.png)
Member frhunter13 is in the process of loading and testing GS Custom 450gr Flat Point bullets for use on Cape buffalo and will soon report on the results here. The object is to achieve 2,350 ft/sec for proper penetration through the shoulder to the heart.
To keep it all together this has been transferred from his post in another thread:
frhunter13 wrote:
I have 2248 now with my Barnes 450 TSXFB COAL 3.30 in the magazine so I think 73g TAC is fine. TAC or H335 can get the 450 Barnes Solid to 2379 fps 3.29 COAL (their factory ammo COAL). There have been too many successes with these bullets to discount them. TAC can get the 500 TSXFB to 2194 fps 3.31 COAL. 3.30 COAL also probably with a tad less powder. There are many more options with US powder per this web site: http://www.barnesbullets.com/files/2014/11/458WinchesterMagnum.pdf
Oops it the the 500 Banded that gets to 2194fps. The 500 TSXFB can only reach 2040 fps.
Yep, but the PMP cases will be different - I just want to know their capacity too.
It's 95.2 with fired cases with the Hornady I am using. I measured this myself. I use the fired case capacity because that includes the chamber size.
PMP does not manufacture cases or load for the .35 Whelen. They do sell ammunition and components overseas but I doubt the .458 Win Mag will be amongst that. I know their ammunition is popular in England, Australia and northern Europe. I am waiting for the case water volume, forgot to ask that.
Once you bring the .458 we may find it wise to load some locally made GSC with S321 in PMP cases and test them.
The people I usually buy from like Natchezss and Midway and Cabellas and Cheaper than Dirt etc, do not carry PMP 35 Whelen of 458 WinMag. I see PMC sometimes but not in those calibers.
PMP Case mouth diameter.
The average case mouth diameter of PMP .458 Win Mag cases is .456" with less than .001" spread.
Today, Sunday June 4, 2017 I continued my efforts to prep my 458 Winchester Magnum and my 35 Whelen for upcoming adventures in Africa.
I took five shots with the 450g GC Flat Head bullets using BLC2 Powder.
Note that I based this first BLC2 effort on known loads for conventional bullets, planning to use velocity to gauge pressure in accordance with Quickload. I find Quickload accurate for relative changes to book loads, if not always so accurate with absolute calculations.
First Shot: COAL 3.278", 78g Powder No crimp: 2236 fps.
Second Shot same as first with gas check: 2230 fps. Realize the first shot was with a clean, lubricated barrel, so I take this result to mean the gas check made no difference.
Third Shot: COAL 3.25", 78g Powder Crimped : 2286 fps.
Fourth Shot: COAL 3.278", 79.2g Powder, not crimped: 2273 fps **
Fifth Shot: COAL 3.48" hand inserted, 81.5g Powder not crimped: 2316 fps **
There were no over pressure signs at all, and the action cycled smoothly.
So it looks like by simply crimping the loads of the 4th and 5th Shots I am in the 2325-2366 fps range. I consider this a success, and hope to verify the scope settings next time out. I notice that at 25 yards the bullets were hitting in the same place as the Barnes 450g TSXFB. According to the ballistics, the GC Flat Head drops off away from the TSX considerably after 100 yards.
The 35 Whelen needs a little more powder because I was getting 2657 fps first shot with a conservative load of BLC2 and Barnes 225g TSXB bullets. I can kick this up a bit to 2700 fps.
The rain is simply Southern Winds that carry Gulf of Mexico storms into our area. We had 16" in May which is one of our heaviest annual rainfall months. This often continues into June.
Quite.
Crimping could help, however the COAL must match a crimp point which looks possible here only if I use brass that has been fired several times so that it is longer. I did that with these rounds thinking I would crimp. Without seeing the velocities to estimate actual pressure, I am not taking the chance on crimping. I might add one that is crimped to fire if the others don't develop pressure though. So I will do that,
That rain - is it from a tropical off-shore system or inland convection?
