Fixing to rebarrel a 7x57 hunting rifle. What is the ideal twist rate for the heavier bullets in this caliber.

most of them come with a one in 9 or 9.25 twist...

I have worked with 7 mm in 7/08, 7 x 57 and 7 Rem Mag.. all with the same twist and each one shot the 160s, 175s with the same level of accuracy.. and no stabilization problems..

muchas gracias!

I built mine with a 1:9 and it seems to work with all bullet weights.

I have a 1-10, and it gives me trouble with long 175 gr pointed bullets.

I have a 280 with a 9" twist that likes 160 gr bullets better than 175 gr. Can't say for sure it's twist rate causing that or it just is. The one thing that makes me think it is twist rate is that the 154 - 160 gr bullets and the 175 gr bullets shoot about equal accuracy at 100 yds, but there is a distinct opening up of the groups at 200 yds with the 175 gr bullets compared to the 160 grs. I'm thinking it's because the 160gr is better stabilized at 200 yds.

I think the twist rate thing has to do with Americans having had trouble with anything metric. IMO the only reason the 7x57 survived in the USA is because the number is easy to remember. Two sevens and a five - 7x57 sort of has a rhythm to it. Has little to do with it being a great cartridge. Americans also have trouble with conversions to inches from metric, and tend to just round things off – and use the one size fits all mentality. Hence the “invention” of the 280, when there was already a perfectly good 7x64. Hence the rounding off of twist rates to even inches. The C.I.P. twist rate for the 7x57 is metric and it’s not an even number in inches. It’s about 8.7”, anticipating heavy bullets.

I suggest that if you want to use heavy bullets, and be sure, get a barrel made to C.I.P. specs.

I have a CZ 550 in 7x57, twist rate is 8.7". It's Euro specs, C.I.P. I'm working up loads with 175 gr bullets to test it, but don't know the results yet. I have several hundred 175 gr 7mm bullets, so I'm thinking surely I'll have better results with the fast twist CZ barrel. One thing for sure, the C.I.P. twist rate was designed for heavy bullets, so I can be assured that if the rifle doesn't shoot as accurately as I want with the heavy bullets, the one factor I can eliminate as being the source of a problem is the twist rate.

KB

I went with the 9 inch twist in my 25 in barrel and it shoots light 120gn GS HV through to 160 gn Woodleigh's. Never had the need for 175's but as kabluey says the origional twist was 8.7 for the 160 - 175 bullets of military persuasion. I have had 1 in 9 for a coupkle of 7x57's and a 7x61 S&H and felt very well served with them.

Von Gruff.

quote:

Originally posted by Von Gruff:
I went with the 9 inch twist in my 25 in barrel and it shoots light 120gn GS HV through to 160 gn Woodleigh's. Never had the need for 175's

Von Gruff.

Agreed. I think the 154 - 162 gr 7mm bullet is probably ideal as the heavy for the 7x57, for which 1 in 9" twist is probably perfect. I just have a bunch of 175 gr bullets, so it's a shoot um or sell um deal. I'm glad I have the CZ, so it's an option.

KB

I did 7x57/280AI with 1/9 twist barrel. I decided on another 280AI using a Bartlein 5r 1/10 twist barrel. If I had to do it over again on the 7x57 I would of gotten a 1/8.5 twist from Kreiger I think it would of given alittle more velocity with 175gr bullets might even done a 1/8 twist. Well good luck on your project

See your from Gainesville, TX, I retired my good rope horse down at Bobby Harrison place. Bobby raised him got his first AQHA world champion.

quote:

IMO the only reason the 7x57 survived in the USA is because the number is easy to remember. Two sevens and a five - 7x57 sort of has a rhythm to it. Has little to do with it being a great cartridge. Americans also have trouble with conversions to inches from metric, and tend to just round things off – and use the one size fits all mentality

quote:

See your from Gainesville, TX, I retired my good rope horse down at Bobby Harrison place. Bobby raised him got his first AQHA world champion.

Yep...I know Bobby well. Was out at his place a couple of weeks ago. He is trying to move back to Miss.

i would think 1:8.5. my ruger no.1 is a one in 9.25. it shoots 175 round nosers fine, but not the spitzers. most folks shoot 140s and i think that is why ruger slowed down the twist. the old rugers were one in 9. think they changed in the early to mid 1980s.

I have a Ruger 77 Mark II in 7x57. I don't know the twist rate, but it shoots 150 and 160 grain bullets very well -- I've gotten 3-shot groups at 200 yards that measure 1 inch or less with both those bullet weights.

But I haven't been able to get it to shoot well with bullets under 150 grains or over 162 grains.

This rifle has a long throat. I load for it to an overall length of 3.08 to 3.10 inches

i'd lean towards less than 9" if you're gonna shoot more than 154's allot.
my 7x57 imp'd starts getting loose with 160's and up with it's 1in9 barrel. not allot, but i cans see the difference in groups size consistantly and proportionatly to the weight increase. 130's to 154's will hover right around an inch, 160's about 1-1/2 and the 175's open up to about 1-3/4 to 2-1/4. that said, all but the 175's are still decent hunting size and the 175's are ok for for a couple hundred yards on an elk, i suppose. i don't know just how much they'd tighten up with a faster twist, but the trend is definately evident, so i can only assume by the rules that a little more rpm would help. also, i haven't done allot of load developemnet on the heavier bullets because i don't need them for deer, so something might be gained there.

I have both 1-10 and 1-9 twist 7x57's and can't tell the difference as all I shoot are 140 gn Nosler Partitions.

For both of mine, I used one in nine twist barrels. The heaviest bullet I use in the 7x57 is 160grs. As a matter of fact, this twist will work with almost all 7mms

The original military spec was 1:8.66 which preferred the heavier bullets so a 1:9 should be ideal if you are looking to use mostly heavy bullets ie 160gr+

I have 2, an old FN action with 9 twist bbl per gunsmith, a ruger 77 action with 10. the ruger action wears a glass stock and was put together as a "loaner" for business guests on company lease years ago. for whitetails and NM pronghorns I used 140gr noslers exclusively, very consistent minute of angle or close, VERY deadly, at least a dozen different users all but one with one shot kills. The older rifle is my favorite, good shooter, seems to handle 140's and 160's equally well, 1.25". never hunted with 175's but it shot the only ones I ever tried (cheap roundnose of who knows what brand) into 1".