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8 twist 22” 300 Win Mag with 215 Berger Hybrids

My 300 WM is a 24" and runs the 215s at 2800 with H1000. Super accurate and the elk sure can't tell it doesn't have a long barrel .
 
I am building a new long range elk rifle and I need some advice from the wise folks on this forum. First off, I'm 100% committed to using my Thunderbeast Ultra 7 can on this build. I shoot supressed on all my rifles and just can't go back to shooting without a can.

That constraint creates some issues when you consider I want to use 215 or 230 grain hybrids. Additionally, I am trying to keep the barrel (with the can) under 30" so the complete package isn't too unwieldy in the field. That forces me into a 23" or shorter barrel. I realize this hampers the 300's capability a bit, but I am curious what I can expect going to a shorter fast twist barrel and a slightly faster powder then say h1000. Possibly 4831, etc.....I will primarily use this for elk hunting, but I will shoot over 1000 yards on steel year round.

This is what I have in mind for the build, so please tell me what you think....by the way I have all these parts. The only thing I haven't done is cut, chamber, thread and crown the barrel.

Stiller predator action
McMillan edge gamescout stock
HS precision bottle metal with 3.7" mag box. Can run 215-230s at 3.6" COL
Bartlein 8 twist .308 barrel. Light Palma contour, currently uncut
Timney trigger
4-16x42 f1 NF ATACR
20moa rail
TB Ultra 7 can

Do you think I can get to 2850ish FPS with 215 berger hybrids and still have a supressed gun that is reasonably maneuverable in the field? I am 6'4", so I am more comfortable with slightly longer rifles, but a supressed 26" barrel is just too much of a good thing in my open opinion. Therefore, an 8 twist 22" tube seems to scratch the itch, but I have no experience with this combination. What do you all think?

Regards,
Ted[I run a 300 win mag shooting 215gr hybirds with 77.5 grs of H-1000 and am getting 3018 but I have a 28inch proof barrel most of my buds run the same but less H-100 they are running 74grs of H-1000 and there speeds are around 2844 - 2870 with 24-26 barrels also we are all useing 1 in 9 twists all you can do is build it and see
 
My 300 WM has a 25" barrel and a 1:9 twist and my best loads do 2840 fps with both RL26 and H1000. I have pushed the velocities a little higher in testing but the SD starting opening up so I opted a little slower for my go to loads. Nothings says your max loads will give either best group or best consistency in SDs which is something to keep in mind. I.e. you may not need to be singularly concerned with your fps objective vs packability in selecting your build as the reality of selecting a load might dictate velocity a little up or down anyway. (Granted longer is going to be faster)

I have a Thunderbeast Ultra 7 in 30 cal which is relegated to other platforms. My experience with it on my 308 GAP 10 was positive in terms of consistency and accuracy. I also saw slightly increased signs of pressure and a modest velocity boost when it was mounted. You may gain back a bit of what you lose with a shorter barrel with the suppressor, though not anywhere near what 7" of barrel would have gotten you. If I recall right, I saw 30-40 fps on the 308 which had a 20" barrel.

For some more objective input on barrel length vs velocity you might want to check out this article:
https://rifleshooter.com/2013/12/30...rrel-length-change-velocity-a-16-300-win-mag/
 
Maybe you should consider a 30-06 in that same set-up. You have to really dial back the load from a barrel that short in a magnum. The fireball at the end of the barrel is going to be huge at times when you are not running your can! A load that worked great in my 26 in barrel had too much flash in a 22 inch barrel. Daytime might be fine but at Nautical Twilight it will be blinding. In fact I was shooting over the roof of my car at the time. The 26 inch barrel golden the 22 inch left scorch marks in the paint of the car.

I can not believe I am about to say what I am about to say! "Sigh" A 30-06 AI with a 1:8 twist 23 inches long would be about perfect. Not that I would ever do a 30-06 AI. I would just stick to 30-06. I ran into a guy at an F-Class venue a few years back that was shooting a 32 inch or 36 inch 1:8 barrel 30-06 AI he was shooting stuff you would normally expect someone to use a 30 Cal Magnum for. I think he was using a Polygonal Barrel.

I think you would be wasting powder with a 300 WM in a barrel that short. Does it matter nope. It seems odd though to waste powder and the performance of the cartridge by limiting it to a 23 inch barrel when one step backwards would be a better fit!

No animal is going to be any less dead from a 30-06. Truthfully even when I have taken shots of opportunity with way to little rifle the animal was never offended that I had taken it's life with a wimpy 243 Win or the rainbow trajectory 45-70. Thankfully I have never had any animal dead or alive talk to me!

I would let math not whims chose my cartridge. You can run 210's in an 30-06 I was shooting right next to a guy doing it at 1000m in F-Class. I doubt you will see the 2950-2850 fps with 300 Win Mag 208gr.-220gr. bullets with a 23 inch barrel. So why even put the powder in the case" It is like putting a LS-V8 in a Geo Metro or Toyota Starlet huge waste of man power, and materials because it would not hook up far better to put a more powerful 4 cylinder or V6 in it! Same thing applies here.

All of my opinion above being said the US Army's refit to M24E1 is a 24" hammer forged 5R 1:9 barrel running 300 Win Mag with a 220gr. projectile getting a claimed 2850fps. The Ammo though is grossly exceeding Saami and CPS standards. I think it goes with out saying you would have to run a can on that to keep the flash down! Not that anyone on this sight would ever run a Cold Hammer Forged barrel. LOL

That guy at the F-Class meet was not running Saami pressures I can assure you he was doing to that 30-06 AI what the Army and Navy have done to the 300 Win Mag.
 
