gas checks catching in M1 Garand gas port?

[JKH]

Hey Guys,

I just got to try several loads last night in my one Garand, I loaded 10 rounds each of LEE 180grn RN, 200grn RN and the 160grn TL spitzer type boolit made for the 7.62x39

My load consisted of 35 grains H4895 without filler, function was great with fairly vigorous ejection so I could most likely drop the charge a few grains and still have good function. This load was extremely smokey, is this typical of the H4895? The cases had very heavy black soot so I am leaning in that direction.

All the boolits were cast from wheel weights (200 and 160's were water quenched), gas checks are mine made on a Freechex II tool using .008" aluminum lith plate material, sized to .309 after light tumble lube with LLA and then 2 more light coats to finish.

Cases were full length sized and case mouths flared with an RCBS tool, I set the seating die to just straighten the case mouth out with no crimp, primers were standard CCI large rifle.

I set up my target at 45 yards (to lazy to go to the back field) and proceeded to shoot at some 200 yard targets reduced for 100 yards so I had a nice big aiming point that I couldnt possibly miss, really! The 200's were all over and yielded around a 10" group, wow! the 180's gave a bit better results with 3 1/2" to 4" groups (actually the second group after I moved the target board in to 25 yards), the 160's were closer to the 200's (at 25 aposed to 45!), needless to say (but I will of course) I was sorely disapointed!:(

Looking at the targets I noticed that some of the holes were oval, however, the main part of the hole was perfectly round like a properly stabilized projectile would make but they had a small crescent shaped cutout off one sides, the boolits tended to be in double groups to the left and to the right (literally 2 boolits in one hole to each side).

A lot of things were going through my mind with most being unrepeatable in mixed company[smilie=1: then I foound a loose gas check about 10 feet in front of the rifles muzzle in the grass (I scowered every inch between my deck and the target but found no more), this check was crumpled on one side and folded over like it had dragged across something and was pulled off the base of the boolit but had to have seperated after leaving the bore. Is it possible that the gas checks were catching the gas port in the barrel? IF so, the folded over piece which was hanging out the back could possibly have accounted for the extra cut beside the boolit holes. I checked the sights carefully for movement (none) and finally ran a clip of ball through it just to make sure it wasnt me or the rifle (it wasnt, it grouped very tightly even after firing 8 rounds in under 3 seconds).

Has anyone else run into an issue with gas guns like this before? I am going to try sizing some boolits to .310" and also a lighter charge of H4895 and also try a different powder (maybe BLC2 or IMR's 4227 or 4198, maybe 4350). If you have any thoughts, ideas or just plain WAG's please lay 'em on me! I really want to shoot cast through this Garand but just cant abide by getting shotgun pattern like results:-?

Thanks in advance, I'll try to post pix later on.

Jeff

P.S. I finally tryed the .22 cal boolits in my .220 swift, those shot extremely well:drinks:

[StarMetal]

Just off the top of my head real quit have you pulled the gas system apart and checked for any debris in there? Other then finding a fired bullet in mint condition it's going to be hard to prove. If it snags a gascheck I would think it's doing something to jacketed too. How about when you clean it. Can you pull a tight patch through somehow as I know you can't really clean them from the breech?

One more statement. I've shot lots of gas operated rifles using fillers and never do I find any of the filler in the gas system. Now on cleaning the barrels I can fell the patch go by the gas port hole on the rifle that have the larger hole diameter, which is few, mainly my Yugo SKS.

Joe

[JKH]

Hi Joe,

I was thinking about pulling the gas plug while trying to fall asleep last night, will try that this evening.
I typically use a bore snake on my M1's to protect the muzzle but have never noticed any snagging.
My gas checks usually dont get sized by the push through sizer as the are just at or slightly under .309" could that cause a problem? I have used similar 8mm checks that shot great in bolt guns.

I have read that fillers can really tighten a group in some rifles, maybe its just a case of wildly fluctuating pressure curves, is H4895 known to have issues like this?

