Home Forums Hunting & Shooting General Big Game 308 Win for Big Game: 180gr out of 20" Barrel

Interestingly after I got my 300 WSM Frontier compact, I was told by a friend purely off the cuff which was a totally knee jerk reaction, that quoting him,,,,,"I basically got the equivalent of a 24" barreled 308.

A few weeks later with him as my witness using HIS chrony, I blew his assessment to Mars and beyond.

Well hardy har har,,,,,,,,,,

Couple a faster bore along with some RL17 (only), I believe it is possible for some 308s to maybe get 2750 to 2800 fps with a 180 gr bullet from a 20.5" barrel without pressure signs.

If Montana`s 308 can go 2700 fps using a 200 grainer, than 2750 to 2800 using a 180 is very feasible from HIS rifle.

..........No pressure signs uh??? Well then, I rest my case!

There are a bunch of guys running 208 AMax in the 308s over RL17.

Typical speeds are 2550-2600 with 20" bbls, and 2650-2700 fps in 26" bbls.

I'm at 4000' ASL.

That affects retained velocity, but not muzzle velocity.

You really are naive...

..........Nope! I don`t think so!

Feel free to do as you believe. I'll pass.

Please also recall that Shane trusts his face to QuickLoad as well. I teach mathematical modeling using numerical methods. I'm well aware of mathematical models - their shortcomings and strengths. I trust Shane knows of what he does - and the risks inherent.

I've evaluated all the above. I'll still pass.

................Each rifle has its own tolerance for maximum loads as to what is acceptable and not acceptable for "that" individual rifle. If Montana says he is getting no pressure signs from "HIS" rifle, then who are we to say it cannot be done? HE owns, loads for, shoots and chronys HIS rifle,,,,,,,,,,,WE don`t!

Depending on the bore whether slower or faster and from two identical rifles using the same identical charge, there can be a 100 fps (maybe more) swing difference in velocity which can go in either direction.

Then add in to the equation some RL17, which can and does increase velocity in various cartridges "without" pressure increases. I don`t see why it would seem impossible for a 20.5" barreled 308 to ship a 180 gr bullet from its muzzle at velocites ranging from 2700 to 2800 fps using RL17 only.

Montana is already doing 2700 fps with a darn 200 grainer using RL17 with no pressure signs. Now IF that is true, then it is quite obvious HIS rifle is capable of 2750 to 2800 fps using a 180 gr bullet using the RL17.

With my own rifles, and to determine what the max loads are, I look for sticky bolts, shiny marks on the case heads, the usual pressure signs from the primers, shortened case life and all the rest of it.

Like someone who exercises who listens to his body, rifle owners should also heed and take notes on what their rifles are telling them as well.

Based on those pressure signs and when I first begin to see them, I determine the max loadings each of my individual rifles can handle and live with whatever the maximum velocities happen to be.

When I can reload Win 308 cases 10+ times with snug pockets, I'm comfortable with the pressure.

Here's some relative comparisons of boltface pressure based on case head diameter, and operating pressure of a few common rounds chambered in the Rem 700 action.

338 Lapua - 16,564 lbs pressure (.588" head diameter (.272 sq-in),60.9K lbs psi max pressure)

300 SAUM - 14,560 lbs pressure (.534" head diameter (.224 sq-in), 65K lbs-psi max pressure)

308 Win - 10,912 lbs pressure (.473" head diameter (.176 sq-in), 62K lbs-psi.)

You'd have to run the 308 at about 90K psi to get boltface pressure in the 15K range.

Long way of saying, it's gonna take some trying to blow up a 308, with a powder like RL17. If primer pockets are still tight, after 10+ compressed loads, I'm nowhere close.

I've never said that.

What I trust is my analysis of everything I'm seeing.

No it will never work. After all no big game was ever killed with the 30-40, 303 British, .318 Westley Richards and so on.

Here's a little follow up.

Ran these over the chrono today.

308 Win, 20.5" 1/12 Rem barrel
180gr Rem PSPCL
Win brass
CCI 200
Reloder 17
2.80" OAL

I just shot two rounds of each charge.

50.0 gr - 2587, 2602 (Avg 2595, ES 15)

51.0 gr - 2660, 2649 (Avg 2655, ES 11)

52.0 gr - 2690, 2685 (Avg 2688, ES 5)



The 52gr charge was fairly compressed. All loads left a lot of soot on the necks. No bolt stiffness. Primers looked normal.

I think a 180gr bullet is a tad light for optimum performance of RL17 in a 308 case. I get more speed from 50gr under a 208gr, than from the 180gr.

Your 50.0 grain load is about what I would expect from a 308/180/20" at SAAMI pressure. I had a Ruger UL in 308 and it ran 28-2850 with 150's, 2650 with 165, and 2575-2600 with 180's using max charges of H 4895 and Varget.

I've also ran 150 and 165 in a 15" 308 Encore and lost ~ 75-100 ft/sec from my 20" Ruger.

I mean no disrespect to you but we definitely see things much differently as I tend to rely on pressure tested data over QL calculations. I have a spreadsheet version of QL and use it alot to develop pressures/loads for wildcat cartridges I have for my Encore/Contender. I tend not to rely on QL or any other mathematical model but use linear interpolation of known data and case capacity.

As an example, the Re 17 load data I have from Alliant for the 308 shows a max charge of 48.6 for a 180 and COAL of 2.800. They also list 50.0 as the max charge under a 165. Both charges are compressed but would venture pressure is close to SAAMI. I also make the assumption that powder companies are developing load data in full compliance with SAAMI. I would not be comfortable with the loads you list.

Just for conversation, here's chrono results I've had for four different bullets, all loaded with 50gr RL17, in the same 20.5" 308, same Winny brass.

180gr PSPCL, 2.80" OAL - 2595 fps

200 Accubond, moly'd, 2.82" OAL - 2620 fps

200gr Sierra GK, 2.81" OAL - 2620 fps

208 AMax, moly's, 3.00" OAL - 2620 fps

I get the most value from QL using it as a tool to estimate correlations between pressure/velocity/load density, of a given case/bullet. This saves me time and money.

I've found the calcs are generally close, but not always.

Bigsqueeze: He's a Marine. He can accomplish things most people can't, and does more by 0800 than most people do all day!

Leave it up to a devil dog to go bending physics...haha!

Now that we have had some Marine on Marine banter...can we all play nice?

I've never been a 308 win guy, but after recently buying 2, I'm learning to like them. One is a ruger hawkeye and the other is a winchester (FN made in SC) model 70 fwt. These rifles are fun to shoot and I look forward to taking them hunting in the future

Welcome to the .308 brotherhood

Red Beard, Hellyeah........... I'd go longrange for elk or moose with the 308.

My pick would be a Hornady or Sierra 165/180/ 200. They penetrate like a fine stud horse.

***** Be more concerned about bringing a good camera or two for lots of trophy pics after the kill*****( and a good pair of boots fer ya feets)

Instant classic.