Lapua Scenar VS SMK

[planalpha]

Hi experts-
I'm pretty new so was wondering if there was much difference in performance in the 308 Win Lapua Scenar 155 HPBT and the SMK 175 in a factory 700 with a 26" barrel? I just shoot paper/steel and mainly will be shooting under 600 yards but occasionally will have the opportunity to shoot out to 1000 yards. I had worked up my first load (Lapua 155 Scenars, 44.7 grains of RL15, 2.80 OAL, Winchester brass, Wolf primers) and they shoot wonderfully, but the price and availability of the Scenars vs the SMK 175s makes me want to switch. There is also much more data on the SMKs.
Before I go through the effort of working up a new load I thought I'd ask you all if one was widely accepted to be superior to the other in the context of my use/rifle.

Thanks in advance!

 

[USMCj]

Re: Lapua Scenar VS SMK

155 Scenars are my choice over 175SMK's. You can push them faster, and they have the same or better BC than the 175's. You load is very mild though, try working up to 46.2gr of RL15, Ive gone as high as 46.9 without pressure signs in Lapua brass.

 

[desertHK]

Re: Lapua Scenar VS SMK

Understand your issue! I also have the same feeling as well. I have two loads. One for the 155 scenars and one for 175 SMK. For everyday practice and drill, I use the 175 SMK. If I need the extra edge on precision, then I go to the 155 scenars. Having said that, the 175 SMK is very accurate. Just my opinion.

 

[Mk4]

Re: Lapua Scenar VS SMK

I've been using 175 SMKs for several years but have been using (more recently) the 155 Scenars and 178 AMAX's. I think that I would dump all of them if Hornady ever made their new high BC 178 BTHP available to reloaders.

Currently, its only available as loaded ammo.

 

[planalpha]

Re: Lapua Scenar VS SMK

USMCj-
I see others using higher loads but I can't get anywhere near that. I started at 44.1 and immediately got flat primers. I went up to 45.7 and the bolt started getting sticky. Do you think I'm crimping too tight?

Thanks for the info you guys!

 

[LR-WSM]

Re: Lapua Scenar VS SMK

Why are you crimping .308's that are run in a bolt action rifle?
Crimping rounds is done for semi auto's to prevent bullet movement in / or / out under recoil while in a magazine. It will help uniform start pressure but if the crimp is too tight it is akin to starting the bullet in the lands. An inside champfer along with an ouside debur is all you should need with a properly set up full length or neck die. If you are loading to mag length, back your seating die off 1/2 turn and readjust the stem for desired seating depth. You should realize a little extra room on the load under normal neck tention.

My .02

 

[planalpha]

Re: Lapua Scenar VS SMK

LR-WSM-
I have been crimping them because I wanted consistent bullet pull weight since I've noticed the bullets seat easy or hard depending on the brass (read about doing that in "Modern Reloading"). All of my brass is Winchester, but the brass I bought seats easy even after a neck sizing. But the Winchester range brass I full length sized (and tried neck sizing a few too) takes quite a bit more force to seat. I am limited to the mag size for seating depth and probably nowhere neat the lands. I do like the idea of crimping just in case cycling the bolt could possible push the bullet into the case.
Am I off on any of these assumptions?

Many thanks!

 

[Tangodown911]

Re: Lapua Scenar VS SMK

Crimp....bolt gun....very bad.

Try no crimp and report back. Also run them through a chrono, that is, crimp vs. no crimp.

 

[Mk4]

Re: Lapua Scenar VS SMK

If you are talking about a roll crimp...not needed...period.

A Lee Factory Crimp die is another matter.

 

[LR-WSM]

Re: Lapua Scenar VS SMK

planalpha,

Bullets that are easy to seat are normally equated to new or anealed (softer) brass. Bullets that are harder to seat are associated with older work hardend brass. The harder the brass, the less springback you will have when sizing making it harder to get a uniform neck tension.
Feeding your rounds from an internal or DBM won't or shouldn't effect your COAL if everything is in proper working order. You may ding a couple up effecting your rounds consentricty but other than that you should be GTG.

Crimping isn't normally done these days where precision rifles are employed. It's not a bad thing, but it may be more of an obsticle in achieving your goals.

Good luck to you

 

[planalpha]

Re: Lapua Scenar VS SMK

Ahhh. Thanks for the great information everyone! BTW, I should have specified, I'm using a Lee Factory Crimp die.
Great to know why the bullets were seating harder in the old brass, that makes perfect sense about the anealing.
So nix the crimp. It looks like it's back to the drawing board as far as my load goes.
Thanks again, experts!

 

[Mk4]

Re: Lapua Scenar VS SMK

The Lee Factory Crimp die is a great asset to the final assembly of any rifle round. Properly used, it can make a difference. All my rifle rounds are loaded primarily for accuracy. I've seen some difference in loads with and without the Lee Factory Crimp. Anyways, I don't refer to it as a crimp die in the traditional sense. More like a tool to make the case mouth perfectly round.

Works for me in all my rifle loads.

 

[planalpha]

Re: Lapua Scenar VS SMK

Mk4-
How much "crimp" do you add? Do you follow the die's instructions or do you add/reduce any based on results?

 

[tiNdvenTFHwMdqKW]

Re: Lapua Scenar VS SMK

I believe the Lee factory crimp instructions say something about crimping as much as you need to. I don't think it is written in stone.

I may be wrong though - I don't have the instructions near by.

You might also want to crimp a bolt action round if you are out hunting with it in case you drop the gun or have any sort of jarring that could affect the rounds.

