155gr bullet choice for 1:13 twist

Get or give advice on equipment, reloading and other technical issues.

Moderator: Mod

Message
Author
!Peter!
Posts: 99
Joined: Sun Oct 30, 2016 6:35 am

155gr bullet choice for 1:13 twist

#1 Postby !Peter! » Fri Sep 28, 2018 1:33 pm

Hi All,
I've got a couple of 1:13 twist barrels with plenty of life left in them that came with a rifle I brought. I'm thinking of using them for practice and club days. What 155gr bullet would people recommend. I know the #2155 SMK will work but is there anything else?

Appreciate any advice.
Peter

Wal86
Posts: 155
Joined: Sun Nov 20, 2016 5:10 pm
Location: Kilmore, VIC

Re: 155gr bullet choice for 1:13 twist

#2 Postby Wal86 » Fri Sep 28, 2018 1:53 pm

Peter,

You will have no problems stabilizing any of the 155gr projectiles allowed in fstd, with a 1-13 twist... I would recommend the berger 155.5gr fullbore, these are very forgiving projectiles...
Hope this helps

Cheers
Alan

!Peter!
Posts: 99
Joined: Sun Oct 30, 2016 6:35 am

Re: 155gr bullet choice for 1:13 twist

#3 Postby !Peter! » Sat Sep 29, 2018 12:40 am

Thanks Alan,
While they will all stabilise, I know the berger hybrids prefer at least 1:11 & berger's twist calculator recommends 1:12 for the 155.5 fullbore.

What's the experience with the hbc 155.5?

Thanks
Peter

argh
Posts: 74
Joined: Wed Sep 04, 2013 4:25 pm
Location: Central Coast, NSW

Re: 155gr bullet choice for 1:13 twist

#4 Postby argh » Sat Sep 29, 2018 6:36 am

We have had a few guys here with 12 twist fail miserably with hybrids. The Berger VLD would be a good option along with the HBC. Both are a good price too.

scott/r
Posts: 563
Joined: Wed Aug 27, 2014 8:22 pm
Location: far north brisbane

Re: 155gr bullet choice for 1:13 twist

#5 Postby scott/r » Sat Sep 29, 2018 8:19 am

I've got an old mauser with a just as old 26" madco 1:13 that absolutely loves the 2156 match kings. Doesn't like the 2155 much, but the 2156 will give a great x count every time I pull it out of the back of the cupboard.
Scott.

williada
Posts: 730
Joined: Wed Jul 22, 2009 12:37 am

Re: 155gr bullet choice for 1:13 twist

#6 Postby williada » Sat Sep 29, 2018 10:00 am

Peter, the Optimus HBC will run very well for the shorter ranges with a 1:13. The designated twist suggested by internet programs provide a general approach and are not distance specific. If you get down the mud it matters for centre count.

Graham M asked me to consider different twist rates for project Penumbra back in the early 200O's and being a military man at the time he had access to better computer modelling for the projectiles we were using. Even produced a 60.9 at 300 yards with a 1-15 in F Standard later down the track while using up the old Sierras. But to put 1:13 in perspective, the wife shooting TR at 1000 yards using a 26 inch 1.13 at Rosedale produced a 99 and lost one to weather to top score. Not a lot of centres, but the job was done to demonstrate the groups were still manageable. Same barrel and projectiles (although I sent back a bad batch with a longitudinal score in the jacket nose) won the Champ of Champs at the district level in TR for her recently. So by all means use that old 1:13.

That being said, temperature will be a big influence on performance at the longs. I would prefer a tangent ogive if they were obtainable with this twist rate. The HBC is manageable with secant but I would steer well clear of VLD's.

The other factor to consider is the terrain. Over high mounds etc there may be insufficient torque with a 1:13 over the longer distances if atmospheric stress factors come into play.

!Peter!
Posts: 99
Joined: Sun Oct 30, 2016 6:35 am

Re: 155gr bullet choice for 1:13 twist

#7 Postby !Peter! » Sat Sep 29, 2018 1:08 pm

Thanks argh, scott/r, williada, for you input.

Price is a consideration in this case. Incidently I have a stash of 155 hybrids and 1:10 barrels :D :D :D but just looking to not "waste" the 1:13.

So from the advice it looks like the #2156 SMK would be the best choice with the 155.5 HBC a close second.

