Laupa vs Sierra

[Alaskapopo]

I have been using 77 grain Sierra Match Kings with good results in my precision rifle set up.

My groups are averaging .65 for 5 shot groups at 100 yards with my best loads. A friend of mine stated I could do even better with Laupa 77 grain Senclare bullets. I ordered some. What has been your guys experience. I have also tried 75 grain Hornady Boattail Match Hollowpoints and they have not been as accurate for me.

Pat

[Graham Smith]

The Lapua Scenar bullets all have an excellent BC which allows them to perform well at distance, but at 100 yds you are unlikely to see any difference between the two. At that distance, the exact load is much more important, and that means the powder, the charge, and the OAL.

Also, you don't say what the barrel length and twist are. If you are shooting single shot with a sled rather than a magazine, and have a twist that can handle it, then have a look at the Berger VLD bullets.

[Alaskapopo]

The Lapua Scenar bullets all have an excellent BC which allows them to perform well at distance, but at 100 yds you are unlikely to see any difference between the two. At that distance, the exact load is much more important, and that means the powder, the charge, and the OAL.

Also, you don't say what the barrel length and twist are. If you are shooting single shot with a sled rather than a magazine, and have a twist that can handle it, then have a look at the Berger VLD bullets.

The Larue is a 1/8 20 inch barrel. I want bullets that work in the magazine.

Pat

[Graham Smith]

The Larue is a 1/8 20 inch barrel. I want bullets that work in the magazine

For mag length, then the VLDs may be a bit long. The 1:8 is enough for the 77's, but if you are only shooting out to 100yds, then you don't really need anything that heavy, in fact, you might even want to consider a light bullet. Have a look at this

[Alaskapopo]

The Larue is a 1/8 20 inch barrel. I want bullets that work in the magazine

For mag length, then the VLDs may be a bit long. The 1:8 is enough for the 77's, but if you are only shooting out to 100yds, then you don't really need anything that heavy, in fact, you might even want to consider a light bullet. Have a look at this

I do most of my shooting at 100 yards. But once a month or so I drive to Kenai and shoot out to 600. So I do want the long range performance. Thanks for the help.

pat

[springy]

Have a look at this

Many thanks for posting this link on loading. For me, the 308 section is super informative.

[Graham Smith]

But once a month or so I drive to Kenai and shoot out to 600. So I do want the long range performance.

There's a certain amount of mixed opinion about what's best for a middle distance like 600yds. One camp is firmly on the side of heavier bullets with a high BC that can resist wind while the other side favors lighter bullets that can be fired at really high velocities. When I had a go at distance with my 18", I was shooting 69gr SMKs at 2900fps. With a 20" barrel, you could probably squeeze 3000fps out of them. Still and all, at 600yds assuming a 2700fps muzzle velocity, the 77gr Sierras will give you a better velocity curve than the 69's and the Scenars will be better still and ultimately the higher velocity bullets will be less effected by external factors.

Of course, this is all theory and there's more than one published set of BCs for these bullets. Ultimately, it's about what your gun likes. If you have access to the 600yd range for testing, then it's simple, make up several batches of bullets with different loads and OALs and shoot a series of 5 shot groups. Keep doing that till you find the "sweet spot" for your rifle.

[twodownzero]

I'd be willing to bet that Sierras shoot better from a magazine than the Lapua bullet.

If you were loading .30 cal, I'd sell you a bunch for my price and let you decide for yourself.

I've got 1,000 155 grain Scenars that I'm working on now, and my comparisons at 200 yards suggest that the Sierras shoot better out of my rifle.

Closer to the lands, it's hard to tell, but from the magazine...the Sierra ogive seems to tolerate the jump better.

It's at least .060" to the lands from the magazine in my bolt rifle. Obviously yours may be different and that will change your experience.

Edited November 30, 2010 by twodownzero

[pjb45]

I used 69 SMK out of Sabre Defence 1 in 18 barrel around 2880 fps. I get those type of groups at 100 yards. (VV133 powder).

