Help with. 308 Win with 200 gr Lapua Mega and N-140

S

Saguaro 66

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CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

I need help reloading .308 Win with 200 gr Lapua Mega and N-140 trying to get the maximum energy for hunting at close range.

I have been going up until 43'5 grains of Vihtavuori N 140.( Being 41.2 the maximum load from Vihtavuori pages). However those 43.5 give no signs o.p. and good accuracy is maintained

My question is if I may go to 44 grains, or more, of N - 140 without getting risky
What is the maximum energy I can get with this bullet/ powder ? Anybody is got the experience or the software to know more accurately

Rifle Tikka CTR

Thanks!
 
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First off,, I would not go over max,, and I cannot recommend it.. I would have stopped at max. Try changing powders or getting a gun in an appropriate cartridge if you don't feel 308 is enough.

What are you trying to hunt? I did a little research on the Iberian Peninsula. These are the game animals I found,

Game animals as lited
Spanish Red Deer
European Fallow Deer
European Roe Deer

Mouflon Sheep
Aoudad

Pyrenean Chamois
Rupricapra Pyrenaica Parva

Eurasian Wild Boar
Sus Scrofa

Eurasian Wild Boar
Sus Scrofa

Eurasian Wild Boar


I am guessing you plan to hunt the Boar? As you are using a heavy big game bullet? In my opinion you have more than enough power for any of the animals on the list, with the load you have. You don't need to keep pushing.
 
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....."First off,, I would not go over max,, and I cannot recommend it.. I would have stopped at max. Try changing powders or getting a gun in an appropriate cartridge if you don't feel 308 is enough."...

Thank you for your answers.

- Normally with any cartridge I add powder until I see any signs of o.p. then back up. In this case I haven't notice any signs of o.p.
I don't feel comfortable going over the MAX but at the same time I understand than a Maximum load is a conservative indication intended for different rifles including older ones with weaker actions and/or firing in hot weather. The Tikka CTR are very solid rifles and hunting season is during winter, which helps to keep pressure down considerably.

As you guessed I'm after wild boar. I live in the hills and do hunt a lot during hunting season which happens during relatively cold weather
Local winter boars are very hard to kill, they may get a heart shot and still run 300 feet into the thick bush or fall I into a deep creek and become very difficult to find and take with you.
When they run very fast is extremely difficult to place the shot in the right place. So the more stopping power the best for a fast ethical killing. Let's not forget than a big wounded boar can become aggressive and dangerous.

I use different rifles and cartridges depending the situation. The Tikka CTR works great in thick forest because is short, very solid and action runs smoothly so follow up shots are easier than mauser action.
I wished it was a 9.2 x62, which would be more appropriate, if not ideal, for this kind of hunting, but it's not.

Some of the local hunters with over 40 years experience carry 30.06, 9.2x62, 12 g shotgun etc... nevertheless too often some boars are hit 1 or 3 times and still manage to disappear into the deep forest. I hate that, I don't like to leave a wounded animal. If you kill an animal it's got to be eaten by the hunters family and friends

I have been successfully using the CTR. 308 for many years. However I wonder if a few extra grains of N-140 can give the .308 a bit more energy and stopping power.... but I don't really know.
This is why I'm asking here. I'm just trying to get the maximum reasonable stopping power out of my Tikka CTR. 308

Thanks
 
In my experience, I have found some loads are listed as max but the listed pressure is lower than other powder options. It may be because the powder is not all getting burnt and is just getting wasted. The only way to tell if you are getting more energy is with a chronograph. You need to check the bullet speed. You might not be getting any extra velocity for the extra powder....

For example. I had pistol powder that was too slow for my short barrel guns accurate #7. I tested up to max. I believe 8.6g bit saw no velocity increase after 8.0g. So I decided to load at 8g only with that powder because more was just a waste.

Buy or borrow a chronograph and test your loads.see if you are even getting any more speed or not. You might need to try a new powder to get more speed, rather than putting more in. It's not worth blowing your gun or yourself up over.
 
,,,,"Buy or borrow a chronograph and test your loads.see if you are even getting any more speed or not. You might need to try a new powder to get more speed, rather than putting more in. It's not worth blowing your gun or yourself up over."....

You are absolutely right
 
It's not always right, but usually very close in predicting velocity. QuickLoad predicts all of 110 fps difference between Vihtavouri's max and your 44 gr. That means a minor difference in bullet drop at range and virtually no difference in the lethality of your bullet. I'm not averse to pushing things a bit, but only when I get a real benefit.
 
...." I'm not averse to pushing things a bit, but only when I get a real benefit."...

Clean cristal clear.

