.375 H&H 300g bullets best velocity

[65WSM]

If you want a dense ball powder, MagPro, might be useful. It is a St Marks (Florida) powder just like Winchester 780. I can get amazing velocity with 140 Bergers and Accubonds in the .270 WSM. I haven't found any other applications where it has a velocity advantage. I have tried 6.5 WSM, 6.5-284 (9 twist so 130 Accubonds and Berger VLDs) but it has its place and is available.

 

[benchracer]

I finally succeeded in getting an acceptable group during load development. Using 300 gr SGK's and RL-17, I obtained a 1.1" group @ 100 yards. Pics and details coming soon...

 

[benchracer]

Here is a pic of the 1.1" group that I obtained with 300g SGK's and RL-17. I later chronoed this load using my Magnetospeed V1. The 10 shot average from my rifle was 2780fps. While it is certainly not a match winning group, it is adequate for now and at least serves to illustrate that the old H&H has untapped potential. I am encouraged by the lack of vertical exhibited in this group and look forward to giving it a try out to 600 yards or so.

I noticed the other day that I have contact between the forearm and barrel on my rifle, so I am going to have some bedding work done. Will see if that shrinks my groups or not.

 

[benchracer]

Here is a pic of my rifle:

 

[benchracer]

Here are pics of the rest of the groups in the powder charge runup. I decided to seat the 300g SGK for a light jam (about .010") because this rifle had shown very little in the way of seating depth preference in past testing, so it seemed to me that seating to jam might be worth a try. These groups are pretty representative of what I have been struggling with in my testing up to this point. They are all pretty big groups, with several of them having a maddening tendency to print two shots close together and one shot way out of the group. Note that the third shot on the 76.9g group didn't even hit paper:













Though these groups don't show any of the classic signs of bedding issues, I am hoping they will tighten up some after I have the factory bedding/barrel channel clearance tweaked by a gunsmith.

 

[benchracer]

These are the bullets I have worked with to one degree or another so far. From left to right, Barnes 250g TTSX, Hornady 300g SPBT (discontinued), Sierra 300g Game King, Cutting Edge 300g MTH, and Sierra 350g Match King.

Now that I have the 300g Game Kings shooting acceptably, I will see if I can obtain similar results with the Cutting Edge bullet. Based on previous behavior, I would expect the MTH to produce 2800+ fps with RL-17 if its accuracy node is similar to that of the 300g Sierra.

On the far right is a 350g Sierra Match King loaded to a COAL of 4.040", which is slightly more than a .010" jam. I shot a basic velocity runup across my Magnetospeed chrono using RL-22. The max loads topped out at 2600+ fps with no pressure signs in 85* weather. If I can get this bullet to shoot, it would give me an affordable long range practice load and may just cause me to forget the 300g class cup and core bullets.

 

[Cold Trigger Finger]

Looking good. One thing I can offer is, your stock is not conducive to the best recoil management!! I had *those hog back stocks on 2 CZ 550 . One a Medium action in 9.2×62 and one in 300 Win Mag. The 300 was the full size action. They would slap the snot out of me every time I squeezed the trigger. The American style is much more comfortable . Especially once you fit it to yourself. The MPI Safari style was fitted to me it seamed right from the start. All the dimensions were just perfect. Boyd's and Richard's laminated stocks are very good IMO and affordable.
For my use I will stick with the Extreme powders by Hogdon's because Ishoot at below 40°below . Rl 15 falls on its face in cold weather. But I was having better success with Rl 17 last winter in my 6.5 Creedmoor so I would give it a try and see how it does in the cold.

 

[benchracer]

H4350 is still capable of 2700+ with either the Sierra or the MTH. I just couldn't get any accuracy with either the Hornady SPBT or the MTH. RL-17 paired with the Sierra bullet has done a lot better. I hope the same trend will hold with RL-17 and the MTH.

 

[benchracer]

Looking good. One thing I can offer is, your stock is not conducive to the best recoil management!! I had *those hog back stocks on 2 CZ 550 . One a Medium action in 9.2×62 and one in 300 Win Mag. The 300 was the full size action. They would slap the snot out of me every time I squeezed the trigger. The American style is much more comfortable . Especially once you fit it to yourself. The MPI Safari style was fitted to me it seamed right from the start. All the dimensions were just perfect. Boyd's and Richard's laminated stocks are very good IMO and affordable.

I understand what you are getting at. Overall, though, I really like the way the hogback stock handles under field conditions. It is only a disadvantage from the bench and really doesn't bother me much. Learning to shoot my CZ from the bench did take some getting used to, though.

For my purposes, I am intentionally avoiding doing anything to turn my rifle into a more specialized rig. I want to see how far I can take it without biasing it toward long range use. That said, I have considered changing the stock. If I go that route, I would do so in favor of the B&C stock, with aluminum bedding block, that is available directly from CZ-USA.

 

[Akmtnrunner]

Benchracer, any updates to your efforts? I'm especially curious if you have hunting experience with those SMK's or MTH's. Are they good performers on game at long range?

 

[benchracer]

Benchracer, any updates to your efforts? I'm especially curious if you have hunting experience with those SMK's or MTH's. Are they good performers on game at long range?

My testing is currently suspended while I have some bedding work done on the rifle. I'm not expecting it back from the smith any time soon.

I haven't yet progressed from range testing to field trials, so I don't have actual long range data or terminal performance information yet, either.

The 350 SMK was designed to withstand CheyTac level velocities, so it is necessarily a pretty tough bullet and very unlikely to expand reliably at the launch speeds generated by an H&H. From the beginning, my intended use for the SMK was as a less expensive projectile for long range practice vs the $2 ea. MTH. There are some guys on this site who have experimented with annealing the SMK's and with fitting them for aluminum or brass tips to improve bc and expansion characteristics. I am interested in those efforts, but lack the skills and tooling to play along.

There have been quite a few shooters on LRH who have posted their results using MTH's in various weights and diameters, though I have seen none using the 300 grain .375 MTH. Still, such results may give some idea of what to expect in terms of accuracy, ballistic performance, and terminal performance from these bullets.

I am eager to continue my experiments, but the cost of components requires me to be efficient in my testing. If I don't make sure that everything is in order before sending bullets down range, I am doing nothing but blowing money from the muzzle of my rifle. When I have my duckies in a row, I will resume work on this project. For the time being, I have been devoting my time and money to other projects...

 

[newlife457]

Gentlemen,

I have a .375H&H Win 70 Classic Stainless. I shoot 71.0g H4895 under 300SGKs with Fed215M primers and WW cases. It prints 1"MOA from the bench at 100 yds.

I am going to give RL-15 a try and see if I can get smaller groups.

 

[TCFELK2]

do not rule out the 300 gr. woodleigh...have taken 2 cape buffalo with this bullet...end result is knock down hammer power at a short distance in the 375 H & H...don't overthink this...bullet choice should be based on shooting need...speed & velocity don't always solve every issue...punching holes in paper or putting down a fine game animal

 

[benchracer]

do not rule out the 300 gr. woodleigh...have taken 2 cape buffalo with this bullet...end result is knock down hammer power at a short distance in the 375 H & H...don't overthink this...bullet choice should be based on shooting need...speed & velocity don't always solve every issue...punching holes in paper or putting down a fine game animal

Either you didn't actually read the thread or the details of the discussion haven't sunk in yet. Try to wrap your head around the name of the forum where you are posting: LONG RANGE HUNTING.