so I assume it was checked and found OK to sell. I would appreciate any additional comments from the Garand experts.0 -
you may be doing by accident what many people try to do on purpose. BUMP FIRING . I have a friend that hooks his thumb in his belt loop and can BUMP FIRE, most any semi auto rifle or shot gun. 0 -
Back in the day I shot on a military team using the M1 Rifle. Some team members would experience doubles and others never did. I think it is trigger technique but would not guess anything beyond that. 0 -
I'm somewhat surprised some of the "sky is falling" crowd hasn't told you that getting more than one shot per trigger pull makes that a full auto weapon and you need to turn out the lights, pull down your blinds, don't answer the phone, melt it down, stir the ashes, and throw them in the lake. [:D] 0 -
Most of the doubling problems are traceable to worn hammer catches or wear to the sear portion of the trigger/sear unit (two separate pieces riveted together). The actual specs for these items exist but are so filled with variables and "ranges" that it is hard to pin them down. There are also ordnance gauges specifically for checking the level of wear but these gauges are so rare that they are more collectors items than functional gunsmithing tools. Both hammers and trigger/sears are relatively inexpensive and most folks simply replace them when this sort of trouble pops up. 0
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