I did dig up one boolit, it had skimmed through the sod for about 3 feet before burying itself in a small risse several inches, the boolit was definitely going point first but the dirt had abraded almost all traces of the rifling off and the gas check was gone presumably swept off as the sides were worn down to the diameter of the gas chek heel.

[SierraWhiskeyMC]

4895 is normally a VERY clean-burning powder. The black soot on the outside of your cartridge cases indicates to me that there was not sufficient pressure building up to expand the case against the chamber wall to create an effective a seal before the boolit left the case neck.

Crimping the case neck into the boolit's crimp groove should help that situation a good deal.
[eta]
Ensure your cases are the same length to ensure a consistent crimp.

[JKH]

Hi SWMC,

The soot was basically limited to the neck area like most standard loads, but I can try crimping. Pressure was definitely up there though as ejection was almost as psirited as ball loads and pitched the cases about 8' away.

I can put a light crimp on the cases with my seating die, will that do? or should I use a spacer and try my LEE .308 FCD?

[StarMetal]

Okay you've shed some light. First let me say your 35 grain load isn't a wimpy one. About the gas check. In my opinion that aluminum isn't thick enough for a 30 caliber bullet. I'm positive on the Lymans, no super sure on the Lee bullet. I make my own gas check tools and find I can use hardware store aluminum flashing for 22's up through 6.5. Then from 7mm up I have to use thicker aluminum. I've also found my gaschecks stay on the bullet pretty good. First thing I would do is try some Hornady 30 caliber gas checks first then report back.

Joe

[JKH]

Joe,

I actually have some of the 160 grn TL boolits ready with factroy copper checks, I got these from another member to try before buying the mold, I ahd intended to try those side by side with mine.

I have been using this lith plate material for a while, they work great on my 8mm boolits in a bolt gun, in fact and old Turk Mauser with cleaning rod washed out muzzle put 5 shots in one hole at 50 yards with the saem lead and check material. I had loaded some fo the 180's before using BLC-2 in this same Garand, I didnt shoot for groups but was able to hit the 100 yard 10" steel plate regularly but did not get semi-auto functioning.

So, lith check and copper, filler and no filler, crimp and no crimp and reduce the load (to ?)

Thanks guys!

Jeff

[StarMetal]

You can tell if the check material is thick enough by either miking the bullet shank and adding to that figure double the thickness of your check. In your case that would be adding 2x.008 for .016. Another way is when you size them you can see if there are sizing marks on the check sides.

The reason for a filler is to position the powder against the primer end of the case if it's a position sensitive powder or the powder is such a minute amount in the case.

Joe

[madsenshooter]

My old Krag really likes that TL boolit, 34grs of Bartlett's new 4895 really shot good out of it yesterday! I was shooting pretty hastily as I was just trying to empty up some brass for another loading project, yet I wound up with a 10 shot group of 1" wide by 2" tall at 100 yards. The necks were a little blackened but I could see the cases sealed behind them. I'd guess velocity to be right up around 2000fps. I was using Hornady checks. I could get literally tons of .011" litho plate from work.

[craigf]

It's virtually impossible for a gas check to be pulled off the end of the bullet while engraved in the barrels rifling. It is possible, though unlikely, that the gas check is coming off at the moment it exits the case but before engaging the rifling. The likely scenario is that it's coming off while the bullet is in free flight. As for aluminium gas checks, my opinion is stay away from them. Aluminium oxide is extremely hard and damaging to the insides of a barrel. Secondly, copper gas checks actually "bite" into the bullet when sized, and, have virtually zero springback. Aluminium doesn't, on both counts.

[JKH]

craig,

thanks for the input, the more I examine this particular check the more I think it came off one round I fired into the ground 20 feet from the muzzle, it does exhibit a fold though that could have been caught by the gas port but without recovering more it is hard to say for sure.

Alumuminum lith plate is extremely smooth and polished on one side, not quite mirror like but not far off, it is also coated so that no bare aluminum is touching the bore. Lith plate is also anealed, the plates I use have absolutely no spring back and grip the bullet base tightly (which is a major function of a properly made check maker). Some copper checks have an internal ridge that bites into the heel but not all.