Thanks again.
Peter

pjifl
Posts: 613
Joined: Fri Jun 17, 2005 12:15 pm
Location: Innisfail, Far North QLD.

Re: 155gr bullet choice for 1:13 twist

#8 Postby pjifl » Sat Sep 29, 2018 1:48 pm

I am not convinced that the higher twist rates often recommended today are better for competition shooting. You have to factor in that the bullet manufacturers, and many of the 'expert' writers have to give recommendations that cover all shooting conditions - including an Alaskan winter ! The current fad seems to favor higher twist. Remember that extra high twist gives more rifle torque, more fouling, and more barrel wear. Everything is a compromise !

I heard of trials many years ago over 1000y that showed excellent accuracy for twist rates that today would be regarded as inadequate. These were done in North Qld where conditions werefairly warm to hot which is probably relevant. I think you should not be frightened to experiment.

Peter Smith.

Tim L
Posts: 345
Joined: Mon May 19, 2014 7:11 pm
Location: Townsville

Re: 155gr bullet choice for 1:13 twist

#9 Postby Tim L » Sat Sep 29, 2018 6:10 pm

You aren't wrong Peter.
When heavy projectiles came into FTR (which isn't so long ago) the 200 needed a 1:10 and the 215 a 1:9. Now the 200 is a 1:11 the 215 a 1:10 and even the 230 a 1:10.

I may just revisit that 230 with a 1:10 and see what happens.

The Berger site puts the 155.5 in a 1:13 and I've shot 168s out of one, so I'd say it's OK.

BenW
Posts: 61
Joined: Tue Mar 17, 2015 7:13 am

Re: 155gr bullet choice for 1:13 twist

#10 Postby BenW » Sun Sep 30, 2018 9:10 am

I have shot the full bores out of a 14 twist maddco with no problems out to 700 yards, elevation in the area of a little over 1/2 MOA for elevation, numerous possible's from 300 to 600. So the 13 twist should be fine even out to the longs so long as you keep them above super sonic. Have played around with the VLD's and it didn't like them, the 2156 Sierra's, the jury is still out, have only shot them once at 800 at Lithgow and it wasn't good but could be Lithgow as well ;)

DannyS
Posts: 927
Joined: Wed Nov 17, 2010 10:33 pm
Location: Hamilton
Contact:

Re: 155gr bullet choice for 1:13 twist

#11 Postby DannyS » Sun Sep 30, 2018 4:40 pm

Berger 155.5 fullbore and a Lilja 1:13 won me the Vic Queens in F Standard. I agree with Wal86.

macguru
Posts: 1281
Joined: Wed Aug 05, 2009 9:49 am

Re: 155gr bullet choice for 1:13 twist

#12 Postby macguru » Sun Sep 30, 2018 7:14 pm

Any berger up to 155.5 except the hybrid

!Peter!
Posts: 99
Joined: Sun Oct 30, 2016 6:35 am

Re: 155gr bullet choice for 1:13 twist

#13 Postby !Peter! » Mon Oct 01, 2018 7:07 am

Thank you all for your input. Selecting twist rate is a compromise which does lead to having different barrels for short and longs if you wanted to optimise the twist.

I've noticed that the berger have revised their website twist recommendations a few times but if you go to their twist calculator and punch in a cool day at sea level they recommend 1:12 for the 155.5 fullbores.

DannyS
Posts: 927
Joined: Wed Nov 17, 2010 10:33 pm
Location: Hamilton
Contact:

Re: 155gr bullet choice for 1:13 twist

#14 Postby DannyS » Mon Oct 01, 2018 8:52 am

Maybe it’s time that you took less notice of bullet calculators and more of what works in real life.

Old Trev-39
Posts: 145
Joined: Sat Sep 12, 2015 2:07 pm

Re: 155gr bullet choice for 1:13 twist

#15 Postby Old Trev-39 » Mon Oct 01, 2018 8:06 pm

As to bullet twist calculators. If you feed in the data for a115gr..30 cal. in a 1in 17 twist it does not work. As the shooters who shoot a .30 B/R. what twist they use and the results, it works very well. even 1in 19 works. So do not believe everything you read.
Cheers,
Trevor.
P.S. A .30 B/R won a 500 Fly in Townsville a few years ago.


Return to “Equipment & Technical”

Who is online

Users browsing this forum: PeteFox and 4 guests