So if velocity is still low, pressure slope and peak is still low - and then by crimping you can increase the pressure rise slope?
So I made four BLC-2 rounds to test with the GS customs. First I verified the safe load with known book loads of 77g for a 500g and 79g for a 405g bullet and then checked 78g with Quickload to get well under max pressure.
So I made
1. One 3.278" round without gas check at 78g.
2. One 3.278" round with gas check at 78g.
3. One 3.278" round without gas check at 79.2g which is closer to max load per Quickload with this bullet. I will shoot this last, maybe. Depends on 1 & 2.
4. One 3.48" hand placed round without gas check at 81.5g well under max at this almost to lands length. This is moving half way toward Lott length.
The effect of the gas check will be seen between rounds 1 and 2.
These are all un-crimped at present until I verify loads.
BLC2 is a commercialized US Military powder and goes by another designator. It is a allot like Win 748 actually. I know this is a good batch too. This will be my critical test with these bullets. Pass or Fail.
It is supposed to rain for seven more days (3 already) and that may flood the range, so this test could be this weekend or next. We got over an inch today.
The GS 450g .457 bullet with .461 gas check.
Yow. I measured the GS Bands at 0.4570 and the bullet at 0.451. The Barnes are .4575 outside and .443 in the channels. My leads are 0.459 . Outside of the gas check is 0.461.
Yes - that double base S321 is a very consistent propellant for the big bores. I use the next slower S341 in the .303. Must be the cleanest burning powders I have ever used because burn rate is not controlled by graphite coating but by chemical additives.
Michael the alert icon shows you have commented twice but the comments do not show. Same happened to mine in another category. I reported the issue to the forum service provider.
Wish I could get some S321 here in the states to play with. There is a powder here that seems to match it though. Hodgdon BLC2. I might try that with the GS bullets. BLC2 is slightly more dense, so the compression will be less, and I like that.
What I am afraid of is that the bottom band of the GS bullet is not wide enough or close enough to the base. As the bullet moves out of the case and before the first band hits the lands, there may be a point where there is not a good seal. This is why with lead bullets the gas check is always on the base of the projectile. This should actually be rectified in the bullet construction. There is no reason I can see not to put a band right at the bottom of this bullet. You might pass that recommendation on.
Sounds like a 458 Lott result. Who gets 3.6" out of a 458 Winchester unless its an oversize receiver? The max is 3.34 supposedly. Although by pushing one in by hand I could get out to 3.75". Back to the single shot. Too bad I can't get any S321 here in the states for the GS bullet.
The biggest penetration issue has always been bullet deflection and the rear-end side-swiping bone. A 450gr solid at 2,230 ft/sec which is known to stay nose-ahead all the way will do the job.
The Somchem factory results with the Barnes 450gr FB at 3.6" COL and using 77.2 gr S335 from a 24" barrel is 2,272 ft/sec.
I went with 61g BLC2 in the Whelen. 59g got me a shock when it brought my 250g Speers to 2700 fps. No pressure signs but I backed off anyway. Several other people are using the 61g of BLC2 with this 225g Barnes so I know it will at least get me over 2660fps without any doubt at all. My rifle is a bit tight so it reacts rather unpredictably. I might see anywhere between 2660 and 2800 fps with the 225.
I have decided to go with 74.7g Xterminator with the GS 450's, and I am debating sticking with the 2230 fps on the Barnes 450 TSXFB. What's another 12fps anyway. The brass looks perfect and the action is ok, maybe a little tight on extraction. So I think I will stick with the present load. The Xterminator load should get me around 2260 fps on the GS 450g flat nose bullets. I can't get any reasonable numbers with AA2230 using Quickload. It certainly does not agree with the book loads I have seen with this or any other caliber, or with the GS table of S321, so I believe he needs better data on that powder. That said, I will only go with something if all my sources agree more or less.
Until next weekend.