The Wilson company page suggests you need 1x13 for stability in cold weather versus the 1x15.  Most barrel options I am looking at are 1x15 only in anything that is not a real custom barrel.

I think most 30 cal bullets above a 150gr are too long for the magazine and receiver so, I don't see it being a problem with stuff like heavy SMK and similar bullets.  How cold would it need to get for a 1x15 30 cal barrel to fail to stabilize things like Speer Hot Cores and various similar options in the 110gr~150gr range in the 2000~2400FPS velocity range?

TIA,
Sid

I don't see a 13 hurting anything, hot or cold, compared to a 15.  But then I don't see where cold weather would have that much of an effect on stability either, 13 or 15.  I think more will depend on the load you are shooting, than the weather.

http://www.jbmballistics.com/ballistics/lengths/lengths.shtml

https://bergerbullets.com/twist-rate-calculator/

I get some people don't like him or view him as a bit of a sleazy used car salesman.  However, he has more experience hunting than most people.  Granted he is a bit out of the mainstream for the gun rags but, that doesn't mean he doesn't have a better product than some bankrupt corporation.

I've given up trying to build a lightweight AR-10 so, that took me to a lot of outright wildcats.  The 30HRT/30-68SPC was ruled out because I don't like the magazines and how they stack the rounds and it is more unsupported than I want to deal with today.  The 300BO really falls short if you want to go supersonic.  The 300 HAM'R really gets close to a 30-30 ballistically so, that's why I'm looking at it.

Thanks!  That Berger weblink is very helpful!

I gotn nothing against Bill.  In fact I like him a lot but I don't think twist rate is going to be much of a factor regarding weather.  I personally would lean to the 13 just to cover more bases when it comes to bullet weights and construction.  You are not going to over-stabilize a 110 with a 13 twist.

Very much so.  Also the chart with the various bullet lengths as a lot of manf's don't provide it.

I plan on running mainly Speer Hot-Core 130's and possibly some 125's or 150's.  Running random bullets in the 150gr range that are 30-30 centered generally gives me a stability factor of 2.25 or better.  Heavier will probably kill case capacity too much so, I think fairly short 150's are going to be where the 300 HAM'R top out.

If 110's are 'hand grenading' on me, I can always back velocity off a little with handloads.  If they fly true, they should be really good on the dogs killing livestock similar to what I see with the M193's run really hot on 'pets'.  Nato spec M193's out of my KAC LPR at ~30 yards are super impressive and really humane.

Four local counties recently did a "mutual aid" on one house where they hauled off over 200 dogs so, things have gotten better.  We still have two backyard breeders and some paranoid dopers though, so having a good rifle with me is still a requirement to ensure I'm not attacked by dogs again.

I meant to say you are NOT going to overstabilize a 110 with a 13.  Not sure why I messed that up.  I would do a 13 if available.

Dudes run 110-130s at ~2900fps from Garands often. I haven't seen a report of .30 cals poofing yet.

In my .30 HRTs, which is a faster round than the .30 HAM'R, I use 1:10 twists in all four of them, 6.5 inches to 24 inches.  Accuracy in all is very good, easily MOA in the 16, 18, and 24, and not much more in the 6.5" with 190 gr. and 225 gr. subs.  The 24 inch shoots 110 gr. TTSX bullets to over 2900 fps and a hair over 3000 fps if I want case life to be only three loads.  I don't see why a slower twist would be warranted or needed.  I guess a 1:13 would be OK but I know the 1:10 is, at least in the faster .30 HRT, which if anything, would justify a slower twist to get the same RPMs.  And no, the 110 gr. V-MAX do not go poof when shot at almost 3000 fps.

Thanks Big Bore!

Lots of information here

Only an idiot would view Bill W as "sleazy".

He says what works and he isn't wrong.

300 HAMR is awesome.

Don't worry about the stupid twist rate. Just pick one and go for it. It's an incredibly accurate and efficient cartridge.

Can anyone tell me the barrel profile differences between the PROTECTOR and RANGER barrels that come and go in inventory?  My call to Wilson Combat tech support told me to go to the webpage but, I pointed out that the barrel profiles were no longer listed there (as they were previously in PDFs), only the weight was listed but that doesn't tell me the profile.

I don't want something whippy but, I also need something that is pretty dynamic in its swing so the added weight of the suppressor and thermal scope doesn't slow it down so much I can't track fast-moving hogs on the run or transition to the next one in a timely manner.

I'm thinking 16 inches but, could also go shorter if I need to.  Reasonable weight between my hands is good so, an SBR to bring the CG more to the rear is a viable option however, I'd like to keep this one out of NFA territory even with the suppressor attached and its tax stamp.

TIA,
Sid

Just buy whatever comes in stock.

I think you are over thinking it.

PROTECTOR is .700 on both ends of the gas block and the RANGER is .650, I shoot mostly RANGER profile and get good accuracy from them. I didn't realize this info wasn't on the site anymore, I'll follow up on this. Overall unless you live in a extremely cold area and shoot only 150gr bullets the 1-15 twist is the way to go. I wish we hadn't ever offered 1-13, the confusion it has caused hasn't been worth any positive since most people don't shoot or hunt out in sub 0 weather anyway! I've got both 1-13 and 1-15 that shoot well, but the 1-15 is more forgiving when shooting 110-135gr bullets. Living in TX where a COLD winter day is in the 30s I haven't seen a stability issue with any bullet out of my 1-15 barrels.