I have an IOR and the hash marks are dead on at 200, 300 and 400 yards. Did not really go much farther than that for accuracy.

At 600 yards with the 8 power scope I was in the ball park of a 8 inch plate, but it was the shooter not the rifle or load that was the problem.

[Hannu]

Try 70gr VLD, it works fine from a good magazine allowing uyou to load at ~2.30" (like H&K 416 mag).

I have not been able to find better (magazine fed) ballistics out to 600 yd for .223, than 70gr VLD loaded to 2950 fps. That is from Krieger 20" barrel, 9" twist with .223 Rem chamber, Remington brass, Varget and Federal 205GM loaded .01" from the lands. Average group @300 is 1.9"

[Alaskapopo]

Try 70gr VLD, it works fine from a good magazine allowing uyou to load at ~2.30" (like H&K 416 mag).

I have not been able to find better (magazine fed) ballistics out to 600 yd for .223, than 70gr VLD loaded to 2950 fps. That is from Krieger 20" barrel, 9" twist with .223 Rem chamber, Remington brass, Varget and Federal 205GM loaded .01" from the lands. Average group @300 is 1.9"

How did you get them to go 2950. The fastest I have pushed the 77 grain Sierra's while maintaining accuracy is 2600 fps. I know all barrels are different. The 2600 fps is the average in both my 20 inch Larue Stainless 1/8 barrel and in my 18 inch Stainless Noveske 1/7 polygonal rifle barrel. My load is 24.1 grain N140 with Fed Match primers behind the 77 grain SMK's with Lake City brass.

Pat

[Hannu]

How did you get them to go 2950. The fastest I have pushed the 77 grain Sierra's while maintaining accuracy is 2600 fps. I know all barrels are different. The 2600 fps is the average in both my 20 inch Larue Stainless 1/8 barrel and in my 18 inch Stainless Noveske 1/7 polygonal rifle barrel. My load is 24.1 grain N140 with Fed Match primers behind the 77 grain SMK's with Lake City brass.

Pat

My favourite load : Brass Remington (sorted out), primer Fed 205gm, powder Varget 24.2 gr, Berger VLD 70gr, col 2.290" and MV 2950 fps. Velocity deviation is less than 10 fps with 10 shots, pretty accurate load out to 600 yd. I can get little more velocity with some powders (748, BL-C2, 2520) but accuracy is not as good as with Varget if I am pushing it over 3000 fps.

Chamber has a lot to do with the fact how fast you can push a certain bullet, and specially what powders you can use and maintain good accuracy. Barrels are different for sure, but you may not be able to reach that velocity with Wylde or Nato chamber no matter what you do. Also, many bullets do not shoot good if jump to the lands is excessive and specially if you are pushing them fast and with high pressure. I have found this to be specially true with VLD´s, they need to be seated .01" from the lands to get the best accuracy.

You could try to change powder, N140 is sooo bulky you just can not get enough inside to reach higher velocities.

[Religious Shooter]

24.2 Varget gets 2950 FPS?

Wow! That's a fast barrel.

25.8 of Varget got me 2869 fps from a 20" DPMS with 69 Nosler.

[Alaskapopo]

The reason I am using N140 now is that it has given me the best velocities with the 77 grain SMK's. Its about 100 fps faster than Varget, Re15, N135, and H335. That is what I have tried so far.

Pat

[Hannu]

24.2 Varget gets 2950 FPS?

Wow! That's a fast barrel.

25.8 of Varget got me 2869 fps from a 20" DPMS with 69 Nosler.

Not really... I would say, just a little (25-30 fps) slower than LW50 barrels I usually use. Probably thing making difference is the chamber - any .223 Rem chambered barrel is fast when compared to Wylde or Nato. Specially when hard-to-ignite powders are being used, Rem chambering usually gives noticeably higher muzzle velocities with same pressure level and less powder.

Alaskapopo, you could try more progressive powders like AA 2520, BL-C(2), Win 748 or H414/Win 760. All of those give me 100-120 fps more than N140 with 69-70gr bullets without case capacity problems. Even H335 gives little more velocity than N140, but it can be a matter of chamber.