I haven't got QuickLoad because I have no P.C. and a.f.a.i.k, it only runs with Windows. I wish I had that thing but then I wound't have the pleasure to communicate with you guys. :)

I do have a chronograph but, currently is out of battery and the next shop is miles away so ironically it's easier to ask you guys in the other side of the world, for which I'm very grateful

Heavy R.N. or S.P. bullets at moderate velocities work quite fine with winter thick skin boars so I wanted o try those Lapua Mega. I'm aware than 200 grainers aren't ideal for the .308 but they were given to me so ill try to make the best out of them. And for some reason they are accurate and fly quite well from my CTR even going hot and no signs of O.P.
Nevertheless I'll back up to Vihtavuori's max load:D
 
CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.


shadow9mm said:
In my experience, I have found some loads are listed as max but the listed pressure is lower than other powder options. It may be because the powder is not all getting burnt and is just getting wasted.
Click to expand...

No. It's because the powder with the lower maximum pressure exhibited more pressure variation from shot-to-shot than the ones near the maximum pressure. They try to choose maximum so the highest variation out of ten rounds does not exceed maximum. This is both to allow for powder lot variation and that some listed powders are listed for convenience and are not optimal and may exceed the 4% standard deviation in pressure the standard allows for.


Saguaro 66,

QuickLOAD says your extra 0.5 grains of powder will increase muzzle energy 0.3%. This is less than shot-to-shot variation, so the odds of the animal noticing the difference is small. It looks like a compressed load of N550 might gain about 5% in energy at about 47 grains, but, again, watch for going over the data.

The 308 has a lot of variation in case capacity from one make to the next so, in addition to guns being different, your cases may have more room than the ones the data was developed with. Also, you might have a lot on the slow end of the burn rate range.
 
I ran your numbers in QL also, Unclenick is far more knowledgeable about this kind of stuff than I am, so I'll offer just a "generalized" opinion that your particular load combination appears to yield significant pressure gains at little velocity benefit from even small incremental loads past the recommended max load--in other words you're going to be "stuck" around 2410 +/- fps. I also took at look at the mega bullet, I'm not familiar with it but it appears to be a bonded soft point type bullet, so there are the additional questions of how it will perform at the various ranges, velocities and type of target.
 
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stagpanther said:
I ran your numbers in QL also, Unclenick is far more knowledgeable than I am about this kind of stuff than I am, so I'll offer just a "generalized" opinion that your particular load combination appears to yield significant pressure gains at little velocity benefit from even small incremental loads past the recommended max load--in other words you're going to be "stuck" around 2410 +/- fps. I also took at look at the mega bullet, I'm not familiar with it but it appears to be a bonded soft point type bullet, so there are the additional questions of how it will perform at the various ranges, velocities and type of target.
Click to expand...
From what the OP has said, wild boar that do not go down easy, at close range. From what I saw of the bullet, whether it is bonded or interlocked, it should more than get the job done even at lower velocities.

Personally I would have gone with a Swift A-frame, Barnes TSX, or perhaps Lehigh controlled chaos. But I'm not sure what they have easy availability to over across the big pond.

308 lehigh at the 9:54 mark. turkey leg, rack of ribs, denim before it even gets to the block.
https://www.youtube.com/watch?v=JrEmQNe-TrA

Actually just bought 100 of the .308 152g controlled chaos for my 30-06. Hoping to work up some loads in the next couple weeks.
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the odds of the animal noticing the difference is small
N550 might gain about 5% in energy at about 47 grains

Very well said. I'll stop at 41.5.
Next time I'll try to get a nice can of N-550, just for the pleasure of it

"stuck" around 2410 +/- fps.
there are the additional questions of how it will perform at the various ranges, velocities and type of target.

Stuck in 2400 fps may be just fine.
I used the Lapua Mega before, 185 grain .308 Win. commercial Lapua ammo and it performed very well at about 2400 fps- Lapua Mega are known as "poor man" Nosler Partitions.
I was given a box of Mega 200 grainers and my natural tendencies took me to make something out of them with the intention of improving the performance of the commercial 185's, if possible.
"varius ranges" means average of 45 yards in the local forest, so it should be fine.

From what I saw of the bullet, whether it is bonded or interlocked, it should more than get the job done even at lower velocities.

Yes, if you direct the bullet at the ideal place just about any kind of bullet gets the job done, which is not always the case at full speed, full adrenaline boar in the thick forest. But this is the beauty of hunting and reloading.

Thank you gentleman for your very needed advice and observations
 
I suspect that's due to the shape's normal seating depth difference I found and outlined below.

CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.


Saguaro 66,

Another issue: I looked more closely at the VV data and see you took your load data from a 200-grain Speer Soft Point seated to 71.0 mm COL (2.795)". When you look at that bullet and the 200-grain Mega in the 30-06 data, you find they are seating the Mega to a 4.5 mm (0.177") shorter COL, but the Mega bullet is only 1.45 mm (0.057") shorter than the Speer. That means they are seating the Mega deeper into the case than the Speer. That makes it take up more space in the case, which raises pressure. QuickLOAD thinks it will be about 11% higher pressure using that seating difference, so the Speer data is not valid. This brings my estimated N550 load down to 45 grains to match the pressure of the N140 load, but the bullet energy advantage actually goes up to about +8.6% at that deeper seating.

