M39 @ Camp Perry.

[dpaqu]

I know this subject has been visited numerous times but I thought I would mention this as I have been away from the forum for some time and am looking forward to getting back into the swing of things.

I competed at Camp Perry this summer in the vintage military class with my M39. I bought it in unissued shape and had only fired it a few times. I had hand loaded about 50 some SMK 174gr .311 J-words and got fantastic accuracy. I also shot about 150 rounds of the brass cased Prvi 182gr surplus and that’s what I shot the match with. I did notice that the gun got rather hot while shooting the match. When I got back to our barracks and I was cleaning the gun I grabed one of my friends 30-06 bore gauge tools and placed it in the muzzle and it read a -1. A recently re-barreled (Crition) Garand read a +1.

Do you guys think I damaged it? Cleaning Patches still go down the barrel real smooth.

[NuJudge]

The Vintage military match is thirty rounds, plus some more to sight in. There are only 10 shots rapid fire, which does get a rifle hot, but not hot enough to advance throat errosion unless you do it a heck of a lot. Errosion at the muzzle proceeds much more slowly than at the breech/throat.

The muzzle errosion gauge for a .30-'06 (.300" land diameter) would give somewhat odd readings when put in a almost new 7.62x53R muzzle. The M39 I have has a groove diameter of .310", but I haven't measured the distance across the lands.

[Doc Highwall]

I am not familiar with the number of lands an grooves on your M39 but I would think if it was an odd number you would get a larger reading then if it had an even number of lands and grooves.

[c3d4b2]

I read somewhere that the erosion gage was not an absolute measurement on non USA military barrels.

I believe this is the link:

http://www.fulton-armory.com/TEGauge.htm

[Jack Stanley]

It's pretty hard to damage a barrel with only ten rounds of rapid fire . Some questions you'd need to ask yourself are ; Does the rifle still shoot good and Did I have a good enough time to do it next year too ?

The M39 tend to have a tighter barrel than other 7.62X54R rifles . A machinist with the proper plug gages can tell you what the bore is at the muzzle and driving a lead slug through will give you the groove dimensions .

I hope ya had a Great time at Perry

Jack

[mike in co]

I read somewhere that the erosion gage was not an absolute measurement on non USA military barrels.

I believe this is the link:

http://www.fulton-armory.com/TEGauge.htm

take anything from fulton armory with a large grain of salt.....

[c3d4b2]

I agree there is a lot of misinformation floating around.

What I took away from the article is the erosion age was designed around US military barrel specifications. The gage has a taper that indicates a larger diameter as the numbers increase. If you have barrels from different manufactures with different diameters across the lands (or number of lands?) then the gage probably will not measure the same. If the barrels have the same diameter, but the chambers are cut with different throats the the gage will not measure the same.

[dpaqu]

Some questions you'd need to ask yourself are ; Does the rifle still shoot good and Did I have a good enough time to do it next year too ?

I have not shot the rifle because I'm not sure what to shoot in it. I guess I will have to take it to a gunsmith. Last time I tried to make a chamber cast it did not come out so well. As far as Perry is concerned it was exhausting but well worth it. It motivates me to practice and shoot better. I only wish there where more woman into this whole shooting thing.

[9.3X62AL]

I agree that slugging the bore for groove diameter and pin-gauging the lands will give the most accurate results. This shouldn't be a costly operation from a gunsmith, and many cast boolit shooters do the slugging routinely.

In terms of gauging the proper diameter for a bullet/boolit, the slugging is the primary determinant/predicator. The land diameter measurement may provide a measure of whatever wear has occurred since the barrel was fitted--but only if you have its original specs on hand. With a bore-riding cast boolit, land diameter is more critical, and the bore rider portion should correspond to that dimension closely.

As an example......I have a Rem 788 in 22-250 that has a VERY extended throat. This one makes a Weatherby chamber look conservative. This one has about .290" of freebore with Sierra 60 grain HPs seated @ 2.350" OAL before any land engagement with the bullet ogive could happen. If ever an excuse for re-barreling was clear and present--this would be it.