I am going to reduce my charge of H4895, there was little diference in recoil and ejection velocity between these loads and the ball ammo I was shooting, I may have simply pushed the velocity envelope a little to hard.

I had checked the throat and muzzle erosion of this rifle and it is very low, however, I am thinking of sizing to .310" rather than .309" perhaps that will help but first I will try a reduced load and also some loads with 2400 (they wont function the action of course but will be a good reference point).

What about IMR 4198? I have always preferred IMR powders and have had excellant results for close to 30 years, this is the first time I have strayed into the Hodgdon camp and am not use3d to their product. I also have a bit of IMR 4350, BLC-2 and AA 2230C

Jeff

[StarMetal]

Jeff,

Don't worry about using aluminum gas checks. Some people gain a little knowledge, like the aluminum oxide thing, and go blah blah blah that they are going to wear your barrel out. Hey you out there that believe this, guess what? The pistons are going up and down inside your engine cylinders and wearing the cylinders, rings , and pistons out. Jeffs right about the aluminum being polished and coated.

Joe

[mto7464]

Jeff,

Don't worry about using aluminum gas checks. Some people gain a little knowledge, like the aluminum oxide thing, and go blah blah blah that they are going to wear your barrel out. Hey you out there that believe this, guess what? The pistons are going up and down inside your engine cylinders and wearing the cylinders, rings , and pistons out. Jeffs right about the aluminum being polished and coated.

Joe

No offense, but a poor comparison.

[StarMetal]

No offense, but a poor comparison.

I think it fits the equally poor comments on aluminum gas checks.

Does barrel wear stop the benchrest shooter from not participating?

How many gas checks of any material do you think you would have to put down a barrel before you wear it out?

See the point now?

Joe

[JKH]

I agree with your anology Joe, a firearm is basically the most efficient internal combustion engine extent, it just does not reciprocate.

Lith plate is quite soft and certainly will do much less damage to a bore than copper jacketed ammunition (gilding metal, etc.) and certainly less than mild steel jacketd bullets which have been shown with empirical data to cause no more wear than copper alloy jackets.

Our biggest enemy in bore wear is from heat and pressure, microscopic fissures start at the throat and gradually work their way up the bore causing eroson and even molecular changes to the surface structure of the steel itself. Beyond that, I would say more bores have been ruined from over-cleaning than any other reason with the possible exception of improper (or no) cleaning after firing corrosive primed ammunition (the corrosion is actually NOT caused by the remaining salts from corrosive priming but from the large amounts of moisture that sodium chloride, etc. TRAP and hold against the steel causing rust and pitting).

So, I have to agree with Joe but I do understand what mto7464 is thinking, aluminum oxide is a wonderful abrasive when used in controlled circumstances, in this case however it is a moot point.

Hopefully this weekend I can try again, such miserable failure on my part! I know this Garand will shoot, it does very well with ball ammo so I know at some point I can massage it and get it to purr with some lovely Galina :^ )

Jeff

[Larry Gibson]

JKH

Input from others here has been excellent. Let me add; in a milsurp M1 '06 barrel I size no smaller that .311 or at "as cast" if smaller. All cast bullets that size .311 always give better accuracy. The 4895 is a great powder to use. Your charge is indeed a little too much for the size of the bullets and the lower weighted 160 gr bullet. I suggest you drop back to 28 gr of 4895 and use a 3/4 gr dacron filler and work up in 1/2 gr increments stopping when you have reliable functioning. If you're not sure how to use the dacron ask and I'll tell you. The dacron does a couple things. It keeps the powder back against the primer which improves ignition consistency. It also provides a bit of a gas shield and causes the case neck to expand and seal the chamber better. This will reduce but not eliminate the sooty necks. I've found the use of a dacron filler to be of particular benit to accuracy with the M1 and the '06. Also as mentioned a thicker, stronger GC is probably needed for the top end loads in an M1 to ensure functioning.

