Another Garand question

[jlmurphy]

I have been looking at the Douglas barrels for my Garand. They list a 4 groove and a 6 groove. Can anyone here tell me significance, other than the obvious number of grooves? I have ruled out Krieger barrels, as nicely finished as they are, they are not stress relieved after machining and I have had problems with their barrels changing POI when hot.

 

[30Cal]

The 6 groove works well with the 168SMK, but the 4 groove is probably more versitile (or so they say). I've gotten excellent shooting from both Douglas and Kreiger tubes.

 

[Swampy]

jl,

Conventional wisdom says that if you intend to shoot all Match grade ammo the 6 groove is the better choice. If you plan to shoot a lot of military ball ammo the 4 groove is better.

Personally I can't say for certain if that's true or not. I do own two Match Grade M1's. One has a 6 groove Douglas medium contour. One has a 4 groove Wilson GI contour. The Wilson tube shoots rings around the Douglas.

The Douglas seems to be very finicky regarding bullets and charge weights. The Wilson is much more forgiving.... shoots everything well.

Just my experiences..... No blanket judgements made of either the Dougie or the Wilson tubes.

Best regards,
Swampy

Garands forever

 

[Onmilo]

Douglas barrels are 1-10" twist and design for shooting heavy ball Match loads.
There is some argument that six groove barrels tend to copper foul much more slowly than four groove barrels.
Personally I feel four groove barrels are much easier to clean and don't mind decoppering the barrel every 200 to 300 rounds.

I have been using M-Pro 7 cleaning products for quite a while and have found that the claims they have made to be true.
Regular cleaning with the M-Pro 7 cleaning solvent makes decoppering very easy because of the micro-pore fillers that are in the solvent.

There are several companies that offer cryogenic stress relief services for barrels and your concern about Krieger barrels isn't warranted if you are willing to spend the nominal sum, usually fifty dollars or less plus shipping, for the service.
Superfreezing steel really does work, it is frankly, amazing.

 

[byf43]

Here is the link for "300 Below".

http://www.300below.com/site/home.html


These fine people are the ones that cryo'd my M1A and a friend's .300 win mag.

Both now shoot a LOT better and clean much faster/easier.

Thanks for reading.

 

[jlmurphy]

Krieger Cryo treats their blanks before machining, but nothing afterwards. I used a Krieger #17 contour blank to make a heavy barrel ( 1.000") for a Mini 14. It shot nice groups, but would string the shots as it heated up, finally stopping at 3" high at 100yds. A recent article in Precision Shooting about a Krieger barrel on a M1 Garand mentioned the same problem. I tried to work out the problem with Krieger, but was less than satisfied with their response. I have in the mean time used a Shilen Select Match barrel in the same application. Nice tight groups, no shift in impact when hot. I made sure Shilen stress relieved their barrels after machining.

 

[USSR]

I have ruled out Krieger barrels, as nicely finished as they are, they are not stress relieved after machining and I have had problems with their barrels changing POI when hot.

jlmurphy,

Krieger doesn't stress relieve their barrels because of the method of rifling they do. When you rifle barrels via the button rifling method, as most barrelmakers do, you must rifle the barrel prior to machining the outside of the barrel to the contour you want. This induces stresses in the barrel which must then be relieved. Krieger uses the cut rifling method, which allows them to machine the outside dimensions to the contour desired, and then rifle the barrel. No stress is created, hence no stress needs to be relieved.

Krieger Cryo treats their blanks before machining, but nothing afterwards. I used a Krieger #17 contour blank to make a heavy barrel ( 1.000") for a Mini 14. It shot nice groups, but would string the shots as it heated up, finally stopping at 3" high at 100yds. A recent article in Precision Shooting about a Krieger barrel on a M1 Garand mentioned the same problem.

It's a Mini 14, for Gawd's sake. It wouldn't shoot great no matter what you did to it. Seriously, Krieger makes some of the best barrels on the planet (along with Boots Obermeyer). Does an occasional lemon slip out the door? No doubt. But they are hands down a much better barrel than most button rifled barrels, including Shilen. Just MHO.