Well, there's a ton of guys that claim some very impressive fps from their 300 WM's but my experience is that with a 200 gr. bullet and a 26" barrel, I get around 2900 fps on the upper end. Probably slower with an accuracy load. It's a pretty long case that does better with slow powders and long barrels. I wonder if you might get similar performance and a longer barrel with a 300 short mag. If my memory serves me, it's a shorter action, shorter/fatter case that likes faster powders. You just may significantly increase performance over a stubby Win Mag.
 
There are very good cans out there that slide partially or largely over the barrel to reduce the total length. If it were me I think I'd go for at least a 24-26" barrel and a shorter can or one that slides more over the barrel rather than cutting down to 22".

With the WM you're going to loose 50-75fps for every inch of barrel so you should be able to calculate it pretty close by comparing your proposed 22" barrel to similar loads running in longer barrels.

I believe you're a bit high on the fps loss per inch. It's somewhat closer to 25-30fps per inch. It's probably going to drop off faster than that once he gets under 24" though.

You will still get your highest velocities with the slower powders when pushing heavy bullets even in shorter barrels. R26, VVn570, IMR8133 are known to give higher velocities than H1000. Temp stability just won't be as good.
 
I believe you're a bit high on the fps loss per inch. It's somewhat closer to 25-30fps per inch. It's probably going to drop off faster than that once he gets under 24" though.

You will still get your highest velocities with the slower powders when pushing heavy bullets even in shorter barrels. R26, VVn570, IMR8133 are known to give higher velocities than H1000. Temp stability just won't be as good.

On as short a barrel as the OP is talking, I'm pretty sure you'd be pushing Unburned powder out the barrel with anything slower than H4831. Matter of fact, you can push unburned H4831 out a 22" barrel in a 300 win mag. Stretch out a white bedsheet on the ground in front of your barrel when you top out on velocity and you'll see it.
With the case capacity of the 300 Win Mag, my choice for a short barrel was and still would be H4831SC. I Used to run that in a 22" barreled Remington 721 300 Win Mag. My Dad bought that gun as a 30-06 and later rechambered it for 300 win mag. He passed it to me, and I passed it on a while back.

Just recently Ran a bunch of 200 gr bullets down a 22" '06 barrel using RL26. Topped out at 64.5 gr of powder, 2750 FPS. After that, just spitting unburned powder out the tube. No more velocity to be had. Ended up running them at 64 gr. 2700 FPS.

My point is You'd have a chance at some velocity by generating a little more pressure a little quicker than the slower powders. The slower powders generate better velocity in a longer barrel by continuing to burn down that barrel, holding the pressure on the bullet longer.
Higher velocity with less peak pressure, if you have the barrel length to take advantage of it.
Not saying I wouldn't try RL 26 in that short of a barrel. But for sure, the H1000 and slower would be out.
 
On as short a barrel as the OP is talking, I'm pretty sure you'd be pushing Unburned powder out the barrel with anything slower than H4831. Matter of fact, you can push unburned H4831 out a 22" barrel in a 300 win mag. Stretch out a white bedsheet on the ground in front of your barrel when you top out on velocity and you'll see it.
With the case capacity of the 300 Win Mag, my choice for a short barrel was and still would be H4831SC. I Used to run that in a 22" barreled Remington 721 300 Win Mag. My Dad bought that gun as a 30-06 and later rechambered it for 300 win mag. He passed it to me, and I passed it on a while back.

Just recently Ran a bunch of 200 gr bullets down a 22" '06 barrel using RL26. Topped out at 64.5 gr of powder, 2750 FPS. After that, just spitting unburned powder out the tube. No more velocity to be had. Ended up running them at 64 gr. 2700 FPS.

My point is You'd have a chance at some velocity by generating a little more pressure a little quicker than the slower powders. The slower powders generate better velocity in a longer barrel by continuing to burn down that barrel, holding the pressure on the bullet longer.
Higher velocity with less peak pressure, if you have the barrel length to take advantage of it.
Not saying I wouldn't try RL 26 in that short of a barrel. But for sure, the H1000 and slower would be out.
True, in order to get better velocities from shorter barrels you have to go to faster burning powders. The problem with that is when you are trying to push heavy for caliber bullets you pressure out very quickly with faster burning powders.

If you're going to go with a short barrel in the 18-22" range you'd be better off going with lighter bullets so you can keep velocities up or by going with a lower volume case to start with.
 
It's all a balance. And a lot of times that balance favors slower powders when using heavy bullets. Only way to know is for the OP to try a couple and see. I know my stock 24" barrel would throw a pretty good fireball with H1000 and a 200gr, but velocity was 2936fps average.
 
I must disagree, you don't need faster powders for a shorter barrel. Use the same powder that yields the best results listed in the loading manuals regardless of barrel length. Ross Seyfried and Mic Mcpherson said to stick with same powders that a longer barrel uses.

In Ross's article where he experimented with faster powders and disproved the theory, he made another comment: Heavier bullets loose less velocity when used in a shorter barrel.

I have been reading on this subject for over 40 years. Lots of stuff out there confirming it.
 
If going with the shorter barrel and your heart set on 300WM,

Think about using H4350 or similar burn rate.

I've found I use much less powder to get similar velocities of slower powders.

Just watch for pressure signs
 
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