[Religious Shooter]

Not really... I would say, just a little (25-30 fps) slower than LW50 barrels I usually use. Probably thing making difference is the chamber - any .223 Rem chambered barrel is fast when compared to Wylde or Nato.

Hmmm... I would disagree. You got two exceptionally fast barrels.

24.2 grains of Varget generating 2950 FPS with a 70 grain out of a 20" barrel (AR? or bolt) is exceptional.

If you do a google search nobody is getting 2950 fps with a 68/69/70 grain bullet with a charge of 24.2 grains of Varget.

[Hannu]

That load was earlier rifle test load for UP rifles. Velocities V3m from my memory : 18" 2890 fps, 20" 2970 fps and 24" 3080 fps. I tested around 50 barrels with that load. We were later forced to change the test load, one reason being 70gr VLD bad availability at that time. So I can not think of it as exceptional

From internet, I can not find any load that would have been shot with .223 Rem chamber, 70gr VLD and Varget. Please provide a link if you were able to find such data ?

You should also note, that 70gr VLD gives little higher MV´s than 69gr MK/CC with the same powder charge (at least) in .223 Rem chamber. You can not make straight data comparison with 69gr MK/CC or 70gr VLD, difference is something 20-30 fps.

Many bolt guns for sale in US (for example Sako, Tikka) are also reamed very loose from freebore, like most US made AR-15 rifles.

[Religious Shooter]

What is a "UP" rifle and "V3M"?

You said you changed your loading from 70 gr VLD. What did you change it to and what velocities did you get?

You can compare the general velocities between a 68/69 grain bullet to a 70 grain bullet. Like you said, the difference is probably going to be in the 20-30 fps range.

From my data: 25.6 grains Varget w/69 Nosler => 2869 fps. 20" DPMS barrel. If I used a straighline correlation I would get a predicted 2712 fps if I used a charge of 24.2 grains. That's a 238 fps difference from 2950.

If you take a look at the loads here for 69's and Varget:

http://www.reloadersnest.com/query_pw.asp?CaliberID=18&Powder=Hodgdon+Varget&offset=20

20" AR, 25.3 Varget 2750 fps

27.5" barrel, 25 Varget 2918 fps (+7.5" of barrel)

27.5" barrel, 25.5 Varget 2983 fps (+7.5" of barrel)

Why are people using Wylde chambers or NATO chambers if there is such a huge velocity hit?

[twodownzero]

Why are people using Wylde chambers or NATO chambers if there is such a huge velocity hit?

Just a guess, but probably so they can safely shoot NATO ammo. The Wylde chamber was developed for exactly that.

I am not sure if you've ever tried to load M193 bullets with surplus powder, but let me tell ya, you'll be well beyond signs of pressure in once fired brass before you hit M193 velocity.

[Religious Shooter]

According to Hannu, he can drive 70 grains VLD to 2950 fps with a Rem chamber using only 24.2 grains of Varget.

You can't approach that efficiency with a NATO or Wylde chamber.

With a 20" with a NATO or Wylde chamber you will need about 26+ grains (or maybe high 25's) of Varget to get to that speed with 68/69/70's.

[Corey]

Berger 73gr BT is another potential option to look at. I'm planning on developing some loads with these this winter

[Hannu]

RG, "UP" = Uronen Precision and "V3M" is velocity 3 meters from muzzle. We changed test ammo to factory made S&B Match w/ 52gr Sierra Matchking. MV depends little on ammo lot, but is usually 3300 - 3350 fps (published 3400 fps).

I do not know about surplus powders, but few years ago I loaded my long range match ammo (2 different loads for a match) with 55gr Nosler BT + H335 and it clocked about 3350 fps (1021 m/s) from 18" barrel. I have never measured M193 from 20" 5.56 Nato chambered rifle to be as fast.

Please correct if I remember wrong, but I think Wylde chamber was designed different thing in mind than ability to shoot 5.56 ammo. I remember, it was designed for high power so you could load 80gr MK to 2.50" for long range slowfire.

