optimum bullet weight?

Status
Not open for further replies.
Allen in MT

Allen in MT

Member
Joined
Apr 16, 2012
Messages
155
Location
MT
If there is such a thing what is the optimum 308 cal bullet weight for reloading in a 26" 12 twist barrel for distance steel shooting?
 
I could be wrong in this considering I've never tested it but my understanding is that twist has the most to do with the bullet length & secondly speed. Only when you have two bullets created equally would you be able to call them by weigh. A all brass bullet would have less weight to be considered optimal then it's lead core counter.
 
I personally prefer either a 168 or 175 grain bullet for my extended range shooting in a .308 caliber bullet. I've done well in .300 Savage, .308 Win and .30-06 with these types of "match" bullets. BTHPs in this range have a good BC and with handloads can be super accurate at range. Before I got into .338 Lap with my Savage setup I did some 800-1000yd work with my .308. 175 BTHP let me, a mediocre shooter, put 6.5" groups with 10 shots at a grand with 24power optic. In my experience these work well.
 
DeadEye9 said:
Before I got into .338 Lap with my Savage setup I did some 800-1000yd work with my .308. 175 BTHP let me, a mediocre shooter, put 6.5" groups with 10 shots at a grand with 24power optic. In my experience these work well.
Click to expand...
Why would you call that a mediocre shooter?

I can usually do 3/4" at 100 yards as long as the rifle & ammo can do it & I consider myself a above average shooter at least from the ones I've shot beside. Actually I don't look down my nose at the ones that can shoot 2-3" groups @ 100 yards. Then again I see more then half that of they can hit a pie pan at 50 yards they tell me what a great shot they are. I haven't shot but about 300 yards that if I remember right was about 2.5" but that was a log time ago. I was using a 9x scope then. I use to think I was really good. Unfortunately I can't even see 2.5" at 300 with a 9x anymore. I now use 14-16x just to shoot @ 100.
 
Looked at my notes for you to give some specific loads that work very well for me:
For 168-
Sierra BTHP, 42.5 gr IMR/4895 @ 2.845". Like 1/3" groups at 100 with this load, no exaggeration.
W748 works well for these also, around 43gr proved 1/2-5/8" accurate for me.
With the heavier 175gr BTHP W748 again can make some good loads, 44.2gr gives me MOA groups at ~400yds. Seated to 2.80".
IMr 4064 @ 42.5gr proves very accurate with the 175 as well. As always, work your loads up starting maybe a grain under what I stated and see what YOUR rifle likes, but these loads I've laid out here were all the top of the class for my .308s. Surprisingly good old Varget can make for some very accurate loads as well, if you want any of those just ask. I've tried a ton. Happy shooting.
 
kingmt said:
Why would you call that a mediocre shooter?

I can usually do 3/4" at 100 yards as long as the rifle & ammo can do it & I consider myself a above average shooter at least from the ones I've shot beside. Actually I don't look down my nose at the ones that can shoot 2-3" groups @ 100 yards. Then again I see more then half that of they can hit a pie pan at 50 yards they tell me what a great shot they are. I haven't shot but about 300 yards that if I remember right was about 2.5" but that was a log time ago. I was using a 9x scope then. I use to think I was really good. Unfortunately I can't even see 2.5" at 300 with a 9x anymore. I now use 14-16x just to shoot @ 100.
Click to expand...
Mediocre in the sense that I'm far from a pro. My latest performance with last batch of handloads was around 5.56" 10 shot Group at 1000yd with .338 lapua mag. That's great for me, a record in fact but some guys shoot MOA at 1000 haha.
 
Hmm
I'm confused. MOA is over 10" at 1000 yards. Did I read your comments wrong? Anything under MOA at 1000 yards is a pro.

I can tear a target up at 100 yards but I have no experience at a K. So I'm far from pro. Heck my hat is off to anyone that can hit a GEO Metro at a K.
 
Allen in MT said:
If there is such a thing what is the optimum 308 cal bullet weight for reloading in a 26" 12 twist barrel for distance steel shooting?
Click to expand...
Yes, in my opinion.