That is getting close to making a difference. The general rule of thumb is it takes about 10% energy difference to be noticeable. If your throat is long enough, you may not have to seat the Mega quite so deeply. If you are able to seat it to 69.5 mm (2.736") COL and it still chambers with about 1 mm (0.039") or more of bullet travel to touch the throat (bullet jump) in your gun, then you can use about 46.7 grains of N550 to match the N140 Speer bullet maximum load pressure and then the muzzle energy difference becomes nearly 11% higher and you start to have something that will have added effect. Not a lot, but some.
 
CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

Unclenick, I don't know if I fully understand your illustrative explanation but nevertheless, I'll do my best!

At the moment I only got VV N-140. Due to travel restrictions I may not have N540 or N550 for long time. So I can only work with the N140

The rifle is a Tikka CTR .308, 11 twist, and 20 inch barrel
This rifle has quite a large leape or chamber freebore and mag. (I made some Scenars in the past, COAL 2.888 or 73.3mm and they worked perfectly)

So far:
Lapua Mega 200 gr S.P. Lapua brass used once, RSW primers.
Flat primers but no signs of o.p. Very easy (Tikka notorious) fired brass extraction.

-----Max load VV data: 41.2 grains N140
712 m/s 2235 fps.
C.O.L. 71,0 mm / 2.795 inch
WITH 610 mm (24”), 1 in 12” twist-----

44 grains N140: 740 m/s 2427 fps COL 69.3mm
43 grains N140: 730 m/s 2395 fps. COL 69.4mm 2.734 inch
42 grains N140: 695 m/s 2280 fps. COL 69.4mm 2.734 inch

Primers look the same withe those 3 loads, flat but not too flat .

Is it safe, at least during winter, to stay with 43 grains if there are no signs of O.P.?
 
As a reference I measured velocity of commercial ammo Lapua Mega 185 grains.
With same rifle and temperature: 726 m/s. 2381 f.p.s.

Primer looks bit rounded and definitely less flat than previous hand loads with 200 grainers
So less pressure.

I managed to make a bad picture! An example of handload with 200 grainers on the right. On the left: a fired Lapua Mega 185 commercial ammo.

Thank you!
 

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Your primers both look OK to me. It always has to be born in mind that pressure signs on a primer only tell you how that primer is handling things. Some have thicker or harder cups than others.

That said, you already noted you have a long throat, which does reduce pressure. The other question is, how big do your cases get in your chamber? That is also a peak pressure determinant.

The way you measure case capacity is to take a fired case with the spent primer still in place. The case and mouth must not be dented. Measure the length. Weigh the case and spent primer. Fill the case with room temperature water, tapping the case as it fills so any air bubbles are dislodged and float to the top. Stop when the water is level with the mouth of the case (no meniscus either positive or negative). Wipe any spilled water off the outside of the case and then weigh it again.

Subtract the first weight taken from the second weight taken and let me know the difference between the two weights and the length of the case. I can plug these into both QuickLOAD and Gordon's Reloading Tool and see what results I get there and we should come closer with the computer estimate. Neither program has a direct way to allow for the long throat, but an approximation can be made by adding a small amount to the case water capacity in the program. When you get your chronograph battery, this estimate can be calibrated to your gun and then made to come pretty close.
 
Unclenick, as always, thank you for your sharp reloading advices

Unfortunately at the moment I have only the classic Lee scale and, AFAIK, unable to perform the fascinating operation you mention above with rich detail, that even an uneducated eurohillbilly like me can understand. I guess I have to get myself a precision scale.

I have been hunting with the Tikka CTR .308, 11 twist, and 20 inch barrel

Lapua Mega 200 grains, 43 grains N140: 730 m/s 2395 fps. COL 69.4mm 2.734 inch

No signs of o.p.

Very good results with boars, dropped after no more than 15 yards. However, to be absolutely honest, I'd have archived very similar results with almost any bullet/cartridge combination because, boars were medium size and I was lucky, bullet placement was ideal.


So far:
Lapua Mega 200 gr S.P. Lapua brass used once, RSW primers.
Flat primers but no signs of o.p. Very easy (Tikka notorious) fired brass extraction.

CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

-----Max load VV data: 41.2 grains N140. 712 m/s 2235 fps.

C.O.L. 71,0 mm / 2.795 inch
WITH 610 mm (24”), 1 in 12” twist-----

44 grains N140: 740 m/s 2427 fps COL 69.3mm
43 grains N140: 730 m/s 2395 fps. COL 69.4mm 2.734 inch
42 grains N140: 695 m/s 2280 fps. COL 69.4mm 2.734 inch

Thank you all for your comments!
 
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So far so good ...
The above bullet, powder, velocity has proved great with not-so-good bullet placement in decent size boars. Boars dropped just a few meters after being shot, so no difficult tracking was needed

It seems to me that this combination is significantly more effective with boars in less than 50 meters that using lighter bullets, specially when bullet placement is not ideal. I'll stick to it when I know shots may be under 75 meters
 
At those ranges, you also have some initial yaw, so the bullets may turn sideways in the animal, doing more damage than hollow point expansion alone would do. Glad it is working for you.
 
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