|
Joined: Oct 2001
Posts: 223
Campfire Member
|
OP
Campfire Member
Joined: Oct 2001
Posts: 223 |
If I were to switch from using IMR4350 in a 243 to IMR4451 using 85-87 grain bullets, approximately how much less powder would I need to use to get the same velocity (approximately 3070 fps) if my original load was 44 grains ? From what I've seen Qiuckload estimates say about 2 grains less powder, but just wondering what real-life testing might has shown to date ? Ben
Last edited by BEN243; 12/28/20.
|
|
|
|
Joined: Jul 2013
Posts: 9,189
Campfire Outfitter
|
Campfire Outfitter
Joined: Jul 2013
Posts: 9,189 |
Have you thought to check Hodgdon's online data for a comparison of the two powders for the bullet weight listed? For the 243 and 6mm Rem, 4451 has a slower burn rate, but seems to have more energy.
I belong on eroding granite, among the pines.
|
|
|
|
Joined: Jun 2003
Posts: 42,662 Likes: 12
Campfire 'Bwana
|
Campfire 'Bwana
Joined: Jun 2003
Posts: 42,662 Likes: 12 |
I've tried them both, exact loads. No difference in two 3006s.
A good principle to guide me through life: “This is all I have come to expect, standard lackluster performance. Trust nothing, believe no one and realize it will only get worse…”
|
|
|
|
Joined: Oct 2001
Posts: 223
Campfire Member
|
OP
Campfire Member
Joined: Oct 2001
Posts: 223 |
HuntnShoot, Thanks for the tip, but unfortunately the online data from Hodgdon is for a 85 grain Barnes bullet, which is quite different then the Sierra and Hornady bullets which I use. Also the load listed for IMR4451 is way faster then the load listed for IMR4350. Ben
Last edited by BEN243; 12/28/20.
|
|
|
|
Joined: Jul 2001
Posts: 60,270 Likes: 42
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,270 Likes: 42 |
If I were to switch from using IMR4350 in a 243 to IMR4451 using 85-87 grain bullets, approximately how much less powder would I need to use to get the same velocity (approximately 3070 fps) if my original load was 44 grains ? From what I've seen Qiuckload estimates say about 2 grains less powder, but just wondering what real-life testing might has shown to date ? Ben The difference depends on the particular load, but also on the particular batches of powder. The jug of 4451 I've been using has required a little more powder to match H4350 velocities in several cartridges, about half a grain in rounds with about 50 grains of powder room. The lot before that was a little different.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
|
|
|
|
Joined: Dec 2014
Posts: 9,186 Likes: 12
Campfire Outfitter
|
Campfire Outfitter
Joined: Dec 2014
Posts: 9,186 Likes: 12 |
I'm no ballistics guru, by anybody's yardstick, But Big H's own burn rate chart shows 4451 as a whisker slower than IMR 4350. In the ol' '06 with 180 grainers it damn sure isn't according to the chronograph. The lot I tried is way too perky for grain for grain substitution. I fully realize bore sectional area, bullet weight etc cause powders to "move position" on a burn chart but my advice to anyone is to treat the new powders with common sense, and not pay a whole lot of heed to merchandising and advertising.
Well this is a fine pickle we're in, should'a listened to Joe McCarthy and George Orwell I guess.
|
|
|
|
Joined: Nov 2010
Posts: 586 Likes: 2
Campfire Regular
|
Campfire Regular
Joined: Nov 2010
Posts: 586 Likes: 2 |
MD.
Have you noticed any difference in the accuracy of loads with IMR4451 compared to H4350?
Dyin' ain't much of a livin' boy - Josey Wales
|
|
|
|
Joined: Jul 2001
Posts: 60,270 Likes: 42
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,270 Likes: 42 |
So far IMR4451 has produced loads at least as accurate as H4350 in every rifle, and sometimes more accurate.
What I've done is reduce the charge for the load developed with H4350 a little, then work up to the same velocity achieved, using the same case, primer, bullet and seating depth. Probably have done this with 8 cartridges so far. In fact, have only one H4350 load still in use, for Eileen's .243, but she only uses the rifle every 2-3 years, and has enough loaded ammo to last a while longer.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
|
|
|
|
Joined: Mar 2007
Posts: 1,402
Campfire Regular
|
Campfire Regular
Joined: Mar 2007
Posts: 1,402 |
The new Sierra manual has them within a tenth of a gr. up to 43 gr. with the 85 gr. bullet.
|
|
|
|
Joined: Jul 2001
Posts: 60,270 Likes: 42
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,270 Likes: 42 |
Just checked my records, and my first two batches of IMR4451 got the following average velocities with the same .257 Roberts and 100-grain Ballistic Tips, using 46.0 grains of powder:
Lot 1--3052 fps Lot 2--3104 fps.
Lot 1 was the first batch of 4451 Hodgdon sent me for testing, as I recall 2-3 pounds. I was impressed enough with it that I bought an 8-pound jug afterward--which was Lot 2.
After that test I mixed both batches together, and not surprisingly the results were slightly slower than with Lot 2.
From what I understand from more than one powder company, this is the same method they use to try to approximate the burn rate of "new" batches of powders. They keep older lots on hand that are a little slower or faster, and mix them with new lots to keep things within a reasonable range, usually within 2-3% or previous lots--though some powder manufacturers try to keep the variation within 1%.
Obviously, the longer a powder has been produced, the more new batches can be "adjusted." I remember back in the earlier days of H4350 when published data sometimes indicated it was a little slower than IMR4350, and then "new" data appeared indicating it was a little faster. These days things seem to have settled down.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
|
|
|
|
Joined: Nov 2010
Posts: 586 Likes: 2
Campfire Regular
|
Campfire Regular
Joined: Nov 2010
Posts: 586 Likes: 2 |
Just checked my records, and my first two batches of IMR4451 got the following average velocities with the same .257 Roberts and 100-grain Ballistic Tips, using 46.0 grains of powder:
Lot 1--3052 fps Lot 2--3104 fps.
Lot 1 was the first batch of 4451 Hodgdon sent me for testing, as I recall 2-3 pounds. I was impressed enough with it that I bought an 8-pound jug afterward--which was Lot 2.
After that test I mixed both batches together, and not surprisingly the results were slightly slower than with Lot 2.
From what I understand from more than one powder company, this is the same method they use to try to approximate the burn rate of "new" batches of powders. They keep older lots on hand that are a little slower or faster, and mix them with new lots to keep things within a reasonable range, usually within 2-3% or previous lots--though some powder manufacturers try to keep the variation within 1%.
Obviously, the longer a powder has been produced, the more new batches can be "adjusted." I remember back in the earlier days of H4350 when published data sometimes indicated it was a little slower than IMR4350, and then "new" data appeared indicating it was a little faster. These days things seem to have settled down. I've been mixing lots of powder for some time now. If I buy 6 one ib bottles in mixed lots I pour them into an old Aliant jug and mix them into one lot then pour them back into original cans. I color code the cans as one lot.
Dyin' ain't much of a livin' boy - Josey Wales
|
|
|
|
Joined: Jul 2001
Posts: 60,270 Likes: 42
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,270 Likes: 42 |
Yeah, that's what I generally do too--unless the new batch proves to be very close to the same burn-rate as the older one. They sometimes do.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
|
|
|
|
576 members (06hunter59, 10gaugeman, 12344mag, 10gaugemag, 10Glocks, 1234, 54 invisible),
13,565
guests, and
1,001
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
Forums81
Topics1,195,123
Posts18,542,297
Members74,057
|
Most Online21,066 May 26th, 2024
|
|
|
|