Accuracy Problems With M1917

[vintage hunter]

..Ive hear that it better to shoot heaver bullet out of it because of the 1 in 10 twist of the barrel...

1 turn in 10 inched is the standard twist rate for the 30-06 and will stabilize bullets from 110gr to 220gr reliably. The reason many old military rifles shoot heavier bullets better is because they generally have longer throats than commercial sporting rifles. Plus they've had who knows how many 1000's of rounds fired through them over the years and the throats get worn even longer. Lighter bullets generally have shorter bearing surfaces than the heavies of the same design, if the bullet leaves the case neck before it engages the rifling it can sometimes go a bit squirrely and actually travel down the bore slightly crooked causing the bullet veer off course in flight. Clean the bore thoroughly until all traces of fouling are removed and try some 180 or 200gr flat base bullets. If those don't do any better you could have a stuffed barrel.
Counter boring can also cause accuracy issues if it's too deep and/or off center. I normally won't buy a rifle that's been counter bored unless it's an uncommon variant. I've had several Finn Mosin Nagants over the years that were done this way and they just didn't shoot as good as those that weren't.

[Andrew1995]

Ill pick up some 150gr and 180gr and see where that puts me. Thanks for your help guy!

[browningautorifle]

Have you ever slugged the bore to find out it's true size? We could go round and round until you find that out.

[Andrew1995]

No I have not. I was intending to do do so. But I need too get calipers.

[Bruce McAskill]

The 150 gr. flat base FMJ round is the standard for the M1917. The heavier 172 gr. bullets did not come into use till after WW1 and even then were designed for the machineguns. So it became the standard till the late 1930's when the military went back to the 150 gr. flat base now called the M2 round along with the M1 Garand.

[Calif-Steve]

You have a counter-bored rifle. The job of counter-boring has to be done correctly or the rifle is toast. Do you have a gunsmith you trust? Have him check out the muzzle, good luck.

[Andrew1995]

There is a gunsmith around. I haven't really taken much into him. Do you think he would just give it a quick look over, because to me it looks fine though im not a gunsmith?

[Andrew1995]

I just called a gunsmith at Moss Pawn and Gun (where Iraqveteran8888 works if you know who he is). I told him about the crown he didn't seem concerned at all about it. But he said it was the 150gr Greek surplus and that he had people come in with $1000 rifles with $500 scopes and barely be able to his a beach ball a 100 yards. He said to try 2 or 3 different factory loads and see how it does. I still might take the rifle in and see what my local gunsmith says.

[RC20]

If its a worn barrel you can also move up to 303 bullets (.311 diameter as I recall)

Some swear by them, not sure I would do it in a good shooter but I would also run all the options first.

Greek is pretty bad stuff.

[Wineman]

Slugging a 5 groove will take a bit more equipment than an even numbered barrel: a V blocks and the right equations. On mine I used a thin shim wrapped around the slug and subtracted the thickness x2 from the diameter for the groove. Getting the bore diameter will be a pain with the counter bore. I was able to use a smooth slug that just rotated in the bore. Some people use pin gauges. Mine was 301x310 by my method. The Hornady 0.3105" fmj work well in mine but are hard to find these days.

Dave