OK, here is the deal.

I have a 7WSM with a 26 Lilja Barrel with 1 in 9 twist.

I normally load long range 180 Berger VLDs in it.

However, my several years old Sierra reloading manual shows a non maximum "ACCURACY LOAD" as follows:

Winchester case
WLRM Primer
100 grain #1895 Sierra .284 HP
58.9 grains H4895
Vel from 24" Winchester Barrel 3500 fps.

COAL 2.745"

The justification is that my .260 varmint round with MV of around 3270 runs out of gas at about 700 yards. This thing would give me considerably more oomph at ranges exceeding 700 on prairie dogs. I have all the components, but since you all are experts in this kind of thing, I was hoping for some advice as to whether to proceed.

I don't normally run my rounds or guns this hard. Max recommended load is 60.9 grains giving 3600, but that is probably very conservative based on manual reloading standards prevalent today.

Any thoughts?. This is not a trivial question in my view. I have 70 or so unloaded carts ready to go.

I don't like the heavies for varmint shooting because of ricochet issues.

My 1st question would be; will your 1-9 twist barrel shoot the lighter bullet at these velocities without coming apart say 350-500 yards down range? As far as the max loads, my best advice would be to work up to it, preferably in warm weather and look for the pressure signs.

Regarding MAX loads, I have a dilemma with both of my 204's. They both really like the MAX load of RE-15 (28.0 grains). Additionally, it meets my criteria of repeatability and repeating with +/- 0.1 grains to allow for powder weighing consistencies (I use a balance beam scale). I've tried Benchmark, 10x, H4895, Varget but these two love RE-15, approx .2 x .2 " @ 200 yards. Nothing else is close and I've tried the full scale (MIN-to-MAX) of recommended charges. In the end, I would say shoot what the rifle likes within safety standards of course.

My 6mm Remington, which I'm fooling with currently, likes the middle of the scale for all powders tested thus far.

I see based on your pictures that you use SMK bullets. Do you use them on varmints and if so, how good/bad do they work? I'm asking because ultimately I want a 22 cal varmint rifle and I have quite a few 77 & 80 grain SMK bullets and I need a minimum of a 8-twist to shoot them.

HTH,

I basically use three varmint calibers.

.260 with 100 SVHP, .204 with 32 grain Hornady Red Tip, and .17 HMR Hornady Varmint load. I don't use bigger bullets for varmint shooting. Shoot organizers don't allow them because of ricochet concerns.

Don't know about rifling question. .260 has 1/9 twist as well and seems to do fine with 100 SVHP. Thats part of my question.

The .260 seems to be enough gun out to about 700 or so in my experience. I'm thinking about 7 WSM with sister bullet as described above for longer ranges. Don't know yet how it will do. Raises expected MV from about 3300 to 3500 or so with same weight of bullet.

We shall see. .260 is very accurate for medium to short ranges with 6 groove 25" Lilja barrel.

Don't know if this is much help but;

- With the 223, I've seen many competitors shoot 52-grain bullets in 7 twist barrels out to 200 yards and the accuracy was phenomenal. I've never tried it but they all said "just don't drive them to hard". Also, in the target-shooting world, accuracy is key while velocity is second, somewhat, unless its long range.

- I have seen bullets come apart 400 yds (or so) down range on a 1000-yard course. At 1000 yards the scorekeeper typically sets up directly behind the shooter, blurs the scope slightly (actually focused around 500 yds or so) watching the trace down range. When one comes apart there is slight/brief puff of smoke. Accordingly, the target doesn't go down. Unfortunately, I don't know the recipe the shooter was using.

The following website may be of benefit as it deals exclusively with long range shooting.

http://www.usrifleteams.com/

You'll have to create a user name to look but its free.

HTH,

My .243 WSSM shoots the 62 grain Varmint Grenade at a tad over 3,600 fps through a 1:8" barrel with no problems of disintegration. Same with the 1:9" .223 Remington barrel and the 36 and 50 grain V.G., and Nosler 35 grain Lead Free. Of course these bullets have a sintered powdered metal aggregate core which is harder and less plastic than lead cores, so they may be able to handle rotational and velocity forces better. I have tried to disassemble these bullets, and found the cores to be extremely hard and well bonded to the jacket. Unlike a lead core bullet they can't easily be dug out or scratched with an engraver. I believe they act more as a solid until impact.

I think the problem of rotational or centrifugal forces from a faster twist barrel is greatly exaggerated. I have had bullets vapor trail and puff out before 200 yards in 1:14" and 1:12" twist .22-250 and .220 Swift barrels because of bullet construction, thin frangible jackets and soft lead cores expressly made to disintegrate. Meanwhile, the Sierra 55 grain semi-pointed merrily went all the way to squirrel detonation.

Most competition bullets are made with thinner more consistent jacket walls. My stash of Sierra .30 caliber match jackets walls measure .0125" thick, nothing like the heavier jackets of some non-match jackets let alone the Barnes, Nosler or Hornady expanding copper bullets. Draw these jackets to .284" cut them shorter and process them through three swagging dies and it's a wonder they work at all.

Another factor may be the barrel itself. Rough sharp edges on lands and grooves will engrave stress points on a jacket, acting somewhat like a folded crease we put on paper to tear it cleanly. Add the friction heating of two dissimilar metals and stress of firing - poof! To avoid the barrel problem, I recommend a 5R or polygonal barrel for fast twist applications, or a cut rifled lapped barrel. The rounded corners of the 5R or polygonal barrel are easier on bullets. If a barrel is copper fouling heavily, it's tearing jacket metal off the bullet, acting like a cylindrical file. My 1:9" Pac-Nor polygonal is extremely accurate with the 50 grain .224 V.G. in .223 Remington and, like the lapped cut rifled barrel, cleans up with a few wet patches. Accuracy with the faster twists has greatly improved, eliminating unexplained fliers.

That's my opinion - which does not necessarily mean anything.

You might consider a different caliber as well.

Two come to mind...

22/6mm AI - mine, with a towards the top end load, pushes 75 gr AMax's at 3750. Easily hits 3900, but do not push it that hard. Throat wear will come into play sooner. (I also coat the bullets with WS2/Danzac)

Might consider a 6.5 caliber of something.....maybe a WSM? Run 129's rather hard I would imagine. The 142 SMK's run 3100 out of my 6.5x55 AI....again, WS2 coated bullets.

You are at somewhat of a quandry - enough knockdown power at extended distance AND ability to fly well. Is there a 25 caliber bullet that is long, sleek, and high BC like the 6.5's around? Something in the 100 gr area might be fun.

Here are the current 7mm bullets that I have including two cararucios. All are excellent performers but I have standardized on the 180 Berger VLD at least for now for gong shooting, etc. I bought a couple hundred 100 SVHP to try. Cartarucios in middle, Berger on right.

This large variety of max performance match rounds is what got me interested in the 7 to begin with.



175 .30 Sierra on Right for comparison. I bought 700 180 VLDs back when price and availability were reasonable. Very glad I did!

Critter I'll 2nd your choice on a 7mm/180 berger. I shoot them out off my custom 7 STW. It wears a 30" 1-8 Hart barrel. I'm launch them out at 3000 fps and my son has hit metal gongs at 1450 yards and handles the rifle very well. Caution this cartridge is a throat burner!
Later
Ray P