Remington 300gr.(45-70) bullet

[Hoot]

I started at 34 grains with the Speer deep curls and was getting a lot of soot and I had one hang fire with 7 1/2 primers. I bumped up the load in 1/2 grain increments making it to 37 grains. The recoil was quite brisk at 37 grains and accuracy was terrible. My 100 yard group at 36.5 was about 2 inches smaller, right at 1 1/2 inches. I had no pressure signs working up to 37 grains.

I started my work up after a member had done some hunting with the deep curl bullets and wanted to give them a try. I believe another one of our members posted quickload data and said 34 grains was a bit light on the powder charge but don't quote me on that one. I'd have to dig thru all the posts.

Thanks,
B.

That would have been me and I just re-ran the numbers. According to QL 38gr Lil Gun and a 300gr Speer Gold Dot, which is the same as the 300gr DeepCurl, shows around 34k psi at a COL of 2.18 (to catch the cannelure).

I have loaded them myself, though in my rifle, the accuracy results were not acceptable for me. Of all the 300gr bullets, the XTP Mags had the best accuracy. I tried several powders with them and could not obtain the accuracy I could with lighter bullets like the 275 XPB and of course the 250 FTX. My impression with the 300s was that they were on the verge of accuracy, but needed a little more velocity than I felt comfortable pushing them to.

Hoot

[Hopalong]

I've done a little work with some 300 gr bullets, blems that appear to be Hornaday, but actual manufacturer is unknown. The big difference is that I used 1680. 40.5 gr 1680, COL 2.175, Rem 7 1/2, taper and stab crimps. Chrono: 1929 fps avg, 67 spread, SD 33. That amount of powder is actually above what Hornaday recommends, but is less than the max published by Western Powder in their load data. And that said, I didn't notice any signs of high pressure like flattened primers. Shot just over an inch at 100 yards.

Hop

[Exits45]

I will report Range Data as soon as I recieve my new Pact Chronogragh. Can hardly wait. I am tempted to shoot afew beforehand.

[pitted bore]

... That would have been me and I just re-ran the numbers. According to QL 38gr Lil Gun and a 300gr Speer Gold Dot, which is the same as the 300gr DeepCurl, shows around 34k psi at a COL of 2.18 (to catch the cannelure). ...

Hoot-
As a reality check and for general forum education and my specific edification, would you run QL with 32.3 grains of Lil'Gun, 300-grain XTP Mag bullet, Hornady case, WSR primer, 16" barrel, COL 2.065? This will duplicate the Max Load listed in Hornady's published loading data.

The result should be somewhere close to the max SAAMI pressure for the 450B. Hornady's presentation of loading data can be frustrating, because they show powder charges required to obtain particular rounded-off velocities. It's unclear how close the max load shown is to producing max pressure. What is known is only that their test charge powder weights reached max pressure somewhere between 1900 and 2000 fps.

I'm really curious if QL results show a major difference between 300-grain bullets from Hornady and Speer.

Many thanks.
--Bob

[Hoot]

Here you go. QL trends on the conservative side. A load in yellow could stand to use more powder to achieve maximum performance. Notice the case capacity barely exceeds the 80% minimum. QL predicts that 34.5gr (86%) yielding 1921fps is a better choice. It does not allow you to specify degree of bullet retention as a function of different crimps, nor different primers.

[Exits45]

I had on order a Chorongraph. Which has not shown up yet. So being a litlle impatient I went to the range to shoot the Loadings.
It was a very nice day with 70 degree weather light breeze moving from behind my right to the left almost directly behind me.
From all the loads no high pressure signs or extraction problems. Sorry no information on speed. More on that when the Chronograph
shows up. Range was at 100 yards. Shooting from the portable bench that I have.

First Group


Second group.


Third group.


Fourth group.


Fifth group.

My Rifle. Sorry for burred photo.

[pitted bore]

Hoot-
Thanks for your time and expertise in producing the QL results.

The recipe I requested was the max load according to Hornady's manual:

Code: Select all

Rifle: Bushmaster XM15-E25, Factory barrel, 16", 1 in 24" twist
Bullet:300 gr XTP/Mag  Primer:WSR   Case:Hornady, 2.065 COL
Powder: Lil'Gun
  Velocity  1500   1600   1700   1800   1900
  grains    25.5   27.2   28.8   30.5   32.2

Summary:
QuickLoad gives MV=1814 fps with 32.3 grains at 31,221 psi
Hornady gives MV=1900 fps with 32.2 grains

Which is a better approximation of reality? The results from a QL model? Or, the boots-on-the-ground result from Hornady's test lab?

Our search for an answer is complicated by Horndy's format for presenting reloading information. We don't really know what pressure Hornady has estimated for 32.2 grains with 1900 fps. A MV of 2000 fps would be over-pressure; if not, Hornady would have included the load for 2000 fps in their loading data. The 32.2 grain load produces max pressure or less, but how much less is unknown.

It looks like it would be appropriate to post some of my own results with the 300-grain XTP/Mag bullet, for which I'll open another thread.
--Bob

[Hoot]

I didn't put up many of my 300gr bullet work because I could not get the groups to be anywhere near as good as 275gr and below. I did however do a lot of field work, most of which is still on my thumb drive. The magic powder to emerge from my efforts in terms of best groups and velocity without pressure signs was Alliant Power Pro 300-MP. I got the idea of trying it from reading about loads using it for the 460 S&W. It did 1 1/2 inch groups at 100 yds averaging 2035 and 2075fps with 40 and 41gr of charge. Even at 41gr, I didn't feel like I had hit the pressure ceiling. Its not as soft on the ignition impulse as 1680, but I could not get 1680 to play in my 20" barrel with 300 grainers. Lot of unburned powder came out of the muzzle. MP-300 is a little less harsh than W296 which is a little less harsh than Lil Gun with the 300 grainers I tried. Speaking of which, some members swear by W296 and 300gr bullets. IMHO, Lil Gun is too fast for 300gr bullets. Hard to hit 80% fill without already knocking on the pressure door and that was just using the taper crimp driven into the cannelures. Lil Gun is still my go-to powder for 200-275gr bullets.

FWIW, I did try the Hornady 300gr SSTs, hoping they might behave better accuracy-wise than the different 300gr hollow points, but at 100 yds there was no improvement using my setup.

Hoot

[Hoot]

In case anyone wants to try the 300gr SST bullets for themselves, manventureoutpost has them in stock as well for around $2.00 less per box of 50 than the 250 FTX bullets. Link Here.

Hoot

[Siringo]

I have used two loads for the 300's -- 30.5 grains of LG (most accurate -- MOA) and 32.2 grains of LG (hunting 1.5 MOA). Testing at 300 yards, the 300 XTP was the most accurate, followed by the resized Hornady 300 grain 45-70 bullet, the 300 grain Remington and finally the 300 grain SST.

Not only were the groups much worse with the 300 SST, they shot significantly lower -- with all other components and charges remaining the same (velocities were the same also).