M14 Forum

08 Cayenne

I'm going to get a heavy 22" stainless steel barrel for long range shooting. Will be shooting 175 gr BTHP's exclusively. I was taught that the lower the twist rate the better it is for long range. Is this correct? Any difference in accuracy at 1000 yards using 1-10 or 1-11?

JBS

Here is a Greenhill calculator that can help http://kwk.us/twist.html
If you over spin a lot more than needed the Magnus effect can cause extra drift at long range.

bd111

The 10:1 is today's popular choice for what you want to do. But with these rifles I don't think a really good barrel knows the difference. I've seen and owned hummers and dogs in 10:1, 11:1, and 12:1. Any of them will shoot the 175.

mfdogman

Several month ago I purchased a 22 inch heavy Krieger barrel for my M1A. When speaking to the rep. I stated I would be shooting 168 grain HTBP out to 1000, and possibly working up 175 grain loads in the same application. His recommendation was 1:11 twist.
I have included the link they were very helpful. I believe they will help even if you don't but one of there barrels. They are just that way. The rifle shoots better than me 3/4 inch groups at 100 yards iron sights.
I hope this helps.

http://www.kriegerbarrels.com/M1Gara...246-wp3393.htm

Phil McGrath

Yes run a 1/11 or a 1/10 twist flip a coin if your undesided, some shooters say a 1/12 will work but why risk it, my 1/12 twist barrel with 175 Sierra's don't get along even at 600yds. thats with known accuracy handloads to M118LR right out of the brown box.

82nd ABN

I am sorry to say that I have not shot my rifle past a couple of hundred yards to date, however that will change this year. I too shoot nothing but 175 SMK's and all my barrels are 1/10. I would rather overspin than under spin. I use a 1/10 Kriegers in all of them even the short 18.5 inch barrels. I use the krieger 1/10 heavy in my garand and shoot 168's out of that one. I plan on trying some 155 this year as Nez says for the short line. I don't really see much of a difference between the 168 and 175's at 200 yards. From what I read the new 155 palma has the same BC as the 168 SMK but due to its lighter weight you get more velocity. I am definitely going to get a box of these to do a little experimenting.
Here is an article from the tech pages at Sierra.

Sierra was selected by the International Palma Committee to design and build a bullet that could be shot in the Palma competition from .308 Winchester rifles out to 1000 yards and remain supersonic. The Sierra Palma bullet is a 155 grain Hollow Point Boat Tail MatchKing bullet. The Palma bullet actually has a ballistic coefficient higher than our .30 caliber 168 gr MatchKing, and, due to its weight can be shot at higher velocities than the 168.

The combination of these two factors allows the Palma bullet to be ballistically superior to the 168 MatchKing bullets at 1000 yards. Palma match rifles usually use a 1x13" twist, however, the Palma can shoot very well with a wide variety of twist rates, including 1x10". The first Sierra Palma's were introduced in 1992, and since then, it has been the bullet selected to be loaded into the ammunition used in the International Palma Team Championships. From 1876 through the present, the highly prestigious championship has gone through many changes while bringing together teams of the finest riflemen in the world. Palma competitors must use iron sights, shoot from the prone position, and utilize a rifle that is chambered for the 7.62 NATO cartridge. The match is shot at 800, 900, and 1000 yards.

The 155 grain Palma bullet will appear in the 4th Edition Sierra Reloading Manuals with updated loading information, due out in January 1996. In the meantime, the loading data for the 150 grain MatchKing in our 3rd Edition Manuals provides an excellent reference for loading.

JBS, I tried using that calculator and each time, it comes up with .7. Is there a trick to using it? I assume I should be placing copper in for the bullet or SG. Thanks for posting it though.

Rojkoh

175 MKs will work fine in 1 in 12 or 1 in 11 (better for these bullets). 1 in 10 is a touch slow for the M14 type rifle. Might take a look at the Krieger barrels, I have two here and I am impressed with them. Krieger was taught by Boots. A fair amount of the team shooters are using Kriegers. With 1 in 11 you can swap back and forth between the 155 and 175 MKs. 168s are fine also.

I have no experience with Criterion.

Brownells also has a coating for SS barrels to cover the shiny nature of SS.

82nd ABN

I think you may have made a mistake. A 1/10 twist rate is slow? Ah last time I checked it is faster than 1/11 and 1/12. How and what is your reasoning saying "1/10 is a touch slow".

IC2(SS)19Z50C5

Here is the Liljah website....

http://www.riflebarrels.com/

And here is Dan Lilja's article on twist... You decide...

http://www.riflebarrels.com/articles...ance_twist.htm

This is useful information also....

http://www.riflebarrels.com/products...wist_rates.htm

One reason I had my M721 with McMillan A3-5 stock, 26" barrel in 6.5x55 Swede in 1 in 9 twist made up. All I will ever be shooting is 140 grainers... I trust those who know....

Phil McGrath

The old 155 Sierra(2155) has a similar profile compaired too the 168, the Sierra 155 Palma (2156) is a differnet cat it has a longer berring serface, so the two are nearly the same but there also very different at the same time.

Palma rifles are high end bolt actions with long sight radius and barrels 30+in, there ammo is really cranked up on the preasure side, our rifles are gas operated, have 22in barrels to work with and there sight radius is also shorter, also factor in that we can't drive the 155's as fast as the big dogs can the 155 becomes a bad choise for long range with our rifles, althou they (2156) beat the 168 at 600(NRA mid range) for wind drift because of there speed.

The 155gr ammo requirement is under the International rules, If we go to hosting country all teams have too fire/use 155gr .308 Winchester ammo, If the US Palma is hosting a match in the USA, and forgen teams enter its 155gr .308 Winchester, if no forgen teams enter/fire in the match any weight .308 Winchester ammo can be used, naturally all of the ammo is custom loaded and tuned for each rifle/shooter.

08 Cayenne

Man, that's all great stuff, especially for the middle of the night!! Thanks

82nd ABN

That's the way we roll! Morning noon and night! Lol.

hammonje

I would go 1:10. Maybe 1:11 if I shot lighter pills.

Weight of the projectile has nothing to do with twist, it's length that matters.

gregaba

Hi
While in the Army waiting to go to Nam the Army sent me to Ft. Sill for artillry training for some unknown reason. I was Infantry and a sniper and never did any arty work after my training while in the Army.
During my training on the 109 we were told that the barrel twist started at a low twist rate and the got tighter at the end of the barrell. Ie it would start at say 1-10 and at the end of the barrell change to say 1-18 [just an example as I don't remember what it was exactly].
I asked why and was told it increased accuracy and I know those guys could put a round in a bucket at 10 miles if you would hold it for them.
If I had the money I would build a rifle with a graduated twist with a longer barrel just to see if it would work as good for a rifle as it does on a gun.
Just a though.
Greg

valken

I own Barrels in 1-10 and 1-11. For serria's 175 I find the 1-11 shoot best, for me anyway