For the 308 Win, 190-gr. Sierra HPMK's at temperatures above 50 deg. F. 175 HPMK's at lower temperatures.
 
Last edited:
IMHO 1:12 is on the slow side for 168s and heavier. You might want to try 155gr Palma Sierra or Berger bullets.
 
I personally load the 175gr bullets in my .308... but, I do have some 155gr Palma smk that I want to load development as well as the 186gr scenar... but, my go to load is 175gr nosler CC, lapua Palma brass, cci primers, 44.5gr varget... it's a little hot by the books, but this brass uses a small rifle primer and takes pressure better without issues.
 
Jim,

People shooting 155 Palma bullets from 308 Win cases through 30" barrels typically load at normal max pressures. Barrels that long typically shoot 'em 100 fps faster than 26" ones do with the same load, about 3000 fps. 308's seldom, if ever, get best accuracy with hot loads.

Stokey,

The M14NM rifle's 22" 1:12 twist barrels shot arsenal M118 match ammo's 172 gr. bullet reasonably accurate for arsenal ammo; about 1.5 MOA at 600. If replaced with Lapua 170 gr, 175 or 180 gr. Sierra HPMK bullet, sometimes Lapua 185 gr., they shot almost 1/2 MOA at 600, under 1 MOA at 1000.

The most accurate long range load for match grade 7.62 NATO Garand's 24" 1:12 twist barrels were Lapua 185 gr. or Sierra 190 HPMK's leaving about 2550 fps. Tested almost 1/2 MOA at 600 yards and under 1 MOA at 1000. I've shot Western 197 gr. BTHP and 200 gr. FMJBT match bullets from Win 70 match rifles in 308 Win having 26" 1:12 twist barrels and won long range matches so equipped. They also tested sub MOA at 1000.

Nobody consistently shooting best scores in matches uses ball powder. In the '80's when Winchester took over plant operations at Lake City arsenal, they put ball powder in all the 7.62 match and sniper ammo. 'Twas immediately shunned by military rifle teams 'cause even the best lots barely met accuracy specs. It shot about 50% bigger test groups compared to the IMR powders Remington used when they operated it. I used to take Remington loaded M80 ball ammo, replace its bullet with Sierra 150 grain HPMK's that shot more accurate at 300 yards than the M118 match ammo they loaded
 
Last edited:
I don't know about the lead Palma guys, but a serious F T/R shooter here loads to the point of shortened case life. I don't think he has a manual, it is quant suff all the way. Sounds like an expensive way to save a little on windage but he is not alone.
 
Jim Watson said:
. . . .. .but a serious F T/R shooter here loads to the point of shortened case life.
Click to expand...
My guess is about half of all rifle cartridge reloaders think their loads are safe but are really somewhat or way over SAAMI max average pressures because their "pressure measuring system" is dangerous and based on ignorance. They're siblings of Palm and Tarot Card Readers at circus or carnival venues because they think they can determine peak pressures by observing case and primer shapes and dimensions.
 
Bart B. said:
My guess is about half of all rifle cartridge reloaders think their loads are safe but are really somewhat or way over SAAMI max average pressures because their "pressure measuring system" is dangerous and based on ignorance. They're siblings of Palm and Tarot Card Readers at circus or carnival venues because they think they can determine peak pressures by observing case and primer shapes and dimensions.
Click to expand...

I never react this way, but your reply rubbed me the wrong way. Alot of people respect your opinion, for what reason I don't know. But, there are always more than one way to do anything. Who the hell do you think you are to berate people because they do different than do you. Your f-ing arrogance is sickening. Just keep your belittling comments to yourself! Oh yeah, and merry Christmas
 
I seriously doubt that 1/2 of reloaders are over max. Based on what I'm reading the vast majority that post their loads tend to err on the side of caution and load far more conservatively than necessary. But maybe those who do over load just don't post about it and the numbers may be higher.