It is generally way better accuracy wise than 5.56 Nato with mag length ammo, but freebore is way too long for magazine fed ammo and keeps pressure down.

Why so many rifles use loose chambers ? I can think several reasons:

-US rifle manufacturers want to ream chambers loose because of liability and true .223 Rem chambered rifles (both bolt action and semi-auto) are as rare as chicken´s teeth. In Europe, liability is not an issue because all rifles must be CIP proofed + nobody knows what is high power shooting.

-Like twodownzero said, people want to use 5.56 Nato ammo and loose freebore keeps pressure down

-Shooters do not know what is the difference and how it effects on their shooting

-"It has always been done this way", AR-15 rifles have used 5.56 Nato chambers since 1960´s so why change ?

What is long freebore doing then ? What we should think about, is what happens when primer goes off and we have quite hard-to-ignite powder like Varget.

If we have bullet close to rifling, say for example .01" from rifling (=short freebore), we will have powder burning before bullet starts to move noticeably - which means that burning space does not grow much before powder is burning. If bullet jumps, say .10" (=long freebore), burning space grows 10x more before powder starts to burn, which creates very different situation compared to first example.

Of course, the worst thing is when bullet is completely out of the case before powder starts burning effectively.

With long freebore, you can put more powder and get more velocity, but it is not that simple. With .223, 68-70gr bullet and Varget, you run out of case capacity before you can meet muzzle velocity obtained with short freebore. If you just add more powder than what is reasonable, you are crushing powder grains and creating erratic high pressure spikes. Remember, when you crush or cut powder grain it burns very differently (more degressively) than it was designed to.

Of course, you can meet and exceed short freebore velocities if you just increase col (=more powder space) with long freebore. Lets say, earlier examples had col 2.25" and you load to 2.35" - lots of powder space for Varget and it probably works fine, you can probably also get bullet bearing surface completely out from powder space. But with AR-15 you can do this only by feeding every round straight to the chamber. No magazine will take such a long round.

Many high power shooters load long bullets with very long col for slow fire - they get more powder space and perhaps bullet bearing surface out from powder space - better practical long range accuracy, but do not try to feed that ammo from magazine.

I have found that H&K 416 mags feed 2.29" ammo reliable but that is longest one I have seen so far. Yes there are some 7-10rd mags with very long possible col, but are they suitable for 3-gun / rifle IPSC is another thing...

Plese note, that pressure needed to push the bullet into the rifling is usually many times bigger than pressure needed to push the bullet out of the case.

Sorry, I just do not know how to explain it more understandable

And no, QL can not calculate these effects.

You should also note, CIP maximum pressure for .223 Rem is practically the same (62.300 PSI) as SAAMI maximum for 5.56 Nato, 62.000 PSI. M193 ammo I have tested does not exceed CIP pressure level from .223 Rem chamber, but clearly exceeds SAAMI maximum pressure for .223 Rem.

[Graham Smith]

Of course, you can meet and exceed short freebore velocities if you just increase col (=more powder space) with long freebore. Lets say, earlier examples had col 2.25" and you load to 2.35" - lots of powder space for Varget and it probably works fine, you can probably also get bullet bearing surface completely out from powder space. But with AR-15 you can do this only by feeding every round straight to the chamber. No magazine will take such a long round.

Many high power shooters load long bullets with very long col for slow fire - they get more powder space and perhaps bullet bearing surface out from powder space - better practical long range accuracy, but do not try to feed that ammo from magazine.

It's also worth noting that in many of the loads used for the long heavy bullets (like the Berger VLD), the powder volume is at or over the manufactures max and are 105 - 110% volume - that is, right up to the brim and overflowing. These are exclusively hand loads with the case being tapped to settle the powder as it is slowly added and then tamped down a bit before the bullet is seated. These guys claim that if you do it right, a compressed load burns better than a load that does not fill the case. That's a bit too much voodoo for my brain to cope with.

[01 Z06]

Every barrel is different. Try the Lapuas but just because the Lapuas shoot great in your friends rifle it does not mean that i will on your too.