Your best accuracy with any of those bullets is going to come in the 1800-1900 fps range. However, with the lighter bullets functioning may not be reliable in that velocity range. In that velocity range the 200 and 180 gr bullets should give you all the accuracy you and the rifle are capable of. The lighter 160 gr bullet will probably have to be loaded up into the 2100-2200 fps range for reliable funtioning. Accuracy should be pretty much equal what you get with M2 Ball with it at that velocity range.

Make sure you are using a good lube up to the task of 2100+ fps to avoid leading.

BTW; My guess on the little curley cue (I've seen them many times myself) on close range targets is that it is most often bullet lube being spun off. It also can be small slivers of the driving band being broken off and spun out by the RPM, especially with "hardened" cast bullets that do not have a very ductile alloy.


Larry Gibson

[JKH]

Larry,

Excellant advice! I did quench the 160 grainers and the 200 so that may be causing the crescent shape cut as you have noted. The 180's were air cooled and they did come in under 4" at 25 yards, that is still dismal but at least a starting point.

I think I will concentrate on the 180's for now, all I have checked and lubed have been sized to .309 so I will have to cast some more and see what the as cast diameter is. I made quite a few checks last night and the come out of the tool at .310" and grip the base of the boolits (all 3) very tight so I think the checks are good to go. The bore did not exhibit any leading so I am assuming the checks were doing the job and most likely I just pushed the velocity envelope to hard.

So, I will try some more 180's with and without dacron (I have a huge amount and have used it in other loads so am good to go), and I will try as cast and more of the .309" sized boolits (I have nearly 200 ready to load, hate to waste them!).

With the 180's and 200's I noticed the nose of the boolit on the 200 slipped into the Garands muzzle very easy with no resistance, the 180's were slightly snug and wee mildly engraved by the rifling, could that make so much difference in accuracy between the 2 boolits?

Thanks guys!

Jeff

[Larry Gibson]

JKH


" the 180's were slightly snug and wee mildly engraved by the rifling"

That would definately be the cast bullet I would focus on initially:-)

"could that make so much difference in accuracy between the 2 boolits?"

With the load you were using it sure could. Obviously the 180s were much better supported in the barrel during accelleration and didn'r sustain the adverse obturation the 200s did.


Larry Gibson

[JKH]

Ahh, I am having a "grasshopper" moment now ;^ )
Some times a little bantering back and forth can solve these puzzles quite nicely, you information will save me a great deal of time and agrivation. After I get the 180's performing within reason then I can tackle the other 2.

I have read of others getting good results with that LEE 160 made for 7.62x39 (mine is the tumble lube version) and was rather shocked that it performed worse than even the 200's, I suppose slugging my bore would be prudent, however, if I can get it to shoot as casts without a lot of rigamoral than I will skip that step.

Jeff

[Larry Gibson]

JKH

The problem with the Lee 160 gr bullet is one of design and weight. To get reliable functioning with an M1 many times the velocity given a 10" twist is just to high for that bullet. The long nose doesn't help it any. When you get around to trying it I'd suggest a slow burning powder. I've been finding AA4350 and H4831SC to give reasonable performance in the '06 with a 160 gr cast bullet. Try to keep the velocity under 2200 fps with 2000-2100 fps being even better. Of course functional reliability being the key. I also use a dacron filler with those 2 powders as loading density is under 80% in the '06.

Larry Gibson

[mto7464]

So, I have to agree with Joe but I do understand what mto7464 is thinking, aluminum oxide is a wonderful abrasive when used in controlled circumstances, in this case however it is a moot point.



Jeff

I wasn't thinking really anything, just the the comparison really didn't seem to fit. I can't say anything for or against aluminum gas checks. In a properly running engine the aluminum never touches the sides of the cylinder walls. The rings also make little contact as long as oil is flowing properly. To me just like comparing apples to oranges.:bigsmyl2: Guess I am being a little anal

[madsenshooter]

Jeff,

Don't worry about using aluminum gas checks. Some people gain a little knowledge, like the aluminum oxide thing, and go blah blah blah that they are going to wear your barrel out. Hey you out there that believe this, guess what? The pistons are going up and down inside your engine cylinders and wearing the cylinders, rings , and pistons out. Jeffs right about the aluminum being polished and coated.