A couple weeks back, I took lots this rifle's favored load (the 60 grainer atop 36.0 grains of H-380) with bullets seated at two OALs--book max @ 2.350", and @ 2.610" OAL to provide .030" of leade clearance. This was a repeat of the same experiment from Spring of this year.

Results in a nutshell--5 five-shot groups of each OAL didn't vary significantly at 100 yards. Nice, round, flyer-free clusters running from 9/16" to 3/4". Not bench-rest quality, but sufficient for strafing rats and sluicing coyotes for another year or so.

In short--if the rapid-fire string did any harm--which I doubt--it may not matter a bit. Establish the rifle's groove diameter--match that diameter as closely as possible with a good-quality target-grade bullet--dial it in and get the sight settings established--and go have fun.

That Sierra Matchking .311" x 174 is a WINNER. It shoots lights-out in a friend's .311" x 302" SMLE.

[RU shooter]

Shoot it ! If it still shoots well what difference does it make what some gauge says .I can bet my next paycheck that gauge read the same before you fired that match.....



Tim

[Char-Gar]

Unless the gage is going to shoot your rifle, I would ingnore it. The only thing that counts is how well the bullets play follow the leader on the range. You target is you gage!

[Jack Stanley]

Don't know what to shoot in it ? That's easy , start with the best 7.62X54R brass you can afford . I would think the Sierra Match Kings would be a very good bullet to use but there are bullets made from .308" up to .313" that you can try in the rifle . I'm gonna go out on a limb and say that one of the sizes is gonna work pretty well in that M39 . After all the M39 is sorta known for having good barrels and I'm sure you can find what it likes to use .

If you get started now , by the time Camp Perry rolls around next year . You will be able to increase you points by probably twenty or more ..... this isn't hard but it does take a little time . If you are happy with three foot groups at two hundred yards you don't even have to practice , just buy some surplus and go to the match . I you want your target to be nines and better some effort is required . I will tell ya though It is fun to watch a guy get ninety percent with an old surplus rifle .

Jack

[dpaqu]

Yeah Jack Stanley I shot 238 so there is lots of room for improvement.

I will get it slugged and determine from there whether to shoot .311 or .308 bullets. See how that goes and then try some casting.

[akajun]

Just gonna point out the obvious. An m39 is 7.62x54r and uses a .311 dia bullet. A 30-06 uses a .308 dia bullet. So you stuck a .308 guage in a .311 barrel and it only showed a -1? That pretty amazing as your barrel is pretty much new. Considering that so many m39s are well shot and some even counterbored, you have a treasure!!!

btw I dont think you can fire a bolt gun fast enough, even with constant releoads to damage it. If so, the Finns and Russians would have never won a battle.

[mike in co]

load for it , and shoot it..it still has a long life.......
the hornady 174 fmjbt is a 3105 bullet and shoots well in those rifles.
and try some 308 168's .


mike in co

[NuJudge]

In my similarly new M39, I shoot Sierra .311" 180gr softpoints, with Lapua brass and 4350 powder, and results are almost good enough to get me to forsake my K31 rifles.

CDD

[Dark Helmet]

Still working with Hunter and Sierra 180's here=Darned fast! Gonna try Big Game next. ( Mine slugs .310)

[madsenshooter]

dpaqu, your pic isn't of Camp Perry is it? I didn't notice any trees there. Well, yes I did, they were blocking the nice view of the cooling tower at the nuclear plant. Last time I was there you could see the tower. You're know you're getting old when the little trees get big! Coming up with the proper bore size is no big deal, I just bought drill bits of approximate size and tried them until I found the one that fit snugly into my .233 bore 6mm barrel. If you have a local hardware store that has letter sized bits you can find the needed size, and they're cheap. But most important is the groove diameter, so slugging is necessary. Having said that, I should note that one can shoot jacketed bullets that are undersized and get some good results. Just a couple months ago I shot a .917", 5 shot group at 100 yards using Nosler .308 match bullets. They were shot out of a Krag rifle that has a .310 groove diameter. The gas that escapes past the bullet tends to keep the bullet centered while it rides on the lands. Escaping gas is a no-no in the cast bullet world, but not so much so with jacketed bullets. Wow, you shot a 238! Beat me, I shot 234-1! I messed up bad in offhand.