But I do agree that virtually all of the "signs" that reloaders use to determine over pressure loads are probably as accurate as trying to read tea leaves. For most casual reloaders a chronograph is the best way to determine if a load is over pressure. Pressure and velocity are tied together. If the velocity your chronograph is showing is equal to or less than the velocity shown in the loading manual for that powder charge you are OK.

As to the best bullet weight, you'll just have to experiment. A 1:12 twist should eliminate the heaviest bullets, but you'll never now until you try. I'd think 180-190 gr bullets are right on the edge of being too long. I've tried 180gr hunting bullets in a 1:12 and had no issues. I'm going to experiment with some 200 GR Hornady ELD-X bullets over the winter after hunting season. I have 3 different 308's with 10, 11, and 12 twists. It'll be interesting to see how each performs with the heavier bullets.

It has been about a year ago, but a shooter on another forum I read was loading 215 gr Bergers in a 1:12 308 and shooting them at 1800 yards. I don't recall the exact load, but was right at max but not over. It worked for him
 
farmerboy78 said:
I never react this way, but your reply rubbed me the wrong way.
Click to expand...
Sorry 'bout that. I don't know which half of the reloaders I referred to you're in, but your comment above gives me a good idea. Hopefully, I'm wrong. There's about a 50-50 chance either way.

All reloaders don't put in print on the web's shooting forums their load data. Having shot several hundred 7.62 NATO proof loads in Garands and showing a lot of people the fired cases, over half think they're normal, safe, maximum loads. That's one of several observations I've used to come up with my consensus on what's hot and what's not.

Whatever load that has the highest velocity for a bullet is what most folks typically go with to start working up to. Their stopping point's where they think is OK.
 
Last edited:
For something that has been around as long as gun powder there seems to be quite a bit of mystery, misinformation, & disinformation.

You can't read a chrono to determine if pressure is safe. It can give you an idea if things are headed south tho. If all of a sudden your bullets are slowing down with more powder that should scare you. The bullet is slowing down because the pressure is peaking faster because of increased pressure causing it to burn faster.

Measurement of the amount the chamber is stretching & the math to calculate it is probably the best way to determine the pressure. Amount of crush created on a known surface is probably the second best that we have use. But for those of us that don't have ether we have learned to look at the things we know for signs of change. I can look at a primer that I have been using for years & determine if the pressure is to low, to high, on the high side, or low side of usable.

I don't post my loads very often. There is no need to. Most of my loads are close to our within the same range posted in published information. Those that aren't I don't want someone missing up & blaming me for. Others are for powder I don't know what it is so there is no point there ether.

The powders that react pretty consent to a known powder I write on the bottle what powder to refer to when using published information.
 
In addition, reloaders manuals are going to give you a safe max load that will be safe for every single chamber cut at a specific coal, for liability purposes... which is great, especially for a new loader... you will know 100% that the load is safe... but, if you load to a longer coal, that will allow more case room which will lower pressure for a specific powder. That's why most reloaders read their cases for pressure signs. Because different manufacturers produce cases to varying tolerances... there can be a volume difference lot to lot from the same manufacturer, and especially from company to company. My .308 lc match brass allows me about 43-44gr max with varget and a 175gr HPBT, my lapua Palma allows up to about 45.5gr varget with the same bullet with no issues. Which incidentally my accurate load with the Palma brass is 44.5gr varget with the 175gr HPBT. Which I believe is slightly over pressure by the manuals.

I have heard guys using 190gr bullets in a 1in12" twist will no issues (non vld)
 
Last edited:
I'd hate to bet my rifle on that statement.

My rifles show less pressure with more free bore.
 
farmerboy78 said:
I have heard guys using 190gr bullets in a 1in12" twist will no issues (non vld)
Click to expand...
Remember Winchester introduced the 308 Win in their M70 with a 22" barrel rifled 1:12 twist. They sold 200 grain round nose hunting bullets in hunting ammo that tested MOA at a hundred yards shot from them.
 
Last edited:
Status
Not open for further replies.
Back
Top