Don

 

[jlmurphy]

USSR,
First, the Mini 14 is correctly known as inaccurate because of it's thin barrel, but it shares the same action as the M1 Garand and M1A, and can be accurate. There are many accurate Mini 14's, it is just more work than most people want to do. I live in Ca., and our choices for semi auto are few. My Mini 14 now shoots 1/2" to 3/4 ", while not benchrest by any means, accurate enough for a piston operated semi auto.
Second, I believe Krieger drills and rifles their barrels before profiling. You are correct in that button rifling induces more stress than cut point rifling, but in a barrel blank that comes to them with internal stress, removing any metal causes an inbalance, just like ripping a wooden plank that was previously straight. Most barrel makers stress relieve after machining to catch any new stresses, whether from rifling or profiling, Krieger doesn't. I believe the barrel I received from them had residual stress before it was rifled, the lemon blank, I don't fault Krieger's rifling, but their lack of secondary stress relief let that lemon slip through to me.This is what probably happened with the Garand in the Precision Shooting article also. I wasted a great deal of time and money on a barrel from Krieger, I asked for a replacement, they chose not to.

 

[USSR]

...I believe Krieger drills and rifles their barrels before profiling.

Nope.

Courtesy of Border Barrels:

A button rifled barrel must be rifled and then stress relieved before it is profiled. There is always the problem that any residual stresses are going to make the barrel move when profiling, so leaving you with a barrel that is bent or bell-mouthed.

Cut rifling a barrel puts no stress in the steel and so it is possible to profile the barrel after the drilling stage. Any moving around the barrel is going to do will be done and the barrel can be reamed and rifled after profiling. The problem of stress induced changes in bore dimensions during manufacture can be eliminated.

With cut rifling, the barrel can be completely profiled and fluted after the drilling stage and then reamed and rifled.

Also, Krieger does (or did) offer Cyro treatment after machining, you just had to pay extra for it (I did).

Don

 

[jlmurphy]

I assumed the drilling and rifling was done first because it is nearly impossible to determine the exact point where the drill emerges. Once the exit point is determined, the bore is fixed and the barrel can be profiled. What I was saying is that drilling, rifling, and profiling all remove metal, and if there are residual stresses in the blank ( from the supplier), the finished barrel will have unrelieved stresses when it leaves Krieger. Most barrel makers stress relieve after machining to eliminate this possibility. I have used premium barrels from Hart, Shilen, and Douglas, and Krieger was the only one that shifted POI when hot. I researched stress relief of 416 series stainless steel when my barrel acted up, it is a difficult process. ( Stress relief by controlled heating to high temps, not cryo treatment, on which the jury is still out.) I have to assume Krieger is betting that the few barrels that warp when hot and probably won't be noticed by the majority of shooters is insignificant when compared to the trouble and expense of secondary heat treatment.

 

[30Cal]

This is the first time I've heard that a Kreiger barrel is inadequate. I would like to point out than an M1 is going to be at best a 1MoA rifle, after being bedded, handguard glued and screwed, etc, etc. Virtually anybody can make a barrel that will ultimately be limited by all the stuff you hang off it when you screw it onto an M1 receiver.

Ty

 

[jlmurphy]

My complaint concerning Krieger barrels was that a previous barrel had shifted POI 3'' from cold to hot. It was a 1" heavy barrel in a Mini 14, which I will admit is not a benchrest platform. After eliminating all the usual suspected causes, I found that with the barreled receiver, clamped to a surface plate, warm water forced through the bore would deflect the muzzle .015", every time, and zero when cold. .015" from an 18" barrel is 3.000" at 100 yds. Problem located, I called Krieger, they sounded interested, told me they would call me back, they never did. After no reply, I tried to stress relieve the barrel myself ( I have a welding/machine shop.) The stress relief worked, the shift was gone, but the internal dimensions must have changed, the previous accuracy was gone. I called Krieger again, told them the whole story and at their request, sent the barrel to them, two weeks later they sent it back saying it was good enough.
I have since replaced the barrel with a Select Match Shilen, nice tight groups, no POI shift.
Along the same lines, the November issue of Precision Shooting featured an article on the Fulton Armory M1 Garand, using a Krieger barrel. One the few complaints about the rifle was that it strung shots vertically when hot. No surprise to me! The issue is that Krieger cryo treats their blanks before machining, but no heat treatment stress relief after machining. My complaint is that a premium barrrel shouldn't warp!