Joe

The "coating" on lith plates is known as anodizing, ie a few molecules thick layer of aluminum oxide. They didn't used to have that grey "coating", and if you went to lunch and forgot to put gum arabic on the plate it would oxidize and become ink receptive in the non image areas. Not as much a problem when the plate is pre-oxydized. I suppose there are worse things one could do to a bore. I have an example, got some stuff called Clean Ballistics from Midway because they had it on clearance for $1.95. It appears to be waxes and graphite. I tried using it as a lube and now where the lands on my Krag touch a seated bullet I see little scratches instead of the print of a nice full land. Won't be using anymore!

[StarMetal]

The "coating" on lith plates is known as anodizing, ie a few molecules thick layer of aluminum oxide. They didn't used to have that grey "coating", and if you went to lunch and forgot to put gum arabic on the plate it would oxidize and become ink receptive in the non image areas. Not as much a problem when the plate is pre-oxydized. I suppose there are worse things one could do to a bore. I have an example, got some stuff called Clean Ballistics from Midway because they had it on clearance for $1.95. It appears to be waxes and graphite. I tried using it as a lube and now where the lands on my Krag touch a seated bullet I see little scratches instead of the print of a nice full land. Won't be using anymore!

I don't use that lith plates, so not famaliar with how the surface is. I use new bought flashing from my hardware store.

I reckon a White Laboratory official test is in on how much aluminum checks wear your barrel as compared to the copper ones....and powder abrasion.

Get real.

:kidding:

Joe

[madsenshooter]

The pre-oxydizing made some work for me, I got hired a few times to solve problems companies were having. Well, being a metal oxide, what does it like, hydrogen, or carbon, like when we flux. So the solution to their problems was more hydrogen, a wetting solution with a lower pH. Until the pH was lowered, it was a toss up whether the nonimage areas of the plate would attract the hydrogen of the water or the carbon of the ink. I used to carry a little packet of anhydrous citric acid and that would straighten the problem up, (makes a great flux too). I know, this is off topic, but I'm following the post to figure out how much 4895 it's going to take to cycle my Garand with a 170gr boolit, so y'all can get on with it now!

[TAWILDCATT]

since lead does not have the friction of jacketed bullets you might try a slitly faster burning powder and heavy bullet.I am working on 185 gr with AA 2520.at 31 gr.it does eject.and hits were I aimed.but I only tried a couple for function 30/06 and 308 in two garands.:coffee:

[Crash_Corrigan]

I use a 311284 Lyman WC cast boolit with my Garand. I had dismal results until I started to listen to Larry Gibson started to use dacron filler. With a GC boolit and a piece of dacron fill over 4895powder {29 gr} I got good results.

Then I started to play with paper patching. I left off the GC and using the same load with the 311284 boolit I got 1 to 2 inch groups at 50 yds. I sized the cast boolit down to .308 and then wrapped with two layers of computer paper and sized that down to .309 and it was good. I will try to size the next batch down to .310 and see if this is better.

[JKH]

Larry,

I cast some 180's yesterday, as cast diameter of the drving bands was .312" to .313", load and shoot as is?

When I cast these I sweetened the pot (10 pounds, wheel weights) with + or - 1 7/8 ounces of printers mono-type for the heck of it, probably wont make much difference but I have about 20 pounds + I picked up at a yard sale with about 30 pounds+ of soft lead thin spacer strips all for the princely sum of $2.50 :^ )

I need to Leement this mold some more though or perhaps I just had my temp set a little low, I had a lot of boolits with minor wrinkles and the bands did not always fill out well, I culled them carefully for any defects no matter how minor and tossed them in the "plinker" pile, I miked every single boolit and seperated the good ones in two piles, one for .312" and the other for .3125" to .313"

I hope to load some this week and will start at 29 grains of H4895 with the 3/4 grain dacron filler.

As an aside, what is the easiest way to pull and measure large quantities of bulk dacron fluff? I bought a pillow sized bag which should still be around for my great grandchildren to use, it is somewhat tedious to sit and measure tiny bits of this stuff so any ideas for mass production would be greatly appreciated.

Jeff