 

[Mk4]

Re: Lapua Scenar VS SMK

Honestly, I do it by feel. Not a precision way to set a die but that's how I set it. You can over-crimp with it, so don't over-do it. When I feel a modest amount of pressure when going into the die and can see some light marks on the rim of the case mouth, that's pretty close...for me anyway (YMMV). All you're wanting to accomplish is to put an equal amount of pressure around the case mouth in the seated round.

I told a good friend about this and he was interested enough to do some 'with' and 'without' tests and his results were noticable. You might want to do the same by shooting some with the Lee Factory crimp and some without. See what the results are. Its one more step in the reloading process but one that I do believe is well worth it. All my rifle loads are run through the Lee Factory Crimp die.

It will also help if your cases are trimmed to length.

 

[LR-WSM]

Re: Lapua Scenar VS SMK

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PBinWA</div><div class="ubbcode-body">
You might also want to crimp a bolt action round if you are out hunting with it in case you drop the gun or have any sort of jarring that could affect the rounds. </div></div>

Have you ever used a Kinetic bullet puller?

I'd be alot more worried about the rifle and optics if you have a hard enough drop to cause a seated bullet to move in the neck of a loaded round.

 

[vman]

Re: Lapua Scenar VS SMK

Why would you crimp for a bolt gun?

If your crimping because its proven accurate for someone else, that may be because the increase in pressure from the crimp just happens to put them within an accuracy node... seating depth and powder charge changes would be a better place to start

For the record, I seat my projectiles a bees dick into the case, seriously they are seating VERY FAR OUT of the case. I use a stock standard RCBS F/L die and no jokes, I struggle to get out my projectiles with a kinetic bullet puller! Like i smash that thing down 10+ times and still the projectile wont drop out.

I see no need for crimping for a bolt gun...

But thats just me

Oh, and honestly 308's dont kick hard enough to worry about the recoil knocking projectiles back into the case whilst they are in the mag

 

[vinconco]

Re: Lapua Scenar VS SMK

I'm with Mk4 to the extent that a slight crimp using a lee factory crimp die could have a beneficial effect on consistency in the absence of a better method for achieving consistent neck tension using other means such as neck turning, using a bushing neck die and annealing.

 

[Unsichtbar]

Re: Lapua Scenar VS SMK


Prefer 155 L 46.1 RL 15 2950 fps work up to of course, RL 15 will rise in preasure in hot temps! I switched to 8208xbr could not be happier, very temp stable plus not as hard on cases.
You might find the below link of interest

http://www.appliedballisticsllc.com/index_files/Lapua_Scenar.pdf

 

[learjet]

Re: Lapua Scenar VS SMK

any absolutes discussing the lee fc die are, umm..to be ignored. try your rounds both ways, u may be surprised, and not necessarily in a good way hehe... some guns/loads like the LFC, some dont care for them..just another tool in the toolbox

FYI used to be, and meebe still true; scenars can be had for less than SMKs from powder valley if u buy in bulk

 

[LR-WSM]

Re: Lapua Scenar VS SMK

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: learjet</div><div class="ubbcode-body">

FYI used to be, and meebe still true; scenars can be had for less than SMKs from powder valley if u buy in bulk </div></div>

Not any more. Thier prices on the Scenars went up from $267 per K to $296 per K about 4 months ago
155 Sierra match Palmas are $273 per K

 

[learjet]

Re: Lapua Scenar VS SMK

hey thx, stocked up awhile back, and haent checked lately

 

[Leaddog]

Re: Lapua Scenar VS SMK

Run with the 175's. Unless you are shooting Palma with 30"+ barrels and pushing the bullet over 2900 fps, you are just wasting your dollars.

 

[Unsichtbar]

Re: Lapua Scenar VS SMK

2920 Fps 22" barrel no pressure sighs 8.4 mil 1000yds at sea level or out of my 24" AI 2950 fps no problem.

 

[planalpha]

Re: Lapua Scenar VS SMK

I finally got a chance to chrono my rounds and found them to be too slow for the Scenars based on everyone's experience with them. These were all built before I posted this topic so all have been through the LFCD.
Lot 1 - 155 Scenars/44.7 RL15/2.80/New Winchester brass
2777
2766
2772
Lot 2 - 155 Scenars/44.7 RL15/2.80/Once fired Winchester brass
2777
2783
2795
Lot 3 - 155 Scenars/44.7 RL15/2.80/Old Winchester range brass (much harder to seat bullet than the other lots)
2830
2849
2855

Very interesting about the older/harder brass having a higher speed. I thought the LFCD would have leveled out all of these lots, but doesn't look like it's doing much.
Next I'll be building some without the LFCD and see how it effects the speed and if I can start adding powder without the pressure signs.

 

[LR-WSM]

Re: Lapua Scenar VS SMK

I am not going to bash people that feel they need to crimp thier rounds for consistancy...but. If you want consistancy there will be brass preperation involved. This does not involve picking up range brass (planalph) that has been lying there in the grass and dirt for months, that has been fired an unknown number of times, throwing it in the tumbler and calling it good. Buy a couple bags or boxes of new brass trim them all to the same length, sort them into like weight lots, "2 grain spread" max, prep the case mouth, prime, load, and shoot.(Keep these segregated from your other brass) No need for a crimp. The line of thought here is to remove as many variables as possible while not making the process a pain in the ass. Trying to achieve consistancy in velocity, pressure and accuracy by throwing a crimp on your mixed bag of brass ( planalph) just aint gonna happen no matter how long you try.

 

[colt933]

Re: Lapua Scenar VS SMK

My accuracy improved in a Steyr tactical when I started using the Lee factory crimp die. I had two other Steyrs that both responded well to seating .005" off the lands with no crimp, but this one likes OAL 2.800" and crimped.

155 Sierra Palma moly
47.0 Varget
WW brass
CCI 200
2850 fps